TREE MANAGEMENT - Tropical Fruits - page 99

B fl owering habits, there has to be a combination of both types in the orchard
to get proper pollination, fruit set and yields. Macadamia or carambola require
two or three varieties in the orchard to achieve higher yields, since most
varieties are partially self-incompatible and intercrossing results in higher
yields. In carambola, sometimes a branch of the rootstock is left on the tree
to ensure better fruit set. Date palms are dioecious and wind pollinated, and
one male plant is planted for every 10-14 female plants, distributed uniformly
throughout the orchard. Male date infl orescences can be shaken in front of
female infl orescences to achieve better fruit set, and sometimes pure pollen is
obtained and applied to the female fl owers with dust blowers.
The dichogamy in cherimoya, atemoya, soursop and other Annonas makes
it necessary to hand-pollinate either by collecting pollen of fl owers that opened
the day before in glass jars or by collecting pollen from fl owers in the fi eld in
the male stage to apply it to fl owers in the female stage. This can be done with
a No. 4 fi ne paint brush made with camel hair or with a hand mist blower (see
Fig. 6.4) using pollen dissolved in Lycopodium spores to be able to pollinate
more fl owers. In soursop, which has moist pollen and large fl owers, this can be
done with the fi ngers.
Yellow passion fruit is self-sterile and carpenter bees ( Xylocopa ) have
to be present to get proper fruit set. When bees are absent, hand-pollination
has to be carried out using cloth gloves to collect the pollen from fl owers in
the contiguous plant row to ensure that it comes from a dif erent genotype,
since plants come from seed. This is done in the afternoon since fl owers open
at noon.
The presence of bees, carpenter bees or common fl ies is a great help in
achieving better yields. For bee pollinatation, four to six bee hives per hectare
should be in the fi eld at fl owering. In some places, mango trees in fl ower are
sprayed with a solution of manure to attract as many domestic fl ies as possible
to the orchard to improve pollination.
TEMPORARY SHADE, SHELTER AND BAGGING
Some tropical fruit species that originated in forests may benefi t from being
under partial shade during their fi rst years in the fi eld. This is the case for
mangosteen, durian, jackfruit, acahachairu and other species. Semi-shade is
provided by planting certain bushy plants, such as pigeon peas, castor beans,
bananas or small fast-growing trees, around the planting hole or making a
tent-like structure with palm leaves (Fig. 4.7b), branches with leaves or shade
cloth (Fig. 4.7c). This shade will avoid sunburn damage and provide the plants
with less-stressful growing conditions. Some fruits, such as pineapple, are also
susceptible to sunburn and are protected by tying the leaves together over the