Melkassa Agricultural Research Center Research Articles

Genetic Variability and Association of Yield and Yield-Related Traits under Moisture Stress in Common Bean Genotypes (Phaseolus vulgaris L.) at Melkassa and Miesso, Ethiopia

Twenty-five common bean genotypes were evaluated to assess the genetic variability, trait association, and determine the direct and indirect effects of traits on seed yield. The genotypes were grown in a lattice design at the research farm of the Melkassa Agricultural Research Center, Melkassa and Miesso, in the 2018 cropping season. Analysis of variance revealed that significant differences were observed among the genotypes at individual locations. The phenotypic coefficient of variation values were moderate for number of nodes, seeds per pod, plant height, and hundred seed weight at Melkassa. Moderate genotypic coefficient of variation values were obtained for pods per plant and seeds per pod. At Miesso, moderate phenotypic coefficients of variation values were recorded for number of nodes, hundred seed weight, and plant height. High heritability estimates were obtained for seed yield and hundred seed weight at Melkassa and for seed yield at Miesso, indicating that selection could be fairly easy and improvement is possible using these traits in a common bean breeding program. High genetic advances were obtained for seed yield and pods per plant at Melkassa, while moderate genetic advances as a percent of the mean were attained for plant height, hundred seed weight, and seeds per pod. Similarly, at Miesso, high and moderate genetic advances as percent of mean values were obtained for seed yield and hundred seed weight, respectively. Seed yield showed positive and significant phenotypic association with days to flowering, internode length, and pods per plant at Melkassa and had positive and significant phenotypic association with seeds per pod and hundred seed weight at Miesso. Hence, selection of those genotypes based on the traits with high genotypic coefficient of variability, heritability, genetic advance, and positive correlation coefficient and direct effect on seed yield can be recommended for further yield improvement at the respective location and at the national level in general.

Evapotranspiration and Crop Coefficient of Sorghum (Sorghum bicolor L.) at Melkassa Farmland, Semi-Arid Area of Ethiopia

Sorghum has an enormous role in the economy of sorghum-growing nations. Supplying a precise amount of water to a crop based on crop needs is the main agenda in implementing water-saving agriculture. Non-weighing type lysimeters were used to determine actual crop evapotranspiration and crop coefficient of sorghum at the experimental farm of Melkassa Agricultural Research Center situated in the semi-arid area of Ethiopia. Soil-water balance approaches were applied to obtain actual crop evapotranspiration, while the Penman-Monteith technique was used to determine reference evapotranspiration. Growth stages-wise crop coefficient was computed as a ratio of actual crop evapotranspiration to reference evapotranspiration. The total seasonal sorghum actual crop evapotranspiration during the 2017 and 2018 experimental years was 358.6 and 377.54 mm, respectively. The 2 years average sorghum actual crop evapotranspiration was 368.07 mm. The mean locally developed actual crop coefficient values of 0.55, 1.15, and 0.59 were observed for the initial, mid, and end-season, respectively. The FAO-adjusted crop coefficient values for mid and end-season were 1.01 and 0.52, respectively. The developed Kc values considerably differed from the FAO-adjusted Kc values. So, the determination of actual crop evapotranspiration and crop coefficient for crop growth at local climate conditions is vital for decision-making concerning water management in the area where irrigation is practiced.

Effect of Soil Moisture Stress on Onion (Allium cepa L) Production and Water Productivity at Melkassa in the Central Rift Valley of Ethiopia

