Some environmental parpameters affecting sweet pepper growth and productivity under different greenhouse forms in hot and humid climatic conditions

The influence of environmental parameters on growth rate, fresh yield, and irrigation performance of color sweet pepper (Capsicum annuum var annuum cv.) were studied in three different types of greenhouse forms. The three different systems are; gable-even-span form, flat roof net-house, and modified Quonset greenhouse during 2002/2003 seasons. Diurnal external and internal, air temperature, air relative humidity, vapour pressure deficit (VPD), and light intensity were measured to analysis their correlation with sweet pepper crop yield response. The plants were periodically collected throughout their growth cycles to measure vegetative, flowering and yields. For irrigation performance test three indicators were determined; annual relative irrigation supply (ARIS), irrigation water use efficiency (IWUE), and annual water productivity (AWP). The obtained results showed that, the gable-even-span greenhouse (fully controlled) gave the best growth rate between vegetative and generative parts of the plant as compared with other systems. The greatest plant height (7.7 cm/week) achieved during autumn season for the three different greenhouse forms. While, the plant height rates during winter season for the three different greenhouse forms, respectively, were 5.8, 1.8 and 4.0 cm/week. The obtained data also revealed that the leaf area index (LAI) for the three different forms was 6.16, 2.23, and 2.44, respectively. Therefore, the greatest fresh yield and quality of sweet pepper were achieved by gable-even-span form (fully controlled greenhouse) as compared with other forms of greenhouse. Mean annual irrigation supply (ARIS) values were slightly up to 1 for the three different forms. Mean irrigation water use efficiency (IWUE) values for the three different forms ranged from 3.98 to 9.75 kg/m3, while (AWP) in the fully, controlled greenhouse was higher than 3.18 and 4.08 times from flat roof net-house and modified Quonset, respectively due to increase the irrigation water use efficiency (IWUE) and high value of yield grown off-season