Tamarind monograph.pdf - Crops for the Future

A seedling blight disease caused by Macrophomina phaseolina and
Rhizoctonia solani is also important during the nursery stage. A significant
reduction in blight incidence was achieved by raising seedlings in soils
amended with sawdust or rice husk (Muhammad et al., 2001). Increasing the
number of days between amendment application and planting further
reduces the incidence of seedling blight. The number of compound leaves
and plant height were significantly increased in seedlings produced from
seeds sown at 20 days after the application of soil amendment.
5.4.4.2 Pests
Tamarind trees are liable to be attacked by a large number of insect pests
although in general it is not harmed by many of them except in plantations.
In India alone, over 50 insect pests have been recorded as attacking
tamarind, causing severe economic losses (Joseph and Oommen, 1960,
Senguttavan, 2000). The major pests which attack tamarind include shothole
borers, toy beetles, leaf feeding caterpillars, bagworms, mealy bugs and
scale insects (Coronel, 1991). Among the worst are the sapsuckers, which
affect the tender shoots and fresh foliage. The most destructive among these
are white flies, thrips, coccids and aphids. The defoliators, which include
caterpillars and the chafer beetles can also cause considerable damage. Some
of these insects attack the flower buds and the developing fruits and seeds,
while others damage the fruits during storage.
Some of the most serious pests in India are the hard scale insects (Aonidiella
orientalis Newst., Aspidiotus destructor Sign. and Saisetia oleae Ol.)
(Timyan, 1996). The oriental yellow scale (Aonidiella orientalis Newst.)
(Hemiptera: Diadpididae), is a polyphagus pest which attacks tamarind. The
eggs are laid under a protective covering such as cracks in the bark of the
trees. After hatching, the nymphs crawl in search of suitable succulent parts
of the plant. The scale insects can be controlled by removing the affected
parts in the initial stages. When the infestation is serious, the careful use of
chemical spraying is required; pesticides such as Diazinon or Carbosulphan
at 0.1% solution provide effective control (Butani, 1979). For more
information on the legal restrictions of these products the reader is requested
to see http://www.pesticideinfo.org/Detail_ChemUse.jsp?Rec_Id=PC35079.
Mealy bugs (Nipaecoccus viridis Newst. and Planococcus lilacinus Ckll.)
(Hemiptera: Pseudococcidae) also attack tamarind trees. Nymphs and the
females suck the sap on the ventral surface of the leaflets, the base of leaf
petioles, tender shoots and even the mature shoots. Planococcus lilacinus
also attacks the roots. The leaflets become chlorotic and defoliation is
common. Immature fruit fall is sometimes observed. Mealy bugs can be
controlled by mechanical removal of infected shoots on a small scale. In
serious infestations, chemicals such as Diazinon or Carbosulphan at 1%
solution can, subject to local regulation, be sprayed. Planoccus lilacinus
populations living in the soil can be displaced by raking or be killed using
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