Water availability is becoming a critical issue in Ethiopia in arid and semi-arid areas mainly in Rift Valley. Field experiment was carried out at Melkassa Agricultural Research Center, Ethiopia during growing season 2017/8 under furrow irrigation system and eight irrigation treatments replicated three times in a randomized complete block design. Hence, the objective of this study was to establish critical moisture stress threshold level for improving production and water productivity of irrigated onion under limited water resource condition. In the study, irrigation treatments consisted full supply of irrigation 100% ET C (control) and seven stress levels were imposed on onion nafis variety through growth stages. Obtained results revealed that, the highest seasonal water requirement value of 422.1 mm was by the 100% ET C while, the lowest value of 198.8 mm was by 40% ET C . Analysis of the data obtained showed significant (p<0.05) effects of soil moisture stress treatments on onion growth parameters. Analysis of the data obtained showed significant (p<0.05) effects of soil moisture stress treatments on onion bulb yield and yield components. The study revealed, yield response factor (Ky) for the onion was showed there is yield reduction as crop stressed. Highest Marginal rate of return was obtained from 70% ETc of 24914.3% and decrease to 90% ETc of 2155.4%.The study has concluded that moisture stress through growth stage significantly influenced onion bulb yield. Therefore, the critical stress level of the onion from this study could be irrigated at 75% ET C to increase WP without a significant yield reduction and economically visible. The study suggests that moisture stress strategy should be adopted for optimum yield and maximum water productivity without a significant yield reduction. Keywords: Deficit irrigation, furrow Irrigation, Moisture stress, Onion, Water productivity DOI: 10.7176/JNSR/13-3-02 Publication date: February 28 th 2022

Performance and Genetic Variability of Okra (Abelmoschus esculentus (L.) Moench) Genotypes in Ethiopia for Agromorphology and Biochemical Traits

No research has been done to assess the genetic diversity of Okra (Abelmoschus esculentus) genotypes in Ethiopia based on the combination of agromorphology and biochemical traits of the crop. Such an assessment would assist in the development of high fruit yield and nutritionally good cultivars. Therefore, 36 okra genotypes were evaluated for 29 agromorphological and biochemical traits at the Melkassa Agricultural Research Center (Ethiopia) during the 2018 main rainy season, using a 6 × 6 simple lattice design. Analysis of variance showed significant differences among genotypes for all the studied traits, except number of flower epicalyxes and fruit diameter. Genotypic coefficients of variation and phenotypic coefficient of variation were high for number of branches, internode length, fresh fruit weight, number of mature pods, fruit yield per plant, fruit yield per hectare, seed yield per plant, seed yield per hectare, and seed protein content. Heritability values ranged between 33.63 and 99.81%, while the genetic advance as percentage of mean ranged between 4.29 and 95.45%. High broad sense heritability was coupled with high GAM for plant height, branch, internod length, fruit length, panicle length, fresh fruit weight, number of fruits per plant, number of mature pods, seed yield per plant, seed yield per hectare, and fibre and protein content. In conclusion, this study showed the presence of genetic variation among genotypes for fruit yield, seed yield, and nutritional content, indicating the potential success of developing okra varieties for high fruit yielding and good nutritional content.

Sorghum breeding in Ethiopia: Progress, achievements and challenges

Sorghum is a critical crop especially in semiarid areas where there is inadequate moisture.it is the fifth important crop among the cereals. Sorghum is a C4 plant which is originated and diversified in Ethiopia. It is used for feed, fuel, and consumed by human beings in the form of enjera, boiled porridge or gruel, malted beverages, beer, popped grain, and chips. In Ethiopia, biotic, socioeconomic, and abiotic restrictions limit sorghum production and productivity. Drought, Striga, disease, insect pests and etc are major problems Sorghum breeding program Melkassa Agricultural Research Center, which is part of the Ethiopian Agricultural Research Institute, is in charge of coordination in Ethiopia. National and regional sorghum improvement programs have released many open-pollinated and hybrid sorghum varieties for Ethiopia’s various agro-ecological zones. Nowadays to feed the world population the production and productivity of sorghum should be increased. As a result, the aim of this review is to evaluate the progress, successes, and challenges of sorghum production and productivity in Ethiopia.

Effect of Plant Densities and Nitrogen Rates on Yield and Yield Components of Sorghum Varieties (Sorghum bicolor. L Moench) in Central Rift Valley of Ethiopia

