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Soil acidity is among the major limiting factors for common bean nodulation and productivity. Therefore, field experiments were conducted to investigate the effects of the application of phosphorus (P), lime, and compost on nodulation and dry-matter accumulation of common bean under field conditions at Areka during the long rainy season (belg) and short rainy season (meher). Three rates of compost (0, 5 and 10 t ha-1), three rates of lime (0, 0.64 and 1.28 t ha-1) and three rates of phosphorus (0, 23 and 46 kg P2O5 ha-1) were laid out as a randomized complete block design in a factorial arrangement and replicated three times. All data on nodulation and aboveground drymatter were collected. Results showed that the combined application of P at rates of 46 kg P2O5 ha-1 and lime at rates of 1.28 t ha-1 resulted in the maximum number of total and effective nodules during the long rainy season. Similarly, application of the highest rates of compost along with the highest rates of lime increased the aboveground dry biomass yield significantly over the control during both seasons. Finally, it can be concluded that the application of compost, lime and phosphorus can boost biomass accumulation and nodulation of common bean in acid soils.

Wheat is an important staple crop in arid and semi-arid areas of the Tigray region of Ethiopia. However, the yield and quality of the crop is markedly constrained by low soil fertility, inappropriate rate and timing of nitrogen application. Therefore, an experiment was conducted to elucidate the effect of different rates and timing of nitrogen fertilizer application on the yield, quality, and nitrogen use efficiency of bread wheat varieties during 2013 and 2014 main cropping seasons. The treatments consisted of four rates of nitrogen (23, 46, 69, and 92 kg N ha-1), three timing of N application (½ at sowing + ½ at tillering, ¼ at sowing + ½ at tillering + ¼ at anthesis, and 1/3rd at sowing + 1/3 rd at tillering + 1/3rd at anthesis) and two bread wheat varieties (Picaflor and Mekelle I) and 0 kg N ha-1 (control). The experiment was laid out as a randomized complete block design in a factorial arrangement with three replications. During both cropping years, increasing the rate of nitrogen application up to 69 kg N ha-1 significantly (P< 0.01) increased the total aboveground biomass and grain yields of the crop and decreased with further increase of applied N fertilizer. The highest aboveground biomass (6871 kg ha-1) and grain yields (2775 kg ha-1) of the crop were obtained in response to the application of 69 kg N ha-1, in 2013. The equivalent value for total aboveground biomass and grain yields during 2014 cropping season were (8815 kg ha-1and 3695 kg ha-1), respectively . The highest apparent recovery efficiency of 75% was obtained in response to the rate of 69 kg N ha-1applied in three splits of 1/4 at planting, ½ at tillering, and 1/4 at anthesis. The equivalent values for the highest apparent recovery was 81% in the 2014 cropping season. The highest agronomic efficiency of 25 kg kg-1 and utilization efficiency of 55 kg kg-1 were recorded at the rate of 46 kg N ha-1 in three splits of 1/4 at planting, ½ at tillering and ¼ at anthesis. The equivalent values in 2014 were 34 kg kg-1 and 78 kg kg-1, respectively. Grain protein concentration increased from 10.57% to 11.82% in 2013 and from 8.97% to 9.84% in 2014 cropping season as the rate increased from 23 kg N ha-1 to 69 kg N ha-1. The acceptable marginal rate of return (1618%) and highest net benefit (34141ETB ha-1) was obtained from 69 kg N ha-1 for the variety Picaflor. In conclusion, applying 69 kg N ha-1 in three splits of ¼ at planting, 1/2 at tillering and ¼ at anthesis resulted in optimum grain yield, protein concentration and economic return of the crop.

Potato (Solanum tuberosum L.) is a cool season crop which is susceptible to both drought and heat stresses. Lack of suitable varieties of the crop adapted to drought-prone areas of the lowland tropics deprives farmers living in such areas the opportunity to produce and use the crop as a source of food and income. As a step towards developing such varieties, the present research was conducted to evaluate different potato genotypes for osmotic stress tolerance under in vitro conditions and identify drought tolerant genotypes for future field evaluation. The experiment was carried out at the Leibniz University of Hannover, Germany, by inducing osmotic stress using sorbitol at two concentrations (0.1 and 0.2 M) in the culture medium. A total of 43 genotypes collected from different sources (27 advanced clones from CIP, nine improved varieties, and seven farmers’ cultivars) were used in a completely randomized design with four replications in two rounds. Data were collected on root and shoot growth. The results revealed that the main effects of genotype, sorbitol treatment, and their interactions significantly (P < 0.01) influenced root and shoot growthrelated traits. Under osmotic stress, all the measured root and shoot growth traits were significantly correlated. The dendrogram obtained from the unweighted pair group method with arithmetic mean allowed grouping of the genotypes into tolerant, moderately tolerant, and susceptible ones to a sorbitol concentration of 0.2 M in the culture medium. Five advanced clones (CIP304350.100, CIP304405.47, CIP392745.7, CIP388676.1, and CIP388615.22) produced shoots and rooted earlier than all other genotypes, with higher root numbers, root length, shoot and root mass under osmotic stress conditions induced by sorbitol. Some of these genotypes had been previously identified as drought-tolerant under field conditions, suggesting the capacity of the in vitro evaluation method to predict drought stress tolerant genotypes. Most of the genotypes collected from Ethiopia were found to be susceptible to osmotic stress, except one farmers’ cultivar (Dadafa) and two improved varieties (Zemen and Belete). Field evaluation of the tested materials under drought conditions would confirm the capacity of osmotic stress tolerant genotypes to perform well under drought-prone conditions and the potential interest of in vitro evaluation as a pre-screening component in potato breeding programs.

