EVALUATION OF EVAPOTRANSPIRATION AND FRUIT YIELD OF TOMATO (SOLANIUM ESCULENTUM) UNDER AMBIENT AND CONTROLLED ENVIRONMENTS

Abstract

Greenhouse cultivation of crops, especially vegetable crops is gaining wide acceptance in most tropical countries but the set back is the adoption of te technology, lack of information about the water needs of crops. Hence, reliable data that could be followed for such practice especially in the tropical Africa is not readily available. This project was conducted to evaluate the evapotranspiration and fruit yield of tomato (Solanium esculentum) under ambient and controlled environment. Tomato seeds were planted in the nursery and adequate watering was done to field capacity to enable germination. After four weeks of planting, the healthy and viable seedlings were transplanted to the experimental field at the rate of one seedling per replicate of the treatment container. The result shows that the mean irrigation water supplied for the tomato was estimated as 22.97, 17.23, 11.49, and 10.22 mm/week for 100%, 75%, 50% field capacity and control sample(plot under eainfed agriculture), respectively. The tomato under 75% irrigation level in the greenhouse had the highest number of fruits (69.67 ± 3.06) followed by the tomato grown under 100% irrigation level (65.33 ± 0.58) and 50% irrigation level produces the lowest number of fruit (47.67 ± 2.89) in the greenhouse. The higher tomato fruit weight was recorded at 100% irrigation level though the number of fruit is lower at this irrigation level compared to the 75% irrigation level and the tomato grown under ambient condition (control) had the least fruit yield compared to the tomato grown under different irrigation level in the green house. The significant (P < 0.05) effect of irrigation water on the fruit yield was established by a polynomial model giving a high coefficient (R2) of 0.9036 and 0.7998 for the number of fruit and fruit weight, respectively for all the treatments in the greenhouse. The WUE of the tomato plant ranges between 2.14 ± 0.09 kg/m-3 - 5.57 ± 0.43 kg/m-3 and the highest water use efficiency of (5.57 ± 0.43 kg/m-3) the was recorded under 50% irrigation water treatment and WUE of the tomato plant decreases continuously as the irrigation water increase from the lowest (50%) water supply to the highest (100%) in the greenhouse. The RUE value of 0.29 ± 0.02 kg/MJm-2, 0.56 ± 0.002 kg/MJm-2, 0.6 ± 0.001 kg/MJm-2 and 0.21 ± 0.01 kg/MJm-2 was recorded for the tomato plant grown under 50%, 70%, 100% irrigation level, and control sample respectively. Higher percentage of the radiation received in the greenhouse was absorbed by the tomato plant and highly utilized compared to the tomato grown under ambient condition (control sample). Therefore, in an area with low availability of water supply and non-favorable climatic condition, the tomato plant should be irrigated under 75% water level in the green house to conserve the available water and obtain the desired crop yield.