Utilization of phytohormones for successful crop production under environmental stress conditions

Stress is an external factor that exerts a detrimental effect on overall growth of a plant. Environmental stress is a serious threat for sustainable crop production, and a main cause for food insecurity. Agricultural crops are exposed to a variety of environmental stresses including extreme temperatures and unfavorable chemical and physical soil conditions. Drought stress adversely affects some physiological and biochemical processes in plants, including transpiration, translocation of assimilates and nutrient metabolism. Salinity stress is responsible for loss of turgor, reduction in growth, wilting, leaf abscission, reduction in photosynthesis and respiration, loss of cellular integrity, tissue necrosis and finally death of the plant. Drought and salinity stress negatively affects the growth and yield of crop plants more than all the other stresses combined. Cold stress affects cellular components and metabolism, and temperature extremes impose stresses of variable severity that depend on the intensity and duration of the stress. Many approaches are being used to alleviate the deleterious effects of environmental stresses on successful agricultural crops production in recent years. Application of phytohormones (Abscisic acid, Indole-3-Aacetic Acid, Jasmonic acid and salicylic acid) is one of the curative measures to mitigate the environmental stresses in agricultural crops. Phytohormones play a significant role in enhancing stress tolerance and therefore, reduce the yield loss in crop plants. In this paper, the impacts of environmental stresses on productivity and physiological activities of crop plants, and the effective role of some phytohormones in alleviation of environmental stresses have been reviewed.

Assessment of indigenous knowledge of medicinal plants used for livestock treatment in five selected Kebeles of Kersa District, Jimma Zone, South Western Ethiopia

Plants have been a source of medicine in Ethiopia from time immemorial to treat different human and livestock ailments. The purpose of this study was to identify the medicinal plant species and associated indigenous knowledge in livestock treatment. A cross-sectional study was conducted to assess indigenous knowledge of local people on medicinal plants used for livestock treatment in five selected kebeles of kersa district from March to June 2014. A total of 40 traditional healers (33 male and 7 male) 7-9 from each study sites were selected purpouvely with the help of knowledgeable elders, local authorities and kebele leaders. Ethno botanical data regarding plant species, plant parts used, livestock disease treated, and method of preparation and route of administration were collected through structured interview and field observation. A total of 33 plant species distributed in 24 families were identified in the study area. The majority of the medicinal plants 63.63% were collected from the wild and 33.33% from home garden. The major growth habit of the medicinal plants identified in the study area were herbs 39.39%, followed by shrubs 33.33%.The most frequently harvested plant parts were leaves and roots with proportion of 57.7% and 21.21%, respectively followed by seeds (9.09%) and fruits (6.06%). Pounding and crushing were the most commonly used method of remedies preparation whereas the widely used method of administration is oral. The study reveals that the local people of the study area harvest medicinal plants used to treat livestock health problem from the wild habitat. Therefore, awaring the local people of the study area to conserve medicinal plants in their home garden is recommended.

Optimum planting date for the maximum tuber yield of tropical sugar beet (Beta vulgaris L.) genotypes in the Old Brahmaputra Floodplain

Planting dates for a crop is a non-monetary input but plays a significant role in increasing the yield crop. Therefore, identifying genotype-specific planting dates is essential for obtaining the economic yield of tropical sugar beet. From this perspective, a field experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University in Bangladesh, from November 2015 to April 2016. Five sugar beet genotypes: Shubhra, Cauvery, EB-0616, EB-0626, and EB-0809 planted on four dates: 10, 20, 30 November, and 10 December. Treatments were laid out in a split-plot design replicated three times. Data revealed that planting on 10 November date, genotype EB-0809 produced the highest tuber yield, which was significantly superior to any other genotype combined with other planting dates. It was found that every ten days delay of planting from 10 November to 30 December reduced the tuber yield by 30, 43, and 55%, respectively. Results confirmed that planting the EB-0809 genotype on 10 November is ideal to obtain the highest tuber yield of tropical sugar beet in Bangladesh.

Transportation of Chromium (VI) to Bombyx mori L. from mulberry Plant (Morus alba L.) grown at soil irrigated with Chromium (VI) containing effluents

The research was conducted to determine Chromium (VI) toxicity in population Bombyx mori. The synthetic wastewater used to irrigate soil to evaluate the impact of pH (4 to 8) at 100 mg/L and initial Chromium (VI) concentrations (25 mg/L to 300 mg/L) at 5 pH in its bioaccumulation in B. mori foodchain. By using atomic absorption spectrophotometer (AAS) analysis the amount of Chromium (VI) determined in soil, mulberry plants, B. mori larvae, silk glands and silkworm feces. The results showed that local cobalt pollution can be indicated by using B. mori as a template as its body length, body weight and the mortality rate were found to be strongly related to Chromium (VI) concentration. Higher the Chromium (VI) amount in mulberry leaves causes more toxicity to B. mori population. At 300 mg/L Cr (VI) concentration and pH 4 there was maximum deposition of Chromium (VI) in soil, mulberry plants, B. mori larvae, faeces and silk glands from the synthetic effluent. The maximum deposition was 123.5±0.03 mg/kg, 89.76±.031 mg/kg, 23.31±0.019 mg/kg, 41.32±0.069 mg/kg and 35.67±0.04 mg/kg observed respectively.

