Effect of the Application of Gluconacetobacter diazotrophicus and Its Interaction with Nitrogen and Phosphorus Fertilization on Carrot Yield in the FieldRead the full article
International Journal of Agronomy publishes research focused on crop production and management, crop science and physiology, crop disease and protection, and agroclimatology and soil science.
Chief Editor, Dr. Othmane Merah, is an Associate Professor at the University of Toulouse Paul Sabatier, France.
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Nutritional and Phytochemical Composition of Bambara Groundnut (Vigna subterranea [L.] Verdc) Landraces in Kenya
Bambara groundnut (Vigna subterranea) is a highly nutritious legume with good drought tolerance attributes and is therefore a suitable candidate for food and nutritional security especially in drought prone areas. This study was conducted to determine the nutritional and phytochemical composition of seventeen Bambara groundnut landraces that were collected from Vihiga, Kakamega, Bungoma, Busia, and Kisumu Counties in Kenya. Prior to characterization, a field experiment was set up in Ishiara Ward in Mbeere North Sub-County in Embu County for two cropping seasons to standardize and multiply the seeds. The experiment was laid out in a Randomized Complete Block Design with three replicates. The harvested seeds were analyzed for their proximate, nutritional, and phytochemical composition using standard procedures. The moisture content ranged from 3.47 to 6.24%, total ash from 3.17 to 4.69%, crude protein from 21.18 to 26.00%, and fats from 4.56 to 7.02%. Iron levels ranged from 4.07 to 5.13 mg/100 g, sodium from 25.14 to 129.66 mg/100 g, potassium from 819.34 to 1,131.80 mg/100 g, and zinc from 0.06 to 0.42 mg/100 g. The tannin levels ranged from 0.01 to 0.04 mg/g, saponins from 0.82 to 1.06 mg/100 g, alkaloids from 0.01 to 0.12 mg/100 g, and flavonoids from 4.07 to 8.45 mg/100 g. The landraces BG-125, BS-148, and BS-145 with relatively higher nutrients composition and those with high levels of phytochemicals such as BS-104 and MU-137 are recommended to plant breeders for further selection and production of certified seeds. These selections will also be promoted to the farmers for production through various extension programs.
Prevalence and Host Resistance to Common Bean Rust Disease in Western and Central Kenya
Rust, caused by Uromyces appendiculatus (Pers.) Unger, is among the most devastating diseases of the common bean (Phaseolus vulgaris L.) worldwide. The pathogen is highly genetically variable, causing severe epidemics under favourable weather conditions. The objectives of this study were to determine the distribution of bean rust in major production areas in Kenya and identify potential sources of resistance for breeding. A field survey was conducted in five counties targeting smallholder common bean farmers in western and central Kenya, where data on the incidence and severity of bean rust and crop management practices by farmers were recorded. Additionally, seeds of the evaluated genotypes were collected from farms visited for further testing. A total of 77 common bean genotypes were subjected to natural infection under field conditions and inoculated with races 29–1, 29–3, 61–1, and 63–1 of rust under greenhouse conditions at the University of Embu. The gene pool affiliation of the genotypes was determined through the phaseolin protein marker analysis. Rust incidence and severity data were subjected to an analysis of variance using GenStat statistical software. The results showed that bean rust occurred in all counties although there were significant differences () in incidence and severity among the surveyed localities. Based on a 1–9 severity rating scale, Bungoma County recorded the highest mean severity of 3.99 and an incidence of 71%. Cultivar grown, use of fungicides, management of residues, and crop spacing had a significant effect on bean rust severity. Under field and greenhouse conditions, the genotypes revealed high variations in response to rust, with 71% of the genotypes being susceptible under greenhouse inoculations. Enclave, MU#13, UN2-Darkgreen, UN6-Nakholo, Kat X56, and KMR-11 genotypes were identified as resistant and can be used as prospective parents in common bean improvement programs in Kenya. This study revealed high occurrence and distribution of common bean rust and thus provides critical baseline information for common bean rust management in Kenya.
Effects of Varieties and Different Environments on Growth and Yield Performance of Shallot (Allium cepa var. aggregatum)
Shallot (Allium cepa var. aggregatum) is one of the major cash crops produced in the Amhara region, including East Gojjam Zone, Ethiopia. However, the shallot is being out of production, and there are limited research efforts concerning the influence of the growing environment on shallot varieties. Thus, the objective of the study was to identify adaptable and high-yielding shallot varieties across different agroecologies/location in the East Gojjam Zone of Ethiopia. The experiment was conducted at three locations (Debre Markos, Wonka, and Yelam Gej) during 2019/20 and 2020/21 growing seasons. The study consists of four shallot varieties (Minjar, Huruta, Negelle, and local). The experiment was conducted in a randomized complete block design with three replications. Data on growth, yield, and yield component parameters were recorded and analyzed using SAS Computer Software version 9.0. The present results indicated that the highest plant height, leaf length, number of shoots per plant, number of bulblets per bulb, average bulb weight, total yield, and marketable yield per hectare were recorded from improved shallot varieties Minjar, Negelle, and Huruta. Thus, Minjar, Negelle, and Huruta were better performed for growth, yield, and yield components at all testing locations. Thus, Minjar, Negelle, and Huruta were found to be superior in yield and yield components at all testing locations and were thus suggested to be used by the growers in the study area. It would be advisable to evaluate the varieties in the participatory varietal trail for further dissemination of varieties to shallot growers in the study area.
