;,_ ___,_,__:-, . , TEXAS AGRICULTURAL EXPERIMENT STATION \ R. D. LEWIS, Director, College Station, Texas Hal/din 71.2 Charcoal Rot of Plants in East Texas P. A. YOUNG LIBRARY A. a. m. COLL OF TEXAS geplemfiea 1949 The TEXAS AGRICULTURAL AND MECHANICAL COLLEGE SYST cuss cucnmsr. Chancellor [Blank Page in Original Bulletin] Pre face Charcoal rot is caused by a fungus named Macrophomina phaseoli that has been reported in at least 284 species of plants. These include corn, sorghum, cowpea, bean, lima bean, crotalaria, soybean, pepper, tomato, cotton, sweet potato, watermelon, cantaloupe, squash, pump- kin, radish, turnip and cabbage in Texas. The main symptom of charcoal rot is shredding of the tissues of the stems and the charcoal-like appearance due to the minute black sclerotia of the causal fungus under the bark, in the pith and in the woody tissues. Twelve host plants had gray discoloration of the stern bark, and seven hosts had fruits destroyed by charcoal rot. Charcoal rot of corn was severe in 4 seasons when the total rainfall . in June, July and August was only 3 to 6 inches, but was mild in 2 seasons when the total rainfall in these 3 months was 19 and 20 inches. This apparently is the first report of charcoal rot of cabbage, Heterotlzcca, Sesbania macrocarpa, and of Giant Striata crotalaria, and the occurrence of the spore stage of the causal fungus in water- melon and Irish potato. Methods of culture that invigorate crop plants apparently increase their resistance to charcoal rot. Resistant varieties of some crops help to control charcoal rot. Crops that have their seedling stages and those that mature in cool, rainy weather are unlikely to be damaged by charcoal rot during such weather. Adequate rain or irrigation water in the latter part of the growing season practically controls charcoal rot of sorghum. M6-949-3500-L180 CONTENTS Page Preface . . . . . . . . . . . . . . . . . . . . . . i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5 Description 0f the Causal Fungus . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5 Name of the Disease and Its Causal Fungus . . . . . . . . . . . . . . . . . . .. 5 Subspecies of Macrophomina phaseoli . . . . . . . . . . . . . . . . . . . . . . . . .. 6 Review of Infection Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6 Physiology of Parasitism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7 Parasitology of M. phaseoli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8 Charcoal Rot in Important East Texas Plants . . . . . . . . . . . . . . . . . . . . . .. 8 Corn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8 Sorghum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12 Cowpea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13 Bean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 14 Crotalaria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 14 Lima Bean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Soybean . . . . . . . . . . . . . . . . . . . . . . . / . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16 Sesbania macrocarpa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16 Hubam Sweetclover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16 Velvet Bean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16 Common Lespedeza . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Peanut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17 Clover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Tomato . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17 Pepper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Irish Potato . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19 Radish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19 Turnip . . . . . . . . . . . . . . . . . . . . . . . . .~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Cabbage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2] Cantaloupe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 21 Watermelon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 21 Pumpkin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 21 Squash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 23 Okra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 24 Cotton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 24 Sweet Potato . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 26 Guayule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Heterotheca subaxillaris . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 26 Cosmos sulphureus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 26 Zinnia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 27 Host Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 27 Methods of Controlling Charcoal Rot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 29 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 30 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 30 Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 31 BULLETIN 712 SEPTEMBER 1949 Charcoal Rot of Plants in East Texas P. A. YOUNG, In Charge Tomato Disease Investigations Laboratory, Jacksonville, Texas HE charcoal rot disease of plants was discovered by Halsted in. 1894 (69). It has been found in many parts of the United States, especially in the southern half of this country. Damage by charcoal rot, especially to sorghum, corn and legumes, has stimulated much research work on the cause and control of this disease. The purpose of this bulletin is to describe the parasite that causes charcoal rot, the associated environmental conditions, the symptoms of charcoal rot in farm crops and other plants in Texas, and discuss the parasitism and control of the causal fungus. DESCRIPTION OF THE CAUSAL FUNGUS Charcoal rot of plants is caused by Macrophominsa phaseoli (Maublanc) Ashby. The pycnidia are black, more or less erum- _pent, globose or depressed, and 100 to 216 microns in diameter (6) ; they have no stroma. The ostiole is small and truncate. The conidiophores are simple, rod-shaped and 10 to 15 microns long; they are hyaline and non-septate. The pycnospores are hyaline, one-celled, elliptical, about 3 times as long as Wide, and range in sizes from 12 to 34 by 6 to 12 microns (42, 24). The sclerotia are smooth, black, hard, usually shiny and range in sizes from 27 to 200 microns in diameter (71, 24, 6). This fungus causes seedling blight, stem rot, root rot and fruit rot of at least 284 species of plants in many parts of the World. NAME OF THE DISEASE AND ITS CAUSAL FUNGUS From two common names of the disease and three or mo-re technical names for the causal fungus, it is helpful to select one name for the disease and one for its causal fungus. Black sclero- tia that blacken tissues are the only reproductive bodies that have been found in most ho-sts. They were named Sclerotzfum bataticola Taub. or Rhizoctonaia bataticola, (Taub.) Butler. How- ever, a name for the spore stage is preferred. Hence, when Ashby (6) found pycnidia and spores and proved that they are the same fungus as the sclerotia, he described Macrophominaa phaseoli as the name of the spore stage of the fungus, and listed several synonyms. However, the oldest name of this fungus is Macrophoma phaseoli Maublanc (46). Ashby changed the genus name to Mascrophomina because Petrak (54) described it as a Phoma Without a stroma, but this does not distinguish it from many other species of Phonw, and Macrophowza (83, 65, 13). 6 BULLETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION Frequent change in the names of well-known organisms is confusing. Hence, the policy of nomina conservanda. is used to retain the name, Macrophomina pthaseoli (Maubl.) Ashby, as the cause of charcoal rot (89). The spore stage occurs mainly in jute and legume stems, in which the dis-ease has been named ashy stem blight due to the gray discoloration of the bark. How- ever, the sclerotial stage is more common so charcoal rot is the preferred common name of the disease. SUBSPECIES OF MACROPHOMINA PHASEOLI Reichert and Hellinger (60) described the following sub- species: Sclerotium bdtaticola ssp. typica: This contains the isolates from bean, eggplant, pumpkin, potato, pepper and Cicer. In culture, it has a rapid growth of fine, nonpersistent mycelium, and a nearly even distribution of smooth, round sclerotia. Bar- rel-shaped cells and fumaceous hyphae are uncommon. The to- mato isolate produced pink color, while the Cicer isolate pro- duced yellow color. Except in the pepper isolate, the sclerotia form by the fusion of barrel-shaped cells. The pepper isolate is a variety with sclerotium formation by fusion of barrel-shaped cells from one hypha with ordinary cells from another hypha. The isolates from bean and pumpkin were very virulent, where- as those from