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It is difficult to reach the water needed in agriculture. For this reason, insufficient irrigation causes yield and quality losses in plants. The aim of this study was to determine some quality parameters of both flesh of melon and melon seed irrigated with different irrigation regimes. Melon cultivar (Cucumis meloL.) was irrigated by the drip method from transplantation to the beginning of vegetative development, flowering-fruit binding, and fruit development-ripening. In this context, 8 irrigation groups were formed. Sugars, total phenolic compounds, titratable acidity, antioxidant activity and color analyzes were performed on flesh of melons. Oil content and fatty acid composition of melon seeds were also determined. The titratable acidity of samples varied from 0.098 to 0.159%. Irrigation regime had a significant effect on sucrose and total sugar content. Total phenolic compounds and antioxidant activities of samples were ranged from 80.6 to 244.8 (mg GAE/kg) and 0.17 to 0.38 (mmol TE/kg), respectively. The groups of non-irrigated and irrigated at vegetative-fruit development-ripening periods had the highest amount of total phenolic compounds and antioxidant activities. Among the color parameters, there were significant differences only in a* and h values. Although palmitic acid and oil content of seeds were not different, linoleic, oleic, and stearic acids were affected significantly by irrigation regime. As a result, in terms of sugar content, amount of phenolic compound and antioxidant activity, irrigation during VF period can be suggested for cultivation of melons in arid and semi-arid regions.

The proper design and management of trickle irrigation systems are important factors in ensuring the efficient water use in agriculture. In this study, the effects of different irrigation strategies were determined on the yield, net income, and water use productivity of trickle-irrigated sunflower (Helianthus annuusL. cv. Sirena) in a two-year open-field experiment (2013–14) in a semi-arid climate. Two different lateral spacings (L) of 70 cm (one lateral line per one plant row) and 140 cm (one lateral line per two plant rows) were designed, and three different wetting factors (W) were applied for each lateral spacing. Wetting factors of 1.00 and 0.60 were used as fixed values for both 70 and 140 cm lateral spacings. Moreover, two different wetting factors, 0.85 and 0.42, were used for the lateral spacings of 70 and 140 cm, respectively, using the measured wet diameter values in the experiment area. Thus, six treatments were designated as L70W1.00, L70W0.60, L70W0.85, L140W1.00, L140W0.60, and L140W0.42. The study was designed as randomized complete block design with three replications.

Drought is one of the most important abiotic factors that restrict the production of agricultural plants. An effective way to avoid the negative effects of drought on crops is to cultivate high-yielding varieties by grafting them onto drought-tolerant rootstocks with a strong root system. For this purpose, five different plant materials were used: wild watermelon rootstock, i.e., wild watermelon (A1and A2), open-pollinated Lagenaria siceraria(gourd) rootstocks (A3), Cucurbita maxima Duchesne× Cucurbita moschata Duchesne(TZ-148) F1 watermelon rootstocks (A4), and the ungrafted control. Five different irrigation depths were applied considering irrigation water (IW)/cumulative pan evaporation (CPE) rations (I100: 1.0 IW/CPE, I75:0.75 IW/CPE, I50:0.50 IW/CPE, I35:0.35 IW/CPE, and I0:rain-fed). The results showed that the use of rootstock and water stress increased the rate of sugar content in the fruit. The highest positive relationship was found between glucose and total sugar, whereas the highest negative relationship was observed between sucrose and malic acid. Parameters such as glucose, total sugar, and citric acid showed significant changes in drought stress. Fructose and malic acid showed significant differences between the rootstocks. Principal Component Analysis (PCA) revealed that the A2I50application was located in the positive region of both components and showed important results in these parameters. The TZ148 rootstock contributed significantly to the quality of watermelon. In addition, the A2wild watermelon rootstock showed respectable results, especially under water stress conditions. Based on these results, we conclude that the use of wild watermelon rootstock will contribute to the fruit quality in arid and semi-arid areas with limited water resources.