Interaction of growth regulators and photoperiods on growth, flowering, stolon development, tuber initiation and yield in potato (Solanum tuberosum L.)

Seed tubers of potato (Solanum tuberosum L.) var. Kufri Chandramukhi were treated for 24 h with IAA (50 ppm), GA₃ (10 ppm), kinetin (5 ppm) and their combination and planted in earthenware pots. Plants raised were subjected to short days (SD; containing 2, 4, 6, 8, 10 and 12 h light in 24 h cycle) and long days (LD; continuous light) under similar conditions of temperature and humidity. Under short photoperiods of 2 and 4 h duration plants became etiolated, while LD and GA₃ treatments produced taller plants. GAs also increased the number of plants established per seed tuber. The beterob-lastic development ot the leaves is considerably influenced by bot hormonal as well photoperiodic treatments.

The potato var. Kufri Chandramukhi is a quantitative long day plant with respect to floral bud initiation. Floral buds opened into flowers with IAA and GA₃ treatments under LDs and dropped before opening under SDs. The variety is quantitative short day in relation to tuberization. Number of stolons and tubers increased considerably with GA₃ under SD conditions. The tuber fresh and dry weight increased with GA₃ under SDs (10 and 12 h photoperiods).