Search

Farmers are accessing seeds from different sources with different quality standards. Studies on the assessment of seed systems (sources) in relation to seed quality are scarce. This study was carried out to assess the different seed qualities (physical purity, physiological quality, and seed health) of bread wheat seed accessed through the existing seed sources (formal and informal seed sources) in Baso Liben district of the Amhara region, northwest Ethiopia. In addition, this study assessed the experience of farmers in seed production and management. Data were collected from 108 respondents using a semi-structured questionnaire and from farmers and local experts using focus group discussions. Seed samples were collected from 58 farmers (30 farmers who sourced seed from the informal system and 28 from the formal system) for laboratory testing. Data were analyzed using descriptive statistics and t-test (pairwise comparison) using SPSS v23.0. Results showed that about 32.4% of the respondents have experience in quality bread wheat seed production under contractual seed production arrangements with public seed enterprises. Results also revealed significant differences between formal and informal seed sources for various seed quality parameters. Seeds accessed from the formal sources have better physical purity, physiological quality, and 1,000 seed weight than seeds accessed from informal sources. Seed samples collected from the informal source were highly infected with Aspergillus flavus, Aspergillus niger, Chaetomium spp., and Fusarium spp., and seeds from the formal seed source were infected with Alternata spp. and Penicillium spp. Seed quality is a major concern for the seeds accessed from both formal and informal sources. Therefore, the seed quality control mechanisms of various stakeholders, including national and regional seed regulatory bodies, government organizations, research institutes, and seed producers/companies, should be given much attention at each stage of the seed value chain.

The lack of sustainable soil fertility management is a critical challenge for crop production in the world. The problem is more serious in the East Gojjam Zone highlands. Integrated use of lime, manure, and chemical fertilizers is considered as a good approach for sustainable crop production on acidic soils. In 2016 and 2017, a field experiment was conducted to determine the effect of soil amendments on soil fertility and tef productivity in the Gozamin district. Factorial combinations of two rates of lime (0 and 2 t ha−1), two rates of NP fertilizers (0/0 and 46/20 kg N/P ha−1), and three rates of cattle manure (0, 10, and 15 t ha−1) were laid out in randomized complete block design with three replications. The results showed that applying lime in combination with NP fertilizer and manure significantly improved soil chemical properties. Panicle length, effective tillers, and thousand seeds weight of tef increased from 25.1 to 44.4 cm, 2.8 to 11.3, and 0.23 to 0.37 g, respectively, when 10 t ha−1 manure and recommended NP fertilizer were applied together. The highest tef grain yield of 2.31 t ha−1 and net benefit of 2,252.91 USD ha−1 were obtained from the interaction of 10 t ha−1 cattle manure, 46/20 kg ha−1 N/P fertilizer, and 2 t ha−1 lime. This study recommends the combined application of 2 t ha−1 lime, 10 t ha−1 cattle manure, and 46/20 kg ha−1 N/P fertilizer as an effective amendment to improve soil chemical properties and yield of tef in acidic soils of northwest Ethiopian highlands.

Thin-section observations and electron probe analyses, and trace element data are reported from a new mantle xenolith hosted in Miocene alkali basalt from the western flank of Simien shield volcano, Ethiopia. The spinel lherzolite enclaves contain variable proportions of olivine, orthopyroxene, green clinopyroxene and brown spinel, and have undergone deformation and partial recrystallization. They represent unmetasomatized, fertile xenoliths which were subjected to a late-stage melt-rock reaction. Trace element contents of clinopyroxene crystals are extremely low and quite different from those of the other xenoliths within the East African Rift System. Keywords: lithospheric mantle, Simien, spinel lherzolites, xenolith.