tomato and pepper were mildly virulent at 15 to 33° C. S. bataticola ssp. intermedid: This subspecies includes the isolates from cotton and tobacco that are parasitic to bean. It is characterized by prominent. non-unifo-rm, often patchy, per- sistent, fumaceous aerial mycelium. Mycelial growth is relatively slow and sclerotia are irregularly distributed. The sclerotia are rounded, irregular or elongate. The tobacco isolate produced a red-brown color in culture. The isolates from cotton and tobacco were virulent in the inoculation tests. S. bataticola ssp. sesa-mica: This is the isolate from sesame that is nonpathogenic to bean. It is characterized by dense. uni- form, persistent, fumaceous aerial mvcelium in concentric zones, with abundant barrel-shaped cells. Mycelial growth is relatively slow in culture and sclerotia are irregularly distributed. It pro- duced its sclerotia from the ordinary cells of one or two hyphae, and produced a dark yellow color in culture. The sclerotia were mostly irregular and occurred in masses. In addition to these subspecies. M. whaseoli has several physio- logic races that are noted with their hosts (40) in the following pages. The Taubenhaus strain of M. phaseoli did not form pycnidia in jute. REVIEW OF INFECTION EXPERIMENTS M. phaseoli rotted sweet potatoes in 3 to 8 weeks (69). Mar- tin (45) proved the pathogenicity of M. phaseoli in causing pepper fruit rot. Ashby (6) proved the identity of M. phaseoli CHARCOAL ROT OF PLANTS IN EAST TEXAS 7 and S. bataticola. Virulent cultures of M. phaseoli killed young seedlings and injured older plants (11). Single-spore cultures of M. phaseoli always produced sclerotia (24, 26). Hildebrand, et 01., (24) inoculated corn and so-ybean with an iso-late of M. phaseoli from cotton that grew in Texas, and an isolate from soybean that grew in Ontario; these were distinct varieties and were strongly parasitic at 82 to 92° F. They proved the identity of M. phaseoli and S. baitaticola in soybean. Pathogenicity of cultures decreased in about one month. This fungus grows be- tween the cells of sorghum roots (40). One variety of M. phaseoli produced spores in cultures (42). Suspensions of pycnospores were dried on unwounded bean stems and incubated in a moist chamber. Diseased spots ap- peared within 2 weeks and killed the stems. Parasites may attack plants through the natural wounds that are made by emerging secondary roots (33). PHYSIOLOGY OF PARASITISM Seedling blight of sorghum was worst at 106° F. but charcoal rot of the stalks was worst at 100° F. (40, 41). In dry soil, seedling blight was worst at 93 and 98° F., but in wet soil, seed- ling blight was worst at 77 and 82° F. Competition with other organisms in field soils apparently helps. to minimize seedling blight of sorghum by M. phaseoli (14, 40, 42a, 63). Summer weather in Texas is hot and dry most of the time; such weather is beneficial in maturing and harvesting grains and fruits. With the aid of occasional rains that generally p-re- vent drouth-killing of plants, adapted varieties 0-f crops endure hot drouths well and produce fair yields when pests do not dam- age them. M. phaseoli is most strongly parasitic in hot Weather. Extensive killing 0-f bean seedlings by charcoal rot occurred at temperatures of 80 to 106° F. (34). Hot drouth was unusually severe in,1948 when charcoal rot of radish, turnip and cabbage was found at Jacksonville. Although the heads of cabbage and the bulbous taproots of the radish and turnip usually grow best in cool weather, their seed crops often grow in hot weather. Charcoal rot of corn and sorghum stalks usually does not become severe until they begin to mature (40, 41). M. phavseoli is a vigo-rous parasite in killing seedlings and blackening and killing branch roots, but it causes stalk rot especially in plants that are becoming senescent. Annual plants typically become senescent as they mature their crops, and charcoal rot may then injure them seriously. Weather that is too hot or dry for best growth of plants apparently increases their susceptibility to M. phaseoli. The sclerotia and spores o-f M. phiaseoli are small dust-like particles and can be disseminated by Wind. _ lt has been suspected that M. pitaseoli may grow on non- living materials in soils (27), but neither local observations nor a review of literature gave any evidence to support this opinion. 8 BULLETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION Sclerotia of M. phaseoli were found by the writer only in the over-wintered corn stalks that it had killed. M. phaseoli was not one of the saprophytes that the writer found on corn stalks that remained in fields 6 months or longer after the crop ripened. PARASITOLOGY OF M. PHASEOLI A redefinition of the term, parasite, facilitates understand- ing of the parasitism of M. phaseoli. A parasite is an organism that lives in or attached to another species of living organism from which it secures part or all of its food, water or minerals (84, 66, 14). The pathogenic kinds of parasites cause visible or measurable symptoms in the hosts. Environmental conditions commonly influence the severity of parasitic diseases. Many kinds of parasites are more destructive than M. phaseoli, but this pathogenic fungus causes serious damage to some crops under favorable conditions. The worst plant diseases such as black stem rust and late blight vary in destructiveness from slight to disastrous depending on abundance of inoculum and weather that favors or hinders the causal parasites. CHARCOAL ROT IN IMPORTANT EAST TEXAS PLANTS Corn {Zea mays) Charcoal rot decreases. corn yields in East Texas each year- It occurred in epidemic proportions in 1944 and 1948 (89, 4). It was also serious in other states (51, 11, 73; Table 2). Charcoal rot of corn is illustrated in Figure 1 and literature references (40, 41, 43). M. phaseoli causes a black root rot and seedling blight of corn (40). It kills the roots and dwarfs the seedlings of many crop plants, especially at 77 to 92° F. (63). When corn is ripening or ripe, charcoal rot is recognized easily by stripping off the leaf sheaths from the bases of the stalks and cutting diagonally through the crowns (89). Those with charcoal rot are more or less hollow and retted or shredded and are gray or black, due to the numerous black sclerotia in the pith and on the bundles of tracheae (Figure 1). Sclero-tia were found in the pith of a few green corn stalks. The sclerotia usual- ly were found in the lowest 1 to 18 inches of the stalks, but an ear of corn showed numerous sclerotia in pith of the cob and also in. many of the kernels (Figure 2). The sclerotia occurred among the starch grains and made these kernels look gray or black. Numerous sclerotia bulged under the epidermis of these kernels. Nearly one-fourth of the corn stalks with charcoal rot near Jacksonville had gray epidermis as one symptom (Figure 1,lC). Many of the largest roo-ts were hollow and contained sc erotia. Most of the plants of Crotalaria. spectaibilis died of charcoal rot in the hot drouth of 1943 in one field at Jacksonville. This field was used the next 5 years to test the resistance of crop plants to charcoal rot. Charcoal rot killed all of the plants of Ioana sweet corn in 1944, while Texas 12 showed 79 percent of 4f CHARCOAL ROT OF PLANTS IN EAST TEXAS Figure 1. A to C are Yellow Dent corn; D and E are Ioana sweet corn with charcoal rot. A: Cracked, gray epidermis, and dark gray discoloration below epidermis and in branch roots due to many sclerotia. B: Crown of stem that has been retted and hollowed by charcoal rot, and blackened by sclerotia. C: Charcoal rot with gray epidermis of stem that is dotted with black sclerotia, except the left end that has ordinary straw-yellow color. Pieces of 8 hollow roots and 2 pieces of pith are gray or black with sclerotia. D: In.terior of crown was re-tted and ‘blackened. E: The symptom of extremely slende-r internode some- times was associated with charcoal rot; also shown in picture D. ' 10 BULLETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION Upper picture: An ear of Yellow Dent corn with 41 black Sclerotia also are abundant in the pith. of the co-b of this ear. Nearly three-fourths of the corn plants had charcoal rot in this part of the field. Lower pic- ture: Crown of a sorghum. stalk with the interior partly shredded and blackened with the sclerotia of M. phaseoli. Figure. 