Potato is an important food and cash crop which in Ethiopia is produced two or more times in a year. However, its productivity is low owing to a number of constraints including a) limited availability of quality planting materials, and b) poor tuber sprouting due to long dormancy period of improved varieties at the time of planting. Two consecutive experiments were conducted from November 2013 to June 2014: 1) to assess the effects of gibberellic acid (GA3) and storage methods on seed tuber dormancy breakage of two potato varieties; and 2) to assess the effects of dormancy breakage treatments and storage methods on subsequent growth, yield and related traits of potato crop. The treatments in the first experiment consisted of two potato varieties (Bubu and Bate), three levels of GA3 [0, 10 and 20 parts per million (ppm)], and three storage methods [in diffused light store (DLS), in pit store (PS), and in farm-yard manure (FYM)]. The first trial was laid out as a complete randomized design with four replications and conducted at Haramaya University, Ethiopia. The second trial consisted of seed from each treatment in the first experiment, planted in randomized complete block design with three replications on a farmers’ field. The results showed that varieties, application of GA3 and storage methods as well as the interaction among the variety and treatments significantly affected tuber dormancy period, sprouting characteristics and subsequent tuber yield. When tubers were treated with 20 ppm GA3 and stored under FYM, the dormancy period was reduced from 102.5 and 52 to 36.5 and 31 days in improved and farmer’s variety, respectively. Tuber treatment with 20 ppm GA3 and stored under DLS, PS, and FYM, increased marketable tuber yield by 31.6%, 29.6%, and 33.6%, respectively for Bubu variety and by 92.5%, 78.4%, and 80.9% for Bate variety, respectively compared to non-GA3 treated tubers stored under DLS, PS, and FYM. However, tubers of improved variety Bubu treated with 20 ppm GA3 and stored under DLS produced the highest marketable tuber yield of 34.20 ton per ha. Tuber quality attributes (specific gravity, dry matter, and total starch content) were affected only due to interaction effects of variety and GA3 application with the highest values at 20 ppm GA3 for improved potato variety Bubu. In general, the research indicated that treating seed tubers with GA3 and storing under DLS, PS or FYM promoted early tuber sprouting and better tuber yield of both varieties. These results suggest that, use of GA3 treatment combined with different storage methods enhances early tuber sprouting and increases tuber yield. Nevertheless, further research should be continued to evaluate different potato varieties, GA3 treatment, and storage methods under different atmospheric conditions and production seasons.

Striga hermonthica is the most devastating parasitic weed affecting the productivity of cereal crops in Sub‐Saharan Africa. The key challenge for controlling this weed is identifying the optimal management strategies that simultaneously reduce Striga infection while boosting crop productivity. This study aimed to evaluate the potential role of intercropping, vermicompost, and seedbed types on the level of S. hermonthica infestation and sorghum productivity in 2021 and 2022 years. The treatments consisted of three factors: (i) three sowing methods (sole‐cropped sorghum (SS), intercropped sorghum with Babile‐1 (SB1), and Babile‐2 (SB2) groundnut varieties); (ii) four levels of vermicompost (0, 1.5, 3.0, and 4.5 t/ha); and (iii) two seedbed types (open‐furrow and tied‐ridge). The results indicated that pure‐stand sorghum in open‐furrow planting without fertilizer had the tallest height (60 cm), the heaviest dry weight (39 g) as well as the highest Area under Striga Number Progress Curve (ASNPC) (>1200) in the first year with substantial reduction in successive year. The combination of 4.5 t/ha vermicompost, tied‐ridge, and groundnut intercropping gave the maximum sorghum panicle weight (151 g/plant), stover yield (14.21 t/ha), and grain yield (6.01 t/ha) in the year 2022. The greatest grain yield observed at 4.5 t/ha vermicompost under tied‐ridge with SB2 was nearly three times higher than the plot without vermicompost application. This treatment combination significantly suppresses S. hermonthica infestation while improving sorghum yield attributes. Thus, it could reduce food insecurity in the lowlands of Ethiopia via improving sorghum productivity, resources use efficiency, and soil health. [ABSTRACT FROM AUTHOR]

