Results 1 - 10 of 275
Results 1 - 10 of 275. Search took: 0.017 seconds
|Sort by: date | relevance|
[en] The present study evaluated the effect of different associations between coulters and fertilizer furrow openers on soil disturbance, furrow depth and width, according to forward speed. The study was conducted on a farm in Santa Maria (Brazil/RS), in soil classified as sandy loam Ultisol. The experiment consisted of 24 combinations of treatments with three replications in a 2×3×4 factorial experiment. The combinations were formed by the interaction of the factors including: two types of furrow openers (hoe and double-disc), three types of coulters (no-coulter, smooth and offset fluted) and four levels of forward speed (1.11, 1.67, 2.22 and 2.78 m/s). Soil elevation and soil disturbance area profiles were obtained with the use of a micro profilometer, and disturbance values were calculated with the aid of computer software program Auto Cad. The disturbance area was not affected by speed; it was greater when using the hoe opener, and in association with the offset fluted coulter. Speed was inversely proportional to the depth of the furrows made by the hoe opener. Furthermore, the hoe caused the greatest furrow width (0.26 m) in comparison with the double-disc (0.24 m). The use of different coulters associated with furrow openers increased this variable (0.23 m for the no-coulter condition, 0.25 m with smooth and 0.26 m with offset fluted). The use of coulters combined with furrow openers reduces soil swelling, in approximately 8% for the smooth and 20% for the offset fluted. (Author)
[en] Hydrological droughts are a major risk for irrigated agriculture in many regions of the world. The aim of this article is to propose an insurance tool to help irrigators manage the risk of water scarcity in the framework of the Spanish Crop Insurance System (SCIS). Only the United States Insurance System provides this type of coverage, but has very restrictive conditions. To determine the type of insurance scheme that better fits with the SCIS and to the Spanish irrigated agriculture, an expert panel was held with the participation of all stakeholders involved in crop insurance. Following the expert panel conclusions, an hydrological drought index insurance (HDII) addressed to irrigation districts (ID) is proposed. It would compensate water deficits suffered in the whole ID. We detail the conditions that the ID should fulfill to be eligible for HDII. HDII is applied to the Bardenas Irrigation District V (ID-V) in Spain, and the hedging effectiveness of the instrument is analyzed comparing ID-V’s gross margins with and without the insurance contract. Results suggest that the proposed insurance scheme could provide an effective means of reducing farmers’ vulnerability to water shortages and there is no major impediment for it to be included as a new line in the SCIS. This type of insurance can be generalized to any ID fulfilling the conditions mentioned in this paper. (Author)
[en] The aim of this paper was to analyze the segregation of some polymorphisms in three genes (CAPN1, CAST and DGAT1) related to meat quality in the Lidia cattle breed and some of its main lineages. To that effect, 119 individuals from the Lidia breed were analyzed. Although the association between the polymorphisms and the phenotype has never been demonstrated in this breed, the absence of fixed genotypes for these polymorphisms in the studied population makes the Lidia cattle a good candidate to develop selection objectives. The clear differentiation among lineages for most of the genes studied reinforces the high reproductive isolation presented in the Lidia cattle as revealed by previous studies on the structure of the population within the Lidia breed using microsatellite markers. Considering both issues in the design of breeding schemes will be necessary to save the lineages and not to lose this valuable genetic resource. Finally, it would be necessary to carry out an in depth search for new polymorphisms in genes associated with meat quality and to perform needed association analyses between the SNPs segregating in Lidia cattle and traits of economic interest.
[en] Cooperatives are especially important in current agri-food markets. These companies have responded to the current demand requirements with greater market orientation strategies to attract and satisfy customers. To do so, cooperatives have adopted different collaboration alternatives. In Spain, the most common alliance between cooperatives is materialised in second-level cooperatives, which are cooperatives integrated by at least two first-level cooperatives. The aim of this study was to analyse the interaction effects between first- and second level agri-food cooperatives on their productive growth and its components. To get this purpose, a Cobb-Douglas specification with spatial econometrics techniques was applied to evaluate this relationship. We included a spatial connectivity matrix to establish the interconnection among cooperatives of first- and second-level. Our results show a positive interaction effect highlighting the importance of these alliances on the productivity growth in the agri-food sector. The scarce amount of empirical papers explaining how second-level cooperatives influence the performance of first-level cooperatives shows the relevance of our study.
[en] The coffee market is distinguished for being volatile and uncertain in terms of domestic and international prices. Arabica and Robusta coffee are produced in 23 provinces of Ecuador. A decade-long decline of coffee production prompted the Ecuadorian government to launch a public program for replanting coffee trees towards the end of 2011. A grower’s decision to enter, remain in or exit the coffee sector is based on fluctuating profits from each year’s harvest sale. We analyzed the hypothesis whereby the coffee grower’s decision to leave the sector is explained by volatile and uncertain prices. This paper aimed to evaluate the coffee sector with an application of Real Option Analysis for the period 2002-2012. We also defined entry (H) and exit (L) prices for Arabica and Robusta coffee for the analyzed period. Our findings revealed high H and L prices encourage growers to leave the sector for the most part of the analyzed period. High H and L prices resulted from high variable cost due to increasing wages for farm workers. The Ecuadorian government is developing a policy to help growers make production more efficient, encouraging them to remain in the sector in the long run.
