Leaf Chlorosis and Seed Yield of Dry Beans Grown on High-pH Calcareous Soil following Foliar Iron Sprays

Abstract

Iron deficiency chlorosis (FeDC) causes extensive reduction in yields of edible dry beans (Phaseolus vulgaris L.) grown on high-pH and calcareous soils. Fifteen bean cultivars/lines differing in response to FeDC were grown 2 years (1988 and 1989) on a high-pH (8.0), calcareous (2.3% calcium carbonate equivalent in surface 20 cm), and low-Fe (2.2 mg Fe/kg) Typic Haplustolls silt loam in the field (central Nebraska) to determine the effects of FeDC on seed yield of cultivars/lines sprayed with Fe. A significant interaction (P < 0.05) between cultivars/lines × Fe spray treatment was noted for visual FeDC ratings in 1988 only, and no significant interactions were noted for seed yield either year. Sprayed cultivars/lines generally produced higher yields than unsprayed ones. Overall increases were 47% in 1988 and 41% in 1989. Even though only slight FeDC was noted on some cultivars/lines receiving no Fe spray, seed yields were significantly increased when sprayed with Fe. Some cultivars/lines with moderate or moderately severe FeDC ratings did not show a significant increase in yield when sprayed with Fe, while other cultivars/lines did. Seed yield reductions for the cultivars/ lines per unit of FeDC rating (1 = green to 5 = severe chlorosis) were 915 kg·ha-1 for unsprayed and 1518 kg·ha-1 for sprayed plants in 1988 and 344 kg·ha-1 for unsprayed and 608 kg·ha-1 for sprayed plants in 1989.