Factors Impacting Yield of Irrigated Grain Sorghum in Arkansas.

Field trials were conducted in the Mississippi River Delta region of Eastern Arkansas from 2013-2015, evaluating the impact of enhanced levels of various management inputs compared to normal extension recommendations on irrigated grain sorghum yield.  Inputs evaluated included deep tillage prior to planting, starter in-furrow fertilizer, additional fertilizer, foliar fungicides, micronutrients, and increasing plant populations.  All inputs were evaluated individually and then combined together to evaluate yield response when all enhanced level inputs were applied.  No single input gave consistent yield increases compared to the normal extension recommendations, however when all the enhanced level inputs were applied together, grain sorghum yields were increased compared to the normal extension recommendations.   Normal extension recommendations gave 90% or more of total yield potential, while enhanced inputs increased yield less than 10% when applied together.  Economic analysis showed current extension recommendations to be the most profitable.