Fourty five days after planting, plant regulators were sprayed on potato plants. The treatments were a control, 25, 50 and 100 mg L-1 of mepiquat chloride and 250, 500 and 1000 mg L-1 of (2-chloroetyl) trimetylammonium-chloride (chlormequat), with the objective of increasing the production. The experiment was distributed in 4 randomized blocks for each treatment. The main parameters analized were leaf area, chlorophyll rate, dry matter and total yield. The classification of the tubers was also stablished according to their types (I, II, III and IV). Higher chlorophyll degradation rates were observed when mepiquat chloride was used at 25 mg L-1. There was an increase of types I and II tuber yield when chlormequat was sprayed at rates of 250 and 500 mg L-1 and mepiquat chloride at 25 mg L-1. Chlormequat 500 mg L-1 was the most effective treatment and increased total tuber yield by 12.3% and mepiquat chloride 25 mg L-1 increased 3.32% in relation to the control. This increase was probably due to the photossinthetic activity and sink strength of tubers, wich was higher for tubers of types I and II.
Solanum tuberosum; potato; plant regulators; chlormequat; mepiquat chloride