Effects of Different Levels of Wheat Biochar and Water Stress on Quantitative and Qualitative Characteristics of Carla (Bitter Melon) in Potted Conditions

Carla is a medicinal plant whose fruit is used to treat diabetes. In this study, the effect of water stress and biochar on the qualitative and quantitative parameters of Carla plant was investigated. The experiment was performed in greenhouse conditions in a factorial manner and in a completely randomized design with three replications. Treatments included three irrigation water treatments (50%, 75%, and 100% of the water requirement) and four biochar treatments (zero, 1.25%, 2.5%, and 5% by weight of potting soil). During the growing season, water treatments were applied by weekly weighing of the pots and replenishing the water loss up to Field Capacity. The amount of water added to each pot was measured. Harvest at 50 days after planting was done once a week. A total of five harvests were performed. In each harvest, quantitative parameters including plants height, number, weight, diameter and length of fruit, and qualitative parameters of fruit sugar content, greenness index, and leaf area index in each pot were carefully measured. Also, the yield and efficiency of irrigation water consumption at the end of the planting season was determined in each treatment. The results showed that the effects of irrigation water and biochar levels were significant (at 1% and 5% probability) on the measured parameters. With decrease in irrigation water, the amount of quantitative parameters and plant yield decreased. The highest value of the measured parameters was obtained from 100% irrigation water treatment, which was not significantly different from the 75% irrigation water treatment. The use of biochar up to 2.5% by weight of soil increased the parameters. Use of the right amount of biochar reduces the negative effects of stress and improves plant growth compared with the control treatment. Therefore, use of biochar for plants, especially when the plant is under water stress, can be recommendable. In order to reduce the amount of water used in greenhouses and improve plant growth and yield, biochar use is advisable, however, its use under field conditions should be tested.