Developing potato varieties that have enhanced tolerance to soil moisture and high‐temperature stress could improve household food and nutrition security in drought and heat prone areas. A field experiment was conducted at two locations in Ethiopia to evaluate the effectiveness of some stress tolerance indices for the identification of drought and heat tolerant potato genotypes. Treatments consisted of two irrigation regimes and 23 potato genotypes. The experiment was laid out as a split‐plot design in a factorial arrangement with three replications. Irrigation regimes were the main plot factor and genotypes were the sub‐plot factor. Stress tolerance indices were calculated based on the tuber yield under stress (Ys) and non‐stress (Yp) conditions of each genotype. To determine the most desirable stress tolerant genotypes, all indices mean rank (R) and standard deviation of the R were computed. Genotypes Cl‐12(CIP‐304371.67), Cl‐13(CIP‐304383.80), Cl‐2(CIP‐302499.30), Cl‐34(CIP‐397079.6), Cl‐15(CIP‐304394.56), and Cl‐14(CIP‐304387.39) were found to have had top mean ranks and higher tuber yield under drought and heat stress. Ranking methods using all indices best determined desirable drought, heat, and combined drought‐heat tolerant genotypes that consistently coincided with the yield rank of genotypes under a given stress condition. This implies that these indices (stress tolerance index, geometric mean productivity, mean productivity, yield stability index, and tolerance index) could be used in combination to differentiate stress tolerances and susceptible potato genotypes. It is recommended that genotypes that exhibited higher drought and/or heat stress tolerance in this study could be further evaluated in drought and heat prone areas for the development of tolerant potato varieties. Core Ideas: Different potato genotypes (International Potato Center collections, improved varieties, and local cultivar) were evaluated for drought and heat.Promising genotypes tolerant to drought, heat, or combination of both were identified.Stress tolerance indices were used to identify drought and heat tolerant and susceptible genotypes.Stability of the genotypes under different environments were tested.Stress tolerance indices mean rank standard deviation used to group genotypes to stress tolerant and susceptible. [ABSTRACT FROM AUTHOR]

Soil acidity and scarcity of faba bean varieties adapted to lower pH soils are major factors that limit faba bean production in Ethiopia. The dominant soil type in the study area is Eutric Nitisols. Therefore, greenhouse experiment was conducted in 2019 toevaluate the response of faba bean varieties to different rates of lime application. Four rates of lime (0, 2, 4, and 6 t ha-1) and five-faba bean varieties (local, Dosha, Gebelecho, Tumsa, and Bobicho) were used as treatments, which laid out as CRD with six replications. The main and interaction effects of lime rates and varieties significantly (P < 0.05) influenced all growth, yield components, and yield parameters. The root morphological parameters were significantly (P < 0.05) affected by the main effects of the lime rate. Accordingly, the most significant high aboveground biomass of 47.92 g pot-1, and seed yields of (19.16 g pot-1) were obtained in response to the interaction of Tumsa variety with 3 g pot-1lime rate (2 t ha-1). The lowest aboveground biomass of (32.08 g pot-1) and seed yield of (12.84 g pot-1) were obtained in local variety planted without lime application. Overall, in terms of seed yield, Gebelcho and Tumsa varieties performed best by attaining their maximum seed yields in response to the application of 3 g lime pot-1 (2 t ha-1). Thus, 3 g pot-1 (2.0 t ha-1) liming rate with the Gebelcho and Tumsa varieties was found to be the best-combined treatment to improve the yield of the crop in the study area. [ABSTRACT FROM AUTHOR]

Soil fertility problem is a major constraint to faba bean production in Wolaita Zone in Ethiopia. Hence, a field experiment was conducted in Kokate Marachare sub-district during 2019 and 2020 cropping seasons to determine the optimum N, P, and K fertilizers for enhanced uptake and use efficiency of faba bean. Three rates of N (0, 23, and 46 kg N ha-1), P (0, 46, and 92 kg P2O5 ha-1), and K fertilizer (0, 30, and 60 kg K2O ha-1) were tested using RCBD with three replications. Data on agronomic efficiency (AE), agrophysiological efficiency (APE), apparent recovery efficiency (ARE), and utilization efficiency of N, P, and K nutrients were analyzed. The results revealed N, P, and K uptake efficiency (UE) indices of faba bean were significantly influenced by the main effects of the rate of nitrogen, phosphorus, and potassium fertilizers. Thus, applying 23 kg N ha-1, 46 kg P2O5 ha-1, and 30 kg K2O ha-1 resulted higher N, P, and K AE, respectively (33.70 kg kg-1, 13.43 kg kg-1, and 27.32 kg kg-1); PE (76.87 kg kg-1, 104.51 kg kg-1, and 118.83 kg kg-1); APE (40.49 kg kg-1, 104.51 kg kg-1, and 68.07 kg kg-1); ARE (84.48%, 2.00%, and 40.30%); and UE (63.47 kg kg-1, 2.52 kg kg-1, and 56.08 kg kg-1). Therefore, 23 kg N ha-1, 46 kg P2O 5ha-1, and 30 kg K2O ha-1 are recommended for the higher N, P, and K uptake and use efficiency of faba bean. [ABSTRACT FROM AUTHOR]

