Influence of different protected cultivation structures on water requirements of winter vegetables

Protected cultivation structures provide favourable environment for crop growth thereby achieving greater yield and high quality produce. Green house, polyhouse, shade net house & low tunnels are different types of protected cultivation structures, which are commonly adopted for crop cultivation. During extreme cold in winter season (November-February) vegetables can be grown under green house structure. Accurate irrigation scheduling in protected cultivation structures is one of the important factors in achieving high yields and avoiding loss of quality. The objective of this work was to evaluate the effect of protected cultivation structures (Poly house, shade net house and shadow hall) on temperature, relative humidity and water requirement of vegetable crops (Tomato, Cucumber, Capsicum, Cauliflower, Cabbage, Broccoli & Brinjal) with drip irrigation system grown during winter season (November-February). FAO-56 Penman Monteith approach was used to estimate the reference crop evapotranspiration under different kind of protected cultivation structures with different vegetable crops. Study shows that vegetable production in winter for sub humid region reduces due to fall in temperature below optimum level. Green house structure offers a solar energy saver and enhances temperature inside the structures. Daily average reference crop evapotranspiration value was found to be minimum for shadow hall (1.2–2.9 mm day⁻¹) followed by polyhouse (1.3–3.2 mm day⁻¹), shadenet house (1.4–3.7 mm day⁻¹) and open field (2.0–4.9 mm day⁻¹) condition. The total water requirement of drip irrigated vegetable crops in protected cultivation structure is reduced by about 35.6%, 35.2% and 25.5% respectively under shadow hall, poly house and shade net house in comparison to open field cultivation.

Comparing temperature, relative humidity and crop reference evapotranspiration of different protected cultivation structures with open cultivation condition

Estimation of water requirement of vegetables using FAO 56 Penman Monteith equation for Polyhouse, Shadenethouse, Shadow hall and outside condition.