Integrated weed (Orobanche crenata) management on faba bean

Abstract

In Ethiopia pulse crops are widely grown and Faba bean (Vicia faba L., 2n=12) is an old world grain legume of the family Leguminasae. This crop is one of the major pulses grown in the highlands of Ethiopia ranging from 1800-3000 m.a.s.l receiving an annual rainfall of 700-1100 mm, and the country is now considered as one of the secondary centers of genetic diversity. In eastern Amhara region high lands, faba bean is cultivated widely and thought to be an area for the largest collection of faba bean landraces. The production of faba bean is declined from year to year due to various production constraints such as diseases, soil acidity and weeds, particularly root parasitic weeds Broomrape (Orobanche species). These parasitic weeds cause very high levels of crop damage in terms of both yield and quality. Yield losses due to Orobanche weed ranges from 5 to 100% depending on the level of infestation and environmental conditions. Orobanche species are root parasitic flowering plants lack of leaves and totally dependent on their hosts for their life cycle. The parasitic is on a wide range of food legumes such as faba bean, field pea, lentil, vetch, Solanaceae crops, oil crops and root crops. The severe invasion of legume crops, especially faba bean and field pea are by Orobanche crenata. The physical attachment and the damage of the weed are under ground. The weed disperses by wind, flood, birds, animals, crop seeds, humans and farm machinery. It is propagated by seeds which can remain dormant and survive and able to viable in the soil for more than 20 years. Due to the complete devastation of faba bean by Orobanche crenata, farmers forced to replace pulse crops by cereals and spice in south Wollo (Kutaber, Dessie zuria, Tenta and Mekidela woredas); therefore, farmers lost the benefits obtain from pulse crops. The experiment was conducted using completely randomized block design in three replications with the objective of selecting the best integrated Orobanche weed control management at Kutaber woreda 010 kebele (Flago-ber) using Orobanche weed tolerant faba bean(Ashenge), local variety, 0.3 l ha-1 glyphosate chemical and hand weeding for two years (2014-15) on two farmers’ fields on a plot size of 4 m * 5 m (4 m width by 5 m length). The analysis of variance revealed highly significant different between treatments. Ashenge variety gave the maximum and minimum grain yields 3200 and 2868.8 kg ha-1, respectively, using two times sprayed of 0.3 liters ha-1 Glyphosate chemical in 250-300 liters ha-1 water, the local variety obtained maximum and minimum yields 568.8 and 150 kg ha-1 with two and without sprayed, respectively. Hand weeding of Orobanche weed before seed setting was applied and has an additional advantage that could reduce Orobanche weed seed bank. Using this integrated management plus awareness and supporting of farmers by DA’s and researchers, Ashengie faba bean can be cultivated on Orobanche weed infestation area and can give 28-32 qt ha-1.