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Several Crops (several + crop)
Selected AbstractsThe Exploitation of Crop Allelopathy in Sustainable Agricultural ProductionJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 3 2005T. D. Khanh Abstract Crop allelopathy may be useful to minimize serious problems in the present agricultural production such as environmental pollution, unsafe products, human health concerns, depletion of crop diversity, soil sickness and reduction of crop productivity. Several crops including alfalfa, buckwheat, maize, rice, rye, sorghum, sunflower, wheat, etc. are affected either by their own toxicity or phytotoxin exudates when their residues decompose in the soil, that show strong suppression on weed emergences. Allelopathic crops when used as cover crop, mulch, smother crops, green manures, or grown in rotational sequences are helpful in reducing noxious weeds and plant pathogen, improve soil quality and crop yield. Those crop plants, particularly the legumes, incorporated at 1,2 tons ha,1 (alfalfa, buckwheat, rice by-products), which can give weed reduction and increase of rice yield by 70 and 20 %, respectively, are suggested for use as natural herbicides. Allelochemicals from allelopathic crops may aid in the development of biological herbicides and pesticides. Cultivating a system with allelopathic crops plays an important role in the establishment of sustainable agriculture. The introduction of allelopathic traits from accessions with strong allelopathic potential to the target crops will enhance the efficacy of crop allelopathy in future agricultural production. [source] Penicillium strains as dominant degraders in soil for coffee residue, a biological waste unsuitable for fertilizationJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2007Katsuhiko Fujii Abstract Aims:, Coffee residue is an agricultural waste which inhibits the growth of several crops. Therefore coffee residue-degrading microbes in soil were screened, isolated and characterized. Methods and Results:, Forty isolates were obtained after enrichment culture of soil samples. Seven strains (fast degraders) showed strong degrading activity, while 18 strains (slow degraders) showed weak degrading activity. DNA analysis suggested that the fast degraders are Penicillium, and the slow degraders are Penicillium, Trichoderma/Hypocrea, Fusarium/Gibberella, Phaeoacremonium/Togninia or Acidocella. The all fast degraders are cellulolytic, mannolytic and pectinolytic. Conclusions:, Although it is generally thought that fungi such as Trichoderma contribute largely to aerobic degradation of cellulosic biomass, our data suggested that Penicillium overwhelms them in coffee residue degradation. It was implied that polysaccharides in coffee residue are not degraded independently by different microbes, but degraded simultaneously by strains with cellulolytic, mannolytic and pectinolytic activity. Since there is no report of an ascomycete possessing all the three enzyme activities, the fast degraders are ecologically important and have the potential to be used as producers of the costly enzymes from agricultural wastes. Significance and Impact of Study:, The present results advance our understanding of microbial degradation of a phytotoxic agricultural waste, and offer a new tool for recycling it. [source] Reducing runoff by managing crop location at the catchment level, considering agronomic constraints at farm levelLAND DEGRADATION AND DEVELOPMENT, Issue 5 2006A. Joannon Abstract Runoff and erosion cause frequent damage through muddy floods in the loess belt of Northern Europe. One possibility for reducing damage is to lower runoff on agricultural land by spatially alternating different crops at the catchment level. But crop location results from decisions taken at the farm level. This study aimed to assess the existing leeway to modify crop location in the farms of a catchment, in order to reduce runoff at the catchment's outlet. The case study was the Bourville catchment (1086,ha), cultivated by 28 farmers and located in Pays de Caux, France. First, crop location rules in the 14 main farms of the catchment were analysed on the basis of surveys carried out with farmers, distinguishing spatial constraints from temporal ones. These rules made it possible to simulate crop location on each farm territory for the 2001,2002 crop year. Each field of the catchment was classified depending on whether one or several crops could be sown, taking into account both field history and farmer decision rules. Then two extreme scenarios of crop location in the Bourville catchment were built. Runoff simulation at the outlet with the STREAM model showed that runoff could be reduced while sticking to current farmer decision rules in terms of crop location. Depending on rainfall event characteristics, runoff reduction varied between 13·5,per,cent and 4·5,per,cent. Copyright © 2006 John Wiley & Sons, Ltd. [source] Stable expression of AtGA2ox1 in a low-input turfgrass (Paspalum notatum Flugge) reduces bioactive gibberellin levels and improves turf quality under field conditionsPLANT BIOTECHNOLOGY JOURNAL, Issue 6 2007Mrinalini Agharkar Summary Bahiagrass (Paspalum notatum Flugge) is a prime candidate for molecular improvement of turf quality. Its persistence and low input characteristics made it the dominant utility turfgrass along highways in the south-eastern USA. However, the comparatively poor turf quality due to reduced turf density and prolific production of unsightly inflorescences currently limits the widespread use of bahiagrass as residential turf. Alteration of endogenous gibberellin (GA) levels by application of growth regulators or transgenic strategies has modified plant architecture in several crops. GA catabolizing AtGA2ox1 was subcloned under the control of the constitutive maize ubiquitin promoter and Nos 3'UTR. A minimal AtGA2ox1 expression cassette lacking vector backbone sequences was stably introduced into apomictic bahiagrass by biolistic gene transfer as confirmed by Southern blot analysis. Expression of AtGA2ox1 in bahiagrass as indicated by reverse transcription,polymerase chain reaction and Northern blot analysis resulted in a significant reduction of endogenous bioactive GA1 levels compared to wild type. Interestingly, transgenic plants displayed an increased number of vegetative tillers which correlated with the level of AtGA2ox1 expression and enhanced turf density under field conditions. This indicates that GAs contribute to signalling the outgrowth of axillary buds in this perennial grass. Transgenic plants also showed decreased stem length and delayed flowering under controlled environment and field conditions. Consequently, turf quality following weekly mowing was improved in transgenic bahiagrass. Transgene expression and phenotype were transmitted to seed progeny. Argentine bahiagrass produces seeds asexually by apomixis, which reduces the risk of unintended transgene dispersal by pollen and results in uniform progeny. [source] PHA bioplastic: A value-added coproduct for biomass biorefineriesBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 4 2009Kristi D. Snell Abstract The petroleum industry has optimized profits by producing value-added coproducts, such as plastics and chemicals, in addition to primary liquid fuels. A similar coproduct strategy applied to biorefineries processing cellulosic biomass to liquid fuels and/or energy would transform a technology that is marginally economic, depending on oil prices, to a sustainable business with enhanced revenue streams from multiple coproducts. The challenge is finding a biobased coproduct that is compatible with a biorefinery scenario and where markets warrant its production on a similar scale as liquid fuels and/or energy. Polyhydroxyalkanoate (PHA) bioplastics represent a coproduct that would be entirely compatible with either production of liquid fuels by hydrolyzing the residual biomass after PHA extraction or by alternative thermochemical processes. PHA bioplastics possess properties making them suitable replacements for many of the applications currently served by petroleum-based plastics, thus providing tremendous market potential. Proof-of-concept technology for production of these plastics in several crops of agronomic interest has been demonstrated. In this review, we show that the potential for developing biomass-based biorefineries producing liquid fuels and a value-added coproduct is both real and realizable. Examples using switchgrass producing PHA bioplastics as a coproduct are described. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd. [source] | |||||||||||||