International Journal of Agriculture and Biosciences

This work is a comparative study of germination under salt stress conditions on two halophilic species of the Amaranthaceae family; Atriplex canescens (Pursh) Nutt and Atriplex halimus L. Seeds were treated with NaCl at 600- and 900-mM concentrations and stored in an oven at 25°C for 10 days. Observations focused mainly on the germination capacity, the velocity coefficient, the latency, the average germination time and the length of the seedlings. After the reversibility test, we recovered the seeds not germinated under saline stress in order to submit them to an environment without NaCl. Results show that increasing the NaCl concentration reduces significantly the germination capacity of the seeds. Without NaCl, the final germination rate of the seeds of Atriplex canescens (Pursh) Nutt and Atriplex halimus L. varies from 100 to 95% respectively; while this rate drops with salinity for the seeds of Atriplex canescens (Purch) Nutt and becomes zero for Atriplex halimus L. The capacity and the average speed of germination decrease as the salinity increases. In addition, salinity negatively influences the emergence of the vegetative system of the two species of Atriplex. Regarding the reversibility test, the results show that the two species of Atriplex are affected by osmotic and toxic depressions.

Keywords: Atriplex canescens (Pursh) Nutt; Atriplex halimus L.; germination; halophyte; NaCl; reversibility; stress.

A genotype x environment interaction is a change in the relative performance of a character of two or more genotypes measured into two or more environments. Living organisms are made up of genes whose expressions are subject to modification by environment; therefore, genotypic expression of a phenotype is environmentally dependent. This is because genotypes exhibit different level of phenotypic expression under different environmental conditions resulting in cross over performances. In genotype x environment interaction, the magnitude of the observed genetic variation changes from one environment to another and tends to be larger in better environments than poor environments. Genotype x environment interaction is a fundamental component in understanding complex trait variation and the most challenging factor in identification of genetic variation. Interaction involves a change in rank order for genotypes between environments and the relative magnitude of genetic, environmental and phenotypic variance between environments. Genotype x environmental interaction can lead to differences in performance of genotypes over environments. The relationship between selection environments and target production environment had been a major problem because many of the selected activities performed by the conventional approach. Genotype x environment interaction analysis can be used to analyze the stability of genotypes and the value of test locations. Genotypes by environment interactions are almost unanimously considered to be among the major factors limiting response to selection and, in general, the efficiency of breeding programs. Exploitation of genetic variability is the most important tool in plant breeding and this has to be inferred by phenotypic expression. The consequences of the phenotypic variation depend largely on the environment. This variation is further complicated by the fact that not all genotypes react in similar ways to change in environment and no two environments are exactly the same. If relative performance of genotypes grown in different environments is different, then genotype x environment interaction becomes a major challenging factor to crop breeding programs. Genotype x environment interaction is one of the main challenges in the selection of broad adaptation and stable genotypes in most breeding programs. The varietal stability could be challenged not only due to the change in the test environment but also due to change in growing season per environment. Some environmental variations are predictable (soil type, soil fertility, plant density) whereas others also may be unpredictable (rainfall, temperature, humidity). Generally, genotype x environment interaction is the most critical in plant breeding to make selection of genotypes based on their adaptability and stability for desirable traits.

Keywords: Genotype x Environmental Interaction; Environment; Phenotype; Genotype; Interaction; Variation.

