Annona Species Monograph.pdf - Crops for the Future

Chapter 10. Agronomy
is about 1 m tall (Scheldeman, 2002). However, the trunk diameter of the
seedling is a more appropriate growth measurement to determine the best
time for vegetative propagation, which will be explained below.
10.1.2 Vegetative propagation
Due to the generally high variability among seedlings, vegetative propagation
of both scions and rootstocks is desirable. To establish an orchard, the grower
must evaluate different methods of propagating annonas vegetatively, such as
by cuttings, layering, inarching, grafting, budding and micro-propagation, as
different species and varieties react differently in each Annona growing
region.
Seedlings for rootstocks are most effectively kept, in large numbers, in a
protected and well constructed nursery with irrigation (Fig. 10-2 and Fig. 10-
3), where control of pests, diseases and weeds, as well as seedling
fertilization, can be planned and carefully executed. Foliar fertilization
should start on 90-day old seedlings and be repeated monthly, before and
after grafting, until planting out in the field. A formula that has given good
results is composed of 5 g of urea and 15 g of triple superphosphate per litre
of water (Torres and Sánchez, 1992). To avoid herbicide phytotoxicity, most
annona growers in Brazil control weeds in the nursery by hand once a week,
while pests and diseases are monitored daily so as to use a minimum of
pesticides for control.
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