Abstract:
Tomato is one of the most important fruit vegetables that are cultivated
throughout the year in Bangladesh. During warm seasons, tomatoes cultivated in
high raised land areas are often planted under rain shelter. High temperature (both
day and night), humidity, rainfall and light intensity are the basic limiting factors
of the tomato production in summer season. High temperatures reduce fruit set and
fruit production in tomato. During the summer season tomato is available in urban
market at an exorbitant price. There is a great demand of tomato in summer-rainy
season but there is no good variety for this season. Recently BARI has released
some heat tolerant open pollinated and hybrid varieties with some limitations
liking hormone application and smaller fruit size. Considering the factors. the
experiment was under taken to evaluate the two heat tolerant varieties of tomato
under polytunnel with and without plant growth regulator application during
summer-rainy season. The experiment was conducted at the Research Farm of
Olericulture Division under Horticulture Research Center of Bangladesh
Agricultural Research Institute (BARI), Joydebpur, Gazipur during May 2006 to
August 2006. The experiment was laid out in a RCBD (factorial) with three
replications. Two heat tolerant tomato varieties BARI Toamto-4 and BARI I lybrid
Toamto-4 with and without plant growth regulator applications were included in
this experiment. The higher fruit set percentage (42.52%) was recorded from
BARI I lybrid Tomato-4 which was also higher in case of pollen viability
(42.75%), number of fruits per cluster (3.01), number of fruits per plant (12.70)
and yield per plant ( 460 g). Better performance was observed in spraying of 4-
CPA at 40 ppm concentration in respect of percent fruit set (45.38%), number of
fruits per plant ( 16.45) and yield (39.39 t/ha) under high temperature condition. In
combined treatment, BARI Hybrid Tomato-4 with 40 ppm 4-CPA performed a
sigmficant role in number of fruits per cluster (3.41), number of fruus per plant
(22.48), number of fruits per plot ( 144.00), yield per plant (62 I .68 g), yield per
plot ( 15.23 kg) and above all fruit yield (50.57 t/ha).
