EFFECTS OF PLANT AND ORGAN REMOVALS AND LIGHT REDUCTION ON FLOWER AND FRUIT DEVELOPMENT IN STRAWBERRY

摘要

Manipulations including removals of plants, crowns, trusses or leaves to approximately half the control values were applied in the autumn (before flower initiation) or at bloom. In the latter case a 50% light reduction was included as well. Cultivars were 'Rubina', 'Dania' or 'Elsanta'. Autumn treatments released some compensatory development of trusses and an even greater development of vegetative parts the following summer. Fruit size was increased in two out of four experiments and ripening was promoted in some cases. Treatments at bloom ('Elsanta') rendered only small influences. Removals of leaves, crowns and trusses released a small compensatory increase in fruit numbers, the two latter treatments increased fruit size by about 14%. Light reduction did not affect fruit development. Removal of the three largest flowers per truss released a compensatory development of inferior flowers which otherwise remained undeveloped. When concentrations of soluble solids and acids were measured, effects were small or absent. It is concluded that effects are due to a releived competition for root-mediated factors more than for assimilates.