American Research Journal of Agriculture

A. M. M. Al-Naggar1, R. Shabana1, M. M. Abd El-Aleem2 Zainab A. El-Rashidy2

Breeding of low-N tolerant cultivars of wheat is one approach to reduce N fertilizer input, while maintaining acceptable yields. The objective of this investigation was to develop new bread wheat genotypes (transgressive segregants) of high grain yield under low-N stress conditions. Seventy fiveF3 families were selected for high grain yield fromF2populations of diallel crosses among 6 parents under low-N and high-N and evaluated for grain yield and nitrogen use efficiency (NUE) traits in their F3progenies compared with their parents under both high and low N conditions, using a split plot design in lattice (9 x 9) arrangement with three replications. The best F3 families (4) that exhibited the highest grain yield and NUE under low-N as well as under high-N and exceeded significantly their better parents in the respective crosses were identified. They were all selected under low-N conditions and were significantly superior over their respective better parents. Actual significant superiority over the better parent in grain yield/plant ranged from 21.5% for SF11 to 33.7% for SF13 under low N stress and from 14.2% for SF14 to 25.3% for SF11 under high-N conditions. Actual gain from selection for high yield in the best F3 selected families is higher than corresponding expected genetic gains under both low-N and high-N.Superiority in grain yield over better parent were attributed to their high superiority in number of spikes/plant reaching to 80.1%, number of grains/ spike reaching to 31.2% and 100-grain weight reaching to 50.9% under low-N target environment. Selection in F2 populations under low-N for high grain yield caused simultaneously a superiority in NUE, which reached to 30.4% under low-N and 22.7% under high-N environment. Moreover, superiority of the best selectants in grain yield and NUE traits was associated with superiority in grain protein concentration in most cases, which reached to 45.9 and 47% superiority for SF13 under low-N and high-N, respectively over the better parent.

A. M. M. Al-Naggar1, R. Shabana2, M. M. Abd El-Aleem3 and Zainab El-Rashidy4

Grain yield and grain protein content (GPC) of bread wheat are crucial determinants of its profitability and product quality. In general, low levels of nitrogen fertilizer result in a lower protein content in wheat grains and lower grain yield. The main objective of this investigation was to get information on gene action, heritability and expected genetic advance from selection (GA) for GPC and grain yield/plant (GYPP) under contrasting soil- nitrogen conditions. Diallel crosses in F1 and F2 generations among six contrasting wheat parents in GPC and GYPP were evaluated in field experiments across two seasons in a split plot design under two N levels, i.e. low-N (0kg N/fed) and high-N (75kg N/fed). In both F1's and F2's, the magnitude of dominance (H1) was much greater than that of additive (D) component for GPC under both high N and low N and GYPP under high-N, while the opposite was true for GYPP in F1's under low-N, where the additive was greater than dominance variance and GYPP in F2's under low-N, where the additive and dominance components were approximately equal. The average degree of dominance (H1/D)1/2 in F1's was in the range of over-dominance, except for GYPP under low N, which showed partial dominance, but in F2's was in the range of partial dominance for GYPP under both high and low N and GPC under high N, while GPC under low N showed no dominance. Narrow-sense heritability (h2 n) in F1's and F2's was generally of low magnitude; it ranged in F1's from 6.18% (GPC under low-N) to 20.41% (GYPP under high-N); the exception was GYPP under low-N, where h2 n was of high magnitude (67.14%) and ranged in F2's from 10.86% for GPC under low N to 46.90% for GYPP under low-N. The h2 n was higher under low--N for GYPP and under high-N for GPC. In F1's, the values of GA were higher under low-N than under high N for GYPP, but were higher under high-N than low-N for GPC. In F2's, the values of GA for both traits were higher under low-N than under high-N, suggesting that it is better to practice selection in F2's for both traits under low-N conditions to obtain higher values of selection gain. 

YEBOUE N’Guessan Lucie1*, SORO Senan12, TRA BI Crolaud Sylvain1 

Heteroptera Coreidae are all phytophagous insects. They are both meet on cultivated and wild plants. The objective of this study was to identify the Coreinae on the different crops grown in Côte d’Ivoire, evaluate the damage on these plants and identify wild plants that serve as their refuge in the absence of crops. The samplings were carried out in areas cultivated across different regions and in the reserve of Lamto. The insects were captured using a sweep net, a harvesting cage and threshing technics. The catching were once a week in different areas during one year. The results indicate that among Coreinae harvested, Anoplocnemis curvipes, Homoeocerus pallens, Leptoglossus membranaceus and Pseudotheraptus devastans were the mostly encountered on the prospected plants. The polyphagous species was A. curvipes with over than 60 host plants identified. Gossypium barbadense was the most infected by the Coreinae, followed by Cocos nucifera and Vigna unguiculata. The damage caused by these insects on the plants and the yields are function of their number in the field. 

