Irrigation 87
helps in preventing the plants from lodging against windy strokes and also irrigate
through bed system of flooding. Water use efficiency is increased by adopting drip
irrigation. Through the drip system, 6–8 L water/plant/day is required for better
yields. For environmental and irrigation management purposes, it is important to
accurately estimate its crop evapotranspiration and irrigation requirements.
7.1 Drainage
Papaya needs frequent but light rainfall or irrigation, and it must have good drain-
age. It is recommended that the papaya plants are very susceptible to water logging.
Flooding for 48 h is fatal and it may kill the well-established orchard (Ram 2005).
The succulent roots do not tolerate excess water, and two days with hypoxia causes
chlorosis, leaf shedding and even death after 3–4 days with oxygen deprivation
(Campostrini and Glenn 2007). It is, therefore, most important to select upland for
papaya plantation. It may further be shaped sloppy in heavy rainfall areas. It is essen-
tial to make few furrows or trenches for quick and complete drainage of water during
rainy season. Earthing up around the plants may be repeated more than four times
during fertiliser application before the onset of monsoon. Under heavy irrigation,
papayas grow optimally in the soils with an unimpeded depth of more than 1.0 m.
However, if irrigation is well-planned and managed, there should be no problem of
soil with an unimpeded depth of 75 cm, provided that no drainage problems occur at
that depth (Saran et al. 2013a).