Showing papers in "The Journal of Agricultural Science in 2009"
TL;DR: The resistance induced is broad spectrum and can be long-lasting, but is rarely complete, with most inducing agents providing between 0·20 and 0·85 disease control.
Abstract: Plants resist pathogen attack through a combination of constitutive and inducible defences Different types of induced resistance have been defined based on differences in signalling pathways and spectra of effectiveness Systemic acquired resistance (SAR) occurs in distal plant parts following localized infection by a necrotizing pathogen It is controlled by a signalling pathway that depends upon the accumulation of salicylic acid (SA) and the regulatory protein NPR1 In contrast, induced systemic resistance (ISR) is promoted by selected strains of non-pathogenic plant growth-promoting rhizobacteria (PGPR) ISR functions independently of SA, but requires NPR1 and is regulated by jasmonic acid (JA) and ethylene (ET)Resistance can be induced by treatment with a variety of biotic and abiotic inducers The resistance induced is broad spectrum and can be long-lasting, but is rarely complete, with most inducing agents providing between 0·20 and 0·85 disease control In the field, expression of induced resistance is likely to be influenced by the environment, genotype, crop nutrition and the extent to which plants are already induced Unfortunately, understanding of the impact of these influences on the expression of induced resistance is rudimentary So too is understanding of how best to use induced resistance in practical crop protection This situation will need to change if induced resistance is to fulfil its potential in crop protection
161 citations
TL;DR: In this article, the authors employed empirical data collected from farms to calculate the carbon footprints of lamb and beef, and employed two farms in Wales, UK, to undertake such an analysis for two system boundaries.
Abstract: Carbon footprinting is an increasingly important method of communicating the climate change impacts of food production to stakeholders. Few studies utilize empirical data collected from farms to calculate the carbon footprints of lamb and beef. Data from two farms in Wales, UK, were employed to undertake such an analysis for two system boundaries.Within a system boundary that considers the embodied greenhouse gases (GHGs) in inputs and on-farm emissions, producing 1 kg of lamb releases 1·3–4·4 kg CO2 eq/kg live weight (case study farm 1) and 1·5–4·7 kg CO2 eq/kg live weight (case study farm 2). The production of beef releases 1·5–5·3 and 1·4–4·4 kg CO2 eq/kg live weight.Within a wider system boundary that also includes GHG emissions from animals and farm soils, lamb released 8·1–31·7 and 20·3–143·5 kg CO2 eq/kg live weight on the two case study farms, and beef released 9·7–38·1 and 18·8–132·6 kg CO2 eq/kg live weight. The difference in emissions for this system boundary relates to nitrous oxides emitted from the organic soils on case study farm 2.These values overlap with nearly all other studies of GHG emissions from lamb and beef production. No direct comparisons between studies are possible due to substantial differences in the methodological approaches adopted.
105 citations
TL;DR: The antimicrobial activities and fungitoxicity of the phenolics against Ganoderma boninense were expressed in inhibition of radial growth of G.boninense on PDA ameliorated with the three different phenolics with a range of 0.5-2.5 mg/ml.
Abstract: This paper discusses the in vitro antimicrobial activity and fungitoxicity of syringic acid, caffeic acid and4-hydroxybenzoic acid which is found in oil palm root. Experiments were observed for fourteen days, repeated at leastthree times and data were recorded daily. The antimicrobial activities and fungitoxicity of the phenolics againstGanoderma boninense were expressed in inhibition of radial growth of G. boninense on PDA ameliorated with the threedifferent phenolics with a range concentration of 0.5-2.5 mg/ml. Syringic acid was found to be very fungitoxic to G.boninense even at concentration of 0.5 mg/ml, the lowest concentration tested in this experiment. When theconcentration is increase to 1.0mg/ml of syringic acid, the pathogen is inhibited. Caffeic acid and 4-hydroxybenzoicacid were having inhibitory effect with the highest concentration tested; 2.5mg/ml strongly inhibited the growth of G.boninense in comparison to the control.
91 citations
TL;DR: In this article, the authors compared greenhouse gas emissions from rice farming practices, resulting from various farm inputs and irrigation systems in Pakistan, the Philippines, China, Indonesia, Myanmar, Nepal, Australia and the USA.
Abstract: Regardless of the irrigation system deployed, rice production requires a variety of farm energy inputs. The present study estimated and compared greenhouse gas (GHG) emissions from rice farming practices, resulting from various farm inputs and irrigation systems in Pakistan, the Philippines, China, Indonesia, Myanmar, Nepal, Australia and the USA. Results indicate that, on aggregate, emissions related to farm machinery, fuels, agrochemicals and animal labour accounted for 0.018, 0.307, 0.666 and 0.008, respectively. Emissions from tubewell irrigation systems were the highest, followed by canal and rainfed irrigation systems. Average emissions from all selected countries with
tubewell irrigation systems were 1.64 times greater than canal irrigation systems and 2.64 times greater than rainfed irrigation systems. When considering GHG emission efficiencies (emissions/kg of rice yield), developing countries were found to be less efficient than developed countries in both canal and tubewell irrigation systems. The relationship between GHG emissions and rice yield was
statistically significant (P<0.01), with results indicating that a yield increase of 100 kg would increase GHG emissions by 16.51 kg CO2e (kg carbon dioxide equivalent).
83 citations
TL;DR: It was found that final GN content depended strongly on the source-sink ratio established at anthesis between the number of grains set and the amount of nitrogen absorbed at this stage, and Mediterranean wheat breeding that improved yield through increases in grain number/m2 reduced the GN content by diluting a rather limited source of nitrogen into more grains.
