Effect of Sowing Date of Resistant and Susceptible Faba Bean, Vicia faba L. Cultivars on Orobanche crenata Forsk Seed Bank and Faba Bean Production

Abstract

: The broomrape , Orobanche crenat a Forsk (Orobanchaceae) is a serious annual parasitic weed that causes considerable losses in many major crops including faba bean (Vicia faba L.). In Egypt: losses due to O. crenata parasitism may reach 40 to 100%. Despite using several methods to control O. crenata, success has not been achieved. The impact of different control tactics on O. crenata is not well understood . However, Sowing date appears to be one of the potential solutions for controlling O. crenata . In this work we investigated the effect of sowing dates on both the level of infection by O. crenata and the pod yield of faba bean using resistant (Giza 843) and susceptible (Nubaria 1) faba bean cultivars in naturally Orobanche infested soil. Moreover, the Orobanche seeds production was determined as an indication of seed bank future adding in soil. Under Orobanche free conditions, Nubaria 1 cultivar produces more pod yield than the resistant cultivar. The results demonstrated that, late sowing (3 weeks after normal sowing date) reduced significantly the number of emerged O. crenata shoots for both the resistant and the susceptible cultivars., Late sowing similarly contributed to a significant increase in pod yield (dry weight (kg)/plot) especially for Giza 843 (5.15 ± 0.02 Kg /plot), the resistant cultivar, which produced much higher pod yield than the susceptible Nubaria 1 cultivar (2.98± 0.06 Kg /plot) during the first season (2019 - 2020). During the second season (2020 - 2021), the pod yield was (3.85 ± 0.10) and (5.49± 0.76) Kg/plot for Giza 843 and Nubaria 1 cultivars, respectively, compared with the early sowing date. Furthermore, regarding both seasons,