Byline: Muhammad Awais Ghani Muhammad Amjad Qumer Iqbal Aamir Nawaz Tanveer Ahmad Osama- Bin-Abdul Hafeez and Mazhar Abbas
ABSTRACTBitter gourd is an important vegetable among cucurbits cultivated extensively on a commercial scale in Pakistan. Studies were carried out to assess the influence of plant growth regulators (PGRs) at different growth stages on sex expression fruit and seed yield of bitter gourd cv. Faisalabad Long. Three concentrations each of GA3 (25 50 and 75 ppm) Ethrel (400 500 and 600 ppm) and NAA (50 100 and 150 ppm) were applied at three different stages namely S1 (2-leaf stage) S2 (2-leaf and flower initiation stage) and S3 (2-leaf flower and fruit initiation stage). Application of GA3 @ 25 ppm significantly reduced number of days to first flower (40 days) and first harvest (54 days) at S3. Similarly male to female flower ratio was lowest (11.83) in plants sprayed with GA3 @ 75 ppm at S1 while fruit set percentage was highest (90%) with similar application at S2; however both fruit length and fruit diameter were highest with similar dose in plants sprayed at S2. Number of fruits and seedyield vine-1 was significantly higher among all the PGRs (GA3 ethrel and NAA)when plants were sprayed with NAA @ 100 ppm at S2 and S1 respectively. Overallresults revealed that application of NAA proved to be better for different yield and yield related traits in bitter gourd.
Keywords Bitter Gourd Growth regulators Sex expression Yield
Bitter gourd (Momordica charantia L.) from Cucurbitaceae family is also known as balsam pear bitter melon bitter cucumber and African cucumber (Heiser 1979). Like other cucurbits maleness is one of the major obstacles in bitter gourd which significantly reduces the fruit and seed yields. Plant growth regulators (GA3 NAA and Ethrel) a new generation of agrochemical when added in small amounts; modify the natural growth right from seed germination to senescence in the crop plants. Flowering behavior varies with cultivar climatic conditions and cultural practices (Deshpande et al. 1979). The average ratio of staminate to pistillate flowers in monoecious lines throughout the flowering period is typically 50:1 (Rasco and Castillo 1990) but ratios can vary dramatically 9:1 to 48:1 (Dey et al. 2005).Sex expression is a complex characteristic in plants and is influenced by genetic environmental and hormonal factors. PGRs are chemical compounds that alter plant growth and development by modifying natural hormonal action. Some PGRs are naturally occurring hormones while others mimic or interfere with the action of natural plant hormones. They are considered as a new generation agrochemicals after fertilizers pesticides and herbicides and are known to enhance the source-sink relationship and stimulate the translocation of photo-assimilates thereby helping better fruit set (Deepthi et al. 2008). Similarly; in bitter gourd it is possible to increase the yield level by increasing the fruit set percent by use of some growth regulators. Use of PGRs might be a useful alternative to increase crop production. Recently there has been global realization about the important role of PGRs in increasing crop...