Plant density (PD) and nitrogen (N) fertilizer are considered the most important crop management practices in improving sorghum grain yield. In line with this a field experiments was conducted at Melkassa Agricultural Research Center (MARC) and Mieso research sites in the central Rift Valley (CRV) areas of Ethiopia during the main rainy season of 2016 to study the effects of PD and N fertilizer rates on growth, yield and yield components of sorghum. The experiment was laid out in a randomized complete block design in factorial arrangement with three replications. Two Sorghum Varieties, a hybrid (ESH-1) and an open pollinated variety (Teshale) were used with three plant densities (66,666, 88,888 and 133,333 plantsha-1) and four N rates (0, 23, 46 and 69 kg ha-1). Biomass, head weight and grain yield (t/ha) were significantly affected by main factor effects. Moreover, interaction effect of location by variety affected almost all yield related parameters except thousand seed weight. Interaction between variety and density significantly affected biomass, head weight and grain yield with the highest results for ESH-1 at the highest density. Better grain yield, with a profitable marginal rate of return was achieved for the hybrid ESH-1 variety with application of 23 Kg N ha-1 and the highest plant density (133,333) at MARC while it was obtained with application of 69 Kg N ha-1 at the lowest density (66,667) for the same variety at Mieso.

Response of Plant Densities and Nitrogen Rates on Sorghum (Sorghum bicolor. L Moench) Growth and Nutrient use Efficiency in the Central Rift Valley of Ethiopia

Plant density (PD) and nitrogen (N) fertilizer are considered the most important crop management practices in improving sorghum grain yield. In line with this a field experiments was conducted at Melkassa Agricultural Research Center (MARC) and Mieso research sites in the central Rift Valley (CRV) areas of Ethiopia during the main rainy season of 2016 to study the effects of PD and N fertilizer rates on growth and nutrient use efficiency and uptake. The experiment was laid out in a randomized complete block design in factorial arrangement with three replications. Two Sorghum Varieties, a hybrid (ESH-1) and an open pollinated variety (Teshale) were used with three plant densities (66,666, 88,888 and 133,333 plantsha-1) and four N rates (0, 23, 46 and 69 kg ha-1). Growth parameters (LAI, crop growth rate and net assimilation rate) were significantly affected by all main factors and their interaction effects. Nutrient concentration and uptake were variable across main effects; it increased with nitrogen rate while decreased with plant density and was higher for Mieso than MARC as well as for ESH-1 than Teshale.

Assessment of drought tolerance in six maize hybrids (Zea mays L.) using biochemical indices

Maize (Zea mays L.) variety has diverse genetic characters; hence this study was led to assess drought tolerance of maize variety subjected to well water and water stress environments. Drought is one of major factor that results thoughtful influence plant development as well as productivity. The outcome becomes severe where rain fed agriculture is practiced. Evaluation of variety that can better tolerate such condition can help for selection and are important in reducing associated crop loss. The study was performed in greenhouse using CRD with three replications. Six maize varieties MH-140, Melkassa-2 (MH-2), Melkassa-3 (MH-3), Melkassa-4 (MH-4), Melkassa-6Q and MHQ138 developed by Melkassa Agricultural Research Center (MARC) were used and grown in normal and water scarce condition. The collected data were leaf proline, chlorophyll content, soluble sugar content, relative water content, leaf nitrogen content, protein content specific leaf area, specific leaf weight. Data were analyzed by ANOVA using SAS 9.4 software. Mean comparisons were implemented using LSD test at P < 0.01. The study outcomes revealed that high SLA and SLW value was recorded for, Melkassa-4 (MH-4) whereas, MHQ138 is recorded lower value. Leaf proline, chlorophyll content, soluble sugar content, relative water content, leaf nitrogen (N) content and protein content, value had revealed Melkassa-4 the most drought tolerant variety whereas MHQ138 is the least drought tolerant variety among the maize varieties used in this research study.

Effect of Drip Lateral Spacing and Water Levels on Yield and Water Use Efficiency of Onion ( allium cepa l. ) Under Awash Melkassa Climatic Condition

