Row‐applied Iron Chelate for Correcting Iron Deficiency Chlorosis in Dry Bean

Abstract

Row‐applied Fe chelate at 1.8 kg−1 for dry edible bean increased yields on chlorosis‐prone soils. Visual chlorosis ratings near flowering were well correlated with final yield. Yield responses of 10% above the check were economical at current and historic dry bean prices. Chlorosis severity mapping of fields would improve application to the areas most likely to respond to Fe ethylene diamine‐N, N’‐bis (2‐hydroxyphenylacetic acid application. Iron‐deficiency chlorosis (IDC) reduces the yield of dry edible bean (Phaseolus vulgaris L.) grown on high‐pH calcareous soils. The objective of this research was to compare the effectiveness of row‐applied SoyGreen Fe ethylene diamine‐N, N’‐bis (2‐hydroxyphenylacetic acid (FeEDDHA)) on reducing IDC and increasing dry bean yield planted in 56‐cm rows. Two commonly grown varieties of Great Northern and Pinto dry bean were grown in a randomized complete block design during 4 yr with four levels of FeEDDHA (0–2.24 kg ha−1). Visual chlorosis ratings showed significant differences in 3 of 4 yr and higher FeEDDHA rates improved chlorosis scores. Yields were increased in 2011 and 2014 but not on the low IDC severity site in 2012 (2013 plots were lost to hail). Relative yields for 2011 and 2014 versus the chlorosis score showed significant increasing yield as chlorosis severity decreased. The relative yield response to FeEDDHA averaged across different varieties and market classes was about 10% and yield was maximized near 1.8 kg ha−1 FeEDDHA. For the Fe‐responsive years, the check yield was 3096 kg ha−1 of Great Northern beans and 3125 kg ha−1 for Pinto beans, which translates to an additional 310 kg ha−1 of beans. With current and historic bean prices, the yield increase adds over $200 ha−1 at a cost of near $40 ha−1, more than paying for the fertilizer cost.