American Journal of Agricultural Research

  • Space breeding in modern agriculture

    Space breeding, also known as aviation breeding or space technology breeding, is a new type of breeding technology developed in recent decades, which combines space technology, modern agricultural technology and biotechnology. Compared with traditional breeding technology, it can greatly improve the quality of agricultural products in a short period of time, create many high-quality provenances, well solve the problem of food shortage, and bring endless benefits to the world. Therefore, space breeding technology will play an important role in the rapid development of modern agriculture. In this paper, the principles and characteristics of space breeding, development status and future prospects at home and abroad are introduced.

  • Combining Ability and Gene Action of Tomato Hybrids (Lucopersicum Esculantum L.) Genotypes in Azerbaijan

    This work identifies the combining ability of 10 tomato (Lucopersicon esculantum) parents and 45 F1 hybrids obtained from 10 × 10 half diallel. The work aims to identify the parents with the best general combining ability (gca) and crosses with high specific combining ability (sca) for yield, quality and nature of gene action involved. The study was conducted within 2014 and 2017 at Absheron condition in Azerbaijan using randomized complete block design (RCBD) with three replications. The combined analysis of variance showed that variance for gca and sca was highly significant for all the traits studied. This indicates that both additive and non-additive gene actions were operating in the inheritance of these traits. Parental level of gca revealed that introduced genotype (Masalli variety-form) had highest (5843.87) effect followed by Belarusian variety ‘Qarant’ (1930.97) for fresh pod yield and other related traits. The highest sca for hybrids was exhibited by Masalli variety-form x Ilkin, ‘Leyla x Masalli variety-form, ‘Shahin’ x Volqoqrad and Zorka x Shakar for yield and quality traits. This indicates the existence of immense potential for population improvement and heterosis breeding for enhancing productivity and qualities. The ratios of gca mean square to sca mean square were higher than unity for traits, indicating that additive gene action plays a predominant role in the inheritance of most of the traits.

  • Evaluation of some sugar beet varieties under different irrigation intervals

    The present study was conducted in at the experimental farm of the Sakha Agriculture Research Station, Kafr Elsheikh, Egypt during two growth seasons, 2015/16 and 2016/17 using split plot design to evaluate five of sugar beet varieties (Gloria, Toro, Almaz, Betamax and Demapoly) under different irrigation regimes (4 ,6 and 8 irrigations) in north delta. The treatments significantly affected on different characters, irrigation the plants six irrigations were superior than other ones in root length, root diameter, root weight , root yield and sucrose % values. On the other side, Betamax variety was the best for studied characters compared with other varieties.

  • Effects of Compaction at Different Moisture Contents on Selected Soil Properties and Sugarcane Growth and Sugar Yield at Metahara Sugar Estate

    Although soil compaction has been reported as one of the most serious problems in mechanized sugar cane production, its impacts on soil physicochemical properties and plant growth and sugar yield have not been quantified in the Ethiopian Sugar Estates. A field experiment was conducted in 2016 at Metahara Sugar Estate with the objective of evaluating the effects of initial soil moisture content and number of tractor passes on compaction and resulting impact on selected soil physicochemical properties and sugarcane growth parameters and sugar yield. The field experiment consisted of factorial combinations of compacted soils at three different soil moisture levels (on 4th, 8th and 12th days after irrigation) and six tractor traffic passes (0, 4, 8, 12, 16, and 20 passes) which were replicated three times. The result of the study showed that the highest mean values of dry bulk density and penetration resistance were recorded in plots compacted by twenty to and fro passes of tractor. Both bulk density and penetration resistance showed non-linearly increasing pattern with increasing number of passes. The tallest (196 cm) and shortest (171 cm) cane at the age of 8 months were recorded, respectively, in plots with zero and 20 passes of tractor. Significantly higher values of sugar yield were recorded in plots with zero number of passes (control). Imposing of different number of passes on 4th and 8th days after irrigation gave significantly lower yield than the 12th day after irrigation. Bulk density of the studied farm fields recorded after compaction by 20 traffic passes on the 8th day after irrigation, which corresponded to a gravimetric moisture content of 29.30%, was in excess of the root restriction initiation level. These results imply that it is advisable to avoid field operations involving Magnum 315 tractor on light soils before the 8th day after irrigation…

  • Mineralization of phosphorous by phosphate solubilising bacteria isolated from a vertisol

    The current experiment unravels P solubilisation potential of soil under long term fertilizer application. Soil samples collected from a 20 years old long term experimental field. Treatments included fallow (no fertilizer, no crop), control (no fertilizer, with crop), 100% N, 100% NP, 100% NPK, and 100% NPK+FYM. P solubilisation potential of soils determined using Ca3(PO4)2 as inorganic insoluble P source. Abundance of total bacteria, phosphate solubilising bacteria (PSB) estimated along with the efficient PSB isolated to evaluate P solubilisation potential using Ca3(PO4)2, rock phosphate and sodium phytate as P sources. P solubilisation rate was highest in 100% NP and lowest in fallow. Abundance of total eubacteria and phosphate solubilizing bacteria (PSB) was high in 100% NP and low in fallow. The 16S rRNA sequences of the isolates were homologues to Paraburkholderia sp. The efficient PSB isolate solubilised Ca3(PO4)2, rock phosphate as well as sodium phytate. Acid phosphatise activity was highest in Ca3(PO4)2 and lowest in sodium phytate. Study concludes that P solubilisation in vertisol under long term fertilizer application is regulated by nutrients, particularly P fractions and abundance of PSB. The PSB solubilise different P sources by reducing pH of medium as well as through acid phosphatase attributes.

