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An experiment on the "Performance of Bacterial wilt tolerant tomato
(Lycopersicon esculentum Mill.) genotypes under shade" was conducted at the
College of Agriculture, Vellayani, during 2000 - 200 I.
The experiment was laid out in randomised block design with three
shade levels, open, 25 and 50 per cent and replicated thrice. Artificial shade
was provided using high density polyethylene shade nets. Ten bacterial wilt
tolerant genotypes of tomato collected from various sources along with a
susceptible check were used.
The results indicated that plant height at flowering, height at harvest,
internodal length, leaf length, leaf width and petiole length showed an
increasing trend with increase in level of shade, while number of primary
branches reduced with shade.
Shading prolonged vegetative phase and delayed flowering. Flowers
.
per cluster, percentage fruit set and number of fruits per plant were found
unaffected by mild shade of 25 per cent, but under dense shade of 50 per cent,
there was marked reduction in all these characters. Fruit characters like fruit
length, diameter and fruit weight were found unaffected by shade
Yield in open and 25 per cent shade were on par indicating that tomato
plant was tolerant to mild shade. There were significant variation for yield
among the genotypes. LE 45, LE 34 and LE 22 were identified as superior


with tolerance to bacterial wilt and shade. These genotypes are recommended
for large scale cultivation in the homesteads after proper multilocational
trials.
There was significant reduction 'in the incidence of tomato spotted wilt
disease under shade. LE 34 and LE 44 were found least affected while LE 22
showed the highest level of incidence. Fruit borer and serpentine leaf miner
infestation were also reduced under shade. LE 1, LE 2 and LE 42 recorded the
lowest score against fruit borer infestation. Leaf miner infestation was least in
LE 2 and LE 42 while the high yielding genotype LE 45 was affected more.
Anatomical characters like stomatal density and number of vascular
bundles showed a decreasing trend with increase in level of shade.
Chlorophyll ~,chlorophyll Q and total chlorophyll contents increased
with increase in level of shade. The shade tolerant genotypes showed higher
content of chlorophyll under all shade levels. On the contrary, open condition
showed maximum accumulation of proline compared to both the shade levels.
Mild shade proved favourable for improving the fruit quality in tomato.
There was an increase in the content of vitamin C .under 25 per cent shade
level. Vitamin A content of fruits were found unaffected by mild shade of 25
per cent. But 50 per cent shade reduced both vitamin C and A contents
considerably. The external appearance of the fruits was also superior under 25
per cent shade. Genotype LE 22 was superior for vitamin C content while LE
34 and LE 42 recorded the highest vitamin A content.