TDOC . 5-1658 Z TA245.7 August 1990 B873 A NO.1658 Stabilizing Soybean Production in Northeast Texas with Early Planting of Early-Maturing Soybean Varieties ‘S The Texas Agricultural Experiment Station, Charles J. Arntzen, Director, The Texas A&M University System, College Station, Texas mus Aw UEWERSTTY LIBRARY [Blank Page in Original Bulletin] * 5v 6i 114153.91 8410580770! Aug-i Stabilizing Soybean Production in Northeast Texas With Early Planting of Early-Maturing Soybean Varieties G. R. Bowers, Jr., L. R. Nelson, and G. A. Finch III‘ Introduction Soybeans have been produced in Northeast Texas for many years but production has varied widely. Harvested acreage has fluctuated from a high of 129,000 acres in 1979 (3) to a low of 32,100 acres in 1985 (2). Changes in soybean acreage are often abrupt. In 1980, 108,300 acres were harvested (4), dropping to 63,600 the following year (5). Average annual yields have been equally sporadic, ranging from 25 bu/A in 1979 (3) to 13 bu/A in 1980 (4). Acreage fluctuations generally result from environ- mental and price instabilities. Nonirrigated soybeans grown on the area’s blackland soils are most susceptible to environ- mental hazards. Historically, the area experiences a pro- longed hot, dry period in July and August, coinciding with the blooming and seed-filling periods of Maturity Groups (MG) V, VI, and VII soybean varieties planted in May or early June, which are harvested in October. This traditional soybean-production system is occasionally successful on the deep, well-drained river bottom soils and in years of good summer rainfall. However, soils with good water storing capacity are limited and comprise only 20% -— 35% of the area. Production of conventional maturity soybeans is a high-risk enterprise in most of Northeast Texas. In the late 1970’s and early 1980’s,an interestexisted in adding soybeans to the cotton-sorghum rotation of the Coastal Bend area of Texas. The conventional Upper Gulf Coast production system of planting MG V through VIII soybean varieties in late May and early June was attempted but with poor results because of drought periods in July and August, similar to those of Northeast Texas. Research by the Texas Agricultural Extension Service and the Texas Agricultural Experiment Station, coupled with producer experience, found that planting MG IV soybean varieties in April gave more satisfactory and consistent results. These varieties matured in late July or early August, thereby avoiding drought stress during critical developmental stages and utilizing stored soil moisture and spring rainfall more efficiently. Since the environmental stress periods experienced in both areas were similar, the strategy developed for the Coastal Bend was applied to Northeast Texas. Previously published results (1) of this research showed that April- planted MG III and IV varieties provided a potential produc- tion system for the drought-prone areas of Northeast Texas. This report details results from the 1988 study and summa- ‘Respectively, associate professor, Texas Agricultural Experiment Station, Beaumont; professor and technician II, Texas Agricultural Experiment Station, Overton. KEYWORDS: Soybean] drought sl:ress/ production systems/ North- east Texasl yield. rizes the results from a 3-year study comparing the agro- nomic performance of MG III and IV varieties planted in April with MG V, VI, and VII varieties planted in May. Materials and Methods Test plots were located near Blossom and Hooks, Texas. The test at each location consisted of four replica- tions in a split-plot randomized complete block design with two planting dates as main plots and 12 