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Crop Productivity (crop + productivity)
Selected AbstractsDoes Plant Variety Protection Contribute to Crop Productivity?THE JOURNAL OF WORLD INTELLECTUAL PROPERTY, Issue 2 2009Lessons for Developing Countries from US Wheat Breeding The application of intellectual property rights (IP) in developing countries is and remains highly controversial, particularly as regards applications to food/agriculture, and pharmaceuticals, which have direct ramifications for large numbers of peoples. One dimension complicating a reasoned dialogue on the public benefits of IP, particularly when many developing countries are implementing the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) as mandated by membership in the World Trade Organization, is a dearth of information on their actual operation and effects. In this study, we address one particular aspect of the limited documentation on the effects of IP systems, the effect of plant variety protection (PVP) on the genetic productivity potential of varieties. Specifically, we examine wheat varieties in Washington State, United States, which are produced by both public and private sector breeders. Results from the study show that implementation of PVP attracted private investment in open pollinated crops such as wheat in the United States and provided greater numbers of varieties of these crops, which are high yielding from both the public and private sectors. These results may provide some insights for policy makers from developing countries on the effects of IP for plants as their TRIPS commitments are being implemented. [source] Rights and Access to Plant Genetic Resources under India's New LawDEVELOPMENT POLICY REVIEW, Issue 4 2004Anitha Ramanna Recognition of ,Farmer's Rights' is an attempt by developing countries to evolve a counterclaim to breeders' Intellectual Property Rights (IPRs) promoted under the TRIPs Agreement of the WTO. India is one of the first countries to have granted rights to both breeders and farmers under the Protection of Plant Varieties and Farmers' Rights Act, 2001. This multiple rights system aims to distribute rights equitably, but may pose the threat of an ,anticommons tragedy' i.e. too many parties independently possessing the right to exclude others from utilising a resource. If under-utilisation of plant genetic resources results, the Act will have negative consequences for sustaining crop productivity and for the welfare of the very farming communities it seeks to compensate. [source] Seasonal changes in the effects of elevated CO2 on rice at three levels of nitrogen supply: a free air CO2 enrichment (FACE) experimentGLOBAL CHANGE BIOLOGY, Issue 6 2003HAN-YONG KIM Abstract Over time, the stimulative effect of elevated CO2 on the photosynthesis of rice crops is likely to be reduced with increasing duration of CO2 exposure, but the resultant effects on crop productivity remain unclear. To investigate seasonal changes in the effect of elevated CO2 on the growth of rice (Oryza sativa L.) crops, a free air CO2 enrichment (FACE) experiment was conducted at Shizukuishi, Iwate, Japan in 1998,2000. The target CO2 concentration of the FACE plots was 200 µmol mol,1 above that of ambient. Three levels of nitrogen (N) were supplied: low (LN, 4 g N m,2), medium [MN, 8 (1998) and 9 (1999, 2000) g N m,2] and high N (HN, 12 and 15 g N m,2). For MN and HN but not for LN, elevated CO2 increased tiller number at panicle initiation (PI) but this positive response decreased with crop development. As a result, the response of green leaf area index (GLAI) to elevated CO2 greatly varied with development, showing positive responses during vegetative stages and negative responses after PI. Elevated CO2 decreased leaf N concentration over the season, except during early stage of development. For MN crops, total biomass increased with elevated CO2, but the response declined linearly with development, with average increases of 32, 28, 21, 15 and 12% at tillering, PI, anthesis, mid-ripening and grain maturity, respectively. This decline is likely to be due to decreases in the positive effects of elevated CO2 on canopy photosynthesis because of reductions in both GLAI and leaf N. Up to PI, LN-crops tended to have a lower response to elevated CO2 than MN- and HN-crops, though by final harvest the total biomass response was similar for all N levels. For MN- and HN-crops, the positive response of grain yield (ca. 15%) to elevated CO2 was slightly greater than the response of final total biomass while for LN-crops it was less. We conclude that most of the seasonal changes in crop