EFFECTS OF CHILLING AND GROWTH-REGULATORS ON RUNNER PRODUCTION OF 3 STRAWBERRY CULTIVARS UNDER TROPICAL CONDITIONS

The effect of chilling alone or in combination with gibberellic acid (GA3) and benzyladenine (BA) on runner production in three strawberry cultivars was observed during the warm and cool seasons in a field experiment under tropical conditions in Kenya. Chilling alone promoted a significant production of 18 and 10 runners per mother plant in the cold and warm season respectively in the cultivars tested. When chilling was combined with BA + GA3, runner production per mother plant was raised to 23 and 14 in the cool and warm seasons respectively. Chilled plants provided with exogenous GA, produced almost the same number of runners as those receiving chilling only, whereas those treated with exogenous BA had significantly more stolons than those of treatments receiving chilling only. Daughter plant production followed a similar pattern as that of stolon production. The control plants produced fewest stolons but most branch crowns. More stolons, daughter plants and branch crowns were produced during the cool than in the warm season.