Effects of different irrigation regimes on the yield and yield components of dry bean (Phaseolus vulgaris)

Water stress is one of the most important yield-limiting abiotic factors for dry beans (Phaseolus vulgaris L.). This study was conducted 1) to identify the effects of different irrigation scheduling on yield and yield components, 2) to define the number and intervals of irrigation water requirements in dry beans and 3) to compare the performances of two dry bean varieties in different irrigation schedules. The experiments were carried out in the fields of the Anatolian Agricultural Research Institute from 1992 to 1996. Two dry bean cultivars, Yunus90 and Karacasehir90, were used to study the effects of five irrigation schedules (S1: High, S2: Medium, S3: Low, S4: High-Low, S5: Low-High rates of irrigation). The results indicated that year (Y) × irrigation regime (IR) interactions were important for yield and yield components. Karacasehir90 was less affected by water stress than Yunus90 when rainfall was low in the growing season. Differences between irrigation schedules were more distinct when rainfall was low. The highest yield and yield component values were obtained from S1, while the lowest values were obtained from S3 and S4. These results showed that water stress after flowering had the most adverse effect on yield. Thus, it is recommended that farmers use supplemental water chiefly after flowering when water sources are limited.