response to elevated CO2 are directly or indirectly associated with N uptake. [source] The 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] Smallholders, institutional services, and commercial transformation in EthiopiaAGRICULTURAL ECONOMICS, Issue 2009Berhanu Gebremedhin Smallholders; Institutions; Commercial transformation Abstract This article examines the role of institutional services of credit, input supply, and extension in the overall commercial transformation process of smallholder agriculture in Ethiopia. Survey data collected in 2006 from 309 sample households in three districts of Ethiopia are used for the analyses. Tobit regression models are used to measure the effect of access to services on the intensity of inputs use for fertilizer and agrochemicals. A probit model is used to measure these effects on the adoption of improved seeds. Intensity of use of seeds is analyzed using an ordinary least squares model. Logarithmic Cobb,Douglass functions are estimated to analyze the effect of access to services on crop productivity. Heckman's two-stage estimation is used to examine determinants of household market participation and the extents of participation. Results show that access to institutional support services plays a significant role in enhancing smallholder productivity and market orientation. Our results imply that expanding and strengthening the institutional services is critical for the intensification and market orientation of smallholder agriculture in Ethiopia. In particular, appropriate incentives and regulatory systems are urgently needed to encourage the involvement of the private sector in the provision of agricultural services. [source] Labile soil organic carbon, soil fertility, and crop productivity as influenced by manure and mineral fertilizers in the tropicsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 5 2010Siba Prasad Datta Abstract In recent years, organic agriculture has been receiving greater attention because of the various problems like deterioration in soil health and environmental quality under conventional chemical-intensive agriculture. However, little information is available on the comparative study related to the impact of use of mineral fertilizers and organic manures on the soil quality and productivity. A long-term field experiment was initiated in 2001 to monitor some of the important soil-quality parameters and productivity under soybean,wheat crop rotation. The treatments consisted of 0, 30, and 45,kg N ha,1 for soybean and of 0, 120, and 180,kg N ha,1 for wheat. The entire amount of N was supplied to both the crops through urea and farmyard manure (FYM) alone or in combination at 1:1 ratio. Results indicated that Walkley-and-Black C (WBC; chromic acid,oxidizable) exhibited a marginal increase under only organic treatments as compared to control treatment (without fertilizers and manure) after completion of five cropping cycles. In case of labile-C (KMnO4 -oxidizable) content in soil, relatively larger positive changes were recorded under organic, mixed inputs (integrated) and mineral fertilizers as compared to WBC. Maximum improvement in the values of C-management index (CMI), a measure of soil quality was recorded under organic (348,362), followed by mixed inputs (268,322) and mineral fertilizers (198,199) as compared to the control treatment after completion of five cropping cycles. Similarly there was a substantial increase in KCl-extractable N; in Olsen-P; as well as in DTPA-extractable Zn, Fe, and Mn under organic treatments. Although labile soil C positively contributed to the available N, P, K, Zn, Fe, and Mn contents in soil, it did not show any relationship with the grain yield of wheat. After completion of the sixth cropping cycle, organic treatments produced 23% and 39% lower grain yield of wheat as compared to that under urea-treated plots. Relatively higher amount of mineral N in soil at critical growth stages and elevated N content in plant under mineral-fertilizer treatments compared to FYM treatments were responsible for higher yield of wheat under mineral fertilizers. [source] Subsurface drainage for reversing degradation of waterlogged saline landsLAND DEGRADATION AND DEVELOPMENT, Issue 6 2006D. P. Sharma Abstract In irrigated agriculture of arid and semiarid regions waterlogging coupled with salinity is a serious problem. Experimental evidence at several locations has led to the realization that subsurface drainage is an essential intervention to reverse the processes of land degradation responsible for the formation of waterlogged saline lands. This paper presents the results of a study