138 Papaya
like, lentil, gram, greengram and blackgram should be preferred, because they add
nitrogen into the soil and suppress the weeds.
12.2.9 Crop Rotation
A suitable crop rotation is necessary for a viable papaya production. Taking con-
tinuously the same crop year after year results in the complete exhaustion of some
essential macronutrients and micronutrients. Besides, it increases the intensity of
pests and diseases, which leads to poor production of the fruits. Intercropping of
leguminous crop after non-leguminous crops and shallow-rooted crops after deep-
rooted crops removes this problem. A few suitable crop rotations in India are
- Papaya (October–May), maize (June–September), wheat (November–April)
and maize (June–September). - Maize (June–September), papaya (October–May), green-manure crop
(June–September) and wheat (November–April). - Sugarcane (February–February), greengram (March–June), maize (June–
September), papaya (October–May), green-manure crop (June–September)
and Potato (November–February).
12.2.10 Diseases
Plants heavily infected with viral diseases either fails to produce fruits or give mark-
edly reduced yield. As a result, papaya was wiped out between 1950 and 1980 in
NEPZ of India. The juvenile papaya seedlings which have least faced the period of
rainy season are generally free from this disease. Therefore, seeds should be sown in
the nursery in the beginning of September and crop should be planted in October, so
that it escapes rain in the first year. The plants become hardy in the ensuing winter
and summer seasons. Thus, there is little infection of viruses in the next rainy season
and fruiting in papaya is at its maximum (Ram and Ray 1995).
Humid and heavy rainfall area is very favourable for the spread of root-rot dis-
ease. The tap root or deeper roots are found rotten. This is owing to over-saturation
of water in the subsoil. The uptake of nutrients by the superficial fibrous roots is
partial; as a result there is no fruiting or poor fruiting in papaya. Therefore, the area
having very high water-table should be avoided. However, the up and sloppy land in
such an area may be utilised for papaya planting. If at such places there is danger of
root-rot, 100 g copper sulphate and 1.0 kg lime should be added along with organic
manures in the pits as a basal dose which is very effective. The long-term applica-
tions of inorganic fertilisers not only decrease the crop productivity (Chand et al.
2006), but also make the plants susceptible to insects and diseases, besides deteriora-
tion of fruit minerals and quality.
12.2.11 Plant Growth Regulators
Papaya trees are fast-growing and prolific and can often result in widely separated
internodes; the first fruit is expected in 10–12 months from germination and in