Abstract: Wheat yield and grain nitrogen concentration (GNC; mg N/g grain) are frequently negatively
correlated. In most growing conditions, this is mainly due to a feedback process between GNC and the number of grains/m2. In Mediterranean conditions, breeders may have produced cultivars with conservative grain set. The present study aimed at clarifying the main physiological determinants of
grain nitrogen accumulation (GNA) in Mediterranean wheat and to analyse how breeding has affected them. Five field experiments were carried out in north-eastern Spain in the 2005/06 and 2006/
07 growing seasons with three cultivars released at different times and an advanced line. Depending on the experiment, source-sink ratios during grain filling were altered by reducing grain number/m2
either through pre-anthesis shading (unshaded control or 0.75 shading only between jointing and anthesis) or by directly trimming the spikes after anthesis and before the onset of the effective grain
filling period (un-trimmed control or spikes halved 7–10 days after anthesis). Grain nitrogen content (GN content ; mg N/grain) decreased with the year of release of the genotypes. As the number of grains/m2 was also increased by breeding there was a clear dilution effect on the amount of nitrogen
allocated to each grain. However, the increase in GN content in old genotypes did not compensate for the loss in grain nitrogen yield (GNY) due to the lower number of grains/m2. GN content of all genotypes increased (increases ranged from 0.13 to 0.40 mg N/grain, depending on experiment and
genotype) in response to the post-anthesis spike trimming or pre-anthesis shading. The degree of source-limitation for GNA increased with the year of release of the genotypes (and thus with increases in grain number/m2) from 0.22 (mean of the four manipulative experiments) in the oldest
cultivar to 0.51 (mean of the four manipulative experiments) in the most modern line. It was found that final GN content depended strongly on the source-sink ratio established at anthesis between the
number of grains set and the amount of nitrogen absorbed at this stage. Thus, Mediterranean wheat breeding that improved yield through increases in grain number/m2 reduced the GN content by diluting a rather limited source of nitrogen into more grains. This dilution effect produced by breeding was further confirmed by the reversal effect produced by grain number/m2 reductions due to
either pre-anthesis shading or post-anthesis spike trimming.
78 citations
TL;DR: This paper summarizes findings about the natural occurrence of AMF in different soils in which coffee is cultivated, some ecological aspects of this specific association and outlines trends for future investigations, which must elucidate the real benefits of mycorrhizae to coffee plants.
Abstract: Despite previous research on mycorrhizal association with plants, the data on associations with coffee (Coffea species) are very sparse despite the great economic importance of this crop for many tropical developing countries. The present paper reviews the main aspects of the association between arbuscular mycorrhizal fungi (AMF) and coffee plants. This review includes topics on mycorrhizal effects on coffee nutritional status, pathogenAMF interactions and responses to several environmental stresses. It also summarizes findings about the natural occurrence of AMF in different soils in which coffee is cultivated, some ecological aspects of this specific association and outlines trends for future investigations, which must elucidate the real benefits of mycorrhizae to coffee plants. © 2009 Copyright Cambridge University Press.
73 citations
TL;DR: There is very limited knowledge of the use of rhizobacteria in agriculture in Ethiopia and South Africa, and the current study generates valuable information towards application of plant growth promoting rhizOBacteria as alternatives to chemical fertilizers.
Abstract: The screening of rhizobacteria for growth promotion of sorghum (Sorghum bicolour (L.) Moench) was conducted under greenhouse conditions for a total of 78 bacteria isolated from the rhizosphere of sorghum in Ethiopia, and 86 isolates from the rhizosphere and rhizoplane of grasses in South Africa. Three isolates from Ethiopia, all identified as Bacillus cereus, enhanced growth promotion by resulting in statistically significant increases in at least five parameters. Of these, B. cereus (KBE7-8) resulted in significant increase in shoot and root biomass. Among effective isolates from South Africa, B. cereus (NAS4-3) and Stenotrophomonas maltophilia (KBS9-B) showed significant increases in all the parameters measured. The isolates which resulted in significant growth promotion colonized the roots effectively with a count up to ⩾108 cfu/g. In the study conducted to elucidate the possible modes of action by these effective isolates, indole 3-acetic acid-like substances were detected in culture filtrates of the isolates ranging from 4·2 μg/ml by Serratia marcescens (KBS9-R) to 22·8 μg/ml by B. cereus (KBS5-H) in the presence of 2 mg tryptophan/g nutrient broth solution. Higher rates of solubilization of tricalcium phosphate on Pikovskaya agar medium were shown by Chryseomonas luteola (KBS5-F), S. marcescens (KBS6-H) and B. cereus (KBE9-1). There is very limited knowledge of the use of rhizobacteria in agriculture in Ethiopia and South Africa. The current study therefore generates valuable information towards application of plant growth promoting rhizobacteria as alternatives to chemical fertilizers.
72 citations
TL;DR: In this paper, the effects of manure application on grain yields in nine long-term experiments that consist of one continuous maize, four wheat-maize and four rice-based cropping systems across a wide range of agro-ecological regions in China.
Abstract: Rice (Oryza sativa L.), wheat (Triticum aestivum L.) and maize (Zea mays L.) are the main crops grown in China. Applying organic manures is an important practice in sustaining soil fertility and agricultural productivity in these cropping systems. The current paper presents the effects of manure application on grain yields in nine long-term experiments that consist of one continuous maize, four wheat–maize and four rice-based cropping systems across a wide range of agro-ecological regions in China. The study shows that regular manure application can increase soil organic carbon (SOC) and grain yield across all the sites. Overall, regular use of manure results in larger increases in SOC in the maize and wheat–maize systems than in the rice-based systems. Application of manure tends to increase the grain yield in the maize and wheat–maize systems during the final years, but increases the grain yield in the rice-based systems during the initial years of the long-term experiments. There is only one site that shows significant improvement in the yield trend in association with the application of manure. The effects of manure on yield trends are probably determined by the initial yield and/or the ‘organic C effect’ that may cause gradual improvements in SOC and soil physical properties.