conducted from 1995 to 2000 to evaluate the impacts of subsurface drainage on soil properties, groundwater-table behaviour and crop productivity in a waterlogged saline area of 2200,ha. A subsurface drainage system was installed at 1·6,m depth with 60,m drain spacing covering an area of 1200,ha (23 blocks) during 1997,99 and compared with an undrained block of 1000,ha. Subsurface drainage facilitated the reclamation of waterlogged saline lands and a decrease in the soil salinity (ECe, dS,m,1) that ranged from 16·0 to 66·3,per,cent in different blocks. On average, 35·7,per,cent decrease in salt content was observed when compared with the initial value. Provision of subsurface drainage controlled the water-table below the root zone during the monsoon season and helped in bringing the soil to optimum moisture content for the sowing of winter crops. In the drained area, the increase in yields of different crops ranged from 18·8 to 27·6,per,cent. However, in the undrained area the yield of different crops decreased due to the increased waterlogging and soil salinity problems. Overall the results indicated that investment in subsurface drainage is a viable option for reversing the land degradation of waterlogged saline lands in a monsoon climate. Copyright © 2006 John Wiley & Sons, Ltd. [source] Genetic dissection of cotton physiological responses to arid conditions and their inter-relationships with productivityPLANT CELL & ENVIRONMENT, Issue 3 2004Y. SARANGA ABSTRACT Testing of the extent to which different complex traits share common genetic control provides a means to distinguish associations that are truly diagnostic of genetic potential for improved adaptation to abiotic stress, from incidental phenotypic correlations. In two generations of progeny from a cross between Gossypium hirsutum and Gossypium barbadense, quantitative trait loci (QTL) mapping was used to evaluate correspondence in genetic control of selected physiological measures and productivity under water-limited and well-watered environments, respectively. A total of 33 QTLs were detected for five physiological variables [osmotic potential (OP), carbon isotope ratio (,13C; indicator of water use efficiency), canopy temperature, chlorophyll a and b], and 46 QTLs for five measures of crop productivity [dry matter, seed cotton yield (SC), harvest index, boll weight, and boll number]. QTL likelihood intervals for high SC and low OP corresponded in three genomic regions, two of which mapped to homoeologous locations on the two subgenomes of tetraploid cotton. QTLs for ,13C showed only incidental association with productivity, indicating that high water use efficiency can be associated with either high or low productivity. Different cotton species have evolved different alleles related to physiological responses and productivity under water deficit, which may permit the development of genotypes that are better-adapted to arid conditions. [source] Would transformation of C3 crop plants with foreign Rubisco increase productivity?PLANT CELL & ENVIRONMENT, Issue 2 2004A computational analysis extrapolating from kinetic properties to canopy photosynthesis ABSTRACT Genetic modification of Rubisco to increase the specificity for CO2 relative to O2 (,) would decrease photorespiration and in principle should increase crop productivity. When the kinetic properties of Rubisco from different photosynthetic organisms are compared, it appears that forms with high , have low maximum catalytic rates of carboxylation per active site (kcc). If it is assumed that an inverse relationship between kcc and , exists, as implied from measurements, and that an increased concentration of Rubisco per unit leaf area is not possible, will increasing , result in increased leaf and canopy photosynthesis? A steady-state biochemical model for leaf photosynthesis was coupled to a canopy biophysical microclimate model and used to explore this question. C3 photosynthetic CO2 uptake rate (A) is either limited by the maximum rate of Rubisco activity (Vcmax) or by the rate of regeneration of ribulose-1,5-bisphosphate, in turn determined by the rate of whole chain electron transport (J). Thus, if J is limiting, an increase in , will increase net CO2 uptake because more products of the electron transport chain will be partitioned away from photorespiration into photosynthesis. The effect of an increase in , on Rubisco-limited photosynthesis depends on both kcc and the concentration of CO2 ([CO2]). Assuming a strict inverse relationship between kcc and ,, the simulations showed that a decrease, not an increase, in , increases Rubisco-limited photosynthesis