2. or gray kernels containing the sclerotia of M. phaseoli. the plants with severe charcoal rot and 21 percent of the stalks with moderate charcoal rot. Yellow Dent showed 55 percent of the stalks with severe charcoal rot and 45 percent with moderate charcoal rot; the yield and quality of the ears were poor. Three fields of Texas 12 yielded only 8 bushels per acre. Lodging usually is rare in thin stands of corn in East Texas. Livingston (40) correlated temperature and rainfall. with severity of charcoal rot. When the average air temperature in summer was below 73° F. and rain exceeded 10 inches in July to September, charcoal rot was not very serious, but this disease was destructive in the regions with warmer or drier weather. CHARCOAL ROT OF PLANTS IN EAST TEXAS 11 At Jacksonville maximum daily temperatures in the summer usually range from 85 to 103° F. (average about 90° F.). Most nights are uncomfortably warm, so the temperature is presumed to favor M. phaseoli. Charcoal rot Was very destructive in 1943, 1944, 1947 and 1948 when the rainfall in June, July and August totaled 3.07, 5.25, 6.39, and 4.41 inches, respectively. In contrast, charcoal rot was not severe in corn in 1945 and 1946 when the rainfall in June, July and August totaled 20.32 and 19.16 inches, respectively. Early corn ripens in July and August near Jack- sonville. The correlation of charcoal rot with rainfall resembles that in Nebraska (40, 41). \ * Enough Water at the right time, while the corn is maturing, appears to be the best control for charcoal rot of corn stalks. Pro-mising resistance occurs in some varieties (58) (Table 1). Resistance to charcoal rot appears to be increased by maintain- Table 1. Resistance of corn varieties and hybrids t0 charcoal rot at Jacksonville. Percentage of plants with charcoal rot* Variety 1945 1946 1947 1948 Texasl8....................... 8 12 39 32 Texas l2 . . . . . . . . . . . . . . . . . . . . . . . . 23 4 80 40 Parents of Texas 12: KYS . . . . . . .. 35 .... .... .... Parents of Texas 12: 127C . . . . . . . . 23 . . Parents of Texas 12: 132A . . . . . . . . 18 . . Parents of Texas 12: K4 . . . . . . . . . . 13 . . . Texas8. . . . . . . . . . . . . . . . . . . . . . .. l0 5 Texas 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 63 **36 Texas 9W . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 54 24 TexasllW . . . . . . . . . . . . . . . . . . . . .. 63 15 Texas7W . . . . . . . . . . . . . . . . . . . . .. 5 .. Texas Golden Prolific. . . . . . . . . . . . 22 20 75 . . . . Prolific Sur cropper . . . . . . . . . . .. .... .... .... 27 Funk G711. . . . . . . . . . . . . . . . . . . .. 13 ... . 59 29 FunkG788 . . . . . . . . . . . . . . . . . . . . .. 47 FunkG7l6 . . . . . . . . . . . . . . . . . . . . .. 17 9 DeKalb 1024 . . . . . . . . . . . . . . . . . . . . 13 . . . . DeKalbl022 . . . . . . . . . . . . . . . . . . .. 6 United U79 . . . . . . . . . . . . . . . . . . . . . . 27 . . . . 64 37 Ioana Sweet Corn . . . . . . . . . . . . . . . . . . . . . . . . 78 54 Reese Drought Resister. . . . .. . . . .. 15 .... 50 .... Ferguson’s Yellow Dent . . . . . . . . . . . 17 16 . . . . . . . Surcropper . . . . . . . . . . . . . . . . . . . . . . . . . . 16 . . . . 34 I0wealthTXl . . . . . . . . . . . . . . . . . .. 4 Mexican June . . . . . . . . . . . . . . . . . .. . . .. ... . 45 Ohlahoma Yellow Dent . . . . . . . . . . . . . . . . . . . 57 Squaw (Gay) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 MolerWhite . . . . . . . . . . . . . . . . . . .. 68 Kreid Yellow Dent . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 GoldenJune . . . . . . . . . . . . . . . . . . .. 13 Dixiell . . . . . . . . . . . . . . . . . . . . . . .. 27 *The soil was fertilized with 500 pounds of 5-10-5 fertilizer per acre. The corn was planted in replicated rows each year. Succulent growth of plants in rainy periods decreases their resistance to later drouths. **Texas 20 in 1948 showed charcoal rot in 66 percent of the 5,439 plants that were cut in representative rows in 4 fields of 1 acre each. 12 BULLETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION ing vigorous growth of the corn. This can be accomplished profitably in East Texas by plowing humus into the soil, mixing 300 pounds or more of 5-10-5 fertilizer per acre in the rows, planting in March, side dressing about 15 inches from both sides of the rows with 100 pounds of ammonium nitrate per acre when the corn is 6 to 12 inches tall, and controlling weeds. Sorghum (Sorghum vulgarel The symptoms of charcoal rot of sorghum include damping- off of seedlings, black or brown cankers in the fibrous roots, retting and hollowing of the bases of the stems, blackening due to sclerotia (Figure 2), sclero-tia on the vascular bundles, pre- mature dying of the stalks, lodging of the stalks, decreased yields and inferior quality of the grain (40, 14a, 37). The mycelium of M. phaseoli was intercellular (40). Many varieties of so-rghum were tested at Jacksonville but none showed severe symptoms of charcoal rot. Some black, fibrous roots and crowns were found. The rains apparently were adequate to enable the drouth-resistant sorghum to avoid serious injury by charcoal rot. Darso and Chiltex varieties were very susceptible (14a, 89). Seedling blight of sorghum by charcoal rot was worst at 93 to 108° F. but stalk rot was worst at 101° F. (40). Low soil moisture in the latter part of the growing season favored dam- age by charcoal rot. Charcoal rot often is destructive to sorghum in the usual dry ‘seasons in West Texas. Lodging of the stalks increases losses (19, 16, 17, 58, 59, 29, 30, 31). Varieties of sorghum generally are susceptible to charcoal rot (32). Midland has juicy stalks and a minimum amount of lodging. Promising resistance to charcoal rot was found in some varieties of sorghum (27, 40). Thick-stalked, leafy varieties showed least damage from char- coal rot (19). Thick stalks may give mechanical resistance to lodging. A stalk rot of sorghum that sometimes is associated with charcoal rot in West Texas is caused by Fusowium moniliforme (75, 16). Charcoal rot appeared to be worst in land that was continu- ously cropped in sorghum, and was practically controlled by adequate rain or irrigation water throughout the growing sea- son (29, 31). The most damage occurred when abundant early season moisture was followed by drouth when the seed began to form- Lodging was severe in the milk stage of the grain. Late planting of sorghum sometimes helps to minimize dam- age from charcoal rot probably because rainy and cool weather occur as the sorghum matures (32). However, late planting provides weather that may be hot enough to favor seedling blight unless rains invigorate the seedlings. Competing organ- isms in the soil may control M. phaseoli. CHARCOAL ROT OF PLANTS IN EAST TEXAS 13 i Cowpea (Vigna sinensis) a Cowpeas show both the charcoal rot and ashy-stem-blight symptoms that are caused by M. phaseoli, and produce both sclerotia and pycnidia in the same plants (Figure 3). The gray to white bark is more prominent in the blackeye than in the Purple Hull variety. M. phaseoli killed the youngest leaves of cowpeas in rainy weather (79). The tips or outer halves of the leaves were light Figure 3. phaseoli with the black pycnidia protruding through the epidermis of two stems. The bark was rotted off the taproot, showing the woody sur- face that was blackened with sclerotia. Bottom: Irish Cobbler variety of potatoes showing a normal tuber in center. The other two tubers were blackened by M. phaseoli; the left tuber was blackened mainly near the eyes. Top: Gray stem blight of blackeye peas caused by M. 14 BULLETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION brown to gray and contained many pycnidia. The tissues were water-soaked at the margins of the dead spots. Purple Hull and ordinary selections of blackeye varieties are very susceptible to M. p-haseoli Whereas the Iron, California No. 1 and Blackeye 8152 (California) varieties are resistant (85, 44). Tests at Jacksonville showed charcoal rot in only 6 percent of the plants of Blackeye 8152 in contrast with 55 per- cent of the plants with charcoal rot in the Purple Hull variety in 1943 (91)- Bean (Phaseolus vulgarisl In beans and cowpeas, the sclerotia are abundant under the bark-of the stems and taproots (Figure 4). M. phaseoli appar- ently grows abundantly in and near the cambium. Pinto, Yel- low Wax and Stringless Greenpod varieties were very suscep- tible to charcoal rot at Jacksonville. Some bean plants also showed the pycnidia of Phoma. pampaena Speg. in the bark of dead stems in 1944. Mycelium of M. phaseoli penetrated small bean roots and grew into the crowns (43). M. phaseoli attacks mature bean. plants. in fields (49). Charcoal rot causes reddish-brown, often sunken spots in bean stems, and the centers of the spots become gray with sclerotia (21). Bean plants that become infected while they are young rarely bear seeds, and crop losses so-metimes are large. M. phaseoli infected bean seedlings at the cotyledonary nodes