58 citations
TL;DR: In this paper, it is suggested that, besides traditional mainstream agriculture, other alternative farming systems should be developed and implemented, which should match the demands of society in terms of sustainability.
Abstract: Dutch agriculture has undergone significant changes in the past century, similar to many countries in the European Union. Due to economies of scale and in order to remain economically profitable, it became necessary for farmers to increase farm size, efficiency and external inputs, while minimizing labour use per hectare. The latter has resulted in fewer people working in the agricultural sector. Consequently, Dutch society gradually lost its connection to agricultural production. This divergence resulted in a poor image for the agricultural sector, because of environmental pollution, homogenization of the landscape, outbreaks of contagious animal diseases and reduced animal welfare. Although the general attitude towards agriculture seems to have improved slightly in recent years, there is still a long way to go in regaining this trust. In order to keep the Dutch countryside viable, farmers are considered indispensable. However, their methods of production should match the demands of society in terms of sustainability. This applies both to farming systems that are used in a monofunctional way (production only) and to multifunctional farming systems. For researchers involved in development of these farming systems, this requires new capabilities; contrary to the situation in the past, citizens and stakeholder groups now demand involvement in the design of farming systems. In the current paper, it is suggested that, besides traditional mainstream agriculture, other alternative farming systems should be developed and implemented. Hence, Dutch agricultural research should remain focused on the cutting edge of economy and society. Despite all efforts, not all of these newly developed systems will acquire a position within the agricultural spectrum. However, some of the successful ones may prove extremely valuable.
56 citations
TL;DR: In this article, the effects of selected management practices on net whole-farm emissions, expressed in CO2 equivalents (CO2e) from a beef production system, as estimated for hypothetical farms at four disparate locations in western Canada, were compared for each farm using a model based, in part, on Intergovernmental Panel on Climate Change (IPCC) equations.
Abstract: As agriculture contributes about 0·08 of Canada's greenhouse gas (GHG) emissions, reducing agricultural emissions would significantly decrease total Canadian GHG output. Evaluating mitigation practices is not always easy because of the complexity of farming systems in which one change may affect many processes and associated emissions. The objective of the current study was to compare the effects of selected management practices on net whole-farm emissions, expressed in CO2 equivalents (CO2e) from a beef production system, as estimated for hypothetical farms at four disparate locations in western Canada. Whole-farm emissions (t CO2e) per unit of protein output (t) of 11 management systems (Table 2) were compared for each farm using a model based, in part, on Intergovernmental Panel on Climate Change (IPCC) equations. Compared with the baseline management scenario, maintaining cattle on alfalfa-grass pastures showed the largest decrease (0·53–1·08 t CO2e/t protein) in emissions for all locations. Feeding lower quality forage over winter showed the greatest increase in emissions per unit protein on the southern Alberta (S.AB) and northern Alberta (N.AB) farms, with increases of 1·36 and 2·22 t CO2e/t protein, respectively. Eliminating the fertilization of forages resulted in the largest increase (4·20 t CO2e/t protein) in emissions per unit protein on the Saskatchewan (SK) farm, while reducing the fertilizer rate by half for all crops showed the largest increase (11·40 t CO2e/t protein) on the Manitoba (MB) farm. The findings, while approximate, illustrate the importance of considering all GHGs simultaneously, and show that practices which best reduce emissions may vary among locations. The findings also suggest merit in comparing emissions on the basis of CO2e per unit of protein exported off-farm, rather than on the basis of total CO2e or CO2e per hectare.
52 citations
TL;DR: The tissues of cvs Domat, Lecquest, Ascolona, Hojoblanca and Gemlik were found to enhance the structural stability of cellular membranes in the CA stage by increasing both the activity of such enzymes as CAT, APX and NADPH oxidase to activate the antioxidative systems and the expression of 43 kDa dehydrins.
Abstract: Seasonal patterns of antioxidative enzymes and proteins and their relations to cold-hardiness of nine olive (Olea europaea L.) cultivars (Ascolona, Domat, Gemlik, Hojoblanca, Lecquest, Manzanilla, Meski, Samanli and Uslu) are documented in the current study. Fully expanded, uniformly sized leaves from 2-year-old shoots of the cultivars were collected from 20-year-old trees in cold-acclimated (CA, in January) and non-acclimated (NA, in July) stages. Leaf samples were exposed to low temperature at 4, −5, −10 and −20°C for 12 h to determine their cold-hardiness (LT50; assessed by electrolyte leakage). Cold-acclimation produced an increase in freezing tolerance of all cultivars (by lowering LT50). Domat and Lecquest were found to have the highest cold-hardiness among the nine cultivars investigated. Ascolona, Gemlik, Hojoblanca had moderate cold-hardiness, while Samanli, Meski, Uslu and Manzanilla were more sensitive. Activities of catalase (CAT: EC 1·11·1·6), ascorbate peroxidase (APX: EC 1·11·1·11) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase significantly varied depending on the cold-acclimation stage and the cold-hardiness level of the cultivars. Activities of the three antioxidative enzymes and total soluble proteins (TSP) were higher in the CA stage than in the NA stage. Although no accumulation of major polypeptides, except a 23 kDa protein, was detected either in CA samples or NA samples by SDS-PAGE, anti-dehydrin immunoblots revealed that the 43 and 23 kDa polypeptides were detectable during cold-acclimation of olive cultivars. Accumulation of both 43 and 23 kDa dehydrin was significantly higher in the CA stage than in the NA stage in all cultivars. Accumulation of 43 kDa dehydrin was correlated with cold-hardiness of the cultivars, while 23 kDa dehydrin was considered as cultivar-dependent since its accumulation was not parallel to LT50 values of the cultivars. Indeed, the tissues of cvs Domat, Lecquest, Ascolona, Hojoblanca and Gemlik were found to enhance the structural stability of cellular membranes in the CA stage by increasing both the activity of such enzymes as CAT, APX and NADPH oxidase to activate the antioxidative systems and the expression of 43 kDa dehydrins.
