DRY GIBBERELLIC-ACID COMBINED WITH TALC OR FIR BARK ENHANCES EARLY STEM AND TUBER GROWTH OF SHEPODYPOTATO

Gibberellic acid (GA(3)) powder was applied to seed pieces of Shepody potato in combination with water, fir bark and talc carriers. In a gre enhouse study, emergence, stem growth and tuber number from seed piece s treated with dry GA(3) and carriers were compared with that of an un treated control. All carriers alone reduced stem emergence. GA(3) (0.5 , 1 and 2 mg/kg) combined with talc, and 0.5 and 2 mg GA(3)/kg with fi r bark+talc enhanced emergence. Only 2 mg GP(3)/kg enhanced emergence when applied in solution. Emergence of stems from pieces treated with GA(3) and fir bark was no different or slower than the control. In the absence of GA(3), water and talc increased stem number and fir bark-c ontaining treatments reduced tuber number. All concentrations of GA(3) applied with talc or fir bark+talc, and 2 mg GA(3)/kg with fir bark i ncreased stem and tuber number. With water, 0.5, 1 and 2 mg GA(3)/kg i ncreased stem number but only 2 mg GA(3)/kg resulted in more tubers. O ne and 2 mg GA(3)/kg combined with talc resulted in the most stems and tubers 58 days after planting. GA(3) was as effective or more effecti ve in speeding emergence and increasing stem and tuber number when app lied in the dry form with talc or fir bark+talc as when applied in sol ution.