On farm demonstration of faba bean (Vicia faba L.) varieties in orobanche infested areas of Ofla district, South Tigray, Ethiopia

Faba bean variety demonstration was conducted at Adigollo kebelle (Ofl a district, South Tigray, Ethiopia in 2016 main cropping season to demonstrate the performance of the Orobanche tolerant faba bean variety. The tested materials were improved (Hashenge) and local faba bean varieties. The demonstration was conducted in six farmers’ fi eld that has plot size of 20 m by 20 m. Farmers were selected based on their interest to share their plot of land Farmers’ perception was collected individually and in group discussion form to evaluate the yield and yield components of the varieties at maturity stage. Moreover, grain yield and orobanche count per plot was measured from each plot. Based on the biological data, Hashenge variety gave higher grain yield (3.54 t/ha) as compared with the local variety (1.14 t/ha). Accordingly, Hashenge variety has shown 201.5% grain yield advantage over the local variety. On the other hand, orobanche count per plot was taken from each farmer’s plot. In this regard, the population of orobanche weed grown in the plots of Hashenge variety was lower as compared to the local variety grown plots (27.36 and 43.52 plants per m2, respectively). This shows more resistance to orobanche weed was recorded in the improved variety (Hashenge). Based on farmers’ perception, the Hashenge variety has better yield and other yield component performance as compared to the local variety and it was appreciated by farmers for further popularization and scaling up/out. Therefore, the improved and orobanche tolerant faba bean variety should be scaled out not only to the southern zone of Tigray region but also to other orobanche infested areas (locations) of the country, like south Wollo and North Gonder of the Amhara region, Ethiopia. Research Article On farm demonstration of faba bean (Vicia faba L.) varieties in orobanche infested areas of Ofl a district, South Tigray, Ethiopia Birhanu Amare* and Tsehaye Birhane Tigray Agricultural Research Institute, Alamata Agricultural Research Center, P.O.Box 56, Tigray, Ethiopia Received: 04 August, 2020 Accepted: 26 October, 2020 Published: 27 October, 2020 *Corresponding author: Birhanu Amare, Tigray Agricultural Research Institute, Alamata Agricultural Research Center, P.O.Box 56, Tigray, Ethiopia, E-mail:


Introduction
tons per ha [1]. In rural areas, where diets are cereal based, faba bean is an extremely important source of household nutritional security as it is high in protein and is important in diversifying diets. Faba bean also helps to improve soil fertility and soil health and sustain the productivity of barley and wheat through nitrogen fi xation and when used as a rotational crop, it also helps reduce pest and weed infestations [2].
Crenate broomrape (Orobanche crenata) is occasionally known by the synonym Orobanche speciosa. This out-crossing species shows genetic diversity, but no clearly defi ned local races [3]. The parasite belongs to the class Dicotyledonae order Scrophulariales, and family Orobanchaceae. Orobanche is commonest in the Mediterranean countries, the Middle East and East Africa (Ethiopia), while other species have a wider distribution [4]. O. crenata is important in Ethiopia where it infests many legume crops, particularly faba bean, fi eld pea, chickpea, lentil and dekoko (Pisumsativum var. abyssinicum) [5][6][7]. The distribution of the weed in Tigray region is increasing at alarming speed from some localized areas to almost throughout Citation: Amare  the whole southern zone of the region [7,8]. In highly infested areas, farmers are avoiding growing food legume crops, resulting in substantial reductions to both the extent of cultivated areas and to food legume production. The parasitic weed O. crenata, though known to have been a problematic weed in parts of North Wello and neighboring areas in the Amahara region for quite some period, and has become a major pest of faba bean and fi eld pea in the highlands of the southern zone of Tigray in the last two decades . The weed reduces the ability of the host plant to absorb water from the soil under moisture stress conditions, and causes drought stress and wilting of the host resulting in heavy yield loss. The effect is more pronounced in northern Ethiopia where moisture availability is limited. The total areas infested in Tigray region have been estimated more than 5000 ha in fi ve districts. Faba bean yield losses due to this  Moreover, it is located 12 o 31' N latitude and 39 o 33' E longitude with its annual rainfall of about 833 mm [9]. The area represents highlands of South Tigray Zone with moderate rainfall (average annual rainfall of 600 mm), which extends mostly from half of Jun to late-September and the dominant soil type is clay soil and slightly acidic with a pH of 6.167 [10] Table 1.

Treatments and design
The demonstration was conducted at Adigollo kebelle of Because this district is highly infested with orobanche weed that can reach up to 100% yield loss in local faba bean varieties [10].
In this research, the improved faba bean variety (Hashenge) that was released from Alamata agricultural research center and one local faba bean variety were used. About 6 farmers were selected based on their interest to share their plot of land and their perception was collected individually and in group discussion including other additional four farmers to evaluate the yield and yield components of the varieties at maturity stage. Moreover, grain yield and orobanche count per plot was measured from each variety.

