Tamarind monograph.pdf - Crops for the Future
Tamarind monograph.pdf - Crops for the Future
Tamarind monograph.pdf - Crops for the Future
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Divakara, 2002; Shanthi, 2003). A maximum heritability of 0.5 and <strong>the</strong><br />
highest genetic advance percentage were recorded over a mean of 42.5 <strong>for</strong><br />
pulp weight (Table 7.2). The highest genetic advance was observed <strong>for</strong> pulp<br />
weight. Pod length showed highest positive phenotypic correlation with<br />
pulp weight. Hence, selection based on pulp weight and pod length is useful<br />
in tamarind improvement programmes. Fur<strong>the</strong>r, because of <strong>the</strong> presence of<br />
significant positive correlation coefficients between pod length and pod<br />
width, <strong>the</strong>y are suggested as selection criteria <strong>for</strong> <strong>the</strong> identification of<br />
superior trees.<br />
Table 7.2 Heritability and genetic advance of tamarind<br />
Character Heritability Genetic advance percentage<br />
over mean<br />
Pod length 0.30 16.3<br />
Pod width 0.40 10.0<br />
Pulp weight 0.50 42.5<br />
Number of seeds/pod 0.20 13.6<br />
Single seed weight 0.05 2.2<br />
Source: Shanthi (2003).<br />
7.3 Genetic improvement<br />
Genetic improvement through <strong>the</strong> use of superior clones has been described<br />
by Kulkarni et al. (1993). <strong>Tamarind</strong> has a relatively long generation time and<br />
is primarily outcrossing, thus any conventional breeding approaches would<br />
require considerable investment in time and money. There are trees with<br />
very high yielding potential exceeding 800 kg/tree/year and such trees could<br />
be selected <strong>for</strong> vegetative propagation by air layering or grafting methods to<br />
produce fast growing trees <strong>for</strong> local (home garden) and commercial<br />
(orchard) use. Such trees can be grown with comparative ease and minimum<br />
management and should prove to be profitable due to <strong>the</strong>ir commercial value<br />
<strong>for</strong> small-scale farmers in African and Asian countries.<br />
Provenance trials need to be conducted in many parts of <strong>the</strong> tropics to select<br />
<strong>the</strong> best germplasm <strong>for</strong> fur<strong>the</strong>r improvement. Germplasm needs to be<br />
rigorously characterised and evaluated to select desirable traits. If quick<br />
growing and high yielding strains are selected <strong>for</strong> different uses, tamarind<br />
would rapidly become a desirable tree <strong>for</strong> small scale plantations in a short<br />
period, particularly since it continues to bear fruit <strong>for</strong> many years. More<br />
trait specific research and combining desirable characters toge<strong>the</strong>r is needed<br />
to develop cultivars. An emphasis should be to select <strong>for</strong> agro<strong>for</strong>estry<br />
systems and small scale plantations. The desirable ideotypes should be<br />
developed to fit into various niches of <strong>the</strong>se systems as well as <strong>for</strong> more<br />
intensive commercial production. This will require more attention to tissue<br />
culture since it offers a way of cleaning stocks from diseases. Then planting<br />
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