Abstract:
Tomato is a widely grown, high-demand vegetable in Sri Lanka. Despite
the increase in tomato growing area, the improvement in quality and yield is still
negligible. This study aimed to determine the effects of foliar application of salicylic
acid on the growth and yield of selected tomato cultivars. The pot experiment was
conducted in a greenhouse. It was laid out in a complete randomized design in facto-
rial arrangements with twenty replications. Certified seeds of Lanka sour and Thilina
were sown in nursery trays, and healthy seedlings were transferred to pots after three
weeks. The treatments consisted of three concentrations (150, 200, and 300 ppm) of
salicylic acid and the control (deionized water). Foliar applications were applied to
the plants during the vegetative, flowering, and ripening stages of the plants twice at
one-week intervals. The results showed that there was no interaction effect (P<0.05)
on vegetative growth of the cultivars. However, a significant difference was observed
between the concentrations in the vegetative growth. The highest dry weight
(1.98±0.29 g) and chlorophyll content index (17.08±0.29) were obtained with 150
ppm salicylic acid. The lowest dry weight (0.62±0.25 g) and chlorophyll content in-
dex (11.08±0.01) were obtained with 300 ppm salicylic acid. However, there were
significant (P<0.05) interaction between cultivars and salicylic acid concentrations
on yield components and yield. The highest fruit number (28±0.3), single fruit weight
(186±1.2 g), and yield (5.1±4.6 plant kg-1) were obtained from the Lanka sour at the
concentration of 150 ppm. The lowest fruit number (17±0.1), single fruit weight
(65±0.2 g), and yield (1.5±0.7 plant kg-1) were obtained from the Thilina cultivar with
300 ppm concentration. Hence, it could be concluded that the use of the Lanka sour
cultivar and foliar application of salicylic acid at 150 ppm should be encouraged for
tomato production to obtain higher growth, yield components, and yield.
