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Soybean Irrigation Serially Timed During Stages R1 to R6. I. Agronomic Responses 1
Author(s) -
Kadhem F. A.,
Specht J. E.,
Williams J. H.
Publication year - 1985
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1985.00021962007700020026x
Subject(s) - cultivar , irrigation , loam , field experiment , mathematics , yield (engineering) , agronomy , biology , horticulture , soil water , physics , ecology , thermodynamics
Previous research has shown that irrigation timing during the reproductive development of soybean [ Glycine max (L.) Merr.] J genotypes is a crucial determinant in ultimate yield response. To obtain more detailed information on this relationship we evaluated the agronomic responses of 16 soybean cultivars to nine irrigation treatments in a 3‐year field experiment. The experiments were conducted in 1980, 1981, and 1982 near Mead, NE on a Sharpsburg silty clay loam (fine, montmorillitic, mesic Typic Arguidoll). In treatments T 1 thru T 7 , only a single irrigation was applied, which coincided with the average R stages 1.1, 2.5, 3.7, 4.7, 5.6, 5.9, and 6.4, respectively. “Check” treatments included T 0 , which was not irrigated, and T 8 , which received a total of seven irrigations coincident with those for T 1 thru T 7 . Averaged over years and cultivars, the seed yield responses (kg/ha) were: T 0 : 3470c, T 1 : 3595abc, T 2 : 3530bc, T 3 : 3740a, T 4 : 3670ab, T 5 : 3630abc, T 6 : 3575bc, T 7 , 3560bc, and T 8 : 3540bc. The irrigation treatment X cultivar interaction was significant, primarily because T 3 (R3.7) or T 4 (R4.7) generally resulted in the highest yields for indeterminate cultivars, whereas T 8 resulted in the highest yields for determinate cultivars. Averaged over irrigation treatments and years, the determinate cv. Hobbit was the highest yielding, both with and without irrigation. Significant increases in plant height, nodes/plant, and lodging occurred with the T 1 , T 2 , T 3 , and T 8 treatments, but only with the indeterminate cultivars. Precise irrigation timing and proper cultivar choice seem to be crucial if high yields with minimum lodging are to be attained.