Regulation of siliqua and seed quality in Indian mustard (Brassica juncea) by application of salicylic acid

Abstract

Heat stress is a severe problem for the agriculture, affecting crop growth and yield. Salicylic acid is an important plant
growth regulator which not only promotes plant growth and development, but also induces stress resistance in plant
cells. The present investigation was carried out during rabi 2023-24 at Instructional Farm of Bidhan Chandra Krishi
Viswavidyalaya, West Bengal. The experiment was conducted with mustard variety TBM-143. Seeds were sown in three
different dates D1, D2 and D3. Spraying of Salicylic acid in different plots was done with Salicylic acid as control (T1),
@200 ppm (T2), 400 ppm (T3) and 600 ppm (T4). Physiological and biochemical parameters viz. siliqua length (cm), siliqua
width (mm), germination percent, siliqua fresh weight (mg), fresh weight of seed (mg), dry weight of seed (mg), seedling
fresh weight (mg), seedling dry weight (mg), seedling length (cm), vigour index I, vigour index II, imbibition rate (12
hours), á- amylase activity(μg min-1 g-1) (24 hours), Peroxidase activity (.A min-1g-1) (24 hours) were estimated. D1 was
identified as optimum date for sowing of TBM-143 for most of the characters. In case of heat stress mitigating chemicals
the higher physiological and biochemical characters were recorded when salicylic acid was applied @ 400ppm. Interaction
effect between date of sowing and heat stress mitigating chemicals was also observed. As the sowing delayed, there was
poor performance due to terminal heat stress. Thus by applying heat stress mitigating chemicals, the seed quality could
be maintained even delaying in sowing by the month of middle of December.