  • The Role of Property Rights to Grazing Lands in Small-Scale Farmers Development in Taung, Maralleng in Mohale’s Hoek

    Property rights are social institutions that define and delimit the range of privileges granted to individuals of specific resources, such as land and water. They are the authority to determine different forms of control over resources thus determining the use, benefits and costs resulting from resource use. The paper has attempted to determine how the situation of property rights to grazing lands affects the grazing lands’ use and development of smallholders in the Taung Maralleng area. Data was collected from 43 households who were selected using random sampling. To capture data, a questionnaire was administered through face-to-face interviews. Institutional analysis and ANOVA were used for descriptive analysis to describe the property rights situation, security of property rights and the impact of property rights on the grazing lands’ use and management. The results show that some rights holders have secure rights to grazing land resources while other farmers have insecure rights to grazing land resources. The results from institutional analysis show that the situation of property rights negatively affects resource use and management in the Taung Maralleng area. There are various institutional factors that negatively affect development of smallholder farmers and grazing lands’ use and management in the Taung Maralleng area.

  • AN ANALYSIS OF INSTITUTIONAL FACTORS INFLUENCING PARTICIPATION IN MILK MARKETS: CASE OF MASERU URBAN

    The study was undertaken with the purpose of investigating institutional factors influencing participation in milk markets in Maseru urban. Out of 30 dairy farmers, 30 were selected using a survey method and data was collected using a structured questionnaires. The data generated was analysed using both descriptive statistics and logit model. Descriptive results show that dairy farmers use formal market channels more than informal market channels. Empirical results show that market information, membership in organization and collective action, government support and contractual agreements influence participation in formal markets while social capital, path dependency, delayed payments and distance to milk collection centres influence participation in the informal markets.

  • Modelling of unsteady spatially distributed drying parameters assessed non-destructively in a small industrial food dryer

    Modelling of unsteady moisture diffusion in relation of product temperature become complex due to complexity involve in solving complex numerical equations. In this study, a simplified methodology (determination of drying parameters: lag factor and drying constant) used to model change in food quality with its temperature in an industrial dryer using potato slices (6mm thick, 60°C). A shiftable real time data acquisition box was developed. Linear and exponential models were developed to estimate product quality as a function of dimensionless moisture ratio, linked with change in product temperature. The experimental and models predicted color kinetics using variable values of lag factor and drying constant revealed good correlation coefficients (R2 = 0.88-0.99, P ˂ 0.0001). The change in spatially distributed quality parameter with product weight loss was successfully assessed and modelled unsteadily, providing a better way to optimize the design process as a function of food physiognomies in an industrial dryer.

  • Estimation of Yield Advantage and Competitiveness of Onion-Rosemary Intercropping over Sole Cropping at Wondo Genet

    Different cropping system and planting patterns of onion and rosemary evaluated to estimate yield advantage and their competitiveness during 2013-14 and 2014-15 growing seasons under irrigated condition at wondo genet Sidama zone, Southern Ethiopia. The experiment comprised of six treatments: sole Onion (250,000 plants ha-1), sole Rosemary (83,333plants ha-1) and four onion-rosemary intercropping mix proportion: 100 onion: 80 rosemary, 100 onion: 60 rosemary, 100 onion: 40 rosemary and 100 onion: 20 rosemary, using randomized complete block design with three replications. Analysis of variance revealed that; intercropping of onion with different population densities of rosemary significantly affected dry bulb yield; highest dry bulb yield was recorded at solitary cropping than that of intercropped. Similarly; essential oil yield of rosemary significantly influenced by cropping system; highest essential oil yield obtained in sole planted than intercropped. The highest value of land equivalent ratio (1.52), land equivalent coefficient (0.57) and relative crowding coefficient (6.07) obtained when onion intercropped with 80 % rosemary population density. However, positive values of actual yield loss and maximum intercropping advantage obtained in treatments where onion intercropped with rosemary at 20 and 40 % population density. Generally, these finding suggest that intercropping of onion with rosemary at 80 % population density enhanced yield advantage and Competitiveness as indicated by higher land equivalent ratio and relative crowding coefficient. Therefore, the inclusion of onion with 80% a rosemary population density elevated yield advantage and competitiveness over sole planted crop per unit area as indicated by higher LER and relative crowding coefficient.

  • Evaluations of faba bean (Vicia faba L.) Genotypes for agronomic traits and crude protein content across seven faba bean

    Faba bean (Vicia faba L.) is an important cool season protein rich food and feed legume belongs to fabaceae family. Twelve faba bean genotypes were evaluated in 2018/2019 cropping season across seven environments in Ethiopia using randomized complete block design with four replications. The combined analysis of variance showed highly significance difference among genotypes, environments and genotype by environment interaction effects (P