| Abstrakt: |
Background and Objectives: Bean plant is very sensitive to water and soil conditions and its yield is damaged even in short periods of stress. Water shortage has very negative effects on grain yield and bean yield components. Due to the fact that drought stress is one of the most important environmental stresses in the agricultural sector, many efforts have been made to maintain crop yields under drought conditions. Conditions are shortages or high water prices. Therefore, due to the importance of this issue, this study was conducted to investigate the effect of drought stress on yield, yield components and radiation use efficiency (RUE) in growing different types of beans in Mashhad climate. Materials and Methods: To investigate the effect of irrigation treatments on grain yield and yield components and radiation use efficiency in three types of experimental beans in the form of split plots based on randomized complete blocks in three replications in the spring of 2016-2017 and 2017-97 in the research farm of faculty of Agriculture, Ferdowsi University of Mashhad was implemented. Experimental factors include normal irrigation (irrigation based on 100 percent of plant water requirement) and drought stress levels (irrigation based on 75 percent of plant water requirement and irrigation based on 50 percent of plant water requirement) as the main plot and three types of beans including red beans (Phaseolus calcaratus) white beans (Phaseolus lanatus) and pinto beans (Phaseolus vulgaris Pinto Group) were sub-plots. Data analysis was performed using SAS software and comparison of the mean of treatments based on Duncan test at a probability level of five percent. Results and Discussion: The results showed that the interaction effect of irrigation and bean type on grain yield, biological yield, harvest index, number of pods per plant, number of seeds per pod and radiation use efficiency (RUE) were significant. Because red beans were able to use the light reaching the vegetation more efficiently, as a result, grain yield, biological yield and harvest index (1421.44 and 4126.6 kg / ha and 35.76 percent) caused higher the amount of these traits (872.67 and 2225.5 kg / ha and 30.52 percent) in pinto beans were reduced. Based on the results, normal irrigation treatment showed the highest grain yield biological yield and harvest index (1602.28 and 4811.9 kg / ha and 39.24 percent) and the lowest grain yield, biological yield and harvest index. (1093.222 and 3388.8 kg/ha and 33.06 percent) were obtained in drought stress treatment (irrigation based on 50 percent of water requirement). While normal irrigation increased the number of pods per plant in red beans and white beans (13 pods per plant), this irrigation treatment (with a reduction of 38.08%) reduced this trait in pinto beans (8.05 pods per plant). In drought stress treatment (irrigation based on 50% of water requirement), red beans and pinto beans had the highest (6.82 seeds per pod) and the lowest (2.47 seeds per pod) number of seeds per pod, respectively. The highest 100-seed weight was obtained in normal irrigation (28.39 g) and drought stress (irrigation based on 50 percent water requirement) resulted in the lowest amount of this trait (26.04 g). Among bean varieties, the highest 100-grain weight (31.16 g) was obtained in red beans. As the intensity of drought stress increased, the radiation use efficiency decreased and the radiation use efficiency in normal irrigation conditions (1.8 g / mJ) was higher than that in drought stress treatment (irrigation based on 50 percent of water requirement). Red beans (1.9 g / mJ) had higher radiation use efficiency than white beans (1.6 g / mJ) and pinto beans (1.5 g / mJ). Normal irrigation treatment (irrigation based on 100 percent of plant water requirement) increased radiation use efficiency in red beans (1.3 g / mJ) and drought stress (irrigation based on 50 percent of plant water requirement) in white beans reduced this trait. Conclusion: According to the results, normal irrigation and red beans seem to be desirable to achieve higher yields. [ABSTRACT FROM AUTHOR] |
