Dry gibberellic acid combined with talc or fir bark enhances early stem and tuber growth of Shepody potato

Gibberellic acid (GA₃) powder was applied to seed pieces of Shepody potato in combination with water, fir bark and talc carriers. In a greenhouse study, emergence, stem growth and tuber number from seed pieces treated with dry GA₃ and carriers were compared with that of an untreated control. All carriers alone reduced stem emergence. GA₃ (0.5,1 and 2 mg/ kg) combined with talc, and 0.5 and 2 mg GA₃/kg with fir bark+talc enhanced emergence. Only 2 mg GA₃/kg enhanced emergence when applied in solution. Emergence of stems from pieces treated with GA₃ and fir bark was no different or slower than the control. In the absence of GA₃, water and talc increased stem number and fir bark-containing treatments reduced tuber number. All concentrations of GA₃ applied with talc or fir bark+talc, and 2 mg GA₃/kg with fir bark increased stem and tuber number. With water, 0.5, 1 and 2 mg GA₃/kg increased stem number but only 2 mg GA₃/ kg resulted in more tubers. One and 2 mg GA₃/kg combined with talc resulted in the most stems and tubers 58 days after planting. GA₃ was as effective or more effective in speeding emergence and increasing stem and tuber number when applied in the dry form with talc or fir bark+talc as when applied in solution.