Annona Species Monograph.pdf - Crops for the Future

Chapter 10. Agronomy
Figure 10-13. Water distribution (degree of opening) of different microsprinklers
that can be used in annona orchards. A) Type 360°; B) Type
180°; C) Type 300°; D) Type 280°. Adapted from James (1988)
Whatever the perennial crop, there is a need to establish a strategy to
determine when and how much water must be delivered to the tree. To
determine the need for water, the evaporation of water must be measured and
then compared to a pre-established evapotranspiration coefficient of the crop
in that region. The evapotranspiration coefficient is determined by using
climatic variables, such as solar radiation, temperature, relative humidity
(RH) and wind velocity (Pinto and Silva, 1994). A formula to calculate the
irrigation requirement for sugar apple in Brazil's semi-arid northeast is based
on the averages of air temperature and RH (Santos, 1997). The amount of
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