International Journal of Agronomy

Clary sage (Salvia sclarea L.), a member of the Lamiaceae family of aromatic plants, is used as a flavoring in the food, fragrance, and cosmetic industries. Egypt’s food and pharmaceutical industries require more natural resources, thus new crops have been introduced to meet the demand. In addition, various environmental conditions, such as water stress, influence aromatic plant growth and essential oil output. The microorganisms included in biofertilizers that have enzymes that solubilize minerals include plant growth-promoting rhizobacteria (PGPRs). Therefore, a field experiment was carried out to test how irrigation management, i.e., 100% of reference evapotranspiration (ETo) (full irrigation) or 50% ETo (water stress), can affect herbal yield, essential oil, and physiological aspects of clary sage, as well as how to improve clary sage plants utilizing biofertilizer in the field in Egypt’s Mediterranean climate zone. The main processes through which PGPRs aid clary sage plants in coping with water stress include increased macro and micronutrient concentrations (P, N, K, Ca, Mg, Zn, B, Mn, Cu, and Fe), dehydrogenase activity, essential oil, and physiological and growth traits of photosystem II (Fv/Fm), chlorophyll content (SPAD-value), plant’s health (normalized difference vegetation index, NDVI), shoot dry weight, and leaf area in clary plants. Application of different PGPRs reduced canopy temperature (CT), thus improving clary sage plants either under 100% ETo or 50% ETo. Consequently, the usage of PGPRs is appropriate for alleviating environmental stresses experienced by clary sage plants and has potential use in maintaining productivity in water stress and may thus be regarded as an important component of sustainable agricultural practices.

Weed infestation is considered as one of the major biotic stresses of dryland crop production. Weed species occurrence, abundance, and densities differ due to spatial soil fertility variability, and management practices by farmers. Weed surveys are therefore vital for tracking such changes and in turn developing appropriate weed management strategies for farmers. A weed survey was carried out in Wedza, eastern Zimbabwe to assess farmer knowledge and perceptions of major weeds in maize fields across catena landscape positions. A multistage sampling procedure was used, involving random sampling of six villages within a 20 km radius, divided according to the catena position and economic status of the farmer. Two hundred and forty-nine (249) households were interviewed using a structured questionnaire. The data were coded and processed using the CSPro software package, and then analysed using the SPSS program. Factors that predicted the spatial distribution of weeds were determined using a binary logistic model. From the survey, 52.8% and 42.3% of farms are on the upper catena and lower catena, respectively, and only 4.8% are on the middle catena. Thirty-one weed species belonging to 15 families were listed by respondents and identified by enumerators in the study area and were categorised into three main groups (broadleaf, grasses, and sedges). Acanthospermum hispidum and Striga asiatica were considered as problem weeds in maize fields on the upper and lower catena, respectively. Xanthium strumarium was perceived as a new invasive weed in low-lying arable fields. The binary logistic model predicted farm location on the landscape and fertiliser use as the main factors affecting weed types, distribution, and abundance. Moreover, farms on lower catena had more Striga infestations compared to upper catena. The results suggested an integrated weed management approach to control A. hispidum, Striga species, and the invasive fast-spreading X. strumarium in the area.

The critical stage for any breeder is the selection of crossing parents to drive improved inbred for subsequent breeding cycles. In our study, we estimate breeding parameters such as mid-parent value (MPV), variances among and within crosses, the heritability of relevant traits and their correlations, the usefulness of crosses, and regression of cross means on MPV. 900 F4:5 Recombinant inbred lines (RILs) derived from 30 crosses were tested together with their parental lines in a modified split-plot p-rep design at two locations. The analysis revealed significant genetic variation among parents, crosses, and RIL for almost all traits. Heritability for parents ranged from 49.50% (malt extract) to 93.60% (plant height) and heritability for crosses ranged from 29.52% (grain protein concentration) to 87.0% (days to maturity), whereas heritability for RIL was the lowest with 27.40% for beta-glucan and the highest to 73.60% for thousand kernel weight, respectively. Significant () genotypic correlations with high impact for practical breeding were found between malting traits. Accordingly, the genotypic correlation ranged from −0.73 to 0.78 whereas the phenotypic correlation ranged from −0.60 to 0.65, respectively. Significant () regression of cross-mean on MPV where R² ranges from 0.27 to 0.70 and is higher than 0.5 for most of the traits demonstrates that cross means can accurately be predicted from MPV and selection among crosses at an early stage is highly effective. Based on the usefulness criterion, 16 superior crosses were identified compared to the planet as the actual leading malt variety. Starting from a simple additive genetic model with random mating, we discuss deviations from the initial model and their impact on the actual estimates implying how to design a state-of-the-art cereal breeding program.