TL;DR: Time of allocation to a fresh plot altered the distribution of grazing behaviour variables over the day, and affected NGR and milk fat content, but herbage intake and milk production were not changed.
Abstract: Twenty Holstein cows were split into two equal groups to test the effect of daily move to a previously ungrazed strip after morning milking (MA) or afternoon milking (AA) on herbage intake, grazing behaviour, rumen characteristics and milk production using a randomized block design with three periods of 14 days each. Milking took place at 06.00 and 16.00 h. The chemical composition of grass was similar between treatments, but an interaction between treatment and time of sampling was found in all variables except acid detergent lignin (ADL). The most pronounced differences existed in sugar content. Grass sugar content was greatest following afternoon milking. However, the difference in sugar content in grass was much larger in MA (158 v 114 g/kg dry matter (DM) at 16.00 and 06.00 h, respectively) than in AA (147 v 129 g/kg DM at 16.00 and 06.00 h, respectively). Neutral detergent fibre (NDF) was significantly higher at 06.00 h than at 16.00 h (469 v 425 g/kg DM) in AA, but was equal between morning and afternoon in MA (453 g/kg DM). Herbage intake, determined using the n-alkane technique, did not differ between treatments. Grazing behaviour observed using IGER graze recorders were similar between treatments, except for ruminating time, bite rate and the number of ruminations and boli per period of the day. However, interactions between treatment and time in grazing behaviour variables were found. Grazing time was longer and number of bites was greater following allocation to a new plot (after milking in the morning in MA or milking in the afternoon in AA) when compared to allocation to the same plot after the subsequent milking per treatment (after milking in the afternoon or morning in MA and AA, respectively). In comparison to AA, grazing time in MA was more evenly distributed during the day but lower during the night. The combined effects of differences in grazing behaviour and chemical composition of the grass between treatments in different periods of the day probably caused higher intake of sugars in AA, resulting in a significantly higher non-glucogenic to glucogenic volatile fatty acid ratio (NGR) in the rumen in AA than MA. Milk fat content was lower in MA than AA, but milk production and milk protein and lactose content did not differ. In conclusion, time of allocation to a fresh plot altered the distribution of grazing behaviour variables over the day, and affected NGR and milk fat content, but herbage intake and milk production were not changed.
TL;DR: The antimicrobial properties of the stem bark extracts of Ximenia americana werescreened against Escherichia coli, P.aeruginosa, Staphylococcus aureus,P.
Abstract: Ximenia americana is endemic in Northern Nigeria, and has been reported to be used in treatment of various types ofailments. In the present study, the antimicrobial properties of the stem bark extracts of Ximenia americana werescreened against Escherichia coli, P.aeruginosa, Staphylococcus aureus, P. vulgaris, Candida albicans, B. subtilisusing the disc diffusion method. The result revealed the methanolic and water extract showed significant (P
TL;DR: The results show that the growth regulatory properties of metconazole can be used to improve several key aspects of growth that are believed to restrict current farm yields.
Abstract: The effects of the anti-gibberellin triazole metconazole on yield, lodging resistance, seeds/m2 (sink size) and rooting in the presence of negligible amounts of disease were investigated using five multi-site experiments carried out in the UK between 1999 and 2007. The green area index (GAI) of the crop at the time of application had the greatest influence on the yield response across 173 comparisons between metconazole-treated and untreated crops. Crops with a GAI in March (growth stage (GS) 3·3–3·5 ‘green bud’) of 0·8–2·8, which represented moderate to large sized UK commercial crops, had an average response of +0·21 t/ha to metconazole applied at the full recommended rate of 1·2 litres/ha. Crops with a GAI of less than 0·8, which represented small commercial crops, had an average response of −0·14 t/ha. Applications between green bud and early flowering gave the greatest yield increase. Positive yield responses were associated with a reduction in lodging, or more seeds/m2, or a combination of both. The proportional area lodged was reduced by 0·1 for each 50 mm reduction in crop height (R2=0·60; P<0·001). Across six field trials, metconazole applied in spring increased root length density between soil depths of 0·40 and 1·00 m from an average of 0·478 to 0·601 cm/cm3 (P<0·05). It was estimated that this could increase yield by 0·2–0·3 t/ha in a dry season. The results show that the growth regulatory properties of metconazole can be used to improve several key aspects of growth that are believed to restrict current farm yields.
TL;DR: Re-evaluation of the recommendations for N fertilization of pastures older than 2 years is justified as a large proportion of the excretal N is immobilized and accumulates in soil.
Abstract: The aim of the present study was to investigate the nitrogen (N) dynamics in soil and N utilization by grass in dung pats and urine patches, and to quantify the amount of soluble organic N (SON) in grassland soil. The experiment was conducted in 2003/04 at MTT Agrifood Research, Maaninka, Finland. The study consisted of three treatments: dung pats, urine patches and a control patch without excreta. The soil (to a depth of 0·6 m) and herbage were sampled on 10 occasions over the course of 1 year. TN and SON in soil averaged 14 400 and 60 kg/ha N, respectively. Changes in soil mineral N were short-lived and a large proportion of excreta N was immobilized. The grass took up 27 kg excretal N/ha from the dung pat and 71 kg N/ha from the urine patch, which equals 0·07 and 0·19 of the excretal N given to each treatment, respectively. As a large proportion of the excretal N is immobilized and accumulates in soil, re-evaluation of the recommendations for N fertilization of pastures older than 2 years is justified.