and killed the hypocotyls but did not attack the roots (34). Rapid infection caused pre-emergence damping-off of the seedlings; subepidermal sclerotia in the hypocotyls caused the symptom of ashy stem blight. Thirty-five pounds of beans were planted in a 1-acre field near Jacksonville on June 30, 1946 for a cannery crop. The soil was soaked by abundant rains 2 days later. Only about 100 bean plants emerged in this field and charcoal rot was the probable cause of the killing of the other seedlings in the very warm soil. Dry brown spots without borders were the first symptoms caused by M. phaseoli in the tips of bean leaves (79). Pycnidia developed in the spots and the veins were red near the spots. The leaves were killed and the fungus sometimes grew from them into the stems. Pycnospores from bean leaf spots produced typical sclerotia in culture. The bean leaf spots caused by M. phaseoli occurred in rainy summer weather. Croi-uluric spp. Crotalaria, spectiabilié: Charcoal rot of crotalaria is identi- fied by the decay of the bark on the taproot and base of the stem, dying of the plant and many black sclerotia under the bark (Figure 4). Charcoal rot also causes stem cankers (86). Most plants of the late variety died with charcoal rot in the hot drouths of 1943 and 1948. Reuter’s early variety of crotalaria r CHARCOAL ROT OF PLANTS IN EAST TEXAS 15 Figure 4. A and C: The ashy-stem-blight form of charcoal rot of the Pinto bean showing gray epidermis and retting of bark; B shows a gray pod that is dotted with many pycnidia. D: Charcoal rot of Hubam sweetclover showing white stem and black taproot. E: Char- coal rot of Bliss Triumph Irish potato showing white to gray parts of stems and black tapro-ots with retting of bark. F: Charcoal rot of Crotalaria spectabilis showing retting of bark on stem and- taproot, with the deeper tissues blackened with sclerotia. resists charco-al rot (91)- In the rainy seasons, the late variety outgrew weeds and made fine crops without cultivation (37a). However, in the dry seasons, competition with weeds decreased the growth of the crotalaria. 16 BULLETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION Crotalaria mucronata var. Giant Striata (47): This variety Was very resistant to drouth and charcoal rot in fields in bmltu and Cherokee counties in 1948. Crotalafia. retusa»: This species did not show any symptom of charcoal rot in the rainy season of 1946. Crotwlarvla intermedia. (77): This species was very suscepti- ble to charcoal rot in Smith county in 1948. Lima Bean (Phaseolus lunafus) Charcoal rot of lima beans was found in Texas in 1944 and 1948. Diseased plants showed retted taproots with sclerotia un- der the bark and in the pith cavity of stems. M. phaseoli was transmitted in lima bean seeds (5). Soybean (Glycine max) Sclerotia of M. phaseolz‘ form under the bark of diseased soy- bean stems, and the plants die prematurely (24, 28). The first symptom was gray cankers that did not spread much until the plants became old. The variety of M. phaseoli from Ontario formed pycnidia, and also produced sclerotia in soybean stems to a height of 9 inches. The infections appeared about 3 months after the inoculations. Another variety of M. phaseoli was iso- lated from cotton that grew in Texas; it had smaller and more numerous sclerotia. Leopard spots were caused in soybean leaves, pods and stubble (Table 2). Charcoal rot caused serious losses in soybeans (35, 52, 53, 9, 41, 28). Charcoal rot in the Ogden variety of soybeans was found at Jacksonville in 1944. The sclerotia occurred in the retted bark of the stems to a height of 1 to 4 inches. Elongate sclerotia were in the Wood o-f the stems. Sesbania macrocarpa In the rainy season of 1945 at Jacksonville 83 percent of the Sesbania plants had charcoal rot (Fig. 7, D). Sclerotia of M. phaseoli were found under the bark of the taproots, and pycnidia were found in the bark of a stem. This appears to be the first report of charcoal rot of Sesbania macrocorpa. Hubam sweetclover (Melilofus alba var. annual Hubam sweetclover was damaged seriously by charcoal rot at Jacksonville (Figure 4, D). Sclerotia of M. phaseoli occurred under the bark of the taproots, and bulged under the epidermis of the gray parts“ of the stems (89). Velvet Bean (Sfizolobium deeringianuml Plants of a Vining variety of velvet beans did not show char- coal rot in 1944 except 5 plants from which gophers cut the taproots. These plants had retted crown tissues. with sclerotia of M. pihaseoli (89). This variety did not show any charcoal rot in 1945, but some of its plants showed charcoal rot in 1946. In 1948, 18 percent of the bunch variety of velvet beans had char- CHARCOAL ROT OF PLANTS IN EAST TEXAS 17 coal rot with sclerotia under the bark and in. the woody tissues of the taproots that showed some retting. The diseased tissues were black. Common lespedeza (Lespedeza sfriafal A field of lespedeza near New Summerfield on October 29, 1946 showed all of the plants to be killed by charcoal rot with sclerotia under the bark of the stems. These plants had been mowed in hot, dry weather and the land had grown corn in 1934. No symptom of charcoal rot was found in the lespedeza plants that were growing in the adjacent pasture that had not been cultivated or mowed (91). This difierence probably was due to the infestation of the soil with M. p-haseoli from the corn crop, and weakening of the lespe-deza by mowing in hot, dry weather. Peunui (A rachis hypogaeal M- phaseoli damages peanut roots, stems and seeds. This fungus was found in a runner variety of peanut with one kind of concealed damage to the nuts, and rots of the pegs and seeds (20, 81, 82, 5). The sclerotia occur in rotted taproots. Clover (Species of Trifoliuml M. phase-old blackens the roots of red clover and decreases its root system (22). It makes a reddish color in potato-culture media. M. phaseoli was found in seeds of subterranean clover (12). Tomaio (Lycopersicon esculenfuml M. phaseoli kills some tomato plants at Jacksonville each sum- mer (89). Some otherwise green. tomato plants show dead brown branches that have been killed by charcoal rot. Such stems have gray or brown bark, and are nearly hollow with many sclerotia on the interior wall and in the remains of the pith (Figure 5). Sclerotia also were found under the bark near the tops of the taproots; some of the tissues were retted. The spring crop of tomatoes in East Texas matures in June when the weather usually is rainy. Tomato plants with charcoal rot were found only in hot, dry weather in July to September. Commercial varieties of green-wrap tomatoes apparently resist charcoal rot. In 1946, Selection Y841 of yellow-fruited tomato showed 16 percent of the plants with charcoal rot in September, which indicates unusual susceptibility. A culture of M. phaseoli from tomato developed pycnospores on snap-bean stems (42). Toma- toes were infected by artificial inoculation with M. phaiseoli (45). Pepper (Capsicum annuuml California Wonder variety of bell pepper plants showed seri- ous wilting in the summers of 1944, 1947 and 1948 in Cherokee county (90). In most cases, the pathogen was. evident only as elongate black sclerotia in the woody tissue in the bases of the taproots of wilting or dead plants (Figure 5) (69). Nearly 18 BULLETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION Figure 5. Top: Charcoal rot of tomato stems showing gray epider- mis, hollow stems with interior blackened with sclerotia, and gray pith with sclerotia. Bottom: Plants of California Bell pepper that were normal except the center plant that was wilted by M. phaseoli with sclerotia in the wood in the base of the taproot. spherical sclerotia were found in the pith of the bases of some dying branches on main stems. The symptoms ranged from slight wilting and drooping of the leaves to defoliation and browning of the stems. Pimento pepper plants did not show any charcoal rot when they grew beside California Wonder pepper CHARCOAL ROT OF PLANTS IN EAST TEXAS 19 plants with serious charcoal rot in October 1948. Sclerotia occur under the bark of pepper stems (23). The pathogenicity of M. phaseoli in rotting pepper fruits was! proved (45). The develop- ment of the sclerotia was traced. Experimental inoculations caused infections with M. phaseoli in pepper, sweet potato, to- mato, cucumber, apple, eggplant and turnip, but not in carrot, parsnip nor red beet. Irish Pofufo (Solanum fuberosuml Black eyes or larger black areas characterized tubers of Irish potatoes with charcoal rot (Figure 3). The black discoloration was shallow. These spring-crop potatoes had been left in the hot, dry soil until July, about 7 weeks after the usual digging time. Some of the potato stems were