Annona Species Monograph.pdf - Crops for the Future

Chapter 10. Agronomy
occurs in January/February, with harvesting from July to September.
However, a summer pruning with fruit thinning (June-October) can lead to
harvesting from October to March, effectively increasing the fruit
availability. The highest winter fruiting occurs when summer sprouts are
pruned as compared to pruning non-fruiting shoots or pruning in late May. In
India, light pruning is carried out on budded plants. In São Paulo, Brazil, the
summer pruning is from January to March with harvest from August to
October, since the late pruning (after March) can promote flowering during
periods of low temperature, leading to reduced fruit set (Kavati and Piza Jr.,
1997). There are no such problems in north-eastern Brazil, since high
temperature, low precipitation and irrigation stimulate successful fruiting of
sugar apple, which is managed by pruning.
10.3.3 Orchard maintenance, intercropping and
cover-cropping
In most annona orchards, weeds were traditionally eliminated by using hand
tools, such as mattocks. Nowadays, this practice has been substituted by
herbicides in commercial orchards. In Spanish cherimoya orchards the
herbicides most commonly used are simazine or terbumeton mixed with
terbuthylazine as pre-emergence treatments, and glyphosate or a mix of
paraquat and diquat as post-emergence treatments (Farré et al., 1999). The
irrigation system is often used to apply the pre-emergence herbicides.
However, phytotoxicity may occur after herbicide application.
Mulching is a very common maintenance system used mainly during the first
years after planting, since it has a number of positive effects. These include
improved distribution of humidity in the soil, reduction of evaporation losses,
avoidance of crust formation on the soil, increased development of healthy
feeder roots improving efficiency of fertilizer use (Farré et al., 1999; George
et al. 1987), and reduction of weed infestations. As consumers demand
chemical-free fruit, mulching will become increasingly more important. In
practice, dried grass is a practical and cheap material to be used for
mulching.
Annonas can be grown as a mono-crop in high density orchards or as an
intercrop among larger fruit trees, such as mango and citrus (Ochse et al.,
1994), or on small holder farms. Even as the main crop, the space between
sugar apple trees may be planted with other fruit crops, such as papaya,
which is a common practice in north-eastern Brazil (Plate 3). It is also
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