Water being scarce resources, irrigation water is the most limiting factor for vegetable production in the central rift valley of Ethiopia. Drip irrigation technique together with deficit irrigation application improves crop yield and water use efficiency. Hence, the objective of this study was to enhance onion production and WUE through the application of drip irrigation technology and deficit irrigation application. Field experiment was conducted at Melkassa agricultural research center during the cool cropping season of 2019/2020 to investigate the effects of drip lateral spacing and irrigation levels on onion yield, water use efficiency and net return. Two levels of drip lateral spacing viz., lateral placed in every row and between two rows, and three levels of deficit irrigation viz., 80% ETc, 70% ETc and 55% ETc, and one-full irrigation (100% ETc). The treatments were arranged in split plot with three replications. Data were analyzed using statistical package appropriate to split plot with the help of SAS software. The result showed that onion yield, yield parameters and water use efficiency was affected by the effects of drip lateral spacing and irrigation water levels but not affected by their interaction effect. Onion bulb yield decreased with increased levels of water deficit. In contrast, both water use efficiency and irrigation water use efficiency increased with increase in water deficit level. Maximum onion bulb yield of 41.43 t ha-1 were obtained from lateral spacing in every row and full irrigation application level of 100% ETc and has no a significant difference with every row lateral spacing, and 85% and 70% ETc irrigation application levels. The highest water use efficiency of 13.33 Kgm-3 was recorded from every row drip lateral spacing and irrigation application of 70% ETc. Therefore, onion could be irrigated every row drip lateral spacing with 70% ETc application to increase water use efficiency without a significant total bulb yield reduction.

Yield and Quality Response of Snap Bean (Phaseolus vulgaris L.) to P and S Fertilizers Application under Different Irrigation Regimes in Central Rift Valley of Ethiopia

Snap bean (Phaseolus vulgaris L.) is a leading exportable vegetable crop and it is a protein source for consumers in many parts of Ethiopia. However, its’ current national productivity of 4.12 t ha -1 is lower than its’ potential as a result of inadequate moisture and poor soil fertility. Therefore, the field experiment was conducted at Melkassa Agricultural Research Center during the dry season in 2017 and 2018 to evaluate the response of snap bean to phosphorus and sulfur fertilizers application under different irrigation regimes on yield and quality. The experiment was laid out in split-plot design with three replications. Four drip irrigation regimes (100, 85, 70 and 55% ETc) were assigned to main-plots. Four fertilizer types (0, 21 kg P ha -1 , 30 kg S ha -1 and 21 kg P ha -1 +30 kg S ha -1 ) were allocated to sub-plots. The analysis of variance revealed that the interaction effect of irrigation regimes and fertilizers application had a significant (P ≤ 0.05) effect on first grade and total pod yield. The main effect of various irrigation regimes had a significant (P ≤ 0.05) effect for all yield and quality parameters except, second grade pod yield and pod diameter. On the other hand, application of different fertilizers types had non-significant effect in all parameters. The highest marketable yield was recorded from the interaction effect of 100% ETc with different fertilizers types’ application. The partial budget analysis indicated that the best treatments were 85 and 100% ETc without fertilizers application, which gave higher net benefits of 111,879.2 and 160,242.6 ETB ha -1 , respectively with an acceptable marginal rate of returns for snap bean production. Therefore, snap bean producers could consider 85% ETc without fertilizers application where scarcity of irrigation water is limiting and 100% ETc without fertilizers application where there are no water shortages, in the central rift valley of Ethiopia with similar soil properties. Keywords: fertilizers, irrigation, plati, yield DOI: 10.7176/JNSR/12-15-03 Publication date: August 31 st 2021

Response of Maize (Zea Mays L.) To Soil Moisture Stress Condition at Different Growth Stages, Central Rift Valley of Ethiopia

Water resources availability is a crucial limiting factor for crop production in arid and semi-arid area. Consuming these limited resources carefully and efficiently is unquestionable. The planning of irrigation permitting to the water stress tolerance and water use efficiency of crops remains the only way to guarantee the continuity of production in an arid area. Considering this an experiment has been conducted in Melkassa Agricultural Research Center where shortage of moisture is a problem. The experiment was laid out in RCBD with three replications having 15 experimental treatments. The treatments had four crop growing seasons or stages (Initial, Development, midseason and late season stages. Melkassa II maize variety was used for seed materials. Water stress had significant different effect on grain yield, above ground dry biomass, plant height and water productivity (P 0.05) difference in grain yield among treatments stressed only at initial stage, late stage and non-stressed. However, stressing of maize at development and mid-season crop growth stage led to significant reduction of grain yield, above ground dry biomass and plant height. Therefore, stressing maize at combination of development stages and mid stages was more sensitive with significant yield penalty.

