In India, pomegranate occupies an area of 209 thousand hectare and annually produces 2442 thousand MT. The major growing states are Maharashtra, Karnataka, Gujarat, Andhra Pradesh and Telangana. Himachal Pradesh leads in production for anardana. Since last two decades the production of pomegranate has spread to non conventional areas and even to high rainfall areas where the crop suffers from additional abiotic stress including nutrient deficiencies. Zinc deficiencies in commercial pomegranate orchards have become more common than exception. Hence an appraisal on soil zinc deficiencies and superimposing specific crop for district-wise crop based zinc delineation maps is essential for preparing strategic guide in realizing potential yields of pomegranate in different regions of the country.
Crop boundary:
Ten states covering 72 districts were identified as prime pomegranate producing states of India. Boundary map of pomegranate was prepared using district maps of respective leading producing states(Figure 1).
Figure 1.Major pomegranate growing areas in India
Deficiency symptoms:
Pomegranate being a new crop in many areas, zinc deficiency has been the most widespread deficiency. The young leaves from vegetative shoots of pomegranate are more affected than reproductive shoots. Typical zinc deficiency symptoms in pomegranate include little leaf and mottle leaf(Plate A,B).The symptoms are also characterized by irregular green bands along the mid-rib and main vein on a background of light yellow to almost white. In severe Zn-deficiency, the leaves turn abnormally narrow and pointed with the tendency to stand upright coupled with extremely reduced size(Plate A,B). As the deficiency progresses, the leaves are affected over the entire periphery of the tree, and the twigs show dieback symptoms.
Plate A & B. Zinc deficiencies in pomegranate showing (A) beginning of interveinal chlorosis of younger leaves, and (B) a full scale zinc deficient foliage with clear interveinal chlorosis with veins remaining green.
The pomegranate Zinc map(Figure 2) prepared using the soil DTPA zinc status of Indian soils shows that out of 72 districts, 23 districts are reported to be low in available zinc and 34 districts were reported to be well supplied with soil zinc. Keeping this in mind and the pattern of fertilizer use in pomegranate 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.
Figure 2. Zinc fertility status of pomegranate growing regions of India
Management of Zinc in Pomegranate:
Optimum leaf zinc concentrations for pomegranate ranges from 40 to 70 ppm. If leaf Zn falls below this range then application of zinc is recommended. Zinc deficiency in pomegranate, can be ameliorated by foliar application of zinc sulphate. Spray the plants with 0.25-0.5% zinc sulphate solution (250-500g zinc sulphate per 100 liters of water depending upon severity of deficiency) after the flush emerges and turns green following defoliation. However, in some places where new flush emerges during monsoon, the spray should be done in June and if further delayed flush appears then zinc sulphate should be sprayed during August. Apart from this in pomegranate, zinc deficiency becomes acute immediately after fruit set on plants; therefore one maintenance spray of 0.3% zinc sulphate solution may be given in pre-monsoon from the first year of planting. Pomegranate special is a micronutrient formulation specifically developed for pomegranate crop by IIHR, Bengaluru is very effective in correcting the zinc nutrition problems of the crop.
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