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Nutrition
Papaya is a heavy feeder crop. Mineral nutrients are taken up by the plants grown
under full sunlight as macronutrients (K > N > Ca > P > S > Mg) and micronutri-
ents (Cl > Fe > Mn > Zn > B > Cu > Mo) for the proper growth and development
of papaya plantation. Among them, nitrogen, phosphorus and potassium, which are
very important in metabolism and frequently limiting in tropical soils, are extracted
in high amount, a tonne of fresh-harvested fruits contain 1770, 200 and 2120 g of
each of these nutrients, respectively, and among the micronutrients, namely, Fe, Mn,
Zn, B, Cu and Mo are extracted 3364, 1847, 1385, 989, 300 and 8 mg of each nutri-
ents, respectively. High-density plantings may extract 110, 10 and 103 kg of N, P and
K per ha, respectively; however, this can be much higher, depending on the yield.
The fruits signify 20%–30% of the nutrients removed.
If sufficient amount of balanced fertiliser is not applied to the plants, they will
fail to produce fruit or give meagre fruiting. Adequate and efficient manuring of
young and mature trees is essential to maintain the health of papaya and to obtain
profitable yield. It starts from raising the seedlings in the nursery for the production
of vigorous healthy plants. During preparation of nursery bed, 20.0 kg fine compost
should be applied in each nursery bed measuring 3.0 × 1.0 m. After germination,
where the seedlings are one month old, application of liquid solution of fertiliser
ratio 10:10:10 produce healthy seedlings, especially in poor soils. Both organic and
inorganic manures are beneficial to the papaya plants. Organic manures like, farm-
yard manure (FYM), sheep manure, neem cake, wood ash and bonemeal improve
yield and quality of papaya fruits. Hence manuring in papaya should be half from the
organic manures and half from the chemical fertilisers. Papaya responds well to the
application of biofertilisers (Azotobactor and Azospirillum), and organic manures
(vermicompost at 20 kg/plant) improve yield and quality of fruits.
An experiment in fruiting orchard, carried out all over the world, has indicated
positive response to nitrogen, phosphorus, potash and micronutrients in papaya.
Cunha and Haag (1980) estimated the removal of major and minor nutrients per
tonne of papaya fruit. From the uptake studies, requirement of N, P and K was esti-
mated to be 140:40:200 g/plant/year. However, from field experiments, 140–350 g
N, 70–375 g P and 0–500 g K per plant per year have been found to optimum
depending upon cultivars and agroclimatic condition. Application of 200 g N was
also found optimum for fruit yield at Pusa but papain yield increased with dose
up to 300 g at Coimbatore. Invariably 200–250 g each of NPK is recommended
for high yield of papaya. The highest yield of Coorg Honey Dew papaya at NPK
(250 g + 110 g + 415 g, respectively)/plant/year applied in six split applications. In
another experiment, he reported a dose of NPK (125 g + 125 g + 500 g, respectively)/
plant/year in six split applications to be the best. At Coimbatore, a dose of 200 g each
of NPK/plant in four split doses during 1, 3, 5 and 7 months after planting resulted
in higher yield of papaya variety, CO-l. For the papain production, a dose of 250 g