at the current atmospheric [CO2], but the increase is observed only in high light. In crop canopies, significant amounts of both light-limited and light-saturated photosynthesis contribute to total crop carbon gain. For canopies, the present average , found in C3 terrestrial plants is supra-optimal for the present atmospheric [CO2] of 370 µmol mol,1, but would be optimal for a CO2 concentration of around 200 µmol mol,1, a value close to the average of the last 400 000 years. Replacing the average Rubisco of terrestrial C3 plants with one having a lower and optimal , would increase canopy carbon gain by 3%. Because there are significant deviations from the strict inverse relationship between kcc and ,, the canopy model was also used to compare the rates of canopy photosynthesis for several Rubiscos with well-defined kinetic constants. These simulations suggest that very substantial increases (> 25%) in crop carbon gain could result if specific Rubiscos having either a higher , or higher kcc were successfully expressed in C3 plants. [source] Enhanced crop productivity and compatibility through intercropping of sesame and sunflower varietiesANNALS OF APPLIED BIOLOGY, Issue 2 2009V.I.O. Olowe Abstract Field trials were conducted during 2002 and 2003 to determine the productivity and compatibility of the cropping systems obtained from intercropping varieties of sesame (E8, PBTil and 530-6-1) and sunflower (Funtua, Record and Isaanka) in the humid forest,savanna transition zone which is outside the current growing areas. Intercropping did not affect the number of branches per plant, number and weight of capsules per plant, weight of seeds per plant, 1000 seed weight or seed production efficiency (SPE) of all sesame varieties in both years, except SPE in 2003. In both years, intercropping sesame with sunflower varieties significantly reduced grain yield of PBTil and E8. However, 530-6-1 produced grain yield similar to the monocrop when intercropped with Record and Funtua in 2002 and 2003, and Record in 2003. In both years, intercropping significantly depressed the grain yield of the three sunflower varieties because of reduction in their head diameter, head weight, number and weight of seeds per head and lower number of plants per unit area relative to their monocrops. E8, 530-6-1 and PBTil intercropped with the three sunflower varieties recorded land equivalent ratio values in the range of 1.13,1.37, 1.32,1.46 and 1.22,1.35, respectively. Based on competitive ratio values, E8 demonstrated the greatest ability to compensate for intercrop competition with taller sunflower varieties. It was concluded that growers can successfully cultivate sesame (530-6-1 and PBTil) under intercropping with sunflower in the humid forest,savanna transition zone. [source] Sustainable production of crops and pastures under drought in a Mediterranean environmentANNALS OF APPLIED BIOLOGY, Issue 2 2004NEIL C TURNER Summary Mediterranean environments are characterised by cool wet winters and hot dry summers. While native vegetation in Mediterranean-climatic zones usually comprises a mixture of perennial and annual plants, agricultural development in the Mediterranean-climatic region of Australia has led to the clearing of the perennial vegetation and its replacement with annual crops and pastures. In the Mediterranean environments of southern Australia this has led to secondary (dryland) salinisation. In order to slow land degradation, perennial trees and pasture species are being reintroduced to increase the productivity of the saline areas. The annual crops and pastures that form the backbone of dryland farming systems in the Mediterranean-climatic zone of Australia are grown during the cool wet winter months on incoming rainfall and mature during spring and early summer as temperatures and rates of evaporation rise and rainfall decreases. Thus, crop and pasture growth is usually curtailed by terminal drought. Where available, supplementary irrigation in spring can lead to significant increases in yield and water use efficiency. In order to sustain production of annual crops in Mediterranean environments, both agronomic and genetic options have been employed. An analysis of the yield increases of wheat in Mediterranean-climatic regions shows that there has generally been an increase in the yields over the past decades, albeit at a lower rate than in more temperate regions. Approximately half of this increase can be attributed to agronomic improvements and half to genetic improvements. The agronomic improvements that have been utilised to sustain the increased yields include earlier planting to