Volume 8, Issue 4

Generation Mean Analysis of Net Blotch and Scald Diseases on Barley
Original Research
The information on the nature and magnitude of genes controlling the resistance to net blotch and scald in barley is useful in resistance breeding. Thus, field experiment was conducted at Holetta, Ethiopia in 2015 on barley using six basic generations of (P1, P2, F1, F2, BC1, and BC2) which was derived from ‘HB42’x‘Sabini’ parental cross which were evaluated in RCB design with three replications to investigate the gene actions and interactions gene effects involved in controlling resistance to net blotch and scald diseases in barley. The result of scaling tests and generation mean analysis indicated the predominance of non-additive gene effects including epistasis gene effects than additive gene effects for all parameters and this was also confirmed by variance component analysis. Moreover, the digenic epistatic model failed to explain variation in generation means for all parameters may due to the presence of higher-order interaction and linkages. In general, the results suggest greater influence of non-additive genes including epistasis in the control of both disease parameters studied making early selection ineffective. And ‘HB42’ cultivar contained double resistance to scald and net blotch diseases which needs further study for its exploitation as source of resistance in improving barley yield.
World Journal of Agricultural Research. 2020, 8(4), 142-149. DOI: 10.12691/wjar-8-4-6
Pub. Date: October 22, 2020
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Changing Pattern of Rainfall Amount and Raindays in Samaru, Northern Nigeria and Their Implications on Crop Production
Original Research
The rainfall amount and number of rainy days determines the length of growing season, which equally determines the types of crops to be planted in a particular region. This study analyzed the pattern of rainfall in Samaru Zaria, Kaduna State, Northern part of Nigeria from 1961-2017 using data collected from the Institute for Agricultural Research Samaru, Zaria. The result from this research reveals that an inverse relationship exists between the amount of rainfall and the rainy days. Hence, the higher the rainfall amount the lower the rainy days and vice versa. This is attributed to the current change in climate which increases the intensity of annual rainfall but shortens the duration of the rainy days. The equations generated for amount of rainfall pattern was (y= 3.162x - 5270.9) and number of rainy days was obtained as (y = -0.172x + 417.85). As expected, the months of November to March had the lowest mean rainy days (MRDs) <1 day. As a recurrent pattern for the period of study, the onset of appreciable rainy days was observed in the month of April and the number of rainy days increased steadily to reach its peak in August and a sharp decline in October. From the obtained data, the onset and cessation of rainfall could be predicted to fall towards the end of April and Septemberrespectively.
World Journal of Agricultural Research. 2020, 8(4), 134-141. DOI: 10.12691/wjar-8-4-5
Pub. Date: October 14, 2020
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Management of Bacterial Wilt Using Grafting Technique in Tomato (Ralstonia solanacearum)
Original Research
Tomato farmers have been facing a major threat of entire crop loss because of bacterial wilt of tomato. Grafting of highly productive scion onto resistant rootstock is one of the best methods to prevent crops from bacterial wilt disease. An experiment was conducted using tomato (RS-101) and eggplant (KER-DC-117) rootstocks grafted with six scion varieties in different combinations to make total of nine treatments replicated three times in completely randomized design in the naturally infected farmer’s fields at Dahachok, Nepal in 2019. All the three treatments with eggplant rootstock (KER-DC-117) were found to be resistant. Karma 777, Shrijana and Samjhana scions grafted onto tomato rootstock (RS-101) were moderately resistant, whereas Sarita and Karma 555 grafted onto tomato rootstock (RS-101) were moderately susceptible. Non-grafted Sarita was highly susceptible with 100% disease incidence. There were no bacterial browning and bacterial oozing in treatments with tomato rootstock (RS-101). The yield and number of fruits was maximum with Karma 444 grafted onto eggplant rootstock (KER-DC-117). So, Karma 444 + ER (KER-DC-117) is the best scion-rootstock combination to manage bacterial wilt against tomato at Dahachok, Kathmandu.
