Effect of Chlormequat Chloride on Vegetative Growth, Photosynthetic Activities, and its Residual Dissipation in Thompson Seedless Grapevines

Abstract

Chlormequat chloride is one of the important plant growth regulators which is a highly stable gibberellins biosynthesis inhibitor used to inhibit vegetative growth and cell elongation. Considering the importance of plant growth inhibitors, the present investigation was carried out to understand the effect of Chlormequat chloride with its different concentrations on vegetative growth, photosynthetic activities and its residual dissipation in Grapevines at two different locations one at Pune, Maharashtra India and second at Nashik, Maharashtra, India during the year 2018-2019. Chlormequat chloride was applied as a foliar spray, where the whole vines were sprayed at concentration of   500, 1000, 1500, 2000 and 2500 ppm with untreated control as a water spray; as a treatments with different developmental stages Viz 5th, 7th, and 15th leaf stage after foundation pruning. Morphological observations were recorded at 45 days and 90 days after foundation as well as fruit pruning. Application of Chlormequat chloride recorded reduced shoot length and Internodal distance while increased in cane diameters, leaf thickness after both the pruning’s in this investigation Photosynthetic activity, yield per vines and percent fruitfulness had significantly influenced with the application of Chlormequat chloride in grapevines. The dissipation of Chlormequat chloride was stable and indicated a non- linear pattern of degradation. Thus, implied that simple first-order kinetics might not be adequate to explain the dissipation behaviour of Chlormequat chloride in grapes.