Agriculture Reference
In-Depth Information
A. muricata
and
A. reticulata
as rootstocks (Sanewski, 1991). This is complicated
by cultivar dif erences in compatibility with common rootstocks. Atemoya
cultivars 'Bradley' and 'Page' are compatible with custard-apple rootstocks, but
'Gefner' shows partial incompatibility with the same rootstock (Table 6.3).
Sweetsop is usually seed-propagated. The seeds should be sown within
a week after extraction from the fruit. Inarching can be done to
A. reticulata
,
with 70% success (George and Nissen, 1987b). The same success is obtained
for grafting and budding. Rooting of tips has been successful in some cases, as
well as air layers, but they are more costly.
Rootstocks
There are several possible combinations and incompatibilities among
Annona
and
Rollinia
species. Cherimoya rootstocks normally include seedlings of
cherimoya and, in some cases, soursop and sweetsop. For atemoya, cherimoya
and atemoya are normally used as rootstocks and also
A. squamosa
, but it is
susceptible to bacterial wilt caused by
Pseudomonas solanacearum
. Sweetsop
is normally not grafted or budded, but it could be done with seedlings of
sweetsop, cherimoya or
A. glabra
(Table 6.3).
A. muricata
or
Annona palustris
are not good rootstocks for sweetsop.
Field preparation
A soil sample should be taken 4-6 months before planting to determine lime
requirements and soil nutrient levels. Soil phosphorus can also be adjusted
at this time or in the planting hole. Minimal tillage can be achieved with a
2-m-wide band cultivated where the trees are to be planted. Drainage should
be installed at this time to avoid fl ooding, with either contour or subsurface
drains. Windbreaks should be established prior to transplanting. Napier or
Buf alo or Bana grass (
Pennisetum purpureum
Schumacher) can be used when
shelter is required in the fi rst 12 months.
Transplanting and spacing
Transplanting should be done at the beginning of the wet season if there are
seasonal dry periods and no irrigation facilities. In the subtropics, planting
should not occur if there is a risk of frost. Plants should have attained a height
of 30-50 cm at transplanting time, with the union of grafted or budded plants
placed 15 cm or so above the ground. Trees should be irrigated as soon as
possible after transplanting, with wind and sun guards sometimes required.
