Agriculture Reference
In-Depth Information
Fig. 6.4.
Hand-pollination of atemoya using a hand-blower to disperse the pollen
collected the day before on to the open
fl
ower (courtesy of R. Manshardt).
Light and photoperiod
Light penetration to the base of vigorous atemoya trees with a dense canopy
in close spacing can be 2% of full sunlight, and there is very little fruit set.
Pruning practices and spacing need to be adjusted for this shading ef ect on
growth. No photoperiod responses have been reported. All three species need
some sort of pruning to obtain better light penetration into the canopy.
Wind
The soft wood of the trees makes them susceptible to wind damage and limb
breakage. Tree shaking may also be partially responsible for the penetration of
collar-rot organisms. The fruit skin is easily damaged by rubbing and exposure
to drying winds, leaving black scars.
Annona
leaf stomata are very sensitive
to changes in RH and rapidly close in response to declining RH (Marler
et al.
,
1994). Productivity can be improved by windbreaks and under-tree sprinkling
to raise the RH above 60%.