TL;DR: Early season vigour was strongly associated with yield, with the strongest correlation occurring under low-moisture, low-nutrient, high-competition conditions at the certified organic farm.
Abstract: Wheat (Triticum aestivum L.) variety mixtures represent a relatively unexplored avenue for maintaining and stabilizing yield for both organic and conventional producers. The present study examined the responses of three Canadian western red spring wheat varieties in sole crop and in variety mixtures to varying levels of simulated and natural competition, as well as environmental stress at one conventionally and two organically managed locations in central Alberta, Canada, between 2003 and 2005. Three modern hard red spring wheat varieties (Superb, semi-dwarf; AC Intrepid, early maturing and 5600HR, tall), along with 13 two- and three-way variety mixtures, were planted under two levels of simulated weed (Brassica juncea L.) competition at each of the eight location-years. The B. juncea weed competition treatment decreased yields at all locations. Overall yield was lowest at the certified organic farm and highest under conventional management. Sole-crop semi-dwarf Superb and all three Superb-Intrepid mixture entries consistently yielded among the highest, regardless of management system, testing location or competition treatment. The 1:1 and 1:2 Superb-Intrepid mixture entries were the most stable of all entries tested. Early season vigour was strongly associated with yield, with the strongest correlation occurring under low-moisture, low-nutrient, high-competition conditions at the certified organic farm. Spring wheat variety mixtures may provide greater stability with little or no reduction in yield, while providing greater competitive ability.
TL;DR: The experiment used C. sinensis scions grafted onto Citrus aurantium (bitter orange) rootstock to understand carbon fluxes in orange orchards and found that carbon fixation in the fruits and in the canopy of single trees was almost twice as much in the traditional than in the intensive system.
Abstract: Orange (Citrus sinensis L.) is one of the main fruit crops worldwide and its evergreen orchards may have a great potential for carbon (C) sequestration, but no data are currently available. In order to understand carbon fluxes in orange orchards, an experiment was undertaken on traditional and intensive planting systems. The experiment used C. sinensis scions grafted onto Citrus aurantium (bitter orange) rootstock. One orchard contained 14-year-old trees of the cv. Tarocco Scire (a blood orange) grown in a traditional system with 494 trees/ha. The second orchard contained 12-year-old trees of the cv. Newhall (a seedless navel orange) grown in an intensive system with 1000 trees/ha. Net primary productivity (NPP) was obtained by measuring the annual canopy growth of single orange trees and the above ground dry biomass of the ground cover; soil respiration seasonal pattern was measured with an infrared gas analyser (EGM-4, PP System) from June 2005 to May 2006, every 2 weeks from 12·00 noon to 15·00 h for maximum respiration and from 02·00 to 05·00 h for minimum respiration; a 24 h cycle measurement of soil respiration was made every 3 months. Carbon fixation in the fruits and in the canopy of single trees was almost twice as much (10·7 kg C/ tree) in the traditional than in the intensive system (5·5 kg C/tree); however, total NPP of the orchard did not change with planting density, being 5·3 t C/ha/year in the traditional system and 5·5 t C/ha/ year in the intensive one. Carbon fixation by the ground cover was higher in the traditional (1·1 t C/ ha/year) than in the intensive system (0·5 t C/ha/year). Annual soil respiration was 5·9 t C/ha/year in the traditional system and 4·2 t C/ha/year in the intensive one. The carbon balance was almost four times higher in the intensive system (1·8 t C/ha/year) than in the traditional one (0·5 t C/ha/year), due to large differences in soil respiration.
TL;DR: PAM is effective in improving growth performance and cytokine response, which suggests that PAM can be used as a diet additive for weanling piglets.
Abstract: The present study was conducted to determine the effects of a polysaccharide of Atractylodes macrophala Koidz (PAM) as a dietary additive on growth performance, immunoglobulin concentration and IL-1β expression in weaned piglets. One hundred and twenty Landrace x Yorkshire piglets weaned at 28 days old (body weight 7·5±0·07 kg) were assigned to five treatment groups (three pens/ group, eight piglets/pen) fed maize/soybean-based diets supplemented with 0, 3, 6 or 9 g of PAM/kg diet or antibiotics (0·4 g flavomycin/kg+0·13 g olaquindox/kg). The experimental period was 28 days. With increasing PAM supplementation levels, average daily gain was greater (quadratic, P<0·05) and the ratio of amount fed to live weight (LW) gain (feed/gain) improved (quadratic, P<0·05) during days 14-28 and overall, and diarrhoea incidence decreased (linear, P<0·05) during days 14-28. Supplementation of PAM also increased (quadratic, f<0·05) serum concentrations of interleukin (IL)-2 and IL-6 on day 14, and increased (quadratic, P<0·05) IL-1β expression in jejunal mucosa and lymph nodes. Concentrations of PAM between 6 and 9 g/kg presented the strongest bioactivity compared to the control group or antibiotic-fed group. These findings indicate that PAM is effective in improving growth performance and cytokine response, which suggests that PAM can be used as a diet additive for weanling piglets.
TL;DR: In this paper, an automated tea dryer system based on programmable controller which controlled moisture content of the tea leaves and temperature of the chamber in different stages of drying is presented, which is designed with 6 to 8 trays.
