Screening of Mango Cultivars for Tolerance to Iron Deficiency

Mango is the most important fruit crop of India cultivated in 1.3 m ha but the average productivity is low at 6 t ha(-1). It was also noticed that productivity between cultivars varied widely in calcareous soil (1/3 of soil in India calcareous) and incipient iron deficiency was suspected as one of the causes. Since mango is managed as a hardy crop and less profitable, use of costly inputs like chelated iron to correct Fe deficiency is not sustainable. Hence a study was undertaken to screen rootstocks tolerant to iron deficiency so that it is corrected at low cost. Eight important cultivars of mango in India were screened for tolerance Iron deficiency in alfisol of pH 7.8 with free CaCo3 of 2.3. The plant growth parameters like height, leaf number size and chlorosis score (1-5) were recorded for 3 months from the data germination of the stones. The leaves were analyzed for P, K, Ca, Fe, Zn, and B to observe difference in uptake. The results indicated out of 8 cultivars of mango cv. Amarapalli was most tolerant to iron deficiency with vigorous vegetative growth and cv. Alphonso was the most susceptible. Leaf analysis indicated the Fe-tolerant Amarapalli had a wider K/Ca ratio at 2.3 whereas the susceptible Alphonso had a K/Ca ratio of 1.28.