S19 - Session O5 - Best practices to avoid fruit drop in an early cultivation of redcurrant

Authors: Miet Boonen, Clara Spruyt *, Bart Vanhoutte, Dany Bylemans

Early spring production of the red currant variety 'Junifer' in heated greenhouses can be an economically sound move. However, several pitfalls can render this intensive and costly cultivation completely unsuccessful. Besides production, raceme quality determines the economic result.. Only sufficiently long racemes with uninterrupted fruit are sold at a high price. Fruit drop in the flower stage or in the stage of fruit set is therefore the biggest dealbreaker for this crop. Fruit drop can not be related to one specific parameter. A combination of various factors, whether climatic, physiological or in terms of cultivation technique, can give rise to fruit drop. After more than 25 years of research, the problem still has not been fully unraveled. However, numerous parameters were examined separately and in combination and best practices could be drawn up. Based on this research, it is known that temperature, humidity and illumination are important climatic parameters influencing fruit drop. Cultivation techniques such as winter and summer pruning, bunch thinning, plant density and fungus suppression can reduce fruit drop. In terms of physiology, pollination, growth regulation and the amount of cold hours are parameters that should not be underestimated. A best practice guide for growers should ensure that this cultivation can be carried out with minimum risk and maximum return.