Abstract: This paper presents an automated tea dryer system based on programmable controller which controls moisture content of the tea leaves and temperature of the chamber in different stages of drying. Several techniques were used for tea drying systems according to the tea genres. The batch tea dryer is designed with 6 to 8 trays. The temperature above the trays is controlled between 50oC and 100oC. Moreover, the moisture content of the tea leaves declined from around 68% to approximately under 3%. In addition, the temperature of the leaves increased from a little less than 30oC to 80oC. A microcontroller as the main processor was deployed to process received data from sensors and also it provides control signals. Thus, this system equipped a data logger memory to record data during drying process. The analyses of dryer products shown the feasibility of using propose system for batch tea drying.
TL;DR: Overall, the fertilized maize–grass and maize–pigeon pea rotations were identified as those that sustained relatively high maize yields, returned large residue amounts to the soil and minimized soil carbon loss.
Abstract: The purpose of the present study was to investigate the effects of seven maize (Zea mays)–fallow rotation and fallow residue management treatments on growth, maize yield and soil carbon within a savannah-forest farming zone of Ghana. Over a 4-year period, maize rotated with bare fallow (control) produced an average maize biomass and yield of 4·0 and 1·0 t/ha/yr, respectively. Maize rotated with elephant grass (Pennisetum purpureum) with the fallow grass residue burning produced an average maize biomass and yield of 8·0 and 2·0 t/ha/yr, respectively. The removal of the fallow grass biomass (9·0 t/ha/yr) by burning resulted in a low total residue (maize stover+fallow residue) returned to the soil (7·0 t/ha/yr). The total residue returned to the soil was 14·0 t/ha/yr. Despite the larger total residue returned to the soil by the incorporation treatment, the performance of the maize was not significantly different from that of the fallow residue burning treatment. Maize rotated with cowpea (Vigna unguiculata), mucuna (Mucuna pruriens) or pigeon pea (Cajanus cajan) produced similar maize biomass of 8·0 t/ha/yr and yields of 2·0 t/ha/yr, but with higher variability for the maize–cowpea rotation. Biomass produced by fallow cowpea, mucuna or pigeon pea were 4·0, 5·0 and 8·0 t/ha/yr, respectively, and total residues added to the soil were 13·0, 13·0 and 15·0 t/ha/yr, respectively. Maize–grass rotation with fertilizer application to the maize resulted in biomass and yield production of 11·0 and 3·0 t/ha/yr, respectively, and fallow grass production of 12·0 t/ha/yr. The total residue returned to the soil was 18·0 t/ha/yr. Soil organic carbon (SOC) declined under all treatments over time, with the control losing about 55% of the initial SOC by the end of the trial. The decline in SOC was 19% for the fertilized maize–grass rotation, but all other treatments lost between 33 and 44% SOC. Overall, the fertilized maize–grass and maize–pigeon pea rotations were identified as those that sustained relatively high maize yields, returned large residue amounts to the soil and minimized soil carbon loss.
TL;DR: In this paper, the effects of continuous pulse cultivation on soil chemical, physical and biological properties by comparing with continuous non-pulse crops and uncultivated soils were analyzed using a polyphasic approach combining traditional soil physical and chemical analysis, culture dependent and independent microbiological analysis and enzymatic analysis.
Abstract: Studies were conducted on Entisols to understand the effects of continuous pulse cultivation on soil chemical, physical and biological properties by comparing with continuous non-pulse crops and uncultivated soils. Soils of a Typic Ustochrept, developed from the same parent material, from 16-year-old pulse cultivation fields, non-pulse crop fields and uncultivated fallow fields in a location with uniform topography were analysed using a polyphasic approach combining traditional soil physical and chemical analysis, culture-dependent and independent microbiological analysis and enzymatic analysis. Among the soil physical properties, only soil aggregate stability and soil compaction showed significant improvement in soils under pulses than non-pulse crops. Compared to uncultivated fallows, the soil pH after pulse cultivation was about 1 unit lower while non-pulse crop cultivation reduced it by 0·36. The chemical and biological variables that contribute most to the discrimination of the pulses effect and non-pulse crops effect on soil quality are organic carbon (C), microbial biomass C, nitrogen (N) and biomass ninhydrin-N, and secondary variables related to N cycle:nitrate (NO3–N), organic and total soluble N. The enzyme activities were significantly higher in soils after pulse cultivation than after non-pulse crops or uncultivated fallow. The soil quality of pulse cultivation fields seems to be markedly different to that of non-pulse crop fields and uncultivated fallows in terms of all the variables studied.
TL;DR: In this paper, the physical and mechanical properties of fennel seed were determined as a function of moisture content in the range of 7.78% to 21.67% d.b.
Abstract: Determination of physical and mechanical properties of seeds and agricultural products is important in the design ofharvesting, handling, and processing equipment. Some physical and mechanical properties of fennel seed weredetermined as a function of moisture content in the range of 7.78–21.67% d.b. The average length, width and thicknesswere 58.87, 18.96 and 15.64 mm, at a moisture content of 7.78 %d.b., respectively. In the moisture range from 7.78% to21.67% d.b., studies on rewetted fennel seed showed that the thousand seed weight increased from 5.5 to 9.2 g, theporosity from 55.91% to 62.21%, the static and dynamic angle of repose from 37.6 to 46.6 and 41 to 53.3, respectively,the coefficient of friction on glass, plywood, and galvanized iron sheet surfaces from 0.55 to 0.74, 0.45 to 0.63, and 0.43to 0.66, respectively, and deformation on width section increased from 1.68 to 1.86 mm. The bulk density decreasedfrom 413.51 to 352.39 kg m-3 and rupture force on both seed length and width sections decreased from 198.93 to 78.68N, and 600.65 to 186.44 N, respectively, with moisture content in the moisture range of 7.78 to 21.67% d.b. But therewas not regular trend for sphericity, true density, and deformation on length section with increasing the moisturecontent.