varieties as subplots. The 12 soybean varieties and their respective maturity groups included Williams 82 (MG III), Asgrow 3966 (MG III), FFR 441 (MG IV), Crawford (MG IV), Egyptian (MG IV), RA 451 (MG IV), Asgrow 5474 (MG V), Forrest (MG V),Centennial (MG VI), Leflore (MG VI), Bragg (MG VII), and Hartz 7126 (MG VII). Seeds of each variety were planted in bedded rows at the rate of eight viable seeds per linear foot ofrow. Supplemental irrigation was not applied. Weeds were controlled with post-emergence herbicides, cultivation, and hand weeding as required. Table I gives general cultural information. Table 1.L0cation, soil type, and cultural information for a test comparing Maturity Group III-VII soybean varieties planted in both April and May 1988 in Northeast Texas. Location: Blossom llooks Soil Type: llouston black clay Severn silt loam Previous Crop: Soybeans Soybeans Planting Date: 22 April, 6 May 21 April, 7 May Test Design: Split-plot randomized Split-plot randomized complete block complete block Plot Size: 4 rows, 34" x 19' 4 rows, 36" x l9‘ Fertilizer: 0-60-60 0-60-60 Herbicide: 2.0 pt/A Dual and 2.0 pt/A Dual and 0.67 pt/A Scepter 0.67 pt/A Scepter Insecticide: 0.75 lb/A Sevin XLR None for blister beetle on 21 June Size Harvested Plot: 2 rows, 14.5’ 2 rows, 14.5‘ Maturity date, yield, plant height, pod height, lodging, seed quality, and seed weight were recorded. Data were sub- jected to standard analysis of variance procedures and means separated with the Duncan’s Multiple Range Test (P=0.05). Results and Discussion The May-planting date at both locations had poor stands due to inadequate soil moisture at and shortly after planting and were subsequently abandoned. Therefore, dis- cussion of the results obtained in 1988 will be confined to the tests planted in April. Table 2 shows the data from the 21 April 1988 planting date at Hooks. Two of the earliest maturing varieties (Asgrow 3966 and FFR 441) were the only varieties with yields significantly lower than the highest yielding variety (Asgrow 5474) in that test. This contrasts with previous findings (1) from 1986 and 1987 when the earliest maturing varieties, such as Asgrow 3966, were among the highest ties for the other traits measured, including plant height, with the four latest maturing cultivars being significantly taller. In general, yields at the Blossom site (Table 3) planted on 22 April 1988 were lower than at Hooks, primarily due to\~ the poor moisture availability of the soil. There was a strong correlation between maturity and yield for the April-planted soybeans in both 1986 and 1987, with the earliest maturing varieties having the highest yields (1). However, in 1988 (Table 3) the late MG IV and MG V i/arieties, such as yielding varieties. Differences were found between varie- Crawford, RA 451, and Forrest, yielded significantly more v Table 2. Performance of soybean varieties planted on 21 April 1988 near Hooks, Texas 0n a Severn silt loam. Maturity Maturity Yield Vvlvlgeiigmiigi Seed Seed Weight Group Variety Date (bu/A) Plant Pod Lodging 1 Quality’ (g/100) III Williams 82 8/26 35.6 abc 27 be 5.3 abe 2.0 cde 2.1 b 14.0 ed III Asgrow 3966 8/25 19.3 e 25 c 5.3 abc 1.8 de 3.0a 14.5 be IV FFR 441 8/28 33.0 be 30 b 5.8 ab 2.5 abcd 2.4 ab 17.1 a IV Crawford 9/16 47.9 ab 36 a 6.3 ab 3.0 a 2.5 ab 17.2 a IV Egyptian 9/15 34.8 abc 20 d 3.8 e 1.4 e 2.5 ab 13.2 ede IV RA 451 10/7 41.8 ab 39 a 6.8 a 2.9 ab 2.5 ab 17.5 a V Asgrow 5474 9/23 54.4 a 28 be 6.8 a 1.9 ede 1.8 b 15.6 b V Forrest 9/24 46.8 ab 30 b 6.0 ab 1.9 ede 2.0 b 12.4 de V1 Centennial 10/22 45.6 ab 36 a 4.5 be 2.1 bede 1.8 b 12.7 de VI Leflore 10/22 40.5 ab 35 a 4.5 be 2.4 abcd 2.1 b 12.0 e VII Bragg 10/30 38.0 abe 39 a 4.8 be 2.6 abe 2.3 ab 13.9 ed VII Hart]. 