Yield and quality of onion seeds is highly affected by environmental conditions during growth and development. Therefore, field experiment was conducted in Axum district for two consecutive years from 2016 to 2017 cropping season to assess influence of bulb planting time (September 30, October 15, October 30, November 15, November 30, December 15 and December 30) on growth, yield and seed quality of onion. The experiment was laid out in a randomized complete block design with three replications. The combined analysis revealed that planting time of onion bulb influenced all the parameters scored significantly (P<0.01). Delaying planting time of onion bulb significantly enhanced earliness of both days to bolting and flowering, where the maximum values was observed in planting time of October 15 (69.92 and 84.89, respectively). Thus, planting time of September 30 induce late maturity (144.83). On the other hand, their minimum days were obtained from late planting time of December 30 (56.67, 65.67 and 128.00 respectively). In line with this, across the different planting time highest values of plant height, stalk height, flower stalk per plant, stalk diameter, umbel diameter, yield, seed yield per plant and thousand seed weight (83.35 cm, 76.90 cm, 7.73, 7.05 mm, 58.55 mm, 27.72 qt/ha, 13.59 g/plant and 3.4 gram respectively) was observed in planting time of September 30. However, their least values (67.93 cm, 67.93 cm, 6.75, 5.83 mm, 48.40 mm, 14.65 qt/ha, 6.05 g/plant and 2.27 gram respectively) was attained in the planting time of December 30. As recommendation, early planting time of September 30 was appropriate planting time to produce high and quality seed yield of onion in Central Zone of the Tigray region.

Keywords: Onion, Planting time, Seed yield, Quality and maturity.

Rice (Oryzae sativa L.) is by far the most stable food crop for over half of the world society, they are dependent for half of their calorie, and its production is enhancing gradually even with in developing nations. Rice sheath rot is a disease complex which can be caused by fungi (Sarocladium oryzae) pathogen and it infects the upper most important plant part (panicle). The study was aimed to evaluate the efficacy of different fungicides and recommend the most effective ones. The experiment was conducted at Fogera National Rice Research and Training Center experimental station for two consecutive years (2017-2019) using X-Jigina cultivar. Nine treatments, four seed dressing (carboxin+ thiram + imidacloprid, imidacloprid + tebuconazol, thiamethoxam 20% + metalaxyl- 20 % + ifenoconazol 2% and imidaclopride 250 gm/kg) and four foliar applied fungicides (epoxiconazole + thiophanate-methyl, mancozeb + metalaxyl WP, tebuconazole, and mancozeb 80% WP were used including untreated check. The treatments were arranged in randomized complete block design with three replications. Disease incidence and severity data were recorded before maturity of the crop in 0-9 scale. The result revealed that seed dressing fungicides were by far better over foliar fungicides. Proseed plus 63 WS (carboxin+ thiram + imidacloprid), Joint 246 FS (imidacloprid + tebuconazol) and ImidalmT 450 WS (imidaclopride 250 gm/kg) fungicides were effective against rice sheath rot disease control, respectively. Furthermore, the study had proved that the highest marginal rate of return was obtained from application of Imidaclopride 250 gm/kg fungicide which was 32.17 extra birr beyond covering cost of investment. In a net shell, effective seed dressing fungicides were much better to manage rice sheath rot disease since its source of transmission is seed.

Keywords: Rice diseases, Sheath rot, Fungicides, Disease incidence, Disease severity, Seed dressing, Disease control.

Tamarix L is the largest genus within the family Tamaricaceae. In this study, we try to simulate the phylogenetic relationships of Tamarix species using the nuclear internal transcribed spacer (ITS) sequences and projecting them to Algeria. The internal transcribed spacer (ITS) sequences were obtained from the GenBank to identify the relationships among Tamarix taxa. The phylogenetic trees were constructed using Neighbour-Joining (NJ) and Maximum Parsimony (MP) inference methods and were found to have very identical topologies. The phylogenetic analyses divide the Tamarix species into two clades. The results of this study revealed that this genus constituted a monophyletic group. This study reveals that phylogenetic analysis of the Tamarix genus in Algeria is not based solely on molecular analyzes. The substitution of a bio-morphological analysis proves complementary in order to effectively distinguish the different species, especially hybrids.

Keywords: Algeria, ITS, Monophyly, Phylogenetic relationships, Tamariacaceae, Tamarix species.

