Foliar application of iron for recovering groundnut plants from lime‐induced iron deficiency chlorosis and accompanying losses in yields

Abstract

A field experiment was conducted at 2‐year interval to determine the optimum time, number of foliar sprays for applying water‐soluble iron fertilizers and chelates, and the relative efficiencies of four different sources of iron for recovery of groundnut (Arachis hypogaea L.) plants from iron‐deficiency chlorosis for plants grown on a calcareous soil. Severe interveinal to complete leaf chlorosis was observed in 38–42% of the population during 30–60 days after emergence (DAE). Foliar applications of iron at 2 kg/ha in the form of 0.1% aqueous solution helped plants recover from chlorosis. However, no significant differences were found among the four iron sources [iron sulphate, iron sulphate+citric acid (400 g/ha), iron citrate, and Fe‐EDTA] with an average recovery of 46, 49, 47, and 46%, respectively. The maximum increase (16 to 24%) in pod yield was obtained when iron sulphate+citric acid was the iron source, while yield increases were 13 to 19, 12 to 18, and 11 to 18% over the control when iron sulphate, iron citrate, and Fe‐EDTA, respectively, were the iron sources. Splitting the application at a dose rate of 2 kg Fe/ha into two sprays at 1 kg each at 50 and 70 DAE, and in four sprays at 0.5 kg each at 30,45,60, and 75 DAE, gave the highest recovery of groundnut chlorosis, and produced the highest pod and haulm (fodder) yields.