Whiteflies are one of the most devastating horticultural pests attacking tomatoes. Although there are several control methods for the control of whitefly pests, the integrated application of entomopathogenic fungi (IPM) with chemical and botanical insecticides has proven more effective than individual control agents. This study was carried out to evaluate individual and combined treatments of entomopathogens B. bassiana, M. anisopliae, B. thuringiensis, Hunter 40 EC, and neem oil for the control of whitefly species on tomato (Solanum lycopersicum) under greenhouse and field condition. The greenhouse study showed that the different treatments resulted in a 58.48 to 100% reduction of nymphs and a 52.06 to 100% reduction of adults on both Galilea and Melkashola tomato varieties under greenhouse conditions. The combined treatments of AAUMB-29 + Neem oil displayed a higher yield (423.3 g fruits/plant) on the Gelilea tomato variety, and AAUDM-43 + Hunter 40 EC displayed a yield of (376.66 g/plant) on the Melkashola tomato variety. Under field conditions, the application of AAUMB-29 + Hunter 40 EC + Neem oil significantly decreased the whitefly population by 91.93% () after 10 days of the fourth spray. The result of fruit yield of tomato was significantly higher in all treatments (31.17 t to 70.42 t·ha⁻¹) compared to untreated control (25.83 t·ha⁻¹). Among the treatments, AAUMB-29 + Hunter 40 EC + Neem oil gave the highest fruit yield of 70.42 t·ha⁻¹ followed by AAUMB-29 + Hunter 40 EC (64.50 t·ha⁻¹) on the Galilea tomato variety under field conditions. The combined treatment of AAUMB-29 + Hunter 40 EC + Neem oil was the most effective with lower whitefly infestation, higher marketable yields, and less percentage of yield losses. Further investigations are required to determine the optimization and practicability of this integrated application of treatments for the control of both sucking and chewing insect pests under field conditions.

Sweet potato (Ipomoea batatas L.) is an important crop which ensures food security in developing countries. It can be harvested at any stage as needed, thereby providing a flexible source of food and income for rural families that are most vulnerable to crop failures and cash income fluctuations. The production and consumption of orange-fleshed sweet potatoes (OFSP) by smallholder farmers in the Sidama region of Southern Ethiopia were explored in this study to identify key problems and opportunities in OFSP production. A preliminary investigation and rudimentary data collection were used to gather data. The data were analyzed using descriptive statistics, multiple linear regression, and index grading. Based on the descriptive analysis, smallholder farmers have small landholdings of 0.51 ha per family. Farmers conserve their planting materials by leaving them in the field. This causes the materials to be extensively infested with diseases, insects, and other vertebrate pests. Farmers (54.4%) do not apply inorganic fertilizersassuming that it stimulates more vegetative growth and results in tasteless storage roots. The continuous cultivation of OFSP without fertilizer application results in nutrient depletion and reduced yield. Further, the production and utilization of OFSP in the Sidama region is constrained by factors such as diseases, lack of storage facilities, lack of planting materials, drought, insect pests, low market price, and shortage of money to purchase inputs. According to the index ranking, drought, shortage of planting material, diseases, and insect pests were the most important. Combinations of social, ecological, and economic factors limit the production of sweet potatoes and therefore, a stronger extension system on agronomic practices and credit system should be made accessible to the farmers.

Heat resilient maize hybrids are an important input in maize cultivated area coupled with high temperature during the flowering period, with a specific focus on the Terai region of Nepal. The research was conducted in the Dhangadhi district from April 2020 to August 2020 in an alpha-lattice design with 26 genotypes and two replications. Analysis of variance suggests that genotypes were significantly different for all traits except plant height and plant population. The phenotypic coefficient of variation (PCV) was higher than the genotypic coefficient of variation (GCV) for all traits. High PCV and GCV values were found in the anthesis silking interval, ear aspect and grain yield and low values in the anthesis days and silking days. Highly heritable traits were days to 50% tasseling (0.74), days to 50% silking (0.74), ear aspect (0.69), number of rows per cob (0.84), number of grains per row (0.61), cob diameter (0.87), and cob length (0.86). Genetic advance ranged from the lowest in plant height to the highest in anthesis silking interval. Correlation studies revealed that grain yield showed a negative and significant correlation with reproductive traits, while a positive and significant correlation between ear height and number of ears per hectare was observed. Cluster analysis grouped 26 genotypes into 5 major clusters, and the intracluster distance ranged from 4034.3 to 34960.3. Thus, traits having high variation can be used as selection indices for indirect selection for the improvement of maize productivity and suggest genotype like ZH182079, ZH1767, and KH15486 with high yield for commercialization and distribution to farmers.