7126 10/27 43.4 ab 37 a 2.1 bede 2.0 b 12.7 de 5.0 abe ‘Lodging scores based on a scale of 1 t0 5 with l: nearly all plants erect and 5: nearly all plants prostrate. lVisual seed quality scores based on a scale of 1 to 5 with a rating of 1 indicating excellent seed quality. ’ Values, within columns, followed by the same letter are not significantly different (1320.05) using Duncan's Multiple Range Test. Table 3. Performance of soybean varieties planted on 22 April 1988 near Blossom, Texas on a Houston black clay. Maturity Maturity Yield Height (_in.) Seed Seed Weight Group Variety Date (bu/A) Plant Pod Lodging ‘ Quality’ (g/l00) lll Williams 82 9/4 22.6 de 24 e 4.3 de 1.9 abe 1.6 d 17.1 be Ill Asgrow 3966 9/3 24.5 ed 24 e 4.8 cde 1.5 e 2.1 bed 16.7 ed IV FFR 441 9/4 26.6 ed 26 de 3.5 e 1.8 be 2.6 b 20.7 a IV Crawford 9/7 34.5 ab 29 d 4.8 ede 1.6 be 2.0 ed 17.8 b IV Egyptian 9/6 30.0 be 29 d a 3.8 e 1.5 e 1.8 d 12.3 hi IV RA 451 9/23 35.2 ab 35 c 4.3 de 2.4 a 2.() ed 14.0 fg V Asgrow 5474 9/21 29.8 be 37 be 8.0 a 2.0 abe 2.5 be 13.1 gh V Forrest 9/25 37.6 a 38 abc 3.8 e 2.1 ab 3.5 a 11.3 i VI Centennial 10/27 23.6 ed 35 e 5.0 bede 1.9 abe 2.5 be 14.9 ef V1 Leflore 10/21 23.3 ed 36 c 6.5 b 2.0 abe 2.0 ed 13.6 g VII Bragg 10/28 16.1 e 40 ab 6.3 be 2.0 abe 2.4 be 15.0 ef . VII Hartz 7126 10/30 21.8 de 41 a 5.8 bed 2.1 ab 2.0 ed 15.8 de M/ ‘Lodging scores based on a scale of 1 to 5 with 1= nearly all plants erect and 5: nearly all plants prostrate. 1 Visual seed quality scores based on a scale of 1 to 5 with a rating of 1 indicating excellent seed quality. ’ Values, within columns, followed by the same letter are not significantly different (P:0.05) using Duncan's Multiple Range Test. than the MG III and early MG IV varieties like Williams 82, Asgrow 3966, and FFR 441. The medium-maturity varieties also significantly out-yielded the MG VI and VII varieties in the test. Significant differences were found for all other traits measured. An inverted pattern of rainfall distribution occurred in 1988 as compared to the 2 previous years. At Hooks the total rainfall accumulation from April through June was 17.8 inches, 8.4 inches, and 3.0 inches in 1986, 1987, and 1988, respectively. The combined total rainfall for the months of July and August was approximately 4 inches in both 1986 and I987, while rainfall totaled 10.9 inches in 1988. This shows that the typical pattern for the area of late-sprin g and early-summer rains, followed by a period of summer droughts, was reversed in 1988. A similar temporal pattern for rainfall occurred at the Blossom site in 1988, with a May-June rainfall total of 1.4 inches and a total rainfall for July-August of 7.0 inches. Results from the 1988 tests confirm the benefits of the early-planted/early-maturity production system (mid-April planting of late MG III and MG IV soybean varieties). The loss of the May planting at both locations further illustrates the difficulty producers faced with the conventional system (planting MG V, VI, or VII varieties in May or early June) in 1988. Soil moisture was low atboth locations until late- June early-July. Delaying planting until that time initiates a production season under suboptimal conditions for growth. Reduced plant height caused by planting past the optimal planting time leads to reduced potential yield. Planting late also moves maturity later into the year exposing the system to the risks of early frosts and harvesting under wet condi- tions. _ Even under the deep, well-drained river bottom soil conditions found at Hooks and in an atypical year like 