Diseases 119
10.7.1 Management
Nursery bed should be treated with formaldehyde (10%) before sowing. Well-drained
soil should be used for planting and the crop should not be excessively irrigated. Before
sowing, the seeds should be treated with bio-control agent, that is, T. viride (5.0 g/kg of
seed) or captan (3.0 g/kg of seed) to protect the newly emerging seedlings. Drenching
of nursery with a combination of carbandazim (12%) and mancozeb (64% W.P.) @
2.0 g/L of water effectively controls this disease 12 DAS of seeds. This can also be
controlled by spraying bordeaux mixture (5:5:50) 12 DAS in nursery (Ram 2005).
10.8 Bud and Fruit Stalk Rot of Papaya
This is a fungal disease (Fusarium solani) which affects papaya buds severely (Ram
1984). The infection affects stalk and newly born fruits drop down. The disease
first manifests as pale yellow discolouration near the base of stalk, which later on
spreads to the whole stalk. Afterwards, some stalks turn dark brown to black. The
flower buds in early stages are normally infected. The corolla and rudimentary calyx
of such a flower turns yellow, dries and finally drops. The infection spreads to the
ovary, which gets shriveled and mummified and ultimately drops. The young papaya
fruits are also affected (Figure 10.7a). The infection starts as water-soaked lesions
appear on the skin with appearance of fructification. Gradually, the infected por-
tion turns brown to black and sunken. The fruits decay and fall. The disease causes
severe losses during rainy season. Plants remain senile during rainy months due to
infection of this disease (Figure 10.7b).
10.8.1 Management
Prophylactic spray of Bordeaux mixture (5%) or copper oxychloride (3.0 g/L of
water) before onset of rainfall and repetition at 15 days interval effectively control
this disease (Ram 1984).
FIGURE 10.7 Bud rot in papaya: (a) infected bud and (b) bud drop during rainy season.