gray or had gray spots with sclerotia of M. phaseoli under the gray epidermis, in the pith, and on the strands of woody tissues. Some stems were hollow. The taproots were retted and were blackened by scle- rotia. Bliss Triumph stems with gray bark had typical pycnidia and spores of M. phaseoli. This appears to be the first report of this spore stage in the Irish potato. Charcoal rot of potatoes in the Texas Panhandle was proved to be caused by M. plhwseoli (18). Gray stolons containing sclerotia and shallow black rot, especially near the eyes of po~ tato tubers, were caused by M. phwseolli (7 6)- Black sunken dots one-sixteenth to one-fifth inch wide, each surrounded by a soft rotted area due to charcoal ro-t, were found in the peel of potato tubers that had been in hot, dry soil (48). Root rot, dry stem rot and blight were symptoms of charcoal rot of potatoes (38). Charcoal rot is practically controlled in East Texas by plant- ing the seed pieces about March 10 and digging the tubers about June 1 before the soil becomes hot and dry and before most of the leaves have died. Bliss Triumph and other early varieties are preferred. The tubers usually are stored under buildings. At the Tomato Laboratory near Jacksonville, potatoes from six successive spring crops were stored on dry sand under a barn, with only small loss of tubers from Fusarium dry rot or charcoal rot followed by bacterial soft rot (89). However, the quality of the tubers was decreased in October by potato roots in the tubers (88). Radish (Raphanus safivusl White Icicle radishes were planted in March 1948. Many plants were left in the rows to produce seed. Only a few seed stalks developed, so the roots. were examined September 9. Nearly all of the fleshy radish roots were retted, hollow and nearly black with sclerotia of M. phaseoli (Figure 6). The black discoloration showed through the epidermis (91). Turnip (Brassica rapal Purple Top turnips were planted in March 1948. Many plants were left in the rows to produce seeds. They were examined in 20 BULLETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION September. Many of the turnips were soft, retted and black inside with the sclerotia of M. phaseoli (Figure 6). One plant had seed pods and its stalk bore sclerotia under the bark. M. phaseoli infected turnips in artificial inoculations (45). Top: Purple Top turnips rotted by M. phaseoli and black- Figure 6. ened by its sclerotia. The upper plant had a seed stalk; the bark was torn from part of its taproot showing the tissues to be blackened with sclerotia. Bottom: Icicle radishes. The upper radish was normal. The two lower radishes were r-etted and hollow with only the peel and vascular system remaining; blackening was due to the numerous sclero- tia of M. phaseoli. If CHARCOAL ROT OF PLANTS IN EAST TEXAS 21 Cabbage (Brassica oleracea var. capifufal Cabbage was transplanted into a field in March 1948. The plants that remained in rows were examined in September. Many of these plants showed typical retting of the upper parts of the tapro-ots and bases of the stems with blackening of the tissues with the sclerotia of M. phaseoli (Figure 7). Sclerotia also were deep in the woody tissues of the taproots. This ap- pears to be the first report of charcoal rot of cabbage. Canfaloupe (Cucumis melol Cantaloupe fruits had charcoal rot and were blackened with sclerotia of M. phaseoli (89)_- About 90 percent of the plants of 5 varieties of ‘cantaloupe were killed by charcoal rot in August 1948. Most of the taproots were retted and were blackened with the sclerotia of M. phaseoli that occurred under the bark and in the pith and woody tissues. Charcoal rot killed many stems that were attached to live taproots. These stems were hollow, gray or brown, with abundant sclerotia in the pith cavities. Other sclerotia were o-n the inner side of the bark of such stems. Many cantaloupe fruits became hollow shells that were lined with dusty black sclerotia. The remaining fragments of pulp tissues were black. Two varieties of long muskmelons showed whitening o-f the epidermis of some stems as an additional symptom of charcoal rot. A culture of M. phaseoli from canta- loupe produced spores on bean stems (42). Watermelon (Cifrullus vulgaris) About 75 percent of the Black Diamond watermelon plants in one field in September 1948 had been killed by charcoal rot. One watermelon fruit showed black rot with the inner wall of the peel blackened with sclerotia of M. phaseoli. There were black layers of tissues in the fruit. The main symptom was hol- lowing and retting of the bases of the stems and tops of the taproots that were blackened with sclerotia (Figure 8). Many sclerotia were found under the bark of watermelon crowns in 1946. One watermelon stem with charcoal rot in a field in 1946 showed typical pycnidia and spores of M. phaseoli. This appar- ently is the first report of the spore stage of this fungus in watermelon in a field. Plants of Black Diamond watermelons resist hot, dry weather in fields in East Texas where they bear marketable fruits throughout the summers unless insects or diseases kill them. Pumpkin (Cucurbifa pepol Small Sugar variety of pumpkin in August 1948 showed 6O percent of its plants to be dead or dying with charcoal rot. They showed typical retting of the bases of the stems and tops of the taproots, and blackening by sclerotia under the bark and among the woody strands. Charcoal rot killed many stem branches from live tapro-ots. A pumpkin fruit was rotted with many 22 BULIIJETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION A: Cabbage taproot showing decomposition of bark with blackened wood below it. B: Bases of two stems of Heterotherl-a sub- aocillaris with charcoal rot; upper stem shows retted bark, while slice of bark was cut from lower stem. C: Crotalaria mucronata var. Giant Striata stem showing charcoal rot of crown tissues; sand adhered to the crown. D: Stems of Sesbantia macrocarpa with charcoal rot. Figure 7. ki CHARCOAL ROT OF PLANTS IN EAST TEXAS 23 sclerotia on the seeds, in the fleshy tissues and on the inner side 0f the peel (Figure 8). Squash (Cucurbifa maxima and C.~pepo var. condense) Ninety percent of the Plants of Table Queen and Yellow Crookneck varieties of squash were killed by charcoal rot in a field in August 1948. The bases of some of the stems and the upper part of nearly all 0f the taproots were retted, and were Figure 8. Top: Small Sugar varie-ty of pumpkin rotted by M. phaseoli and blackened by its sclerotia. Bottom: Charcoal rot of water- melon showing retting of the bases of the stems and tops of the tap- roots, and blackening with sclerotia. 24 BULLETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION blackened with sclerotia on the inner side of the bark and among the woody fibers. Some stem branches were killed on live taproots. Few Table Queen fruits matured, but one of them Was rotted and the fleshy tissues 0f the peel were black with sclerotia. Okra (Hibiscus esculenfusl Sclerotia 0f M. phaseolvj were found in the roots of okra (4). Charcoal rot caused extreme retting of the stems of Greenpod Okra at Jacksonville in 1947 (Figure 9). The long, loose fibers bore many sclerotia. Other sclerotia were in the hard wood of the base of the stem and top of the taproot, and on the inner side of the bark. Coffer) (Gossypium hirsufuml Retting of the bark of the base of the stems and tops of the taproots so that it is easily scraped, and black sclerotia of M. phaseoli on the inner side of the bark and in the hard wood of the taproots characterize charcoal rot of cotton (Figure 9). The cotton plants shed their leaves as they die. These symptoms are easy to distinguish from those of Fusarium wilt and Phymato- trichum root rot of cotton (87). Nine fields of cotton totaling nearly 250 acres in Houston county in October 1948 showed 1 to 70 percent of the plants with charcoal rot (Figure 9). Five of these fields showed 10 to 70 percent of the plants to be dead with charcoal rot as the only apparent cause. All of these fields were sandy except one field with red soil.