Response of giant foxtail and wild proso millet to artificial light quality alteration

Light is an essential requirement for proper plant growth and development. Growth chamber experiments were conducted to determine whether artificial alteration of light quality (reducing the red to far-red ratio-R:FR) differentially affected the growth and development of giant foxtail and wild proso millet, two troublesome annual grass weeds in the United States. Growth phenotypes of both weeds were examined under two R:FR regimes (0.28-reduced R:FR and 1.12-unaltered R:FR) in the absence of competition (control conditions) and under intraspecific and interspecific competition. The reduced R:FR simulated shaded (below-canopy) R:FR conditions in the field while the unaltered R:FR treatment simulated direct sunlight (above-canopy) conditions. Averaged across weed species, reducing the R:FR increased plant height, but reduced tiller production and above-ground biomass under no plant competition (P<0.05). In the presence of competition, reducing the R:FR increased plant height and internode length but reduced the number of tillers and leaf area across weed species. No phenotypic differences were observed for weeds tested under intraspecific or interspecific competition. Our study has shown that the response of both weeds to artificial R:FR alteration is similar to that observed under shaded field conditions. Therefore, by replacing bordering plants with a crop, controlled experiments can be used to test the effect of crop canopies on weed suppression when selecting cultivars to be planted in areas where certain weed species are prevalent, minimizing weed-related yield losses.

Soil test crop response based phosphorus calibration study for bread wheat in Kofele District, West Arsi Zone Oromia, Ethiopia

Nowadays, a balanced fertilizer recommendation is of paramount importance in order to confirm the security and sustainably increase crop productivity for farmers and other stakeholders. Soil test crop response based phosphorus calibration study in two years (2017 and 2018) was done for bread wheat in kofele district with objectives to assess and evaluate yield response of bread wheat to phosphorus-fertilizer applications in soils that have initial high/medium/low levels of phosphorus on Eutric Vertisols. A composite soil samples collection were made in zigzag method from farmer’s land and analyzed for available P in order to identify the level of the required parameters in the soil to select farmland for actual experiment. Accordingly, phosphorus calibration study treatments include application of 0, 10,20,30,40 and 50 kg P ha-1 with recommended nitrogen 69 kg N ha-1 with RCBD design was used with two replications. The plot size of 5mx4m with a seed rate of 150 kg ha-1 and Ogolcho variety which had been recommended for the area was used. So that the result showed that phosphorus fertilizer application significantly affects yield and yield components of bread wheat. Similarly, phosphorous fertilizer application at different rates increased grain yield of bread wheat by 28 to 44% compared to the control. Furthermore, the study was revealed that phosphorus critical (Pc) point for bread wheat was 19, and phosphorus requirement factor was also 3.30. Therefore, future research should focus on verification of the result on farmland before disseminating the technology to the end-user.

Variability in Cooking Time, Iron and Zinc Content in Common Bean (Phaseolus Vulgaris L.) Genotypes

Prolonged cooking time leads to structural changes at the grain cellular level, resulting in loss of nutrients such as iron (Fe) and zinc (Zn) which are among the main nutrients important in addressing micronutrient malnutrition. The aim of this study was to evaluate the diversity of cooking time, Fe and Zn content in a total of 152 common bean (Phaseolus vulgaris) genotypes from around Eastern Africa, in order to identify short cooking genotypes with high Fe and Zn content. Field trials were conducted at CIAT-Uganda research station over two seasons in 2016. Cooking time was estimated using an automated Mattson cooker at CIAT-Uganda while Fe and Zn content was determined using XRF analysis at Rwanda Agricultural Board (RAB) in Rubona. A wide variability was evident from the test genotypes both for cooking time and mineral concentration. Cooking time exhibited a continuous distribution ranging from 35-100 minutes for the first season and 43–122 minutes for the second season. Seventy-three percent of the test genotypes had Fe levels higher than the low Fe check, CAL 96 (55mg/kg) which is popularly known as ‘Nambale’ and a popular commercial variety in Uganda. A total of 15 genotypes (Amahunja, Awash melka, Bihogo, CAB 2, ECAPAN021, G858, Icaquimbaya, KK20, NABE12C, NABE4, NABE6, ROBA-1, RWR1873, RWV3006) were consistent in short cooking time for the two seasons and had a Fe content above the low Fe check (CAL96 – 55mg/kg). A high correlation (r = 0.71) was observed between Fe and Zn whereas a low correlation between cooking time and Fe (r = -0.04) and Zn (r = 0.04) was observed. Great variability was evident for both traits indicating possible improvement by breeding and thus the possibility of having short cooking common bean genotypes with high Fe and Zn content.