World Journal of Agricultural Research. 2020, 8(4), 129-133. DOI: 10.12691/wjar-8-4-4
Pub. Date: September 26, 2020
780 Views438 Downloads
Value Chain Analysis of Wheat (Triticum Aestivum) in Dembecha District, Ethiopia
Original Research
This study aimed to analyze the value chain of wheat in Dembecha district of West Gojjam zone. A total of 130 farm households, 30 traders, 2 bakers, 1 processor, 4 cooperatives and 10 consumers were used to collect the data. Functional and institutional approach of value chain analysis showed input providers, producers, cooperatives, collectors, wholesalers, retailers, and processors were found to be important wheat value chain actors. Four firms concentration ratio (CR4) was found to be 39.78% and there were information asymmetry and observed barriers to enter into wheat market. Buying, selling and pricing strategies showed deviation of wheat market from competitive market norms. Analysis of marketing margins revealed that processors received the highest (39.72%) marketing margin and retailers received the least marketing margins (4.85%) from consumers’ price. Even if wheat in the study area deviate from competitive market norms as a result of oligopolistic market structure and conduct, profitability analysis of wheat market showed all market actors operated at profitable level. Supporting farmers and increase productivity through practical research, develop pie-growing mechanisms among actors, founding agro-processing firm, providing infrastructural facilities, designing advance way of disseminating market information, determining appropriate pricing strategies should be done to strength value chain development.
World Journal of Agricultural Research. 2020, 8(4), 121-128. DOI: 10.12691/wjar-8-4-3
Pub. Date: September 26, 2020
685 Views427 Downloads
Evaluation of the Performance of Sweet Potato (Ipomoea batatas) Clones under Water Stress in the Coastal Lowlands of Kenya
Original Research
The production of sweet potato (Ipomoea batatas(L.) Lam.) in coastal Kenya is diminishing due to unreliable rainfall, coupled with farmers’ use of unimproved sweet potato varieties that are not drought tolerant. A study was conducted at Pwani University from 2016 to 2017, to identify sweet potato clones with best performance under low water stress. Nine clones (6.1A, 4.10, 7.8, 15.10, 7.6AO, 10.10B, 4.2B, 7.6B and 4.2A) and a farmer-preferred variety “Rabai” were evaluated under the following four water stress levels: (i) Watering for the first two months after planting and stressing the plants for the next three months - S3, (ii) Watering for the first three months after planting and stressing the plants for the next two months - S2, (iii) Watering for the first four months after planting and stressing the plants for the next one month - S1, and (iv) Watering throughout the growing period and not stressing the plants at all - S0. A randomized complete block design was used, with factorial arrangement of treatments. Treatments were replicated three times. Tuber circumference was reduced by low water stress irrespective of the time it started, relative to the growing season. Water stress that was imposed early in the season, at three or two months after planting, reduced tuber yield by about 52 and 70%, respectively. Sweet potato clones C2 and C8 performed relatively well across seasons, irrespective of the water stress level. Farmers are likely to realize improved tuber yields by planting sweet potato early in the rainfall season to ensure adequate soil water during the first four months of crop growth. Sweet potato clones C2 and C8 are therefore recommended for multi-locational trials in coastal lowland Kenya, to ascertain their performance across agro-ecological zones.
World Journal of Agricultural Research. 2020, 8(4), 114-120. DOI: 10.12691/wjar-8-4-2
Pub. Date: September 17, 2020
755 Views361 Downloads
Field Evaluation of Some Varieties/Accessions of Maize for Their Performances in a Derived Savannah Belt of Nigeria
Original Research
Vegetation growth is functionally dependent on climate. Though increased yields have been attained through plant breeding, yet it is well established that genetic factors alone cannot cause a plant character to develop to its maximum potential without a favorable environment. Plants can be made to adapt to conditions which deviate from their natural habitat through breeding and acclimatization. Three local, Oba super-2 hybrid and seventeen maize accessions/varieties newly developed by the Institute for Agricultural Research (IAR) Samaru Zaria, in collaboration with the International Institute of Tropical Agriculture (IITA), for the northern guinea savanna belt, were evaluated for their relative yield performances in the derived savanna belt of Nigeria. The assessments were carried out at the Department of Crop Science teaching and research farm, University of Nigeria, Nsukka. Parameters assessed include field germination percentage, days to first tassel appearance, days to fifty percent tassel appearance, days to fifty percent silking, percentage, double cob per stand, percentage triple cob per stand, plant height, days to maturity, percentage harvest index, cob weight, grain weight per ear e.tc. Correlation and path analysis were used to ascertain the degree of association of traits with yield. Biomass weight was observed to have the highest direct positive influence on yield. Therefore, varieties with high biomass weight (Sammaz-14, 17 and 18) consistently produced high yield. This results could be useful to breeders as they work to produce maize varieties that will perform better in the derived savanna zone of the country. That will make for increased availability and choice of planting materials for farmers and ultimately, increased productivity and sustainability of maize production in the derived Savanna Zones of Nigeria. Further screening of these accessions should also be encouraged in the zone until adaptation is established.
World Journal of Agricultural Research. 2020, 8(4), 105-113. DOI: 10.12691/wjar-8-4-1
Pub. Date: September 09, 2020
686 Views425 Downloads