* The cotton plants with charcoal rot were dug for examination and none of them showed any Fusarium wilt, Phymatotrichum root rot, nematode root-knots, or any disease except charcoal rot. The plants had been dead fo-r several weeks before they were examined. They had not been killed by drouth, as the healthy plants in the fields still bore most of their green leaves and produced an estimated yield of one-fourth to one-half bale of cotton per acre. l Summer weather was unusually warm in 1948 and favored M. phaseoli. Rains totaled 4.04 inches in May, 1.11 inches in June, 0.45 inchlin July, 1.74 inches in August and 1.01 inches in September1948 at Crockett in Houston county. The total was only 3.20 inches for June, July and August which is dry enough for serious damage from charcoal rot. The correlation of char- *The above mentioned red-soil field in Houston county was used to test crops in 1949. October 17, 484 plants of Stoneville 2B cotton in 2 rows averaged 21 percent of the plants with charcoal rot. The D.P.L. and Half and Half cotton varieties averaged 30 percent of the plants with charcoal rot; one row showed 20 percent of the» plants with charcoal rot by Septem- ber 1. Pinto and Greenpod beans and Purple Hull peas showed severe charcoal rot by July 3. This summer was unusually rainy, so charcoal rot was much less abundant than last year. Charcoal rot of cotton was found September 7 1n 2 fields in Madison county. At Jacksonville, none of the plants 1n 5.75 acres of Stoneville 2B cotton showed any charcoal rot. CHARCOAL ROT OF PLANTS IN EAST TEXAS 25 Figure 9. A and C: Tap roots and bases of stems of cotton showing retting of bark due to M. phaseoli; tissues were blackened by sclerotia. B: Normal taproot of cotton with the bark scraped to show the White inner tissues. D and E: Greenpod okra stems that were retted by M. phaseoli; tissues were blackened with sclerotia. coal rot and rainfall may be similar for cotton and corn, as summer rainfall exceeding 10 inches is likely to minimize dam- age from charcoal rot. Healthy cotton is very resistant to drouth in East Texas. Charcoal rot of cotton also Was found in one field of the Del- tapine variety near College Station in October 1948. Charcoal 26 BULLETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION rot 0f cotton has been repo-rted from Virginia to Georgia, and in Texas and Oklahoma (Table 2). One variety of M. phaseoli was isolated from cotton that grew in Texas (24, 74). It infected legume seedlings best at 104° F. (74). Many cultures of M. phaseoli were different physiologic races (74). Galloping wilt caused by M. phaseoli destroyed living cortical tissues of cotton (61). Gossypium herbwceum is very susceptible to M. phaseoli; this fungus probably penetrates through the phelloderm that is thinner than in G. hirustum. No charcoal rot of cotton was found in Cherokee county. This county is separated by the Davy. Crockett National Forest and the Neches River from Houston county where charcoal rot of cotton was found (87 )- It is probable that different physiologic races or subspecies of M. phaseoli occur in these different coun- ties (60, 24). Sweet Poiuio Hpomoea bafafasl Several plants of the Porto Rico sweet potato with hollow crowns containing sclerotia of M. phaseoli were found in Smith county September 1, 1948. This appears to be the second report of charcoal rot of leafy stems of sweet potato. Charcoal rot causes small loss of sweet potatoes when storage rooms are kept cool (69). The diseased tubers were black inside with drying and slight shrinkage as external symptoms. The sclerotia were oval oblong, or forked (69, 70). A culture of M. phcvseoli from sweet potato produced spores on bean stems. (42). Guuyule (Parfhenium argenfafuml Brown sunken cankers caused by M. nha-seoli were found near the ground level of 2-year-old guayule plants near Pearsall (56). The cankers girdled the stems and the branches died, but the roots remained alive. Heferofheca subaxillaris Heterotheca plants with charcoal rot were found near Jack- sonville October 8, 1948. This appears to be the first report of charcoal rot of Heterotheca. The sclerotia were under the bark of the blackened taproots, and elongate sclerotia were in the hard, woody tissues of the taproots (Figure 7). Heterotheca is a common wild plant that may help to maintain M. phaseoli in the soil of uncultivated fields. Cosmos sulphureus Charcoal rot retted the base of the stems and top of the tap- roots of this ornamental yellow-flowered cosmos. The sclerotia of M. phaseoli were under the bark, in the pith and on the woody fibers. CHARCOAL ROT OF PLANTS IN EAST TEXAS 27 Zinnia spp. Several ornamental zinnia plants were killed by charcoal rot in 1948. The sclerotia of M. phaseoli were 0n the inner side of the bark near the base of the stems and top of the taproots, and in the hard wood of the taproo-ts. HOST INDEX M. phaseoli is a soil-inhabiting fungus. that causes charcoal rot in many cultivated and Wild species of plants. Numerous tropical and subtropical plants are raised near the southern border of the United Statesand others are likely to be intro- duced for test or use. Foreign weeds appear on farms. Thus, it is imfirtant to know which species are likely to be damaged by charcoal rot or to maintain the causal parasite in the soil. Hence, a host index of attainable completeness is given in Ta- ble 2- Table 2. Host plants of Mwcrophomina, phaseoli (Sclerotiztm bataticola) that causes ashy stem blight and charcoal rot of plants Hosts with notes and references Abutilon theophrasti (71) Acacia decurrens (60) Acacia elata (60) Acacia melanoxylon (60) Acalypha wilkesiana (60) Acer sp. in U.S. (60) Albizzia sp. (60) Albizzia falcata (60) Albizzia moluccana (60) Albizzia stipulata (60) Alfalfa (Medicago sativa) in U.S. (26, 60; PDR 30:38**) Allium sativa (garlic)* bulb rot (60, 64a) Ambrosia artemisiifolia (common ragweed) (72a; PDR 32:117) Ambrosia bidentata (72a) Amherstia nobilis (60) Annona muricata (60) Annona squamosa (60) Antirrhinum majus (60) Apium graveolens (60) Apple (Pyrus malus) (45, 60) Apocyanum cannabinum (72a) Aralia filicifolia (60) Aralia japonica (60) Areca catechu (60) Arrenatherum PDR 27:188** Artocarpus integrifnlia (60) Asclepias syriaca (720) Asparagus* root rot (3), (50) Aster sp. (60) Auc-uba sp. (60) Bean (Phaseolus vulgaris)* 665; 28z86l: 30:73) Begonia Rex bulbosa (60) Begonia tuberhybrida (60), (74) Beet (Beta vulgaris) (60; PDR 30:304) Bidens bipinnata (7211) Bixa orellana (60) Borassus flabellifer (60) Brachypodium: root rot (PDR 28:11-12) Brassica oleracea botrytis (cauliflower) (60) Brassica rapa* (described in this article) 0) Broom corn (26; PDR 29:53l and 547) Buddleia variabilis (60) Cabbage* (Brassica) (described in this ar- ticle) Cacao (chocolate) (see Theobroma) (6) Cajanus sp. (60) Callistephus sp. (aster) (60) (60; PDR 27: ‘Found in Texas. Hosts with notes and references Cantaloupe* Muskmelon (Cucumis melo) (60, 80a; PDR 30z483) Carica papaya (papaya) (60) Carica quercifolia (60) Cassia floribunda (60) Cassia nictitans (42; PDR 29:713) Cassia alata PDR 29:7l3 Casuarina equisetifolia (60) Catalpa sp. (26, 60) Cedar (26) Ceratonia siliqua (60) Chamaechrista procumbens 29:7l4) _ Chamerops sp. (60) Chenopodium album‘! (72a) Chrysanthemum sp. (11; PDR 32:148) Cicer arietinum (chick-pea) (60) Cinchona sp. (quinine) (60) Citron (Citrullus vulgaris); race with hard white flesh* (60, 89) Citrus sp. in U.S. (60) Citrus aurantifolia (lime) (43, 60) Citrus arurantium (sour orange) Citrus limon (lemon) 43, 60; PDR 25:38) Citrus sinensis (orange) (39, 43, 60) Clitoria cajanifolia (60) Clover (Trifoliurn sps.) red & subterranean clover (60; PDR 30zl78) Coffea arabica (coflee) (6, 60) Cofiea robusta (60) Cochlearia armoracia (60) Cocos nucifera (coconut palm) (60) Codiaeum sp. Coffee weed (42) Colutea arborescens (60) Coriandrum sativum (coriander plant) (60) Corn (Zea mays)* (40, 60, 71: PDR 21:11; 27:558 and 612; 28:73; 29:66.6) Coronilla glauca (60) Cosmos sulphureus* (89. 60) Cotoneaster francheti (60) Cotton (Gossypium hirsutum)* (6, 10, 11, 59a, 60, 64, 67, 68. 91; PDR 27; 535, and 538 and 690; 30:222; 31:l27) Cotton (Gossypium barbadense); Sea Island cotton: (PDR 27:616) Cotton (Gossypium herbaceum) Levant cot- ton (62) Cowpeas (Vigna)* (60, 91) Crotalaria juncea* (60) (60; 78; PDR flavoring “PDR means Plant Disease Reporter.