more closely match crop growth to rainfall distribution, use of fertilisers to increase early growth, minimum tillage to enable earlier planting and increase plant transpiration at the expense of soil evaporation, rotations to reduce weed control and disease incidence, and use of herbicides, insecticides and fungicides to reduce losses from weeds, insects and disease. Genetic improvements include changing the phenological development to better match the rainfall, increased early vigour, deeper rooting, osmotic adjustment, increased transpiration efficiency and improved assimilate storage and remobilisation. Mediterranean environments that are subjected annually to terminal drought can be both environmentally and economically sustainable, but to maximise plant water use efficiency while maintaining crop productivity requires an understanding of the interaction between genotypes, environment and management. [source] Large-scale production, harvest and logistics of switchgrass (Panicum virgatum L.) , current technology and envisioning a mature technologyBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 2 2009Shahab Sokhansanj Abstract Switchgrass (Panicum virgatum L.) is a promising cellulosic biomass feedstock for biorefineries and biofuel production. This paper reviews current and future potential technologies for production, harvest, storage, and transportation of switchgrass. Our analysis indicates that for a yield of 10 Mg ha,1, the current cost of producing switchgrass (after establishment) is about $41.50 Mg,1. The costs may be reduced to about half this if the yield is increased to 30 Mg ha,1 through genetic improvement, intensive crop management, and/or optimized inputs. At a yield of 10 Mg ha,1, we estimate that harvesting costs range from $23.72 Mg,1 for current baling technology to less than $16 Mg,1 when using a loafing collection system. At yields of 20 and 30 Mg ha,1 with an improved loafing system, harvesting costs are even lower at $12.75 Mg,1 and $9.59 Mg,1, respectively. Transport costs vary depending upon yield and fraction of land under switchgrass, bulk density of biomass, and total annual demand of a biorefinery. For a 2000 Mg d,1 plant and an annual yield of 10 Mg ha,1, the transport cost is an estimated $15.42 Mg,1, assuming 25% of the land is under switchgrass production. Total delivered cost of switchgrass using current baling technology is $80.64 Mg,1, requiring an energy input of 8.5% of the feedstock higher heating value (HHV). With mature technology, for example, a large, loaf-collection system, the total delivered cost is reduced to about $71.16 Mg,1 with 7.8% of the feedstock HHV required as input. Further cost reduction can be achieved by combining mature technology with increased crop productivity. Delivered cost and energy input do not vary significantly as biorefinery capacity increases from 2000 Mg d,1 to 5000 Mg d,1 because the cost of increased distance to access a larger volume feedstock offsets the gains in increased biorefinery capacity. This paper outlines possible scenarios for the expansion of switchgrass handling to 30 Tg (million Mg) in 2015 and 100 Tg in 2030 based on predicted growth of the biorefinery industry in the USA. The value of switchgrass collection operations is estimated at more than $0.6 billion in 2015 and more than $2.1 billion in 2030. The estimated value of post-harvest operations is $0.6,$2.0 billion in 2015, and $2.0,$6.5 billion in 2030, depending on the degree of preprocessing. The need for power equipment (tractors) will increase from 100 MW in 2015 to 666 MW in 2030, with corresponding annual values of $150 and $520 million, respectively. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd [source] Variable Selection in High-Dimensional Multivariate Binary Data with Application to the Analysis of Microbial Community DNA FingerprintsBIOMETRICS, Issue 2 2002J. D. Wilbur Summary. In order to understand the relevance of microbial communities on crop productivity, the identification and characterization of the rhieosphere soil microbial community is necessary. Characteristic profiles of the microbial communities are obtained by denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction (PCR) amplified 16s rDNA from soil extracted DNA. These characteristic profiles, commonly called community DNA fingerprints, can be represented in the form of high-dimensional binary vectors. We address the problem of modeling and variable selection in high-dimensional multivariate binary data and present an application of our methodology in the context of a controlled agricultural experiment. [source] | |||||||||||||