Maize Yield and Water Use Efficiency Under Different Irrigation Levels and Furrow Irrigation Methods in Semiarid, Tropical Region

Water scarcity is the major limiting factor of agricultural production and productivity in the central rift valley of Ethiopia. Best use of limited water is necessary through water conservation practices. Field experiments were conducted during the dry cropping seasons of 2016 and 2017 on clay loam soil at experimental farm of Melkassa Agricultural Research Centre to evaluate the impact of irrigated furrow methods and deficit irrigation applications on maize (Zea mays) yield and water use efficiency. The study involved three furrow irrigation methods (conventional, fixed, and alternate furrow irrigation) and three irrigation application levels (100%ETc, 75%ETc, and 50%ETc). Furrow irrigation system as main plot and irrigation levels as sub-plot were arranged in split plot design with three randomized complete blocks each year. Greatest yield was obtained under conventional furrow irrigation supplied with 100%ETc of water. Water use efficiency under the same treatment was lesser and shows no significant difference with fixed furrow irrigation and 50%ETc application. Greatest water use efficiency of maize was obtained from alternate furrow irrigation under 75%ETc application and showed no significant difference with 100%ETc application. However, grain yield reduction under 75%ETc applications was very much higher than 100%ETc application. Water saved as a result of 100ETc and 75%ETc applications were 50% and 62.5%, respectively. Therefore, scheduling irrigation time for maize in the central rift valley of Ethiopia and similar semiarid environments could be 100%ETc or 75%ETc application using alternate furrow irrigation. The 75%ETc application has an advantage over 100%ETc applications in saving more water and hence could be applied when water availability is severely limited.

Correlation and path coefficient analysis among agro-morphological and biochemical traits of okra [Abelmoschus esculentus (L.) Moench] genotypes in Ethiopia

Thirty six okra genotypes were evaluated for different agro-morphological and biochemical traits at Melkassa Agricultural Research Center, Ethiopia during 2018 main season using 6 x 6 simple lattice design. The objectives were to assess the correlation of agro-morphological and biochemical traits with fruit yield and to partition the correlation in to direct and indirect effects through path analysis. The genotypic correlation was positive and significant for fruit yield per hectare with stem diameter, plant height, leaf length, leaf width, peduncle length, fruit length, fresh fruit mass, hundred seed mass, seed yield per hectare and ash content. The phenotypic correlation was positive and significant for fruit yield per hectare with stem diameter, plant height, number of branches, leaf length, leaf width, peduncle length, fruit length, fresh fruit mass, number of fruits per plant, hundred seed mass, seed yield per hectare, ash, fat and protein content. Path coefficient analysis indicated fresh fruit mass and seed yield per hectare had positive direct effects on fruit yield per hectare at phenotypic and genotypic levels. These traits also exerted high to low positive indirect effects through other traits on fruit yield at genotypic and phenotypic level. In conclusion, this study showed the presence of association of traits with fruit yield indicating that the prime importance of these traits while selecting higher yield okra genotypes.

English

Currently under production, thirty-eight Ethiopian maize varieties released majorly for three agro-climatic zones over the past thirty-nine, twenty-nine and twelve years for the high altitudes, mid–altitudes and low altitudes, respectively, were conducted at three different research center’s field trials, using randomized complete block design with three replications in 2015 main cropping season to estimate the genetic gains made on yield and yield related traits. The regression analysis indicated average annual and annual relative genetic gains of 62.3 (0.19%), 59.0 (0.57%) and –2.64 (–0.16%) in kg ha–1 yr–1 for grain yields, respectively, at Ambo Plant Protection Research Center (APPRC), Bako National Maize Research Center (BNMRC) and Melkassa Agricultural Research Center (MARC). Correlational analysis on the field studied traits indicated positively significant associations of grain yields with grain filling rate, ear length, number of kernels per row, number of ears per plant, biomass production rate, biomass yield and harvest index; also, negatively significant associations were shown for days to anthesis and days to silking at APPRC. Grain yield showed positively significant associations with ear length, plant height, grain filling rate, thousand kernel weight, biomass production rate and harvest index at BNMRC, while those only with harvest index were shown at MARC. Relatively considerable genetic gains and inconsiderable genetic reductions due to grain yields, grain yield related traits and grain yields associations with the other studied maize breeding traits had been observed across the released maize varieties from the three agro–ecological zones of Ethiopia. Key words: Annual genetic gains, annual relative genetic gains, correlational analysis, highland maize, lowland maize, mid–altitude maize, regression analysis.

