Unfruitfulness 137
2007). Honeybees, thrips, hawk moths and apparently also mosquitoes and midges
have been reported as pollinators of papaya (OGTR 2003). In some countries, the
role of insects in papaya pollination is factored as prominent, whereas in others wind-
borne pollen appears to be of more concern. Accordingly, different recommendations
for appropriate isolation distances from other papaya may reflect the specific condi-
tions at different locations of production. Recognising both insects and wind as agents
for pollen movement, Singh (1990) recommended 2–3 km isolation for production
of foundation seed, but cited no experimental observations supporting this distance.
12.2.6 Weed Control
Weeds grow luxuriantly in the papaya orchard and exhaust most of the nutrients
applied to it. They also compete for light, air and water, which results in poor fruit-
ing in papaya. Even after repeated weeding, they come up regularly. Best way of
manuring is to apply basal dose in pits of 60 cm × 60 cm × 60 cm and then go for
planting because at this depth, the grasses are generally unable to share the nutrients.
The fertilisers in the form of top-dressing should be applied around the covered soil
in the root zone. Weeding is done regularly, especially around the plant, so that the
nutrients applied are not taken up by the weeds. Herbicide usage is the most sustain-
able practice and, when compared to other strategies such as hoe weeding and inter-
cropping, had beneficial effects on commercially important parameters in terms of
reduction in days to 50% flowering and an increase in fruit yield in variety ‘Sunrise
Solo’ (Akinyemi et al. 2004).
12.2.7 Water Requirement
Papaya is a crop that cannot withstand water logging but needs plenty of water,
especially when it starts fruiting. However, this requirement is fulfilled in the rainy
season. If there is drought or scanty rain, irrigation must be provided copiously.
From October to April, when the upper fruits are still developing, the plant should
be irrigated frequently. Irrigation can also be given after top-dressing in the rainy
season, if the rain fails. In areas of high rainfall, B leaches through the soil profile
and out of the root zone. In acidic soils, certain elements may become bound to clay
particles and be unavailable to plants. Some soils are compacted, lacking in oxy-
gen, and need to be aerated. Papaya plants are tolerant to water logging under well-
drained soil conditions (Marler et al. 1994; Benson and Poffley 1998). Waterlogged
plants die within two to four days due to stomata closure and abscission of expended
leaves (Marler et al. 1994). Plants that do not die, do not recover well.
12.2.8 Intercropping
First year of planting, sufficient space is available in between two rows of papaya
plantation, in which intercrops can be grown successfully. The crops selected should
have no adverse effect on papaya. The crops that compete with papaya or suppress its
growth should not be included in the intercropping. Virus susceptible crops (tomato,
brinjal and okra) normally should not be grown. Leguminous crops of low height