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Effects of Timing of Nitrogen Fertilization and a Fungicide on Soft Red Winter Wheat 1
Author(s) -
Roth G. W.,
Marshall H. G.
Publication year - 1987
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/agronj1987.00021962007900020005x
Subject(s) - fungicide , loam , mancozeb , triadimefon , agronomy , nitrogen , fertilizer , human fertilization , chemistry , soil water , horticulture , biology , ecology , organic chemistry
Split spring N applications and fungicides are important components of proposed intensive management systems for soft red winter wheat ( Triticum aestivum L.). Six experiments at two locations were conducted on Hagerstown silt loam (fine, mixed, mesic Typic Hapludalf) soils to evaluate the responses of wheat to a fungicide and delayed or split N applications. Delayed N treatments consisted of a single application of 100 kg ha −1 at either growth stage (GS) 5 or 8. Seven split N treatments consisted of two or three applications made at GS 3, 5, or 8, totaling 100 kg N ha −1 . Split and delayed N responses were compared to those resulting from four rates of N applied at GS 3. Average grain yields for the experiments ranged from 3.2 to 5.9 Mg ha −1 . Yields from split and delayed N were greater than the maximum achieved with GS 3 N applications in only one of the six experiments. In this experiment, the greatest yield increase due to split N, 0.7 Mg ha −1 , occurred when a fungicide was used. A large amount of precipitation (219 mm) at that location between GS 3 and GS 5, and a high fertilizer N requirement apparently contributed to the response to split N. Yield responses to fungicides (triadimefon [l‐(4‐chlorophenoxy)‐3,3‐dimethyl‐l‐(lH‐l,2,4‐trizol‐1‐yl)‐2‐butanone] or triadimefon + mancozeb [zinc ion and manganese ethylene bisdithiocarbamate)) varied between years and ranged from 0 to 0.9 Mg ha −1 . Decisions to use split N and fungicides should be based on factors such as disease severity, rainfall, and anticipated soil N supplying capability.