TL;DR: In this paper, three commonly used N response models (Mitscherlich, linear plus exponential and bilinear) were fitted to each set of fertilizer application rates and the models were then assessed on how well they fitted all the data.
Abstract: The data from 161 experiments testing the response of sugarbeet yield to nitrogen fertilizer were assembled in a database. Three commonly used N response models (Mitscherlich, linear plus exponential and bilinear) were fitted to each set of fertilizer application rates and the models were then assessed on how well they fitted all the data. The bilinear model was judged the most appropriate model for fitting to beet root yield adjusted to a standard sugar concentration. The optimum N application was determined for each experiment. Attempts were then made to correlate these optima with factors associated with the site and the season (winter rainfall, soil texture, amount of soil mineral N at sowing, sowing date, summer rainfall and harvest date). Beet grown in peat soil never responded significantly to any applied N fertilizer and neither did crops treated recently with organic manure supplying large amounts (>150 kg N/ha) of available N. Variation in N optima between other sites could not be explained by factors that could be used to predict the amount of fertilizer to apply. In the absence of any method to make reliable predictions of variations in fertilizer need, the most economical uniform amount was calculated. At present fertilizer prices and beet values, this amount is between 100 and 110 kg N/ha. It is possible that the N fertilizer need of beet crops does not vary predictably because this variation is an experimental error. The crop needs a reasonably standard application of fertilizer because much N has to be taken up early in the crop's development, rapidly and predominantly from the topsoil that, at this stage, contains most of the small fibrous root system.
TL;DR: In this paper, the authors investigated the effect of the amount of soil mineral nitrogen (SMN) at the beginning of spring growth on the optimum N fertilization rate (N opt ).
Abstract: Implementation of the EU Nitrate Directive in Germany will result in nitrogen (N) balance surpluses being restricted to 60 kg N/ha averaged over 3 years, starting in 2009. With N surpluses of more than 100 kg N/ha, winter oilseed rape (OSR) is a main contributor to N balance surpluses in OSR-based crop rotations in northern Germany. The exact calculation of N fertilization rates therefore becomes increasingly important in order to meet the target of less than 60 kg N/ha N balance average surplus over 3 years at a farm level. Currently, soil mineral nitrogen (SMN) at the beginning of spring growth is commonly used as an indicator for calculation of N fertilization rates in spring. However, amounts of SMN at the beginning of spring growth under OSR are usually low and canopy N is only taken into account to a very limited extent. This might lead to N fertilization rates exceeding the optimum N fertilization rate (N opt ). In the present study, the effects of SMN in spring and of canopy N in autumn and spring on N opt were investigated. Multi-site field trials producing different crop canopies, as a result of two sowing dates and two autumn N fertilization levels, with five spring N fertilization levels (0-280 kg N/ha) were carried out in 2005/06 and 2006/07. N opt in spring was estimated by quadratic response functions using the combine-harvested seed yield data from the spring N fertilization treatments. Regression analyses revealed no relationship between N opt and SMN at the beginning of spring growth or canopy N at the beginning of spring growth. In contrast, a significant negative correlation between N opt and canopy N at the end of autumn growth was found. Based on the results of the present study, it is sensible to take autumn canopy N into account when calculating N fertilization rates in spring. If canopy N in autumn is high (>50 kg N/ha), as a consequence, N fertilization rates should be reduced.
TL;DR: In this paper, the authors evaluated the effects of DDG rates on weed suppression, changes in soil properties, and differences in grain yield and quality and showed that DDGs, polymer-coated urea (PCU), andanhydrous ammonia (AA) fertilizer sources had a total N-P-K composition of 38.2-6.9-11.5 g kg-1, respectively.
Abstract: Increased ethanol production may result in excessive dried distillers grains (DDGs) that could be utilized as a fertilizersource for corn (Zea mays L.). Research was conducted to evaluate the effects of 1) DDG rates on weed suppression,changes in soil properties, and differences in grain yield and quality and 2) DDGs, polymer-coated urea (PCU), andanhydrous ammonia (AA) fertilizer sources on grain yield and quality. DDGs had a total N-P-K composition of38.2-6.9-11.5 g kg-1, respectively. There was no corn injury, common cocklebur or jimsonweed control with DDG ratesup to 3600 kg ha-1. Corn grain yield increased 1.41 and 1.56 kg ha-1 for every kg ha-1 of DDGs applied in medium andhigh yield environments, respectively. Grain yield was ranked non-treated control < DDGs < AA = PCU whenfertilizers were applied at N equivalent rate of 140 kg ha-1 in medium and high yield environments.
TL;DR: In this article, the effect of different densities of planting on yield and essential oil components of Fennel (Foeniculum vulgare mill Var. Soroksary) was studied.
Abstract: In order to study the effect of different densities of planting on yield and essential oil components of Fennel(Foeniculum vulgare Mill Var. Soroksary), an experiment was carried out in college of agriculture Karaj at 2008.Experiment was conducted based on completely randomized block design with three replication and five plant densities.Five plants spaces were 10, 15, 20, 25 and 30cm on the row. The distance between rows in all treatments was 40cm.The essential oil extracted by water distilled method from seeds and essential oil was analyzed by gas chromatography(GC). The higher essential oil percentage (% 3.53) was obtained with the lowest densities of planting.The higherpercentage of anethole (%83.07), estragol (%3.47), fenchone (%8.04), p-cymene (%4.45), alpha-terpinene (%0.54),sabinene (%0.51), and alpha-Pinene (%0.48) were obtained with space between plants 25, 10, 20, 20, 15, 20, and 25cm,respectively.