Evaluation on dry forage yields and nutritional characteristics of introduced herbaceous legumes in Myanmar

The study was carried out to evaluate the forage yields, nutritive values and in vitro fermentation parameters of herbaceous legumes. Five varieties of introduced herbaceous legumes; Stylosanthes guianensis cv. Ubon stylo, Macrotyloma axillare cv. Archer, Centrosema brasilianum cv. Ooloo, Stylosanthes guianensis cv. Stylo 184 and Macroptilum bracteatum cv. Cadarga were evaluated at the research farm, University of Veterinary Science, Yezin, Myanmar. No fertilizer and no irrigation were applied for cultivation to test drought resistance. Dry forage yield, nutritive values and gas production at four harvesting times were measured with 4×5 factorial arrangement (5 legumes and 4 harvesting time) in randomized complete block design. There was no interaction between legumes and harvesting time on forage yield, nutritive values and fermentation parameters but they were affected by the main effects of legume types and harvesting time. Among the legume forages, the highest dry forage yields were found in Ooloo, Ubon stylo, and Stylo 184, and followed by the DM yield of Archer and Cadarga. The DM yield of the second harvest was significantly higher (p<0.05) than those of the first, third and fourth harvest which were not significantly different from each other. As a chemical composition, the DM content of Archer was lower (p<0.05) than those of other varieties. Among the legumes forages, the lower CP content was found in Cadarga. The higher NDF was observed in Ooloo. Ooloo, Ubon stylo and Cadarga showed higher ADF in comparison with the other two varieties. Among the harvesting time, the lowest DM content was found at the first harvest. The highest CP content was found at third harvest. The NDF content was not significantly different. The lowest ADF content was found in fourth harvest. According to the dry forage yield, Ubon stylo and Ooloo had the highest dry forage yield and in term of nutritive values, Stylo 184 and Archer had higher nutritive values. As the main effect of forages, Stylo 184 and Archer had higher gas production in comparison with the other varieties. As the main effect of harvesting time, the fourth harvest had the highest gas production in comparison with other harvesting time. It could be better for cultivation by application of fertilizer and irrigation to get more forage yield and quality.

Alternative screening method for drought tolerance in barley genotypes

Lack of genetically stable and durable drought tolerant winter and spring barley genotypes is one of the main contributing to low and unpredictable yields in Kenya and other parts of the world despite annual release of new and high yielding varieties. Therefore, the study was set to identify genotypes exhibiting tolerance to drought through physiological and phenotypic approaches. A total of 32 genotypes were planted in split-plot arrangement in completely randomized design replicated thrice. Genotypes were maintained under 20% and 80% field capacities. Phenotypic and physiological data were collected, converted to ratios then analyzed on Genstat version 14.1 VSN International Ltd at a 5% level of significance. Significant differences were observed in winter and spring barley in terms of growth, tillering ability, grains formed per spike, 1000 seed weight and MSI (p < 0.05). Spring barley expressed higher tolerance to drought than winter barley especially in terms of height, number of grains per spike and seed weight. Water deficiency in cells and tissues might have altered and inhibited physiological and biochemical processes. The phenotypic and physiological methods corresponded and confirmed tolerance to drought in most winter and spring genotypes grown in Kenya.

Assessment of husbandry practice and egg production performance of indigenous chickens in urban and peri urban area of Guder town, Oromia Region, Ethiopia

The study was undertaken from May up to July 2020 in Guder town of Oromia regional state, Ethiopia. The aim of the study was to explore husbandry practices and egg production performance of indigenous chicken in the study area. A cross-sectional systematic random survey of 40 households was undertaken by using semi-structured and pre tested questionnaire. Information on management practices, production systems, egg production performances and constraints of indigenous chicken kept in Guder town was generated by semi-structured questionnaire. The primary data collected from house hold survey was processed and analyzed by using a statistical package for social science (SPSS) version 20.0 software. Descriptive statistics such as percentage, mean, ranking, standard deviation, and cross tabulation were used to analyze the data quantitatively. Data gathered through key informant interviews, focus group discussion and personal observation was analyzed qualitatively to strengthen data obtained from the household survey. Due to its small space and lower capital requirement sample household’s ranked chicken as the first important animals kept in the study area. The main purposes of keeping indigenous chicken in the study area were for home consumption followed by generation of income. The most important feed resources of indigenous chicken kept in the study area were feed obtained from scavenging, house hold wastes, the market left over, and industrial by products. Majority of the households accommodated their indigenous chicken in a separate house constructed for the confinement of the chicken. The higher mortality rate of indigenous chicken in the study area was caused by disease and predator. The most commonly happening and economically important disease in the study area was Newcastle. The commonly observed predators in the study area were cat and dog. Health and feed problems were the first and the second constraint of indigenous chicken production in the study area respectively. Therefore area based development involvement could help to increase the productivity of indigenous chicken and thereby improve the income of small holders.