Soybean Fungicides and Insecticides in Kansas.

With higher commodity prices, Kansas producers are unsure if additional inputs are cost effective to soybean production. The objective of this study was to determine fungicides and insecticides applied to the seed or foliarly and its impact on soybean yield. In general, seed treated with fungicide only and fungicide + insecticide trended to increase final plant population over the untreated check. Yield of the untreated seed across 9 environments averaged 44.5 bu/acre.  Yields tended to increase with the addition of either seed treatment.  Soybean yield from the fungicide treatment averaged 46.0 bu/acre while the yield of the fungicide + insecticide treatment yielded 45.5 bu/acre.  Foliar fungicides applied in 2010/11 increased soybean yield 1.7 bu/acre over the control to 41.2 bu/acre and was significantly different at a p-value of 0.13.  Soybean treated with fungicide + insecticide increased yield 2.5 bu/acre more than the control to 42.0 bu/acre and was significant at a p-value of 0.03.  While no heavy disease pressure was observed after application, cooler and wetter August and September conditions were conducive to soybean yield and likely more conducive to diseases as well.  No significant increase in soybean yield was observed with either the fungicide only or fungicide + insecticide treatment in 2012 due to extreme heat and drought.