Agriculture

The entomopathogenic fungus Beauveria bassiana is a promising biocontrol agent against coffee berry borer, Hypothenemus hampei in coffee. The fungus conidial survival was influenced by both environment and agrochemicals normally used to protect crop plants. The present study evaluates the fungitoxic effect of commonly used chemical insecticides (endosulfan, chlorpyriphos, dimethoate and quinalphos) and fungicides (bordeaux, hexaconazole and triadimefon) on germination, vegetative growth and sporulation of B. bassiana. The insecticides and fungicides were tested at three concentrations (Field Recommendation (FR), half FR, and twice FR). All the tested concentrations inhibited the germination (9.0-81.19% and 19.3-100%), vegetative growth (0.5-62.9% and 37.1-100%) and sporulation (7.0-99.9% and 99-100%) of B. bassiana by the insecticides and fungicides respectively, but dimethoate exhibited minimum inhibitory effect. Dimethoate showed better compatibility to B. bassiana in all the three concentrations. As dimethoate is safer to biological control agent, could be used as an integrated pest management in coffee.

Today in water and soil sciences, many attentions have been arisen on Geostatistical methods to estimate spatial parameter using some data (kriging) or using auxiliary variables (cokriging). The quality of ground water for agriculture is very important, however its measurement is time consuming and expensive. Therefore, finding solution to estimate such parameters from easily measurable parameters is essential. In this study, two estimation models (spatial and regression models) were used to estimate SAR¹ and CL¹ in Tehran region using Geostatistic theory and spatial parameter concept. In this regard, ArcGIS software was used to estimate these parameters. Multi-parameter estimate of cokriging was applied using water salinity as an auxiliary variable. In addition, different estimation methods, cokriging, kriging and regression models, were compared and evaluated by RMSE statistic index. The results of this study showed that cokriging method with high correlations coefficient and with Gaussian Semivariogram is more precise than kriging and the selected regression models in estimating SAR and CL.

Diverse soil management practices exist even within a narrow transect of farming areas in Nepal. This variation is principally due to location of farm households along the spatial gradient, infrastructure availability, market demands and farmers’ awareness to on-farm resource conservation. Over-exploitation of farm resources was negligible and disturbance to agro-ecology was minimal in the past couple of decades. In the last decade, however, due to a massive sprawl in the available farmlands along with a shift of subsistence farming towards market-oriented conventional approach, prime agricultural lands have been over-exploited. This led to negative repercussion on production base and farmers’ livelihoods. This paper concerns with the simulation of farm income through spatial modeling considering the strategy of sustainable soil management practices. Spatial modeling shows higher farm income gains due to intervention in rural areas (low income zone) and peri-urban areas (high income zone) with existing unsustainable soil management practices. Spatial explicit assessment shows that integration of micro-survey into spatial environment and subsequently modeling of present and future situation would add more information on the results from conventional surveys. Therefore spatial effects should be duly considered while formulating agriculture and rural development policies.

Plants respond with changes in their pattern of gene expression and protein products when exposed to low temperatures. Thus ability to adapt has an impact on the distribution and survival of the plant, and on crop yields. Many species of tropical or subtropical origin are injured or killed by nonfreezing low temperatures, and exhibit various symptoms of chilling injury such as chlorosis, necrosis, or growth retardation. In contrast, chilling-tolerant species are able to grow at such cold temperatures. Conventional breeding methods have met with limited success in improving the cold tolerance of important crop plants involving inter-specific or inter-generic hybridization. Recent full-genome transcript profiling studies, in combination with mutational and transgenic plant analyses, have provided a snapshot of the complex transcriptional network that operates under cold stress. The changes in expression of hundreds of genes in response to cold temperatures are followed by increases in the levels of hundreds of metabolites, some of which are known to have protective effects against the damaging effects of cold stress. Various low temperature-inducible genes have been isolated from plants. Most appear to be involved in tolerance to cold stress and the expression of some of them is regulated by C-repeat/dehydration-responsive element binding (CBF/DREB1) transcription factors. Genetic analysis has revealed important roles for cellular metabolic signals, and for RNA splicing, export and secondary structure unwinding, in regulating cold-responsive gene expression and chilling and freezing tolerance. Numerous physiological and molecular changes occur during cold acclimation which reveals that the cold resistance is more complex than perceived and involves more than one pathway. The findings summarized in this review have shown potential practical applications for breeding cold tolerance in crop and horticultural plants suitable to temperate geographical locations.

