Effect of foliar application of plant growth regulators on storage behaviour of potato tubers

Present study was undertaken to find out the effect of growth regulators in storage of potatoes. The study was conducted during the years 2007–08 and 2008–09 at Central Potato Research Institute Campus, Modipuram, Meerut. The study involved three levels of each of GA₃ (50, 100 and 150 ppm) and IAA (50, 100 and 150 ppm) and two doses of paclobutrazol (25 and 50 ppm) with a control treatment. Total 21 treatments of three plant growth regulators alone and in combination were tested in randomized block design (R.B.D.) with three relications. GA₃ and IAA were applied through foliar spray at 45 DAP. While growth retardant (paclobutrazol) was applied at 70 DAP. The potatoes were harvested at 90 days and cured potato tubers were stored at room temperature. Observations on storage parameters, viz., sprout weight, rottage by weight and number basis and total weight losses were worked out. The application of GA₃ and IAA increased the sprout weight and rottage tuber numbers (%) with increasing dose of both growth promoters when applied alone. Paclobutrazol had slightly depressing effect on sprout weight. The number of rottage tubers remained unchanged at PBZ 25 ppm while with application of 50 ppm PBZ, rottage tubers decreased (17.7%). In general, application of GA₃ or IAA increased the rottage per cent (on weight basis) while PBZ decreased the weight loss because of rottage. The total weight losses of tubers (including weight losses due to rottage, sprouting and dryage) increased significantly with the application of GA₃ and IAA over control during both the years. Among two growth promoters tried, GA₃ caused more weight loss than IAA. Unlike growth promoters, the application of growth retardant (PBZ) had depressing effect on total weight losses with increase in its concentration. The study demonstrated that application of growth regulators can be exploited to manipulated storage behaviour of potatoes.