International Journal of Plant & Soil Science

This study aimed to determine the main pathogens present in Senegalia polliphyla (DC.) seeds and to evaluate the fungicidal potential of Metrodorea flavida (K. Krause) extracts. For this purpose, concentrations of 0.5, 1.0, 1.5 and 2.0% of the extract of Metrodorea flavida leaves were used, in an ethanolic or aqueous form. The experiment was carried out using the Blottertest method to assess the incidence of pathogens in seeds and after application of treatments. Thus, the effect of extracts on the incidence of pathogens and the effects of the extracts on the germination and morphological characteristics of the seedlings was analyzed. The main pathogens found in Senegalia polliphyla seeds were Aspergillus flavus and Fusarium oxysporum. The aqueous and ethanolic extracts reduced the infestation of pathogens associated with Senegalia polliphyla seeds, as well as the main fungus found: Aspergillus flavus Link. It was also found that the extracts did not influence the germination and morphological characteristics of Senegalia polliphyla seedlings in all concentrations evaluated, thus being a promising alternative for pathogen control in forest seeds.

Teff is a major staple cereal crop in Ethiopia. However, its productivity is limited due to lack of appropriate sowing methods and utilization of improper seed rate are among the major once. Hence, a field experiment was conducted in Kiltu Kara District to determine the effects of seed rate and row spacing on yield and yield components of teff. Four levels of seed rates (10, 15, 20 and 25 kg ha^-1) and three rows spacing (15, 20 and 25cm) used and combined 12 treatments in total. The experiment was laid out as a randomized complete block design with a factorial arrangement in three replications. All yield components teff were significantly affected by different row spacing except straw yields of teff. The interaction of seed rate and row spacing showed significant difference for yield and yield components of teff. Significantly higher mean values of teff were found by the interaction of 10 kg seed rate ha^-1 and 25 cm row spacing. Significantly higher panicle length (36.9), number of tillers per plant (5), number of productive tillers per plant (4) of teff was recorded from interaction of 10 kg seed rate ha^-1 and 25 cm row spacing. Higher dry biomass (2591 kg ha^-1) and grain yields (1267 kg ha^-1) of teff were recorded from interaction of 10 kg seed rate ha^-1 and 25 cm row spacing. Mean of highest harvest index (49%) of teff was recorded from interaction of 10 kg seed rate ha^-1 and 25cm row spacing as compared to others. Significantly higher straw yields (1488 kg ha^-1) was recorded from interaction of 15kg seed rate ha^-1 and 20 cm row spacing as compared to other treatment combinations. Therefore, the use of 10 kg seed rate ha^-1 together with 25 cm row spacing was the optimum seed rate and row spacing and 10 kg ha^-1 was profitable for the production of teff. To make definite conclusion further research for more seasons and location is required to give recommendation for the study area.

An experiment entitled “Evaluation of the CropSyst model to simulate the effect of irrigation and nitrogen levels on clusterbean” was carried out at village Bajju, Bikaner, Rajasthan during kharif season of 2016. The treatment comprising 3 levels of irrigation (100, 200 and 300 mm) and 4 levels of nitrogen (0, 20, 40 and 60 kg N/ha) comprising a total of 12 treatment combinations in split plot design with four replications. The simulation of CropSyst model was utilized to quantify and verify the interactive effect of different irrigation and nitrogen treatments on the productivity of clusterbean using measurements from field experiment. The soil of site are loamy sand having 86.3, 7.8 and 5.9 % of sand, silt and clay, respectively in 0-15 cm soil depth with pH 8.1 and low soil organic matter content (0.13%). The prediction of the model for seed yield and biomass was acceptable with 17.1 and 22.1 % of RMSE which may be considered good prediction by the model. However, the simulated N-uptake was over predicted by model and did not agreed with field measurements with 39.8% RMSE. The soil moisture content at different stages of growth was well simulated by CropSyst. The RMSE of moisture content ranged from 0.0123 to 0.0278 in clusterbean.

