Tamarind monograph.pdf - Crops for the Future

extensive root system. In experimental plots in India, 25 g urea and 25 g
single super phosphate per plant have been used, although response of
tamarind to fertiliser application is reported as poor (Gupta and Mohan,
1990). In India, inorganic fertilisers are not normally applied to tamarind
trees, but 5 kg of farmyard manure is applied to the planting hole at the time
of planting. Every year thereafter 5 kg of farmyard manure and 5 kg of neem
cake are applied per tree in the months of March and April. The commercial
sweet tamarind growers in Thailand use inorganic fertilisers, mostly urea at
100-200 g/tree, which supports high yields. In the Philippines, the general
recommendation is to apply 100-200 g/tree of ammonium sulphate, about a
month after planting and an equal amount at the end of the rainy season. The
amount of fertiliser is gradually increased as the trees grow. When the tree
begins to bear fruits, about 500g of a complete fertiliser containing high
amounts of nitrogen and potassium is applied per tree twice a year. A full
bearing tree should receive 2-3 kg of an NPK complete fertiliser each year,
the formula depending upon the nutrient content of the soil (Gunasena and
Hughes, 2000).
Ilango and Vijayalakshmi (2002) reported that foliar spray of Cycocel (1500
ppm), Ethrel (500 ppm), Triacontanol (20 ml tree -1 ), IBA (150 ppm),
Planofix (100 ppm), micronutrient mixture (0.5%), ZnSO4 (0.5%) + boric
acid (0.3%) + FeSO4 (0.5%) and Urea (1.5%) significantly improved
flowering, pod set and retention, yield and quality attributes of tamarind
compared to non-sprayed trees. Treatment with foliar feeding urea resulted
in maximum number of flowering (76%), with Cycocel resulted in
maximum pod set (32%) and retention (55%) per unit area, and with
Triacontanol (20 ml tree -1 ) resulted in maximum pod yield (8.3 kg tree -1 ).
Fertilisation during the nursery stage is recommended to produce healthy
plants for afforestation programmes (Thiyageshwari et al. 2003). Among the
treatments, 0.6 g urea, 2 g single superphosphate and 0.6 of muriate of
potash with 5 g of compost and 0.5 g of phosphobacteria recorded
significant increase in shoot length (48 cm), root length (39 cm) and dry
weight (11.2 g).
5.4.3.2 Nitrogen fixation
Leguminous species are associated with Rhizobium bacteria in root nodules
which fix atmospheric nitrogen. Very little information is available on
nitrogen fixing bacteria in tamarind compared to other cultivated legumes.
Tamarind was initially considered to be a non-nodulating species (Allen and
Allen, 1981). However, some evidence suggests that it does form a
symbiotic association with Rhizobium bacteria (Postgate, 1979; Athar and
Mahmood, 1982; Quiniones, 1983) enabling the tree to fix atmospheric
nitrogen under appropriate conditions (Quiniones, 1983; Ding et al., 1986).
Root nodules collected from tamarind trees grown in plantations on acidic
soils in Guangdong Province, China, described as elliptical or circular and
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