Author
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Heatherly, Larry |
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Submitted to: Crop Management at www.cropmanagement.org
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/10/2004 Publication Date: 4/18/2005 Citation: Heatherly, L.G. 2005. Midsouthern usa soybean yield affected by maturity group and planting date. Crop Management at www.cropmanagement.org. doi: 10.1094/CM-2005-0418-01-RS. Interpretive Summary: Soybean is planted from late March through June in the midsouthern USA as a result of time, production, and environmental constraints. These plantings may utilize varieties from maturity groups (MG) IV through VII, and are grown in both nonirrigated and irrigated environments. The range in planting time and maturity of cultivars from the different MGs affects yield. Results from 28 years of field studies at Stoneville, MS determined trends in seed yields exhibited by these disparate plantings. In irrigated April and May plantings, MG IV cultivars produced greater yields with greater irrigation efficiency than did MG V, VI, and VII cultivars. In nonirrigated April plantings, MG IV and V cultivars produced yields similar to each other. In nonirrigated early-May plantings, cultivars from all MGs produced similar yields, but days-to-maturity increased with increasing MG. In nonirrigated late-May plantings, MG V through VII cultivars were superior yielders, whereas MG VI and VII cultivars yielded the most in nonirrigated plantings made after 31 May. Irrigation efficiency was highest with early-maturing cultivars planted early in the season. These results show that planting cultivars that are later than necessary for maximum yield results in increased days to maturity, a concurrent greater risk of detrimental late-season effects from drought and pests, and increased irrigation water use regardless of the planting date. This information allows producers to definitively select cultivars from the appropriate MG based on their planting date and production (nonirrigated or irrigated) environment. Technical Abstract: Soybean [Glycine max (L). Merr.] is planted from late March through June in the midsouthern USA as a result of time, production, and environmental constraints. These plantings may utilize cultivars from maturity groups (MG) IV through VII, and are grown in both nonirrigated and irrigated environments. In irrigated April and May plantings, MG IV cultivars produced greater yields with greater irrigation efficiency than did MG V, VI, and VII cultivars. In nonirrigated April plantings, MG IV and V cultivars produced yields similar to each other. In nonirrigated early-May plantings, cultivars from all MGs produced similar yields, but days-to-maturity increased with increasing MG. In nonirrigated late-May plantings, MG V through VII cultivars were superior yielders, whereas MG VI and VII cultivars yielded the most in nonirrigated plantings made after 31 May. These results show that planting cultivars that are later than necessary for maximum yield results in increased days to maturity and a concurrent greater risk of detrimental late-season effects from drought and pests regardless of the planting date. |
