Growth, root morphology and leaf physiology of watermelon as affected by various rates and forms of nitrogen in the hydroponic system

Authors : Abdullah ULAŞ

Pages : 134-141

Doi:10.31015/jaefs.2020.2.2

View : 13 | Download : 9

Publication Date : 2020-06-15

Article Type : Research Paper

Abstract :The aim of this study was to determine the effects of different rates and forms of nitrogen insert ignore into journalissuearticles values(N); on shoot growth and root morphological and leaf physiological responses of watermelon insert ignore into journalissuearticles values(cv. Crimson Tide F1); under hydroponic growth condition. The nutrient solution experiment was conducted between January - March in 2018 by using an aerated Deep Water Culture insert ignore into journalissuearticles values(DWC); technique in a fully automated climate room placed in the Plant Physiology Laboratory of Erciyes University, Faculty of Agriculture, Kayseri in Turkey. Plants were tested under two N-Rates insert ignore into journalissuearticles values(N1: 1000 and N2: 2000 µM N); and three different N-Forms insert ignore into journalissuearticles values(Am-N: NH4+, Nit-N: NO3-, 50% mixture of both N-Forms Mix-N: NH4+NO3); by growing in 8 L pots filled continuously aerated nutrient solution insert ignore into journalissuearticles values(modified Hoagland);. The experiment was conducted with a completely randomized block design with four replications. From each pot two plants were harvested 42 days after treatment insert ignore into journalissuearticles values(DAT); by separating into stem, leaf and root fractions. The results indicated that shoot growth, root morphological and leaf physiological responses were significantly insert ignore into journalissuearticles values(p<0.001); affected by N-Rate, N-Form and N-Rate x N-Form interaction. The lowest performance under sole Am-N supply was achieved, since it severely reduced shoot and root growth and leaf area development as compared to sole Nit-N and Mix-N treatments. Irrespective of N rates, best growth performance in shoot growth was achieved under Mix-N supply, while root growth significantly improved under sole Nit-N supply. All these clearly indicate that the application of sole ammonium insert ignore into journalissuearticles values(1000 µM N); is detrimentally toxic for hydroponically grown watermelon plants. On the other hand, a 50% mixed of ammonium with nitrate even at a higher dose insert ignore into journalissuearticles values(N2: 2000 µM ammonium N); can be more advantageous for the growth and development of watermelon plants grown in the hydroponic system. Furthermore, our study showed that the effects of N-Form insert ignore into journalissuearticles values(Nit-N and Mix-N); on the improvement of shoot growth, root morphology and leaf physiological development and photosynthesis were significantly higher than the effects of N-Rate. Therefore, the application of nitrogen fertilizers in the form of Mix-N could be a useful N management strategy for growth and yield of watermelon plants under hydroponic conditions.
Keywords : Nitrogen, Watermelon, N form, Ammonium toxicity