Papaya is produced is produced throughout India but commercially in the states of Andhra Pradesh, Gujarat, Karnataka, West Bengal, Madhya Pradesh and Maharashtra. This fruit is cultivated in 136.0 thousand ha. and constitutes 1.8 per cent of the total area under fruit crops. We are producing 6108 thousand MT of fruits. and this contributes 6.3 per cent of the total fruits production in India. The average national productivity is 42.3 MT ha-1.
Production and productivity of papaya is affected by various biotic and abiotic stresses. The production constraints also vary from region to region. Papaya being an exhausting crop requires large quantity of fertilizers. Hence optimum quantity of fertilizers and time of application is important for efficient utilization of nutrients. Response of micronutrients like Zn, has been noted for increasing the quality and yield and also in management of ring spot virus disease. Hence an appraisal on soil zinc deficiencies and superimposing papaya area for district-wise crop based zinc delineation maps is essential for preparing strategic guide in realizing potential yields of papaya in different regions of the country.
Crop boundary:
Based on categorization with respect to area and production per unit area, eleven states covering 86 districts were identified as prime papaya producing states of India. The boundary map of papaya was prepared using district maps of respective leading producing states and presented in Figure 1.
Figure 1.Major papaya growing areas in India:
Deficiency symptoms:
Zinc deficiency is seen in the expanding leaves as interveinal chlorosis that later become purple spots(Plates A,B,C). With increasing deficiency, the youngest leaves remain small, possibly showing necrosis along the edges and on the lamina between the principal veins. The inter-nodal space is also shortened. Zinc deficiency included pronounced raised light green veins on the upper and lower leaf surface distorted strap like leaf lobes and slight yellowing of youngest leaves
Plate A, B, C. Papaya plant showing zinc deficiency with (A) the expanding leaves showing interveinal chlorosis (B). the internodal space becoming shortened with rosette appearance, (C) pronounced raised light green veins on the upper and lower leaf surface with distorted strap like leaf lobes
Sufficient data base is available on soil zinc availability in India. Of the 86 papaya growing districts 20 districts have deficiency of zinc and 45 districts showed sufficient levels of soil available zinc(Figure 1).
Management of Zinc in Papaya:
Fertilizing papaya with zinc containing chemicals is uncommon. However, those farmers who are applying zinc as fertilizers to soils have continued to apply every year leading to accumulation of high levels of zinc in such soils. This has caused imbalance in plant nutrition leading to induced phosphorus and other deficiencies. Keeping this in mind and the pattern of fertilizer use in papaya and the crop ability to absorb nutrients it is advisable to go for foliar application of zinc rather than soil application as a precaution to avoid unnecessary accumulation in the soils leading to nutrient imbalances. A general spray of 0.25 to 0.40% solution of ZnSO4.7.H2O would take care of the zinc requirement of papaya. Use of Arka papaya micronutrient formulation developed by IIHR, Bengaluru @ 2g per liter meets the micronutrient requirement of papaya including zinc.
Figure 2. Zinc fertility status of papaya growing regions of India
Komentar