Investigation of the interaction effect of nitrogen and water stress on greenness and water consumption indices of Carla (bitter melon)

In this study, the effect of water stress and nitrogen on quantitative parameters of Carla was investigated. The experiment was performed in greenhouse in a factorial manner and in a completely randomized design with three replications. Treatments included three irrigation water treatments and three levels of nitrogen fertilizer (100, 125 and 200 kg/ha, N1, N2 and N, respectively). Levels of water stress during the growing season and the weight of the pot and soil water shortage to field capacity in irrigation water by adding the amount was applied to them. Harvesting was done once a week. In each harvest, the parameters of number, weight, diameter and length of fruit and the amount of chlorophyll a and b in each pot were carefully measured. Also, yield and water use efficiency were calculated at the end of the growing season in each treatment. The results showed that the effects of irrigation water and nitrogen levels at the level of one and five percent probability on the measured parameters were significant. With decreasing irrigation water, the amount of quantitative parameters and plant yield decreased. The highest value of parameters was obtained from 100% irrigation water treatment, which was not significant in this regard with 75% irrigation water treatment. Under full irrigation conditions, the use of 100% nitrogen fertilizer increased yield and greenery indices. The highest yield was obtained in N3 treatment (full nitrogen consumption) of 15.4 tons per hectare and the highest water productivity was obtained from N3 treatment (2.12 kg / m3). Also, the interaction of nitrogen fertilizer and water stress showed that in severe water stress levels, full use of nitrogen fertilizer (N3 treatment) reduced the yield of Carla plant. Therefore, in severe water stress levels (50% irrigation water treatment), the amount of nitrogen consumption should be reduced to 75%.