Potato (Solanum tuberosum L.) is one of the most important food security and cash crops in Ethiopia. However, its productivity is generally low. The low yields of the crop could be attributed to a number of factors among which low soil fertility is an important constrain and there is little information on the type and rates of fertilizers to be applied for optimum production of the crop under different agro-ecological conditions of the country. Therefore, an experiment was conducted at Bore Agricultural Research Center, Southern Ethiopia during the 2018 and 2019 cropping season to determine the effect of blended NPS and potassium fertilizer rates on potato, and to assess the cost and benefit of different rates of blended NPS and potassium fertilizers on potato. The treatments consisted of six rates of blended NPS (0, 100, 150, 200, 250 and 300 kg NPS ha-1) and three rates of potassium (0, 100 and 200 kg KCL ha-1) fertilizers, plus100 kg Urea ha-1 applied to all plots equally. The experiment was laid out as a Randomized Complete Block Design (RCBD) in a 6*3 factorial arrangement replicated three times. An improved potato variety called Gudanie (CIP-386423-13) was used as a test crop. The two years analysis of the data revealed that the main effects of blended NPS and potassium fertilizers influenced significantly (P<0.01) plant height, number of main stems per hill, average tuber number per hill, marketable and total tuber yields).However, the two fertilizers did not interact to influence all measured parameters of the crop. The highest marketable tuber yields were obtained in response to the application of 200 kg blended NPS ha-1 (34.63 t ha-1) and the application of 200 kg ha-1 KCL (36.39 t ha-1). On the other hand, the lowest marketable yields of while lowest marketable yield 23.67 t ha-1 and 26.01 t ha-1were obtained in response to the application of nil applications of the two fertilizers respectively. The partial budget analysis revealed that application of 200 kg ha-1 blended NPS and 200 kg KCL ha-1 resulted in the net benefits of 369,654and 389,262ETB ha-1with 2968.69 and 2693.60.00% marginal rate of return respectively. The application of 200 kg KCL ha-1 (200 kg KCL + 46 kg N ha-1) or application of 200 kg blended NPS with 46 kg N ha-1(84 kg N ha-1 + 76 kg P2O5 +14 kg S ha-1) fertilizer rates led to optimum potato tuber production, economic returns and recommended for potato growers in the highland areas of Guji zone.

Keywords: Gudanie, Marketable tuber yield and Partial budget analysis

Thirty-six single cross hybrids that generated by crossing nine double haploid inbred lines during the main cropping season of 2016 were evaluated at Ambo and Kulumsa agricultural research centers during the main season of the year 2017 in 8 X 5 Alpha Lattice design with two replications. The objective was to determine the phenotypic and genotypic association among traits in highland adapted maize inbred lines and to compare the direct and indirect effects of traits on grain yield. Analyses of variances showed significant mean squares due to crosses for most traits studied indicating the existence of sufficient genetic variability which can be exploited in future breeding programs. Grain yield revealed positive and highly significant (P<0.01) phenotypic and genotypic correlation with number of ears per plant, ear length, number of kernels per row and thousand kernel weight. It had also highly (P<0.01) significant positive association with ear diameter at phenotypic level and had positive and highly significant genotypic correlation with plant height and ear height. Path coefficient analysis revealed that plant height, number of ear per plant, ear length, ear diameter and thousand kernels weight had a positive direct genotypic effect on grain yield. Number of ear per plant, ear diameter, ear length, number of kernels per row and thousand kernels weight exerted positive and direct phenotypic effect on grain yield and also indicated positive and strong association with grain yield indicating that they can be used for indirect selection of inbred lines having higher yield potential.

Keywords: Correlation, Double haploid, Hybrids, Path coefficient.

