EFFECT OF GIBBERELLIC ACID ON GROWTH, TUBER YIELD AND QUALITY IN POTATOES (Solanum tuberosum L.)

Abstract

The purpose of this study was to determine the effects of different doses of gibberellic acid (GA3) on growth, tuber yield and some tuber quality traits of potato. The experiment was arranged in a split-plot design with three replicates, cultivars Marabel, Alegria and Agria were arranged in the main plots, and GA3 doses (0, 25, 50 and 100 mg GA3 L-1) in the sub-plots. Gibberellic acid was applied to leaves by spraying on the 50th day after planting (during flowering). The effects of GA3 applications on tuber yield of potato cultivars were varied. GA3 applications resulted in significant decrease on chlorophyll content (SPAD), tuber dry matter and chips quality of potato. But it caused significant increase on number of tubers and tuber yield plant-1. In 2019 and 2020 years, the highest tuber yield was obtained from Alegria cultivar (62.78 and 50.55 t ha-1 respectively). Total tuber yield values increased from 52.08 t/ha to 65.14 t ha-1 in 2019 and from 42.12 t ha-1 to 53.94 t ha-1 in 2020 with increasing to 100 mg GA3 L-1 from 0 mgL-1. Overall, increasing doses of GA3 resulted in a reduction in tuber dry matter and starch ratio. The GA3 applications caused deformations in tuber shape, the deformations increased with increasing GA3 doses.