Genetic Variability in Tomato (Lycopersicon esculentum MILL) Genotypes in the Central Rift Valley, Ethiopia

Investigation of variability existing in crop cultivars is important to crop improvement. The study was conducted at Melkassa Agricultural Research Center (MARC) to assess the genetic variability among 36 tomato genotypes using 6*6 simple lattice designs. There were significant differences among genotypes all traits. High phenotypic and genotypic variances were recorded for number of fruits per plant, average fruit weight, fruit shape index and juice volume indicating the existence of substantial variability. High heritability along with high genetic advance as percent of the mean was exhibited by characters viz. plant height, number of fruits per plant, average fruit weight, fruit shape index and juice volume, reflecting the presence of additive gene action for the expression of these traits and selection based on them would be ideal. Generally, the present study implied the presence of genetic variability among the test genotypes with respect to the traits considered indicating an opportunity to bring about fruit yield improvements in snap bean either through direct selection or hybridization.

English

The current investigation was aimed to study the genetic association of seed yield and its components in 81 mid-altitude sesame accessions based on morphological traits. The genotypes were evaluated in 9 × 9 simple lattice design at Melkassa Agricultural Research Center, Ethiopia, during the 2014 cropping season. The study mainly focused on determining the nature and extent of phenotypic and genotypic correlation and path coefficient analysis among 13 quantitative traits. Analysis of variance revealed significant difference among genotypes for all traits studied. Mean performance of genotypes revealed that the highest mean seed yield/plant (8.6 g) recorded for Oromia-22 and the lowest mean seed yield/plant (2.6g) for Oromia-9; with overall mean of 5.33 g/plant. Whereas, the highest mean oil content (52.15%) noted for Oromia-13 and the lowest (43.35%) mean oil content was recorded for Am-SW-7 genotypes, with overall mean of 47.1%. Characters viz., number of capsules, biomass yield, harvest index and 1000 seed weight showed highly significant and high positive correlation with seed yield. Plant height and number of seeds/capsule also showed highly significant but moderately positive significant association with seed yield; indicating that these traits are reliable yield components and seed yield can be improved through direct selection of these traits. Maximum positive direct effect on seed yield was exerted by number of capsules, biomass yield, days to maturity and harvest index; showing that these traits can be used for selection to improve the primary trait. Hence, the use of these traits in sesame improvement program would increase seed yield. Key words: Correlation coefficient, mid-altitude, quantitative traits, path coefficient analysis.

Correlation and Path Coefficient Analysis in Mid-Altitude Sesame (Sesamum indicum L.) Germplasm Collection of Ethiopia

The present study was aimed to gather information on genetic association of traits with respect to seed yield and its components. The genotypes were planted in 9 × 9 simple lattice designs at Melkassa Agricultural Research Center, Ethiopia, during the 2014 cropping season to determine the nature and extent of phenotypic and genotypic correlation and path coefficient analysis among 13 quantitative traits. Analysis of variance revealed significant difference among genotypes for all traits studied. Mean performance of genotypes revealed that the highest mean seed yield/plant (8.6g) recorded for Oromia-22 and the lowest mean seed yield/plant (2.6g) for Oromia-9; with overall mean of 5.33g/plant.

Screening for Resistance Sources in Local and Exotic Hot Pepper Genotypes to Fusarium Wilt (Fusarium oxysporium) and Associated Quality Traits in Ethiopia