Forty two samples each of two fish species, Tillapia zilli and Chrysichthys nigrodigitatus were collected along the Kpando Torkor Lake in the Volta Region of Ghana. The samples were investigated for levels of organochlorine pesticide residues and their potential health risks to humans were also assessed. Composite sample of muscles and gills of each species were homogenized using a warring blender. The homogenized samples were Soxhlet extracted with hexane/dichloromethane mixture. The extracts were cleaned up on florisil adsorbent and analyzed for organochlorine pesticide residues using gas chromatography equipped with electron capture detector. In all, fifteen organochlorine pesticides (OCPs) were investigated of which thirteen organochlorines namely, ?-HCH, ?-HCH, p,p'-DDT, p,p'-DDD, p,p'-DDE, heptachlor, aldrin, dieldrin, ?-chordane, ?-endosulfan, ?-endosulfan, endosulfan sulfate and methoxychlor were identified. Heptachlor, ?-HCH, p,p'-DDD, ?-HCH, methoxychlor and endosulfan sulphate were the predominant OCP residues measured. The mean residue concentration in muscles and gills ranges from 0.10 to 17.35 ng/g wet weight and 0.56 to 37.75 ng/g wet weight respectively. A 100% incidence was recorded for ?-HCH, ?-HCH, p,p'-DDD, heptachlor, endosulfan sulfate in the muscle. In the case of the gills a 100% incidence was also recorded for ?-HCH, ?-HCH, p,p'-DDD, ?-chordane, endosulfan sulfate and methoxychlor. Risk assessment based on estimated daily intake (EDI) showed that values obtained for EDI for each organochlorine were far below the non-cancer and cancer benchmark concentrations. As a result the consumption of these fishes will have little or no significant adverse health effects on consumers. It is however, advisable to remove the gills from tilapia fish prior to preparation and consumption to reduce the cumulative and concomitant effect of OCPs in tilapia protein consumers in the long term.

The aims of this study were to investigate the performance characteristics of a farm tractor during ploughing (chisel plough) using variable weights from (0 to 500 kg) on the rear tractor wheels, and different traveling speeds from (3.58 to 5.68 km/h). The ploughing depths were (15-20 cm), and the average moisture content was (20.15 %). The soil texture was found to be a (Silty clay). The rear tier sizes of the tractor and inflation pressure were 16.9/14-38 and 150 kPa, respectively. The study was concentrated on the rate of fuel consumption, specific energy, drawbar pull, tractor wheel slippage, tractive efficiency and field efficiency. The obtained results, for the range of tests, showed that the use of 500 kg weight on the tractor rear wheel at 3.1 km/h traveling speed produced the highest value (74.4 %) of tractive efficiency, and (in the meantime) the wheel slippage, filed efficiency, fuel consumption, required power, specific energy were 7.46 %, 80.22%, 15.11 l/h, 46.58 kW, and 43.13 kW.h/fed, respectively. In general, the traveling speed and the weight on the rear tractor wheels were the most important factors that affecting the drawbar pull and the specific energy.

The correlation and path coefficient analysis among seed yield and its components in pigeonpea were worked out in 25 erect and 25 semi spreading genotypes separately during 2007-08. Results of the correlation coefficient analysis revealed that seed yield plant^-1 was positively correlated with seeds plant^-1 in erect group whereas, pod clusters plant^-1, pods plant^-1 and 100 seed weight in semi-spreading group. Path coefficient analysis of various characters towards seed yield indicated that the maximum positive direct effect on seed yield was exhibited by seeds plant^-1 in erect group and days to 50% flowering in semi-spreading group. Whereas, path coefficients for 100 seed weight revealed the maximum positive direct effect due to days to 50% flowering in erect group and days to flower initiation in semi-spreading group.

Ozone(O3) is a beneficial gas which is used for elimination of microorganisms. This gas provided from O2 and it is very unstable and reactive. The Ozone can be used as a disinfectant, decolorizer, detoxifier, precipitant, coagulant and also for removing taste. In this paper, the ozone used to control root-knot nematode in potato greenhouse. Ozone generator that designed for this purpose, produced 36 mgO3/m3. Ozone is injected to water with venture and greenhouse irrigated with ozonated water. After 20 days it is shown that disease have been controlled and stoped, crop increased between 30% and 40%, weeds decreased and plant’s daily growth enhanced.

Since the era of the Green Revolution, Agricultural production worldwide experienced much efficiency with a remarkable aim to eradicate threats of food insecurity. This breakthrough was anchored on science and technology. Among the interventions this era saw to date were the use of fertilizers and pesticides in our day-to-day farming activity to boost yield and control pests/diseases. The study assessed farmers’ knowledge in the use of Agrochemicals given their environmental effects such as on water bodies, occupational hazard and safety, disposal, and storage regarding product use. Questionnaires were administered to farmers cultivating vegetables, food, and cash crops under Open-field and Greenhouse managements in respective Production Specification; Organic and Inorganic productions. The study revealed that 85% of respondents who cultivated cash crops such as Cocoa and Rubber heavily relied on the use of inorganic fertilizers and pesticides. 35.40%, 32.74%, and 19.47% of respondents disposed of Agrochemical containers using Pit burial, Burn/Incinerate, and Indiscriminate methods, respectively, while 12.39% used ecological (biodegradable) materials. 92.7% of the respondents had knowledge about perilous consequence and yet didn't garment recommended protective apparels during application. It was concluded and recommended that the necessity of Agrochemical for pest, disease and weed control were unavoidable in the smallholder farming business in Ghana, despite the gradual rise of inorganic fertilizer and Integrated Pest Management control products. However, needful actions such as Government policy on educational campaign/programs must be intensified. to help appropriately redress misapplications and chemical residue on fresh food produce.