Influence of Sowing Date on Phenology, Biometric, and Yield of Mungbean (Vigna radiata) Cultivars in Chitwan, Nepal
Mungbean is a commercially promising legume crop, accounting for a very low productivity of approximately 0.5 tons ha1 in the Terai region of Nepal. This study aimed to achieve the potential yield of mungbean promising cultivars planting at optimum sowing time. An experiment was conducted at the Agriculture and Forestry University (AFU), Rampur, Chitwan, during the spring of 2019 in a split-plot design (SPD) with three replications and 16 treatment combinations. Four sowing dates at 15 days intervals (13th February, 28th February, 15th March, and 30th March) of 2019; cultivars viz. Kalyan, Pratikshya, Pratigya, and Pant-5 are considered as main and subplot factors. The Dunken test was carried out to compare the mean in R-software at level of significance. The results revealed that earlier planting (Feb 13 planting) resulted in delayed emergence, slower growth, and the lowest yield (1.79 tons/ha). The March 15 to March 30 plantations resulted in significantly faster emergence, germination, and growth showing a higher yield. Pant-5 yielded a higher grain yield, which was statistically at par with Partigya (2.08 tons/ha) and Partikshya (1.983 tons/ha). Vigna radiata plantations from March 15 to March 30 are the optimum sowing times for higher productivity (2.119 tons/hectare) and high potential yield, which can be applied for perfect decision-making in mungbean plantations. Future work on least-squares analysis for understanding the genotypic-environment interaction of economic traits and the effect of different nutrient sources on cultivars has scope.
Growth, Yield Components, and Yield Parameters of Maize (Zea mays L) as Influenced by Unified Use of NPSZnB Blended Fertilizer and Farmyard Manure
A two-year field experiment was carried out to scrutinize the integrated use of NPSZnB blended fertilizer and farmyard manure (FYM) on maize growth and yield components at Koga and Bachima villages in Mecha district and Geray and Jiga villages in Jabi Tehran district. Factorial combinations have five levels of NPSZnB (100, 150, 200, 250, and 300 kg·ha−1), and four rates of FYM (0, 12, 16, and 20 t·ha−1), plus one blanket recommendation (200 kg·ha−1 DAP and 150 kg·ha−1 Urea). A randomized complete block design with three replications was used to set up the studies. Except for days to silking and leaf area index at both locations, and days to physiological maturity, and ear length at Mecha, main and interaction effects on all parameters were detected at both locations. The only main effect of NPSZnB was detected on the harvest index at Jabi Tehnan. Generally, the results achieved from the interaction effect were better and greater than those obtained from the blanket recommendation although this was not the case for the main effects. Grain yields at Jabi Tehnan and Mecha were 5618.5 and 5421 kg·ha−1, respectively, as a result of the unified use of 250 kg·ha−1 NPSZnB and 20 t·ha−1 FYM and shortened days to 50% tasselling by 3.46 days and delayed 90% physiological maturity by 2.95 days than the blanket recommended fertilizer at Jabi Tehnan. As the main effect, compared to the blanket recommendation, 250 kg·ha−1 at Jabi Tehnan and 300 kg·ha−1 NPSZnB at Mecha reduced the days to 50% silking by 0.225 and 0.292 days, respectively. Contrasted with the conventional recommendation, the application of 300 kg·ha−1 NPSZnB minimizes days to 90% physiological maturity by 0.89 at Mecha, and the rise in FYM level from 0 to 20 t·ha−1 caused 0.832 and 0.279 extra days to reach 50% silking at Jabi Tehnan and Mecha, respectively. The yield had a very strong correlation that is positive with growth and yield components. Economic study: the use of 200 kg·ha−1 NPSZnB with 20 t·ha−1 FYM resulted in the maximum net benefit of 36221.06 and 35431.04 ETB ha−1 at Jabi Tehnan and Mecha, respectively. Thus, 250 kg·ha−1 NPSZnB with 20 kg·ha−1 FYM and 200 kg·ha−1 NPSZnB with no FYM application were the most acceptable rates at both locations with a low cost of production to small-scale farmers. For resource-rich farmers, 200 kg·ha−1 NPSZnB with 20 t·ha−1 FYM was also favorable, with the best net benefit at both locations.
Influences of Seedling Age and Variety on the Growth and Bulb Yield of Onion in Northwest Ethiopia
Onion is one of the major cash crops and helps improve the livelihoods of smallholder farmers. Although genetically and morphologically different, seedlings of all released onion varieties are transplanted at the ages ranging from 40 to 50 days, which contributes to the low level of productivity in Ethiopia. Therefore, a field experiment was conducted at the research site of Fogera National Research and Training Center during the 2019/20 irrigation season with the objective of identifying the optimum seedling age for improved onion productivity in Northwest Ethiopia. The treatments consisted of three varieties (Adama red, Bombay red, and Nasik red) and four seedling ages (30, 40, 50, and 60 days) of onion, which were laid down in 3 × 4 factorial arrangement using randomized complete block design with three replications. Growth and yield parameters of onion were collected based on the standard procedures and analyzed using SAS version 9.6. The results revealed that both variety and seedling age significantly () influenced plant height, leaf number, bulb diameter, fresh bulb weight, and marketable bulb yield, while their interaction effect did not influence these parameters. Days to maturity was significantly () affected by main as well as by the interaction effects of variety and seedling age. Younger seedling took longer time to mature, while older seedlings matured relatively early. The seedlings of Bombay red variety at 60 days age gave the earliest maturity days (105.33 days) compared to the other combinations. The highest plant height (50.18 cm), leaf number (12.00), bulb diameter (53.47 mm), bulb weight (84.39 g), and marketable bulb yield (29.97 t/ha) were recorded from Bombay red variety where the marketable yield recorded from Nasik red was statistically similar with that of Bombay red variety. Seedlings with 60 days old performed best in terms of all the tested growth and yield parameters including the highest marketability (32.03 t/ha). Accordingly, 60 days old seedlings and Bombay red and Nasik red varieties can be used to increase the productivity of onion in the study area and areas with similar agroecology.