Food is an essential requirement, and the demand for food shall keep on increasing with the increase in population. The classical breeding programs have contributed enormously to the improvement of various livestock and crops, and subsequently molecular genetics which today constitutes the basis of genetic engineering research has added new direction to livestock and crop improvement. Genetic engineering is the process of genetic modification of organisms through transferring genetic material from one organism to another organism in order to change an organism’s characteristics to the desired traits. A genetically modified organism (GMO) is an organism (plant, animal or microorganism) whose genetic material has been altered using gene or cell techniques of modern biotechnology. Genetic engineering is the improvement program which enhances the efficiency of crop improvement relative to conventional phenotypic selection by changing the focus from the paradigm of identifying superior varieties to a focus on identifying superior combinations of genetic regions and management systems. Plant biotechnology facilitates the farming of crops with multiple durable resistances to pests and diseases, particularly in the absence of pesticides. Likewise, transgenes or marker-assisted selection may assist in the development of high yielding crops, which will be needed to feed the world and save land for the conservation of plant biodiversity in natural habitats. Hence, crops should be engineered to meet the demands and needs of consumers. The genetic base of crop production can be preserved and widen by an integration of biotechnology tools in conventional breeding. Similarly targeting specific genotypes to particular cropping systems may be facilitated by understanding specific gene-by environment interaction(s) with the aid of molecular research. High quality crops with improved nutritional and health characteristics as well as other aspects of added-value may be obtained through multidisciplinary co-operation among plant breeders, biotechnologists, and other plant scientists. Generally, the world population is increasing alarmingly, but productivity is reduced because of several production challenges. Hence, conventional animal and plant breeding methods alone cannot address the serious challenges that the world is facing. Therefore, in order to overcome the food security problems, conventional breeding methods should be assisted and integrated with various biotechnology developments to hasten the genetic improvements. To ensure the rapid and advanced agricultural development within short period of time, the incorporation of genetic engineering in animal and plant breeding is very relevant in the future world. Genetic engineering is not about the replacement of conventional breeding rather than integrating with it in order to make further improvement. There are various challenges in relation to the application of genetic modifications because of its costs in large scale utilization especially in developing countries. The integration of genetic engineering into conventional breeding program is an optimistic strategy for agricultural improvement in the future.

Keywords: Recombinant DNA; Gene cloning; Vectors; Host organism; Gene therapy.

Organic wastes are generally believed to constitute aesthetic, environmental and health problems. To abate these problems, boost the economy of the nation and provide employment to our teeming population, one out of the many samples of organic materials lying waste was chosen for fertilizer production. Fresh sample of rumen content of cow was collected, dried, ground and analyzed for nitrogen, phosphorus and potassium. 10kg of the sample was then composted in two pits with other organic waste materials namely wood, ash, fish scraps and poultry droppings for 28 days. The composted sample was dried and analyzed for the above mentioned elements. Cow bone was also dried, burnt, ground and analyzed similarly. The composted rumen content and bone sample were then compounded in the ratio of 70%:25% by weight. A granulated organic fertilizer with N, P, K value of 9.6 and 4 was obtained with a pH range of 6.5-7.5, good handling characteristics and 19% weight efficacy.

Keywords: Organic fertilizer, Organic Wastes, Rument content, Cow bone.

The present study was conducted with the objectives to evaluate the efficacy of various disinfectants against bacterial flacherie and grasserie diseases of mulberry silkworm. These were evaluated against the diseases at Melkassa Agricultural Research Center laboratory from 2017 to 2018. The treatments were arranged with CRD in three replications. Significant differences were observed among the treatments. Maximum reduction in mortality (17.1%) was recorded from Sodium hypochlorite (NaOCl) at 0.01% concentration. Among considered combinations of lime and vim, high mortality reduction was recorded from combination of 50% lime * 50 vim (43.6%) which was at par with 40% vim * 60% lime (45.8%). Findings illustrated that the tested disinfectants were effective for reduction in mortality of silkworm diseases. Thus, they seem to be effective for the controlling of silkworm diseases and have the potential to be a vital component of integrated management of the diseases.

Keywords: Mulberry silkworm, Pathogen, Mortality, Disinfectant.