Treatments of Gibberellic Acid for Vegetative Growth, Tuber Yield and Quality of Potato (Solanum tuberosum L.) in the Central Highlands of Ethiopia

Abstract

The productivity of potato is low owing to a number of constraints including poor sprouting due to dormancy, which leads to delayed planting and poor crop emergence and vigor. The study was conducted during 2008-2009 with the objectives to determine the effects of different methods and rates of gibberellic acid (GA3) application on dormancy attributes, tuber yield and quality of potato, and its subsequent generation of Gera cultivar. Five levels of GA3 (0, 250,500,750 and 1000 ppm), as haulm application a week prior to haulm destruction, and five levels of GA3 (10, 20, 30, 40 and 50 ppm), as dipping treatments immediately after harvest for 24hrs, were used as treatments. The treatments were arranged in randomized completed block design with three replications both for planting and storage. The result showed that GA3 application affected dormancy period, tuber yield and quality. Haulm applications of GA3 increased marketable tuber and tuber yield per hill as compared to untreated tubers. Moreover, haulm application of GA3 increased dry matter content as compared to the control, while the increment in the dry matter content was also observed in response to dipping the seed tuber. In the same manner, dipping seed tubers in GA3 solution increased tuber specific gravity of the next generation as compared to the control. Therefore, significant increase in tuber number and weight due to GA3 application contributed to the increase of total tuber yield. Both haulm application and dipping treatments of GA3 at higher rates resulted in high total, marketable tuber yield along with significant dry matter content and tuber specific gravity, which help the producers to boost their produce.