Fifty-four hot pepper germplasm (49 local accessions and 5 AVRDC genotypes) were evaluated for resistance to fusarium wilt in a greenhouse at Melkassa Agricultural Research Centre in Ethiopia. A completely randomized design with three replications was used. Each local accession was also analyzed for associated quality traits of capsaicin and oleoresin content. The overall results indicated that disease incidence ranged from 8 (PBC-731) to 100% for Acc-15. Most local collections exhibited higher disease incidences percent than AVRDC genotypes with an overall mean DI <25% of Fusarium wilt. Among the 49 local accessions, however, only two accessions were found resistant (1-10%) while three were moderately resistant (11-20%). Assessment of the same accessions for resistance to the disease using severity index (SI) showed that 11 accessions and genotypes were found resistant (<10% DSI) whereas nine genotypes moderately resistant (10-20% SI), 10 genotypes were moderately susceptible (21-40% SI), four accessions were found susceptible (41-60%) and the rest 20 accessions were highly susceptible >60%. Based on severity rating (1-5 scale), two accessions (Acc-39 and PBC-731) were highly resistant to wilt with severity ratings of 1 and 14 accessions were found resistant with severity rating scale of 2 whereas 38 accessions were susceptible with severity scale of >3. Capsaicin content percentage ranged from 0.16-0.55%, and heat unit ranged 26372 to 88775 SHU, for Acc-32 and Acc-24, respectively. Oleoresin content in international color unit and ASTA value ranged from 32,800 to 118,840 cu and 82-296 ASTA with an overall mean of 69,704 ICU and 172 ASTA value. The highest color quality colors of greater than 250 ASTA was exhibited by 10 accessions (Acc-4, Acc-5, Acc-6, Acc-7, Acc-24, Acc-27, Acc-33, Acc-34, Acc-39 and Acc-31). This study identified resistance accessions with desirable qualities among the 49 local accessions. These materials also had good wilt resistance potential and could be used as source parents in the future hybridization and for simultaneous selection for Fusarium wilt resistance and high processing quality traits in hot pepper improvement program.

Evaluation of Botanicals for Managing Leaf Rust of Castor Caused by Melampsora ricini

The present study was conducted with the objectives to evaluate the efficacy of plant extract against leaf rust of diseases (Melampsora ricini). Botanicals were evaluated against rust disease on castor plants in greenhouse and field conditions at Melkassa Agricultural Research Center. The treatments were arranged with CRD for greenhouse and RCBD in the field experiments in three replications. Significant differences were observed among botanicals in the green house as well as field experiments. In green house, next to mancozeb maximum disease reduction (52 %) and fresh leaf weight (40gm) and dry leaf weight (8gm) were recorded from neem (Azadirachta indica). In field trial, among considered botanicals, minimum incidence (26.36%) and disease index (29.45%) were recorded from neem which was at par with garlic (33.33%), pyrethrum (40.56 %), lantana weed (47.22%) and mancozeb. Findings illustrated that the tested botanicals were effective for managing leaf rust of disease. Thus, they seem to be effective for the management of leaf rust and has the potential to be a vital component of integrated management for leaf rust of castor Melampsora ricini

Correlation and Path Coefficient Analyses of Cowpea (&amp;lt;i&amp;gt;Vigna unguiculata&amp;lt;/i&amp;gt; L.) Landraces in Ethiopia

Understanding the nature and extent of association between yield and yield related traits is the prerequisite study for any underutilized crop improvements of sustainable genetic enhancement. However, there is a lack of sufficient information on seed yield and related trait correlation and path coefficient analysis of cowpea in Ethiopia. To fill the existing knowledge gap, the present study was conducted to determine the nature and extent of phenotypic and genotypic correlation and path coefficient analysis among 18 quantitative traits. A total of 324 cowpea landraces were tested in 18 × 18 simple lattice design at Melkassa Agricultural Research Center and Miesso sub center during 2016 cropping season. The magnitude of genotypic correlations was higher than phenotypic correlations in most traits at both locations; this implies that the traits under consideration were genetically controlled. Seed yield was positively and highly significantly correlated with most of the traits at phenotypic and genotypic levels, indicating the presence of strong inherited association between seed yield and the other 17 traits. Almost all traits genotypic direct and indirect effects were higher than the phenotypic direct and indirect effects; this indicated that the other traits had a strong genetically inherited relationship with seed yield. Genotypic path coefficient analysis revealed that days to flowering, biomass and harvest index at Miesso, and seed thickness, plant height, days to maturity and biomass at Melkassa had relatively high positive direct effect on seed yield. However, seed width and hundred seed weight had exerted negative direct effect on seed yield at each location. Phenotypic path coefficient analysis showed that biomass and harvest index had exerted high positive direct effect on seed yield at both locations. From these results it can be concluded from this study that seed yield in cowpea can be improved by focusing on traits pod length, seed length, seed thickness, seed width, biomass and harvest index at both locations. The information obtained from this study can be used for genetic enhancement of cowpea thereby developing high yielding varieties.