Performance of Faba bean varieties for their yield and yield components
Based on the biological data, Hashenge variety gave higher grain yield (3.54 t/ha) as compared with the local variety (1.14 t/ha). Accordingly, Hashenge variety has shown 201.5% grain yield advantage over the local variety. Even though there was yield variation among the faba bean growers of the varieties, the improved variety (Hashenge) has shown consistence grain yield performance over the local variety. This could be due to the advantage of improved management practices which include the advantage of chemical fertilizer and bio-fertilizer utilization, weeding, and more importantly, due to its tolerance to the parasitic weed (broomrape). Because different farmers had different fi eld management or land preparation practices and soil related variation was also played the variations among farmers Figure 1.
On the other hand, Hashenge variety gave higher grain yield in the variety verifi cation trials conducted prior to the demonstration trial. According to the Alamata Agricultural research center data [11], this variety has a yield potential that can yield more than 5 t/ha. Orobanche count per plot was taken from each farmer's plot of the tested area (Table 2). In this regard, the population of orobanche weed in the Hashenge variety grown plots was lower as compared to the local variety grown plots. This shows more resistance to orobanche weed was recorded in the improved variety. In the fi eld evaluations of yielding Citation: Amare  components conducted by individual and group farmers, the varieties were rated and scored points as showed below (Table   3). Hence, farmers' response indicated that Hashenge variety scored highest result for its yield and yield components at fi eld condition. In the farmers' discussion and interview, days to maturity (earliness), plant height, number of seeds per pod, number of pods per plant, tiller capacity, disease reaction and grain yield estimation were the parameters.

Perceptions of participant farmers towards Hashenge variety compared to the local
During group discussion and variety evaluation conducted in this trial, farmers were viewed the varieties in different parameters listed below.
Based on the farmers' perception, the Hashenge variety had better performance as compared to the local variety and selected for further popularization and scaling up/out. In the discussion, more farmers have highly preferred the improved variety for its higher grain yield, better tillering capacity, larger and export standard seed size as well as orobanche tolerance. In addition, as shown in the plant height score, the biomass of the improved variety was also highly appreciated by farmers of the group and it will be used as a means of minimizing the animal feed shortage.

Opportunities and challenges to faba bean production in south tigray
Opportunities: The agro-ecology in the highland areas of south Tigray (Ethiopia) is very suitable for not only for faba bean but also for highland pulses in general. In the study district, farmers were stopped faba bean production since 1985 due to the sever problem of Orobanche weed and the fi nding of Alamata Agricultural research center that released the orobanche tolerant faba bean variety (Hashenge) plays an important solution for the faba bean producers existed for the last many years. More importantly, the local and export demand for faba bean crop increases from time to time and farmers are appreciated by the local government to produce this crop in large amount. In addition, since pulse crops in general plays in soil fertility enhancement and used as break crops for disease and insect pests, they are currently demanded by seed producing cooperatives at national level and individual farmers. However, the following challenges are greatly affecting faba bean production in South Tigray: Challenges: Orobanche crenata is a species of broomrape, commonly known as bean broomrape. It is a common parasite of the faba bean (Vicia faba). It grows in the Mediterranean basin, and in North and East Africa [12]. It has no chlorophyll, and gets its carbohydrates from the host's phloem, and water and minerals from the host's xylem. In the demonstration areas, the detrimental effect of this weed in crop yield of the faba bean crop can reach up to 100% and causes total crop loss. In addition, the occurrence of other diseases of the faba bean crop such as faba bean gall, checolate spot and Ascochyta blight minimizes the tolerance of the crop to the invasive weed (Orobanche crenata) and causes higher yield reduction in the faba bean production areas of farmers. During this trial reductions in the faba bean biomass occurred in its vegetative and more importantly is in its reproductive organs. According to the farmers found in the study area, they perceived that the severity of the Orobanche weed increases when moisture shortage occurred not only in that specifi c year but also in the previous years.    Since Hashenge variety has better seed size 78.7 to 94 gram per 100 seed weight and attractive appearance, it will be appreciated to those growers who want to export their produce. Because, larger seed size (more than 80 gram per 100 seed weight) and attractive physical appearance of grain color can fulfi lled the export standard. Therefore, this variety which has large seed size and good market look increases farmers' awareness to produce Hashenge faba bean variety instead of local varieties which have smaller seed size. Moreover, the demonstration trial has showed the importance of producing improved faba bean variety (Hashenge) due to its multipurpose advantages and the tolerance of this variety to the parasitic and noxious Orobanche weed.

Conclusion and recommendations
In the demonstration time, Hashenge variety has showed higher grain yield and this variety has recorded a yield advantage of 201.5% over the local variety. The variety consistently gave higher yield and lower broomrape count than local variety across the demonstration areas conducted in different farmers' fi elds. The release of this variety further facilitates the application of integrated approach such as the use of herbicides that enhanced the tolerance or resistance level of the variety explained by higher yield and lower Orobanche population. Therefore, this variety is best option to continue the production of faba bean crop in the orobanche infested areas of South Tigray and to enhance faba bean productivity.
Hence, it is better to popularize and scaled out this orobanche tolerant variety to areas where orobanche infestation occurred.
Moreover, this variety should also be scaled out to other orobanche infested areas, such as southern Wollo and North Gonder zones of the Amhara region and needs an integrated approach with other stakeholders. Development of special seed system so as to ensure seed security and further distribution of the seed in orobanche infested areas is also an important task with maximum care not to introduce the noxious parasitic weed to non infested areas.