Manganese deficiency affects the growth, metabolism and yield of chickpea

The effects of manganese (Mn) deficiency on growth and yield were examined in chickpea (Cicer arietinum) cv 13.G-256. The plants were grown in purified sand supplied with nutrient solution without Mn. The plants were given Mn at two levels, viz., low (2μM deficient) and normal (10μM) levels in the form of MnSO₄.H₂O. In Mn deficiency chlorosis appeared in the young and middle leaves at 35 DAS. Chlorotic leaves turned brown and necrotic. Severe deficiency caused reduction in the branching and flowering. Pods were underdeveloped and seed formation was reduced. In addition to decreased biomass, Mn deficiency also reduced the chlorophyll concentration and photosynthesis as indicated by reduced Hill reaction. Furthermore, amount of Mn, starch, total nitrogen and protein were markedly reduced in various plant parts. The concentration of sugars in leaves and phenols in leaves and seeds were increased. There was a significant reduction in the activities of peroxidase, acid phosphatase and RNase in seeds, although these were enhanced in the leaves. Peroxidase and RNase were higher than acid phosphatase in pod walls. The deficiency of Mn resulted in reduction of seed yield.