Improved agronomic practices increases yield potential of chickpea in different agroecology of the country. In this view a field experiment was conducted to assess the influence of inter-and intra row spacing on yield and yield components of chickpea (Cicer arietinum L.) in Jimma Horro district of Kellem Wollega Zone, Western Oromia, Ethiopia. The treatment consisted of three inter-row spacing (20, 30 and 40 cm) and four intra-row spacing (5, 10, 15 and 20 cm). The experiment was laid out in a randomized complete block design in factorial arrangement with three replications. The highest (52) number of pods plant^-1 was obtained with the interaction effect of 40 cm inter and 20 cm intra row spacing. The highest dry biomass (8457 kg ha^-1) was recorded at 20 cm × 5 cm spacing while the lowest dry biomass (5413 kg ha^-1) was recorded at 40 cm × 20 cm spacing combination. Significantly  higher  (248 g) 1000 grain weight was recorded under 40 cm with 20 cm spacing and lowest (165 g) 1000 grain weight under 30 cm x 5 cm row spacing. The highest (1625 kg ha^-1) seed yield of chickpea was obtained from 30 cm x 15 cm and the lowest seed yield (1096 kg ha^-1) was recorded from 20 cm x 5 cm row spacing. The highest harvest index (34.03%) was achieved for the interaction of 40 cm inter- and 20cm intra-row spacing and the lowest harvest index (12.14%) under 20 cm x 5 cm row spacing. Thus 30 cm inter-row with 15 cm intra-row spacing can tentatively be recommended for the production of chickpea in the study area as compared to the current recommendation of 30 x 10 cm. Further research would be needed at more locations and seasons to give conclusive recommendations.

A two year field experiments were conducted at the College of Agriculture Teaching and Research Farm,   Jalingo, Taraba State, Nigeria, to evaluate the integrated use of 25% rates of  selected herbicides mixtures (atrazine-pendimethalin (AP₁) or primextra (PX₁) and cover crops (a vegetable cowpea, "Akidi" (A), Melon (M) and Sweet potato (S) planted sole or mixed at 20,000 stands/ha (₁) or 40,000 stands/ha (₃) under manual (MT) and tractor tillage (TT) methods used primarily for weed control on soil properties and maize production. The experimental design was a split plot arrangement in a randomized complete block design replicated three times. Tractor Tillage (TT) and Manual Tillage (MT) were the main treatments. The sub treatments included ten integrated weed management (IWM), AP₁A_I, AP₁AS₁, AP₁S₃, AP₁MS₃, AP₁AMS₃, PX₁A₁, PX₁AS₁, PX₁S₃, PX₁MS₃, PX₁AMS₃ in addition to Weeded 3+6 Weeks After Planting (WAP) (C₁) and unweeded(C₂) as controls. Descriptive statistics and Analysis of Variance were used to analyze data and the treatment means were compared using standard error at 5%. The level of Na, organic carbon, TN, %clay and %fine sand were higher in MT than TT during the experimental period while Mg, pH, %silt and clay were higher in TT than in MT. Herbicide groups did not significantly influenced soil properties in this study. The Ca²⁺, K⁺ and A-VP in all IWM treated plots were higher than the value in C₂ . Treatments having Akidi (A₁, AS₁, AMS₃) recorded higher OC than those without (S₃, MS₃). Therefore, MT improves soil condition and should be used in small scale farming and where TT is used, special consideration of soil type and frequency of use should be moderated. Use of IWM ameliorates fertility losses observed, with preference for mixture with at least a leguminous component.

The effect of inoculating indigenous cowpea nodule bacteria of Ethiopia on the crop performance was not tested under field condition with the ultimate goal of selecting effective inoculants. Root nodule bacteria which showed strong symbiotic effectiveness under greenhouse condition were selected for field experiment. Under field conditions, inoculation of cowpea with ECR-0+ECE-21 and ECR-101+ECE-21 resulted in a maximum grain yield (GY, 2713 kg ha^-1) and above ground biomass (BW, 506 g m^-2), respectively. The co-inoculation of cowpea with ECR-0 and ECE-21 and ECR-24 and ECE-21 significantly improved (p<0.05) the N-content and GY as compared to their single rhizobial inoculation. The native strains performed better than the exotic strain (Biofix). Performance of the strains was similar at the two test locations except ECR-14 and ECR-24 that resulted 13% greater of BW at Uke than at Bako. Symbio-agronomic performance of native rhizobia under field condition showed direct correlation (r>0.5; p<0.01) to each other except nodule number. In general, both single and co-inoculation of the native rhizobacterial inoculants improved cowpea performance. This is a promising biofertilizer to enhance cowpea production in Ethiopia, where the farmers cannot afford to buy chemical fertilizers.