‘ 28 BULLETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION Hosts with notes and references Crotalaria intermedia* (42, 60, 77) Crotalaria mucronata (Giant Striata vari- ety)*; (described in this article) Crotalaria spectabilis* (77, 86, 89) Cucumber (Cucumis sativus) (45, 60; PDR 30:485) Cupressus benthami (cedar) (60) Cupressus lawsoniana (60) Cupressus lindleyi (60) Cupressus macrocarpa (60) Cupressus sempervirens (60) Cypress (43) Cyamopsis psoraloides (60) ‘Cydonia oblonga (quince) (60) Cyperus distans (sedge) (60) Dahlia ashy stem blight (60, 71; PDR 32: 156) Dahlia variabilis (60) Daucus carota (carrot) (60) Datura stramonium (72a) Derris elliptica (60) Dianthus barbatus (Sw"et William) (60) Dianthus caryophyllus (carnation) (60) Dimorphotheca sp. (60) Diospyros kaki (60) Diospyros virginiana (persimmon) (60) Dolichos biflorus (a genus of beans) (60) Dolichos lablab (hyacinth bean) (60) Eggplant (Solanum melongena) (45, 60) Elettaria cardamomum (60) Erigeron (aster) (PDR 32:218) Erigeron canadensas (common mare’s tail w-eed) (71) Erigeron ramosus (72a) Eriobotrya japonica (60) Erythrina indica (coral trees) (60) Erythrina lithosperma (60) Erythrina umbrosa (60) Erythrina velutina (60) Eucalyptus globosus (60) Eucalyptus rostrata (60) Eupatorium serotinum (72a) Ficus elastica (rubber plant) (60) Ficus nitida (60) Flax (Linum) retted by charcoal rot (1) Fagopyrum esculentum (buckwheat) (72a) Garcinia mangostana (60) Geranium sp. (60) Gladiolus sp. (60) _ Glottidium vesicarium (bladder pod or coffee bean)* (89) Gourds (11) Grevillea robusta (silk-oak) (60) Guayule (PDR 28:984; 32:284) Guizotia abyssinica (60) Helianthus annuus (sunflower) (37, 42, 43, 60; PDR 32:225) Helianthus cucumerifolius (sunflower) (60) Helianthus tuberosus (Jerusalem artichoke) (60) Hemp (Cannabis) (71; PDR 32:420) Heterotheca subaxillaris*; (described in this article) Hevea brasiliensis (rubber) (6, 60) Hibiscus cannabinus (fiber plant) (60) Hibiscus sp. (60 Hibiscus rosa-sinensis (Rose-of-China) Hibiscus sabdariifa (a fiber plant) (60) Ipomoea hederacea (72a) Ipomoea batatas (see sweet potato) (60) lris sp. (60) _ , Jacaranda (ornamental trees) (60) Jute (2 species of Corchorus; (rope plant; black sclerotia in cortex; also pycnidia) (6, 60) Juglans nigra (walnut) (60) Juniperus sp. (60) Kudzu (Pueraria) (PDR 30:131) Lactuca sativa (lettuce) (60) Lactuca scariola (42, 71; PDR 32:281) Larix laricina (seedling blight of tama- rack) (15) *Found in Texas. (60) Hosts with notes and references Laurus nobilis (Sweet Bay) (60) Lavandula sp. (60) Lespedeza sp.* (37, 42; PDR 30:8) Lespedeza stipulacea (charcoal rot) (71) Ligustrum sp. (privet) (60) Lilium sp. Lilium candidum (lily) (60) Lima bean* (11; PDR l5:114; 30:69) Lupinus sativus (lupine) (60) Lupines; root rot of Lupinus sp. (PDR 25: 341; 30:11) Malus mitis (apple) (60) Mamillaria sp. (pin cushion cactus) (60) Matthiola sp. (stocks) (60) Melaleuca armillaris (ornamental brush) (60) Melilotus alba* (sweetclover) (4, 72a, 89) Mentha piperata (peppermint) (60) Mucona sp. (60) Musa sp. (banana or manila hemp) (60) Musa paradisiaca (60) Muhlenbergia sp. (leaf blight) (PDR 29:281) Mung bean* (36; PDR 28:1019; 30:67) Myrtus commiunis (Myrtle) (60) Nemesia sp. (60) Ochroma lagopus (60) Oenothera biennis (common weed) (72a) Okra* (60) Olea europaea (olives) (60) Onobrychis sativa (sainfoin clover) (60) Panicum maximum (60) Parinarium nobola (60) Peanut* (60; PDR 27z505; 29:368 and 690; 30:13) Peas (Pisum) (37; PDR 30:95) Pelargonium sp. (geranium) (60) Persea (avocado) (60) Persea gratissima (60) Pepper (Capsicum)* (11, 43, 45, 60) Phacelia tanacetifolia (ornamental flowers) (60) Phaseolus lunatus (lima bean)* (60) Phaseolus multiflorus (butter bean) (43, 60) Phaseolus mungo radiatus (60) Phaseolus mungo (black gram) (68) Phlox sp. (sclerotia in base of rotted stem) (72) Phlox decussata (72a) Phoenix canariensis (palm) (60) Phoenix dactylifera (date palm) (60) Physalis alkekengi (Chinese lantern) (60) Physalis peruviana (cape-gooseberry) (60) Picea abies (seedling blight of Norway spruce) (15) Pidgeon pea (Cajanus) (6, PDR 29:711) Pimpinella anisum (anis-a) (60) Pinus banksiana (jack pine) (15) Pinus ponderosa (seedling blight of western yellow pine) (15) Pinus contorta (lodgepole pine) (60) Pinus halepensis (60) Pinus maritima (60) Pinus resinosa (seedling blight of red pine) (l5) Pinus sylvestris (seedling blight of Scotch pine) (l5) Piper betle (Betel pepper) (60) Pisum arvense (pea) (60) Pithecolobium saman (Manila (60) Pittosporum tobira (ornamental tree) (60) Pittosporum undulatum (Victorian box) (60) Poinciana regia (ornamental shrub) (60) Polygonatum lapathifolium (72a) Populus sp. (poplar) (60) Potato (Solanum) (6, 7, 41, 60, 76; 1l:75)* Prunus amygadalus (60) Prunus armeniaca (apricot) (60) Prunus avium (sweet cherry) (60) Prunus divaricata (mvrobalan plum) (60) Prunus domestica (plum) (60) bottle tamarind) PDR 4i CHARCOAL ROT OF PLANTS IN EAST TEXAS 29 Hosts with notes and references Prunus mahaleb (60) Prunus persica (peach) (60) Pseudotsuga taxifolia (seedling blight of Douglas fir) (15) Pumpkin* (8, 50; PDR. 30z488 & 489) Pyrethrum cinerariifolium (chrysanthemum) (50) Pyrus communis (pear) (60) Radish* (60) Rheum undulatum (60) Ribes sp. (gooseberfy) (60) Ricinus communis (castor bean) (60) Rose (Rosa sp.) 43, 60) Rosmarinus sp. (60) Rudbeckia hirta (72a) Rumex sp. (dock) (60) Russelia oflicinarum (6/0) Santalum album (60) Santolina sp. (60) Salvia sp. (sage) (PDR 32 :413) Scabiosa sp. (ornamental flower) (60) Sesame (Sesamum)* (wilt, root rot, ashy stem blight) (4, 6, 60, 68, PDR 32z486) Sesbania macrocarpa* (described in this ar- ticle) Sesbania punctata (60 Setaria lutescens (72a) Sida spinosa (common weed related to cot- ton) (72a) Solanum carolinense (72a) Sorghum annuum (60) Sorghum* (40, PDR 27:532 and 29:545) Solidago altissima (goldenrod) (72a) ‘Found in Texas. Hosts with notes and references Soybean* (60, PDR 27:509; 28:687; 30; 134) Squash* Strawberry (43, 60, 74) Stizolobium deeringanum (velvet bean)* (60) Strophostyles (Phaseolus?) helvola 23zl38, 30:136) Styrax sp. (60) Sugar beet (37, 60, 74) Sugar cane (60) Sweetclover—(see Melilotus) Sweet Sudan grass* (4, PDR 29z546) Sweet potato (lpomoeafi (ll, 45, 69; PDR 27:713; 292346; 30:356) Tagetes erecta (marigold) (60) Tagetes sp. (marigold) (57, PDR 32 :329) Tea (Thea sp.) (6, 60) Tephrosia candida (60) Theobroma cacao (chocolate) (60) Thuja sp. (arbor vitae) (60) Tobacco (43, 60; PDR 18:11?) Tomato* (43, 60, 89) Tristana conferta (60) Triticum sp. (wheat) (60) Turnip*; see Brassica ' Verbascum sp. (mullein) (60) Verbena hortensis (PDR 33zl08) Vicia faba (broad bean) (60) Vicia sativa (vetch) (60) Viola odorata (60) Vitis vinifera (grape) (60) Watermelon* (11, 89; PDR 30:480) PDR Zinnia elegans* (60; PDR 32z335) METHODS OF CONTROLLING CHARCOAL ROT Methods of invigorating crop plants are likely to give in- creased yields. despite some damage by charcoal rot. Abundant moisture from rain or irrigation, Water in the latter part of the growing season practically controls the stem-rot form of char- coal rot (29, 41, 51). Late varieties of sorghum that ripen in cool, rainy weather are likely to escape serious damage from charcoal rot (32). Sorghum and other crops appear to resist charcoal rot in their grand period of growth when they have maximum vitality. Crop plants range from very susceptible to immune to char- coal rot (91). Thick-stalked, leafy varieties of sorghum are damaged least by charcoal rot (19). Promising resistance Was found 1n_some varieties of sorghum (27). Table 1 shows prom- 1s1n_g resistance to charcoal rot in some varieties of corn. Iron, California Blackeye No. 1 and the related Blackeye No. 8152 varieties of cowpeas resist M. phaseoli (44, 85, 91). Giant Striata crotalaria Was almost immune to charcoal rot in 1948. 30 BULLETIN 712, TEXAS AGRICULTURAL EXPERIMENT STATION SUMMARY 1. Macrophomina. phaseoli (Sclerotium biataticola and Rhizoc- tonia bataticola are often-used synonyms) causes charcoal rot in at least 284 species. of plants that are listed in Table 2- Char- coal rot damages corn, sorghum, cowpeas, beans, turnips, cro- talaria, peppers, potatoes, sweet potatoes and melons in many parts of Texas. Charcoal rot of cotton was found in only three counties of Texas. The, symptoms of charcoal rot are described for many farm crops in Texas. 2. The most common symptom of charcoal rot is shredding of the tissues o-f the base of the stems and tops of the taproots that are blackened with sclerotia. Twelve of the host plants showed gray discoloration of the stem bark as one symptom. Seven hosts had fruits rotted by charcoal rot. Seedling blight due to charcoal rot was reported only in sorghum, corn and beans. Pycnidia and spores of M. phaseoli were found in six hosts. - 3. This is apparently the first description of charcoal rot of cabbage, Heterotheca», Sesbania "mwcrocarpa, and Crotalaria mu- cronata. Apparently this is the first report of the pycnidia and spores of M. phaseoli in the stems of the watermelon and Irish potato. ‘ 4. Severity o-f charcoal rot of corn was correlated with the total rainfall in June, July and August. Charcoal rot was mild in the two years with rainfall exceeding 19 inches in these 3 months, and was severe in the 4 years when rainfall totaled only 3 to 6 inches in these 3 months. 