PACLOBUTRAZOL ENHANCES MINITUBER PRODUCTION IN NORLAND POTATOES

The effect of two plant growth regulators, paclobutrazol and kinetin, on minituber yield in greenhouse-grown ''Norland'' potatoes was investigated. Plants were treated with paclobutrazol at 450 mg/L, kinetin at 10 mg/L, or a combination of paclobutrazol at 450 mg/L + kinetin at 10 mg/L as single foliar applications at early stolen initiation. A set of plants sprayed with water served as the control. The experiment was conducted twice. In both cases, paclobutrazol nearly doubled the number of usable tubers/plant without affecting total tuber yield. Kinetin had no effect either on tuber number or tuber weight. Kinetin applied as a combination with paclobutrazol decreased the effectiveness of paclobutrazol on tuber number by 13-20%. Paclobutrazol treatments prolonged tuber dormancy by approximately 3 weeks. The results suggest that paclobutrazol treatment would be effective in enhancing potato minituber production under greenhouse conditions.