Annona Species Monograph.pdf - Crops for the Future

Chapter 10. Agronomy
Adult Tree Phase
Physiologically, the fruits act as a sink for nutrients. Nutrient analysis of
leaves however gives different results from fruits. A new methodology has
recently been tested using fruits as the source of material for nutrient analysis
in adult mango trees. Although, in practice, this method is not frequently
used yet, it would be a useful additional test, together with soil and leaf
analyses.
The quantity of nutrients removed from the soil by fruit trees depends on the
species, the variety and the yield (Kirkby and Mengel, 1987). Guirado (1999)
observed that a cherimoya orchard with a population density of 156 plants/ha
and a yield of 89.7 kg of fruits per tree extracted the following amounts of
nutrients per kg of harvested fruit: 6.8 g N; 0.3 g P; 2.7 g K; 0.6 g Ca; 1.9 g
Mg. Fruit production of soursop however, is more demanding and extracts
larger amounts of macronutrients from the soil than cherimoya, except for N,
Ca and Mg. (Figures are given in Tables 10-11 and 10-12).
Table 10-11. Removal of macronutrients (kg) per tonne of soursop and
sugar apple fruits produced
Macronutrient
Soursop
Avilan et al. Silva et al.
(1980) (1984)
Sugar Apple
Silva et al. Silva et al.
(1984)
(1991)
N 2.97 kg/t 2.70 kg/t 7.17 kg/t 4.94 kg/t
P 0.53 kg/t 0.54 kg/t 0.58 kg/t 0.25 kg/t
K 2.53 kg/t 3.60 kg/t 5.19 kg/t 5.31 kg/t
Ca 0.99 kg/t 0.26 kg/t 0.45 kg/t -
Mg 0.15 kg/t 0.24 kg/t 0.46 kg/t -
S - 0.27 kg/t 0.27 kg/t -
Sources: Avilan et al. (1980), Silva et al. (1984).
Table 10-12. Removal of micronutrients (g) per tonne of soursop and
sugar apple fruits produced
Macronutrient Soursop Sugar Apple
Fe 8.03 18.48
Cu 1.65 2.68
Mn 2.71 3.26
Zn 3.71 6.95
B 2.75 3.12
Source: Silva et al. (1984).
Fertilizer should be applied to adult annona trees in the area under the outer
third of the canopy (Pinto and Silva, 1996; Pinto and Ramos, 1997).
Fertilization by foliar spraying is very important to supplement a soil
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