5. Crops that have their seedling stages and those that ma- ture in co-ol or rainy weather are not damaged seriously by charcoal rot. Methods of crop production that invigorate the plants apparently increase their resistance to charcoal rot. Re- sistant varieties of some crops help to control charcoal rot. This disease is controlled practically by enough rain or irrigation Water in the latter part of the growing season. ACKNOWLLEDGMENTS The writer thanks L. R. Tehon, head of the Botany Section of the State Natural History Survey Division, Urbana, Illinois, for furnishing records for the host index of M. phaseoli; and A. A. Dunlap, L. M. Blank, A. W. Crain, W. H. Brittingham and W. J. McIlrath of the the staff of the Texas Agricultural Experi- ment Station for helpful suggestions. in preparing the manu- script. U! \I 20. 2|. 22. 23. 24. 29. 3o. 31. . Adam, D. B. and J. . Hoffmaster, D. E., J. CHARCOAL ROT OF PLANTS IN EAST TEXAS 31 LITERATURE CITED I Stokes. The association of Rhizoctonia bataticola with retting flax in South Australia. Linn. Soc. N.S. Wales Proc. 67:313-317. 1942. Altstatt, C. E. Ashy stem blight and a bacterial leaf spot of sesame in Texas. Plant Disease Reporter 28:11o4-11o5. 1944. Altstatt, (L. E. Some new records for Sclerotium bataticola. Plant Dis. Rptr. 2821129. 1944. Altstatt. G. E. and P. A. Young. Incidence 0f charcoal rot in north and east Texas. Plant Dis. Rptr. 28:899-900. 1944. 7 Andrus. C. F. Seed transmission of Macrophomina phaseoli. Phytopath. 28:620- 634. 1r 38. Ashby.) S. F. Macrophomina phaseoli (MaubL) comb. nov. The pycnidial stage of Rhizoctonia bataticola (Taub.) Butl. Trans. Brit. Myc. Soc. 12:141-147. 1927. Boewe, G. H. Charcoal rot on potatoes in Illinois. Plant Dis. Rptr. 26:142-143. 1 42. Bioyle, L. W. Sclerotium bataticola on pumpkin and squash in western Oregon. Plant Dis. Rptr. 2821129-1130. 1944. Bretz, T. W. Diseases reported on soybeans. Plant Dis. 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Seedling stem blight of field beans caused by Rhizoctonia bataticola at high temperatures. Phytopath. 23:949-963. 1933. . Larsh, H. W. Diseases reported on soybean in Oklahoma. Plant Dis. Rptr. 2821010 and 1125. 1944. . Larsh, H. W. Diseases of mung bean in Oklahoma. Plant Dis. Rptr. 28:1019. 1944 . Leukel, R. “L, J. H. Martin, and C. L. Lefebvre. Sorghum diseases and their control. U.S.D.A. Farmers Bul. 1959. 1944. . Lewis, R. D. Crotalaria in East Texas. Texas Agr. Exp. Sta. Ann. Rept. 59:66-67. 1946. . Littauer, F. Sclerotium bataticola on potatoes in Palestine. Palestine Jo11r. Bot. Rehovot Ser. 4:142-147. 1944. . Littauer, F. and J. Gutter. Sclerotium bataticola Taubenhaus as a causal agent of a rot of Shamouti oranges. Palestine Jour. Bot. Ser. R. 5 (2) :261-262. 1946. . Livingston, J. E. Charcoal rot of corn and sorghum. Nebraska Agr. Exp. Sta. Res. Bul. 136. 1945. Livingston, J. E. Important diseases of corn in Nebraska. Nebraska Agr. Ex- tension Serv. Circ. 1804. 1945. Luttrell, E. S. A pycnidial strain of Macrophomina phaseoli. Phytopath. 36:978-980. 1946. Lyle, E. W., A. A. Dunlap, H. O. Hill, and B. D. Hargrove. Control of cotton root rot by sweet clover in rotation. Texas Agr. Exp. Sta. Bul. 699. 1948. . Mackie, W. W. A hitherto unreported disease of maize and beans. Phytopath. 22:637-644. 1932. Mackie, W. W. Blackeye beans in California. California Agr. Exp. Sta. Bul. 696. 1946. . Martin, W. H. Sclerotium bataticola, the cause of a fruit rot of peppers. Phytopth. 7:64, 308-312. 1917. Maublanc, A. Macrophoma phaseoli. Bul. Soc. Myc. France. 21:90. 1905. . McKee, R., G. E. Ritchey, J. L. Stephens, and H. W. Johnson. Crotalaria culture and utilization. U.S.D.A. Farmers Bul. 1980. 1946. . Miller, J. C. Notes on diseases of garden crops in Georgia. Plant Dis. Rptr. 30:48. 1946. . Miller, J. J., A. A. Hildebrand, and L. W. Koch. Macrophomina and Fusarium attacking field beans in Ontario. Sci. Agr. 27(6) :251-2,59. 1947. . Miller, P. R. G-men of plant diseases. U.S.D.A. Yearbook pp. 443-450. 1943 to "J47- Pady. S. M. Diseases of corn and sorghum in the Kansas-Nebraska area. Plant Dis. Rptr. 27:563. 685, 361, and 375 to 377. 1943. . Pady, S. M. Notes on the plant disease survey in Kansas. Plant Dis. Rptr. Supplement 149, p. 314. 1944. . Person, L. H. Report on diseases of soybeans. Plant Dis. Rptr. 27:509. 1943. . Petrak, F. Mycologische Notizen. Ann. Myc. 21:314-315. 1923. Poole, R. F. Peanut studies. N. C. Agr. Exp. Sta. Ann. Rept. 61:38. 1938. Presley, J. T. A disease of guayule caused by Sclerotium bataticola. Plant Dis. Rptr. 28:936. 1944. . Preston, D. A. Host index of Oklahoma plant diseases. Plant Disease Rptr. 32:401. 1948. Quinby, R. and C. Stephens. Experiments with corn. Tex. Agr. Exp. Sta. Ann. Rept. 49:263. 1936; 48:223, 1935. . Quinby, J. R. Charcoal rot disease. Texas Agr. Exp. Sta. Ann. Rept. 53:224. 1940. Ray, W. W. and H. IVIcLaughlin. Isolation and infection tests with seed and soil borne cotton pathogens. Phytopath. 32:233-238. 1942. Reichert, I. and Esther Hellinger. On the occurrence, morphology. and para- sitism of Sclerotium bataticola. Palestine Jour. Bot. 6:1o7-147. 1947. wilt of cotton. Compt. Rend. (vDoklady) Acad. Sci. USSR. 49:69-72. 1945. Sarejanni, J. A. and C. B. Cortzas. La nature de la resistance du coton a11 Macrophomina phaseoli. Rev. App]. Myc. 16:249. 1937. . Saburova, P. V. A contribution to the study of the physiology of galloping 9 63. 64. 64a. 65. 66. 67. 68. 69. 70. 71. 72. 72a. 73- 74~ 80a. 82. 83. 84. 85. 86. 87. 88. 8g. 9o. 91. CHARCOAL ROT OF PLANTS IN EAST TEXAS 33 Semeniuk, G. Seedling infection of dent maize by Sclerotium bataticola Taub. Phytopath. 34:838-843. 1944. Smith, A. L. Lightning injury to cotton. Phytopath. 33:150-155. 1943. Smith, H. P., G. E. Altstatt, and M. H. Byron. Harvesting and curing garlic to prevent decay. Texas Agr. Exp. Station Bul. 651. 1944. Solheim, W. G., P. A. Young, and O. A. Plunkett. A systematic presentation of new genera of fungi. II. Trans. Amer. Micr. Soc. 46:187-207. 1927. Stevens, F. L. and P. A. Young. On the use of the terms saprophyte and parasite. Phytopath. 17:409-411. 1927. Stevenson, J. A. Ashy stem blight of Blackeye cowpea in Texas. Plant Dis. Rptr. 21:279. 1937. _ . _ _ _ Sundararaman, S. Rhizoctonia bataticola 1n a species of cotton. Rev. Appl. Mycol. 11:223-224. 1932. Taubenhaus, J. J. The hlack rots of the sweet potato. Phytopath. 3:159-166. 1 1 . Tgagbenhaus, J. J. andT. F. Manns. The diseases of the sweet potato and their control. Delaware Agr. Exp. Sta. Bul. 109. 1915. Teho11, L. R. and G. “l. Boewe. Charcoal rot in Illinois. Plant Dis. Rptr. 23:312-321. 1939. Tehon, L. R. Charcoal rot of hardy phlox in Illinois. Plant Dis. Rptr. 25 (17) : 1 1. glilehon, L. R. and G. W. Boewe. (Unpublished records of the Illinois State Natural History Survey; Urbana, Illinois, 1948.) Tidd, J. S. Diseases of corn in Illinois. Plant Dis. Rptr. 28:900-901. 1944. Tompkins, C. M. and M. W. Gardner. Relation of temperature to infection of bean and cowpea seedlings by Rhizoctonia bataticola. Hilgardia 9:219-230. 193'- . Tulolis, E. C. Stalk rot of sorghum. Plant Dis. Rptr. 30:333. 1946. Watson, R. D. Charcoal rot of Irish potatoes. Phytopath. 34:433-435. 1944; also Phytopath. 33:112o. 1933. . Weimer, J. L. The thinning of crotalaria stands in southeastern United States. Plant. Dis. Rptr. 27:110-111. 1943. Weimer, J. L. Nlacrophomina root and stem rot and anthracnose of Cha1nae- christa. Phytopath. 3421077-1085. 1944. _ Weimer, J. L. 8¢ E. S. Luttrell. A canker of cowpea and Macrophomina leaf spot of cowpea and snap bean. Plant Dis. Rptr. 29:127-129. 1945. . Weiss, Freeman. Check list revision. Plant Disease Reporter 32:413; 31:412. 1947. In Table 2 in this bulletin, single-line reports on disease occurrence are given abbreviated references such as PDR 31:413. Wiant, J. S. Investigation of the market diseases of cantaloupes and Honey Dew and Honey Ball melons. U.S.D.A. Tech. Bul. 573. 1937. . Wilson, Coyt. A diplodia associated with concealed damage in peanuts. Phyto- path. 35:480. 1945. Wilson, Coyt. A survey of the fungi associated with peg and seed rot of pea- nuts in southern Alabama. Phytopath. 37:24. 1947. Young, P. A. Tabulation of the genera Phoma and Macrophoma. Phytopath. 15:47-48. 1925. ‘ Young, P. A. Classification of plants on the basis of parasitism. Amer. Jour. Bot. 14:481-486. 1927. Young, P. A. Blackeye Pea No. 8152 resistant to root knot. Texas Agr. Exp. Sta. Ann. Rept. 55:33. 1942. Young, P. A. A canker disease of Crotalaria spectabilis in Texas. Plant Dis. Rptr. 26:438. 1942. Young, P. A. Cottons resistant to wilt and root knot and the effect of potash fertilizer in East Texas. Texas Agr. Exp. Sta. Bul. 627. 1943. Young, P. A. Potato roots inside potato tubers. Amer. Jour. Bot. 31:368. 1944. Young, P. A. Epidemic of charcoal rot of corn and other crops in East- Texas. Plant Dis. Rptr. 29:898-899. 1944. Young, P. A. Charcoal rot in pepper roots. Plant Dis. Rptr. 32:482-483. 1948. Young, P. A. Symptoms and resistances of crop plants to charcoal rot and ashy stem blight. Phytopath. 39:27. 194g.