Co-Authors:
Bar-Tal, A., Institute of Soils, Water and Environ. Sciences, ARO, Volcani Center, Bet-Dagan, Israel
Keinan, M., Institute of Soils, Water and Environ. Sciences, ARO, Volcani Center, Bet-Dagan, Israel
Fishman, S., Department of Statistics and Operation Research, Israel
Aloni, B., Institute of Field and Garden Crops, Israel
Oserovitz, Y., Extenssion Service Lachish, Kiryat-Gat, Israel
Génard, M., Unité de Recherche en Ecophysiolögie et Horticulture, EMRA, Domaine St-Paul, Avignon, France
Abstract:
The main physiological disorders of greenhouse pepper fruit are blossom-end-rot (BER) and fruit cracking, which are affected by environmental conditions (temperature, relative humidity and radiation) and calcium (Ca) concentration in the fruit. In the literature there is qualitative information on the relations of Ca translocation and distribution in plant organs, to environmental factors, but there is very little quantitative information or mathematical analysis of these processes. The objective of this research was to simulate Ca supply to the growing fruit in relation to environmental conditions in order to predict the final fruit Ca concentration. For this purpose a biophysical model of fruit growth was used. The major assumption in the current model is that Ca concentration in the fruit is regulated by the ratios of phloem/xylem water supply to the fruit. The results are compared with experimental data of greenhouse pepper grown in different irrigation frequencies and different environmental conditions, low air humidity with high temperature and high air humidity with low temperature. The data obtained in those experiments was used to study the effects of the plant water status and environment conditions on Ca concentration in the fruit. The main conclusions are: As the Xylem water potential decreases Ca accumulation and concentration in the fruit is reduced. As the concentration of carbohydrate in the phloem increases Ca accumulation in the fruit increases but its concentration decreases. The relative humidity of the air effects Ca concentration in the fruit through its effect on the water potential of the xylem.