TL;DR: Genotype×environment interaction (GEI) is a major factor in the development of stable and high-yielding safflower cultivars under rain-fed conditions and to quantify GEI effects on the seed yield, multi-environment yield trials were conducted for four consecutive years in 33 different environments during 2003–06.
Abstract: Genotype×environment interaction (GEI) is a major factor in the development of stable and high-yielding safflower cultivars under rain-fed conditions. In order to quantify GEI effects on the seed yield of 17 safflower genotypes and to identify stable genotypes, multi-environment yield trials (multi-environment trials (MET)) were conducted for four consecutive years in 33 different environments (year–location combinations) during 2003–06. The results indicated that GEI was significant using the Hildebrand (1980) procedure for non-crossover interaction (no change in genotypic rank) and by the Azzalini & Cox (1984) and the De Kroon & Van Der Laan (1981) tests for crossover interaction (change in genotypic rank). The rank-interaction was not significant when assessed using the Bredenkamp (1974) method. Fifteen univariate stability methods measuring different aspects of stability were used to determine stable genotypes. A principal component analysis based on rank correlation matrix separated those methods based on a dynamic concept of yield stability (change in genotypic performance corresponds to the predicted level for each environment) from those which are based on a static one (the lowest changes in genotypic performance across environments). The methods could be grouped into three distinct classes: (i) those which were associated with yield level and the dynamic concept of stability; (ii) those which were associated with environmental variance, which represents static stability; and (iii) those which were grouped with non-parametric stability statistics, which also represent static stability. The superiority index of cultivar performance, coefficient of regression, Rank-Sum (sum of ranks of yield and stability variance) and TOP (number of environments at which the cultivar occurred in the top third of the ranks) defined the dynamic stability.In this MET, the genotype PI-537598 was identified as the genotype with the highest yield and high stability of yield.
TL;DR: Non-additive gene effects played an important role in governing glossiness, seedling vigour and proportion of plants with deadhearts and trichome density in sorghum lines resistant to shoot fly.
Abstract: Twelve sorghum lines resistant to sorghum shoot fly were evaluated for their combining ability for shoot fly resistance and traits associated with resistance, using three male sterile lines in two environments. Using a completely randomized block design with three replications, 36 hybrids and 15 parental genotypes were raised. Considerable genetic variation was observed for all the traits studied. Non-additive gene effects played an important role in governing glossiness, seedling vigour and proportion of plants with deadhearts. For trichome density, both additive and non-additive gene actions were important. Among the lines evaluated, those identified to be good combiners were SFCR 1047 for seedling vigour, deadheart proportion and trichome density, RSE 03 for glossiness, deadheart proportion at 21 DAE and trichome density, and SPSFR 94032 for seedling vigour and shoot fly eggs per plant. Genetic diversity and cluster analysis grouped the 15 parents (12 resistant and 3 susceptible parents) into five clusters. Utilization of the resistant lines belonging to different clusters in improving shoot fly resistance in sorghum is discussed.
TL;DR: To determine the effects of different level fertilizer application on growth and physiology of Kenaf planted on BRIS soils, V36 variety was used and planted in three different plots by treatments with fertilizers namely high, medium and low.
Abstract: Hibiscus cannabinus L. or Kenaf is one of the most potential annual crop planted throughout the world. Being fastgrowing and multipurpose, it has been utilized as a substitute of jute and, more recently, as raw product for the productionof pulp and paper. With strong and long fiber yield, mass production of Kenaf throughout Malaysia is critical. Theutilization of less fertile soils such as BRIS soils is important to increase the Kenaf production throughout Malaysia. Thus,the objective of this study was to determine the effects of different level fertilizer application on growth and physiology ofKenaf planted on BRIS soils. V36 variety was used and planted in three different plots by treatments with fertilizersnamely high (1960 kg/ plot), medium (1260 kg/ plot) and low (700 kg/ plot) respectively. Each plot comprises 106,000trees where trees were planted on 20 lines. There were contrasting results on the effects of fertilizer on growth andphysiology of Kenaf in the dry (41 days) and wet season (64 days). Significant effects were only observed for diameter,height, leaf number and area during the wet season. Similar results were also found for biomass. The increasing trendswith increasing the rates of fertilizer were observed in the wet season for growth and biomass parameters. The correlationanalyses between total aboveground biomass with diameter and height were more pronounced in the wet season. AGR,RGR and EG calculated from the differences between the dry and wet season readings for aboveground biomass showedthat the higher rate of fertilizer recorded the higher values of AGR and RGR. However, no trend was observed for EG.
TL;DR: Physical methods for mechanically in-shell Brazil nut sorting by color, size, density and inner deterioration were developed to assess nut quality and reduce aflatoxin contamination as discussed by the authors, which produced a homogeneous color batch and segregated the off-standard ones (darkest, lightest and stained).
Abstract: Physical methods for mechanically in-shell Brazil nut sorting by color, size, density and inner deterioration weredeveloped to assess nut quality and reduce aflatoxin contamination. Nuts were able to be sorted by color utilizing thestandard shell chromaticity components L*, a* and b* at ranges of 31.51 to 48.64, 4.09 to 10.07 and 11.90 to 22.95,respectively. It produced a homogeneous color batch and segregated the off-standard ones (darkest, lightest and stained).By size sorting utilizing three oval sectioned trays with the following dimensions 40x25, 35x23 and 20x19.5 mm[length x width] and vibration, nuts were sorted into three sizes Groups: I, II and III for large, medium and small,respectively. Through density sorting the light nuts (shell/nut