1988, early-maturing varieties like Williams 82 and Crawford yielded as well as late-maturing varieties such as Centennial and Bragg planted early (Table 2, Fig. l). Even though the Hooks site received ample rainfall each month during the 1987 production season, the temporal distribution of the rainfall was not uniform resulting in periods of severe drought stress. All varieties yielded lower in 1987 than in 1986 or 1988. However, the early-planted/early-maturity system out-yielded the conventional system or the early- planted/late-maturity system (mid-April planting of MG V, VI, or VII varieties) (1). In 1986, with the typical early- season rainfall and late-summer drought, the varieties in the early-planted/early-maturity system yielded as well as or better than varieties in the late-planted/early-maturity or the conventional systems (1). * At Blossom in 1988, late-summer rains increased yields in the early-planted/late-maturity system (Table 3, Fig. 2). The lack of spring and early-summer rainfall reduced yields of early-planted/early-maturing varieties such as Williams 82 (Table 3, Fig. 2). Still, the early-planted/early-maturity system was not penalized with significantly lower yields. Under typical weather conditions of late-spring and early- summer rain followed by a late-summer drought found in both 1986 and 1987, the early-planted/early-maturity sys- tem produced yields significantly greater than either of the other two systems (1). 6G l Williorris 8Q i (MG ill‘ 5Q?» Crowforo ~ 1 (MG IV) 45 ~ * ""5"" A40; Cissiiio‘ i ,- .. C» g Eiroqq v 3O - (MG vii) I3 — 13-- E» 25 » >- . 20~ l5— 10- 5 _ D l l l 1986 l987 1988 Yeor Figure I . Yield performance of four selected culti vars planted in mid-April near Hooks, Texas on Severn silt loam from I 986-88. 6O" Wiltiorris 81 55 (MGIII) 5D r Crawford ~ (MC- iv) 45f "G" m; < s? P ~ [3 “v Bragg v 3O ~ (MG vii) l; . _ A? .2 25 ~ 2O - i5 - , A i0 - El //’ l , sa/ 5 F} _ _ __ _ 1986 1987 1988 Yeor Figure 2. Yieldperformance offour selected eultivars planted in mid-April near Blossom, Texas on Houston black clay from I 986-88. Even though the period of drought stress in 1988 occurred at an unusual time ofyear, the early-planting/early- maturing production system was an effective way of dealing with the drought stress. The stability over years and higher yields obtained with the early-planting/early-maturity sys- tem is shown in Figures l and 2. The results from the 3-year study indicate that the early-planted/early-maturity system stabilizes yield and reduces the risks associated with soy- bean production in Northeast Texas. Literature Cited 1. Bowers, G.R., Jr., L.R. Nelson, and G.A. Finch III. 1989. A drought-avoiding soybean production system for Northeast Texas. Texas Agri. Exp. Sta. MP-1680. 2. Texas Agricultural Statistics Service. 1986. 1985 Texas Field Crop Statistics. USDA Bull. 237. 3.Texas Crop and Livestock Reporting Service. 1980. 1979 Texas Field Crop Statistics. USDA Bull. 182. 4.TexasCropandLivestockReporting Service. 1981. 1980 Texas Field Crop Statistics. USDA Bull. 193. 5.Texas Crop and Livestock Reporting Service. 1982. 1981 Texas Field Crop Statistics. USDA Bull. 201. [Blank Page in Original Bulletin] a ‘nu Mention of a trademark or a proprietary product does not constitute a guarantee or a warranty of the product by The Texas Agricultural Experiment Station and does not imply its approval to the exclusion of other products that also may be suitable. All programs and information of The Texas Agricultural Experiment Station are available to everyone without regard to race, color, religion, \/ sex, age, handicap, or national origin. MP—1 658 900-8-90