Title: Improvement of crop production of the greenhouse: validation of energetic research in agriculture field

Biography:

Douja Sellami, PH. D, has his competence in the study of greenhouse crops and his passion for the improvement of these crops. Its open improvement model is based on new ways of using renewable energy. She built this model after years of experience in research, both in biology laboratories and in thermal process laboratories

Abstract

Yield has been often reported to be unstable, depending on the growing conditions. Therefore, a tomato (Solanum lycopersicum L.) crop was grown in three greenhouses during winter in Tunisia. Sidewalls and northern roof of two greenhouses were covered with sandwich panels (Insulated greenhouses (IG)) from which one is equipped with a heating system with latent storage (IGHLS). The other greenhouse was transparent (TG). These greenhouses were mechanically ventilated when air temperature exceeded 28°C. The overall mean air temperature was significantly increased by 1.42 and 4.34 °C (day) and 2 and 3.2 °C (night) in IGHLS as compared to IG and TG, respectively. Temperature maxima in IGHLS averaged about 2 and 4.35°C higher than in IG and TG, respectively. The relative humidity was similar at day but higher at night in TG than in IG and IGHLS with 1% and 2%, respectively. The relative water content was significantly lower in TG (76.86) than in IG (94.02) and IGHLS (117.92). The relative growth rate was increased by optimal conditions, whereas the electrolyte leakage and lipid peroxidation of leaves was suppressed in the IGHLS. Total fruit yield was higher in IGHLS (4,98 kg plant-1) than in IG (3,2 kg plant-1) and TG (2.3kg plant-1). The quantity of undersized (mostly parthenocarpic) and blossom-end rot (BER)-affected fruits was reduced in IGHLS. However, the proportion of marketable yield was significantly higher in IGHLS (4.86 kg plant-1) than in IG (3.05 kg plant-1) and TG (2.22), owing largely to an increased incidence of undersized fruits in TG and IG. Higher undersized fruit incidence coincided with lower fresh weight and Ca concentration in the fruits in TG and IG. It is concluded that in greenhouse with technical modification allowing an increase of night temperature and dehumidification will improve protected tomato production.