Abstract:
Shade tolerance capabilities of nine grain legume cultivars
belonging to three V'bgna species were evaluated at Bandirippuwa
estate, Lunuwila, by growing them in full sunlight and under shade
cloth providing 30, 50, 70 and 80% shade. The objective of this
study was to select shade tolerant cultivars for intercropping under
coconut (Cocos nucifera).
and its components pods
and harvest index (HI) in cultivars were reduced
significantly by shade. while 100 seed weight was least affected.
The magnitude of reduction varied between shade level and cultivars.
which led to a significant interaction between treatments. The reduction
in yield beyond 30% shade was more pronounced in black gram
( V'bgna mungo) cultivars than in green gram ( V'bgna radiata) and cowpea
( V'bgna unguiculata) . The yield reduction at 30% and 80% shade was
appreciably lower in cvs. Sei. 77-262, Bombay cowpea and MI 1 than
others. cloesly correlated with HI (r=0.88***) and seeds
(r=0.58**). The small reduction in these yield components
contributed to the high yielding ability under shade.
Among growth parameters, branch number. specific leaf weight
(SLW) and net assimilation rate (NAR) were markedly reduced by shade.
Growth in black gram cultivars declined rapidly above 30% shade,
whereas the reduction in these parameters caused by moderate (50%)
and heavy (70 and 80%) shade was less in green gram than cowpea
cultivars. Plant height and shoot/root ratio in green gram cultivars
responded to moderate and heavy shade better than cowpea while black
gram cultivars showed the least response. Further, SLW (r=0.66**)
and S/R ratio (r=0.56*)
and hectare
pod 1
plant 1 , seeds pod 1
The seed yield plant
were positively correlated with seed yield.
Yield was