Didem Göktürk1, Tomris Deniz 

Artificial reef which is a human made underwater structure are used in fisheries management to provide new habitats, increase number and biomass of depleted fishery resources, restore habitats, prevent from illegal fishery, reduce fishing pressure on the fish stock and possibly decrease deterioration of habitats. Fish telemetry offers a number of advantages to reveal novel information on fish behaviour in aquatic habitats for tracking the movement of species. In terms of artificial reefs applications, telemetry is important for monitoring fish movement. In the present review we aimed to focus on fish telemetry studies performed on artificial reefs in Turkey.

A.A GIREI1., M. SALIHU., AND U. SALAMATU 

The research determined the structure and performance of cowpea marketing in Yola North and South Local Government Areas of Adamawa State, Nigeria. Primary data was used for the study which was generated using structured questionnaires that were administered on 75 respondents. The cost and returns of cowpea wholesaler revealed that, wholesale cowpea marketers were efficient as shown by the positive sign and magnitude of the gross margin and net incomes while, that of the retailers were lower than those of wholesalers. The results of the marketing margin indicates that wholesalers had lower margin than that of retailers, although the overall marketing margin which was computed to be about 11 percent was higher than that of wholesalers. Therefore, the research concluded that marketing of cowpea in the study area is profitable as determined by the positive sign and magnitude of the gross margin. However, a low marketing margin was obtained in the study, which is an indication of pricing efficiency by the marketers. Hence, market structure of wholesalers of cowpea in the study area was competitive, while that of retailers was not. The study therefore recommends that, Cowpea marketers should have easy access to affordable credit facilities so as to expand their marketing activities. Modem storage facilities and the use of airtight containers should be encouraged among marketers for sustainable cowpea storage so as to improve it shelf life.

A.M. M. Al-Naggar1*, R. Shabana1, M. M. Abd El-Aleem2, B.Zainab A. El-Rashidy2

Because of high production cost of nitrogen (N) fertilizer and prevention of environmental pollution, it is important to improve N use efficiency (NUE) of wheat (Triticum aestivum L.). The objective of this study was to evaluate NUE traits of 6 x 6 diallel wheat F2 progenies and parents at low (LN, no N fertilizer) and high (HN,75 kg N/fed) N levels. Two experiments were conducted during two seasons, the 1st under HN and the 2nd under LN using RCBD in three replications. Data analyzed across seasons indicated that L25, L26 and L27 showed high values of nitrogen use (NUE) and uptake (NUPE) efficiency and the best general combining ability (GCA) effects for these traits. The best F2 crosses in per se performance and specific combining ability (SCA) effects were L26 x Gz168, L27 x Gem7, L26 x L27 and L25 x Gz168). Mean squares due to both GCA and SCA were significant under both low-N and high-N for all NUE components, but the magnitude of GCA was greater than SCA, indicating that additive is more important than non-additive genetic variance in controlling the inheritance of NUE, NUPE, nitrogen utilization efficiency (NUTE) and nitrogen harvest index (NHI) traits. The results indicated that under low-N and high-N, the mean performance of a given parent is an indication of its general combining ability and the mean performance of a given F2 cross is an indication of its specific combining ability effects for all studied NUE components. 

A. M. M. Al-Naggar1, R. Shabana2, M. M. Abd El-Aleem3 and Zainab El-Rashidy4 

Developing high-yielding wheat varieties under low-N requires adequate information on the nature of combining ability of available genotypes and the types of gene actions involved in the expression of grain yield and quality traits under such low-N stress. The objective of present study was to get information about performance and general (GCA) and specific (SCA) combining ability variances and effects for grain yield and quality traits of wheat to help its improvement under low-N environment. Two experiments were conducted during two seasons, the 1st under high-N (75 kg N/fed) and the 2nd under low-N (0 kg N/fed) using a randomized complete block design with three replications. The entries included six Egyptian wheat genotypes differing in low-N tolerance and their F2 diallel crosses (without reciprocals). Data analyzed across seasons indicated that L25, L26 and L27 had high values of grain yield and quality traits and showed the best GCA effects for these traits. Under low-N, the best F2 crosses in per se performance and in SCA effects were L25 x L27, L25 x L26 and L26 x G168. Mean squares due to both GCA and SCA were significant under both low-N and high-N for all studied traits, but the magnitude of GCA was greater than SCA, indicating that additive is more important than non-additive genetic variance in controlling the inheritance of all studied grain yield and quality traits. The results indicated that under low-N and high-N, the mean performance of a given parent is an indication of its general combining ability and the mean performance of a given F2 cross is an indication of its specific combining ability effects for all studied grain yield and quality traits.  

