Annona Species Monograph.pdf - Crops for the Future

Chapter 10. Agronomy
Tree Age N g of P 2
O 5
/plant g of K 2
O/plant
> 4 years 180 120 80 40 180 120 60
Source: Silva and Silva (1997).
Table 10-6. Recommendation of P and K for sugar apple trees of
different ages according to the amount of N fertilization applied (g/plant)
and levels of P 2
0 5
and K 2
0 in the soil analysis in the semi-arid region of
Brazil
Tree Age N g of P 2
O 5
/plant g of K 2
O/plant
Phosphorus in the soil (µg/cm³ Potassium in the soil
(µg/cm³
0-10 11-20 > 20 0-45 46-90 > 90
0-1 year 50 - - - 70 40 20
1-2 years 100 80 60 40 60 40 20
3-4 years 120 120 80 60 120 80 60
> 4 years 180 160 120 80 200 140 80
Source: Silva and Silva (1997).
Besides soil analysis, leaf tissue analysis has been accepted as a way to
understand nutrient uptake conditions from the soil (Mengel and Kirkby,
1987) and should be used during the juvenile phase of plant growth. The
most appropriate methodology for collecting annona leaves for analysis
depends on the tree's age, the position of the leaves in the canopy and the
period for sampling. Cherimoya leaves should be collected from intermediate
branches during the fruiting period or late in the harvest season (Gonzalez
and Esteban, 1974). Collection of the third and fourth leaf pairs from the
intermediate branches of the canopy in the four cardinal points is the most
appropriate for foliar analysis of soursop (Laprode, 1991). Soursop leaves
should be 8-9 months old and should be collected from intermediate branches
of healthy plants, free of pesticide residues prior to analysis (Pinto and Silva,
1996). A sample of 4 leaves per tree from each of 25 randomly selected
plants in the orchard, totalling 100 leaves, is required for complete tissue
analysis. Several authors (Avilan, 1975; Sadhu and Ghosh, 1976; Navia and
Valenzuela, 1978; Silva et al., 1984) have reported a range of nutrients in
normal and deficient leaves of cherimoya, soursop and sugar apple (Table
10-7), which serve as a guide for annona plant deficiencies.
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