Background: Soil morphological, physical, and chemical characteristics are vital for determining suitable land use and increasing crop productivity under certain environmental conditions. Thus, this study was carried out to characterize and classify the soils of the Sentele Watershed in southern Ethiopia. Materials and Methods: The preliminary boundary of the Watershed and soil mapping units (SMU) was defined using a topographic map (1:50,000). Four soil pedons were dug, and soil samples were collected from the pedons and taken to the laboratory for testing soil physical and chemical parameters. The soil pedons were described using FAO soil description guideline. Results: The soils in the Watershed range from intermediately deep to deep (70 to >200 cm), with varying colors (dark brown to reddish-brown); varying structures (sub-angular to blocky); moderate to well-drained; and the texture varying from loam, clay loam, and clay. The pH of the soil ranges from 5.6 to 6.4, from moderately acidic to slightly acidic. The soil OC contents vary from medium to very high (1.12-4.9%), medium to high TN contents (0.135-0.484%), and very low to medium contents of AP (8.9-30.1) mg kg-1 soil. The soils have moderate to high CEC (23.8-34.2 cmol (+) kg soil-1). Ca and Mg are the dominant exchangeable cations, followed by K and Na. The soils belong to Rhodic Luvisols, Silandic Andosols, Rhodic Nitisols, and Vertic Luvisols. Conclusion: The four pedons of the various land mapping units have varied soil morphological, physical, and chemical characteristics. Crop yield is limited by moderate to slight acidity, available phosphorus, and boron. The soils were categorized into one of four classification groups: Chromic Luvisols, Silandic Andosols, Rhodic Nitisols, and Vertic Luvisols. The results show that soils must be used for sustainable agricultural production based on their classification and the potential and limitations they have. [ABSTRACT FROM AUTHOR]

Background: Maize is an important food security crop cultivated in Ethiopia. However, the productivity of the crop is markedly low due to low soil fertility and associated with low soil nutrient availability especially nitrogen and phosphorous deficiencies and the use of inappropriate fertilizer management practices. Objective: A study was conducted in Haramaya District to investigate the effects of mineral nitrogen fertilizer application rates on yield components and yields of maize varieties during the 2019 and 2020 main cropping seasons. Materials and Methods: The treatments consisted of two improved maize varieties (BHQPY 545 and MHQ 138), one composite open-pollinated variety (Raare-1), and six rates of nitrogen fertilizer (0, 23, 46, 69, 92, and 115 kg N ha-1). The experiments were laid out as a randomized complete block design in a factorial arrangement and replicated three times per treatment. Data were collected on thousand kernel weight, stover yield, grain yield, and agronomic nitrogen efficiency. The data were subjected to analysis of variance. Results: The main effect of nitrogen application significantly (p ≤ 0.05) affected thousand kernel weight and harvest index. The highest thousand kernel weight (346.6 g) and harvest index (44.8%) were obtained in response to the application of 92 kg N ha-1. The interaction effect of maize variety and nitrogen rate significantly (p ≤ 0.05) influenced stover yield, grain yield, and agronomic nitrogen efficiency. The highest stover yield (9.62 t ha-1) and grain yield (9.13 t ha-1) were recorded for variety BHQPY 545 at 92 kg N ha-1, which resulted in 55.6% and 67% more grain yield than MHQ 138 and Raare-1 varieties, respectively. The MHQ 138 and Raare-1 varieties produced only 5.9 t ha-1 and 5.5 t ha-1 grain yield at 92 kg N ha-1, respectively. The highest net benefit (138222 Ethiopian Birr ha-1) at 115 kg N ha-1 and marginal rate of return of 301% were obtained from variety BHQPY 545 at 69 kg N ha-1. Conclusion: It is concluded that the BHQPY 545 variety produced the optimal grain and stover yields, with the highest net benefit and marginal rate of return at 69 kg ha-1 as well as with the highest agronomic nitrogen efficiency that exceeded the agronomic nitrogen efficiency of MHQ 138 and Raare-1 by about 2.4-fold and three-fold, respectively. This implies that cultivating this variety at a relatively moderate rate of nitrogen fertilizers enhances the yield of the crop for improving food security and farmers' livelihood in the study area. [ABSTRACT FROM AUTHOR]