A. M. M. Al-Naggar1 *, R. Shabana1, M. M. Abd El-Aleem2 and Zainab El-Rashidy3

Developing high yielding varieties of bread wheat under low soil-N conditions is an important goal for plant breeder in order to overcome the negative impacts of using high rates of N fertilizers. This will lead to a significant reduction in nitrogen fertilizer use. The objective of this investigation was to study the effects of low-N environment (E), genotype (G) and G x E interaction on grain yield and quality traits of wheat F1 and F2 diallel crosses and their contrasting parents in N use efficiency. Genetic materials were evaluated at two seasons (2007/2008 and 2008/2009) in a split-plot design with lattice arrangement, using three replications. Main plots were assigned to N levels (0 and 75 kg N/fed), while sup-plots were devoted to genotypes. Data were analyzed across the two seasons. Low-N caused significant reductions in all studied grain yield components and grain protein content (GPC) in parents, F1's and F2's. The lowest reduction occurred in harvest index (HI), while spikes/plant (SPP) showed the greatest reduction, indicating that SPP is the most determinant component of GYPP. The first three parents L25, L26 and L27 showed significantly higher means than the second three parents Gem7, Gem 9 and Gz168 for most studied grain yield components and GPC trait. The F1 and F2 crosses involving one or more of the first three parents showed higher values of one or more of grain yield component traits than crosses that involved parents of the second group. In general, F1 crosses showed higher means for all studied grain yield and quality traits than their parents. The rank of crosses in F1 and F2 generation for most studied traits was changed from one environment (N-level) to another, indicating a significant G x N interaction. Some F2- progenies under N-limited environment exhibited higher values of GYPP and HI, suggesting transgressive effects in these characteristics, and that selection practiced in such F2 populations could be effective in developing low-N tolerant genotypes.

A. M. M. Al-Naggar1 *, R. Shabana1, M. M. Abd El-Aleem2,Zainab A. El-Rashidy2

Breeding wheat (Triticum aestivum L.) cultivars with improved adaptation to low-N fertilization has gained importance worldwide. This study aimed at investigating the per se performance of nitrogen use efficiency traits, the relative importance of general (GCA) and specific (SCA) combining ability in a set of wheat cultivars and promising lines and their F1 diallel crosses. Parents (6) and F1's (15) were evaluated in in two seasons in two separate experiments using randomized complete block design with three replications; each experiment under one level of N ( 0 or 75 kg N/fed). Results across seasons showed that the rank of crosses in F1 generation for most studied traits was changed from one environment (N-level) to another, indicating a significant G x N interaction. In general, means of NUE, and NUPE of the three parents L25 , L26 and L27 were higher in magnitude than those of the three other parents Gem 7, Gem 9 and Giza 168 under both high-N and low-N levels. Both GCA and SCA mean squares were significant, but the magnitude of GCA was higher than SCA, for all studied traits under the two levels of N, except GPC under low-N, suggesting the existence of a greater portion of additive than that of non additive genetic variance in controlling the inheritance of these traits under the two levels of nitrogen. In general, the best general combiners in F1's for NUE and NUPE were L26 followed by L27 and L25 parents under both high-N and low-N. Under low–N conditions, the best SCA effects were shown the by F1's L25 x Gz168 for NUE and NUPE, L2 x Gem9 and L27 x Gem9 for NUPE and L25 x L 26, L25 x L27 and L27 x Gem9 for NUTE trait. Results indicate that under both N-levels, the best performing parents for grain yield and nitrogen use efficiency and their components are also the best general combiners and vice versa. But under high-N only, the mean performance of a given F1 cross could be considered an indication of its SCA effects. 

Gebrerufael Girmay1*

 Ethiopia is an ancient country with unparalleled history. It has introduced and practiced agriculture no later than the first. However, the country is still one of the poorest agrarian countries to date in the world. This is simply because the country has failed to transform the smallholder subsistence agriculture. This comprehensive literature review synthesis why the subsistence smallholder agriculture persists in the country. The paper focuses on agricultural development policy issues and practices.