Effect of Different Water Regimes on Yield and Quality of Apple under Semi-Humid Region, Libya

This study, which was carried out in 2011/2012, investigated the yield and quality parameters of apple fruits (double red delicious) with different irrigation systems; surface and drip irrigation and with different water levels; 100, 75 and 50% of ET_c. In order to traditional irrigation (rainfall irrigation) treatment, that presented 34.75% from ET_c. The water irrigation requirement was determined by using Penman-Monteith’s equation. An increase in fruit yield and quality (fruit diameter, fruit weight, total soluble solid and sugar) has been noted with drip irrigation method if comparing with surface and rainfall irrigation. The highest fruit diameter (80.9 mm), fruit weight (216.3 g), extra and class 1 fruit ratios (36.2 and 36.5%), total soluble solid (1.551 ton/fed) and sugar (1.38 ton/fed) were observed with DET₁₀₀ treatment. To obtain a high quantity and quality apples, DET₁₀₀ treatment with 100% ET_c and drip irrigation system is recommended during transition from rainfall and surface irrigation to drip irrigation for similar climatic and soil conditions. The results showed that drip irrigation system increases the qualitative and quantitative of apple fruits.