Weekly fruit production of sweet pepper in relation to plant fruit load manipulation

Abstract

Fluctuation in weekly fruit production in greenhouse sweet pepper is a common phenomenon and may be due to competition for assimilates among growing fruits on the plant. Reducing this competition by fruit pruning may result in a more regular weekly production. In order to investigate this hypothesis, sweet pepper plants (Capsicum annuum) the cultivar 'Mazurka' was grown in Rockwool slabs in a controlled climate glasshouse in Wageningen, The Netherlands. Two treatments were applied namely, Normal fruit load (NFL) where all possible flowers were allowed to develop to fruits and Manipulated fruit load (MFL) where only two fruits per week were allowed to develop and grow. Data showed that the MFL treatment had a lower number of aborted flowers and small fruits compared to the NFL treatment. The number of set fruits per plant was very stable in MFL for almost the last two thirds of the season. Despite the manipulation treatment, there was still a fluctuation at the beginning of the season. Fruit yield in all treatments showed the well known fluctuation pattern of production of sweet pepper plants. However, the production was more stable during the summer in MFL compared to NFL. During spring the fluctuation was in the two fruit load treatments but to a lesser extent in MFL. Data are further discussed in relation to climate conditions.