[en] The decomposition and burning of straw results in serious environmental pollution, and research is needed to improve strategies for straw collection to reduce pollution. This work presents an integrated design of multi-functional rice combine harvester that allows grain harvesting and straw baling. This multi-functional combine harvester could reduce the energy consumption required for rice harvesting and simplify the process of harvesting and baling. The transmission schematic, matching parameters and the rotation speed of threshing cylinder and square baler were designed and checked. Then the evaluation of grain threshing and straw baling were tested on a transverse threshing cylinders device tes rig and straw square bales compression test rig. The test results indicated that, with a feeding rate of 3.0 kg/s, the remaining straw flow rate at the discharge outlet was only 1.22 kg/s, which indicates a variable mass threshing process by the transverse threshing cylinder. Then the optimal diameter, length and rotating speed of multi-functional combine harvester transverse threshing cylinder were 554 mm, 1590 mm, and 850 r/min, respectively. The straw bale compression rotating speed of crank compression slider and piston was 95 r/min. Field trials by the multi-functional combine harvester formed bales with height×width×length of 40×50×54-63 cm, bale mass of 22.5 to 26.0 kg and bale density 206 to 216 kg/m3. This multi-functional combine harvester could be used for stem crops (such as rice, wheat and soybean) grain harvesting and straw square baling, which could reduce labor cost and power consumption.
[en] Haplotypes from sequencing data may improve the prediction accuracy in genomic evaluations as haplotypes are in stronger linkage disequilibrium with quantitative trait loci than markers from SNP chips. This study focuses first, on the creation of haplotypes in a population sample of 450 Holstein animals, with full-sequence data from the 1000 bull genomes project; and second, on incorporating them into the whole genome prediction model. In total, 38,319,258 SNPs (and indels) from Next Generation Sequencing were included in the analysis. After filtering variants with minor allele frequency (MAF< 0.025) 13,912,326 SNPs were available for the haplotypes extraction with findhap.f90. The number of SNPs in the haploblocks was on average 924 SNP (166,552 bp). Unique haplotypes were around 97% in all chromosomes and were ignored leaving 153,428 haplotypes. Estimated haplotypes had a large contribution to the total variance of genomic estimated breeding values for kilogram of protein, Global Type Index, Somatic Cell Score and Days Open (between 32 and 99.9%). Haploblocks containing haplotypes with large effects were selected by filtering for each trait, haplotypes whose effect was larger/lower than the mean plus/minus 3 times the standard deviation (SD) and 1 SD above the mean of the haplotypes effect distribution. Results showed that filtering by 3 SD would not be enough to capture a large proportion of genetic variance, whereas filtering by 1 SD could be useful but model convergence should be considered. Additionally, sequence haplotypes were able to capture additional genetic variance to the polygenic effect for traits undergoing lower selection intensity like fertility and health traits.
[en] Farmers’ views on research and extension services (RES) included in the Agricultural Knowledge and Innovation System are rarely investigated. This study analyses the relationship between key factors of innovation behaviour (market orientation, learning orientation, and innovation attitude) and the use of RES through structural equation modelling, focusing on small-scale agricultural holdings. Market orientation and learning orientation appear to be positively correlated, confirming that synergies between both factors provide a background for innovativeness. Learning orientation and farm-holders’ education level, improve knowledge exchange and make the agriculture innovation process more inclusive. However, farmers’ innovation attitude is not clearly correlated with the use of RES. Motivations about “the will to do innovations” are represented by a construct that does not appear to have a determinant effect as a mediator in farmer’s decisions about using RES.
[en] Shortage of irrigation water at critical growth stages of maize is limiting its production worldwide. Breeding drought-tolerant cultivars is one possible solution while identification of potential genotypes is crucial for genetic improvement. To assess genetic variation for seedling-stage drought tolerance, we tested 40 inbred lines in a completely randomized design under glasshouse conditions. From these, two contrasting inbred lines were used to develop six basic generations (P1, P2, F1, F2, BC1F1, BC2F2). These populations were then evaluated in a triplicated factorial randomized complete block design under non-stressed and drought-stressed conditions. For statistical analyses, a nested block design was employed to ignore the replication effects. Significant differences (p=0.01) were recorded among the genotypes for investigated seedling-traits. Absolute values of fresh root length, fresh root weight, and dry root weight lead to select two genotypes, one tolerant (WFTMS) and one susceptible (Q66). Estimates of heritability, genetic advance, and genotypic correlation coefficients were higher and significant for most of the seedling-traits. Generation variance analysis revealed additive gene action. Narrow-sense heritability [F2 = 65; F8 = 79] revealed the same results. Generation mean analysis signified additive genetic effects in the inheritance of cob girth, non-additive for plant height, grains per ear row and grain yield per plant, and environmental for ear leaf area, cob length, grain rows per ear, biomass per plant, and 100-grain weight under drought-stressed conditions. For conferring drought-tolerance in maize, breeders can adopt the recombinant breeding strategy to pyramid the desirable genes. (Author)
[en] The development of chickpea cultivars with high quality grains for human consumption is an important objective in breeding programs. Genotype and environment effects on seed quality traits (sensorial, nutritional and physical) were studied in chickpea dry grain. Twenty genotypes were grown in winter and spring sowings over two campaigns in four different locations in southern Spain. Significant differences were observed in oil, acid detergent fiber (ADF) and protein content between sowing times (S). In winter, oil and ADF content were higher, while protein content was lower. Although, in general, highly significant variation was detected for genotype (G), environment (E) and single interactions (GE, GS and ES), the genotype effect was stronger for ADF, neutral detergent fiber (NDF), oil, starch and protein content, and for physical and sensory traits (r2>27%). In contrast, environment played an important role in variation in the content of amylose and amylopectin (r2=71.7%). No high relationships were found between the sensory and nutritional or physical characteristics studied. In general, our results suggest a high genetic gain for seed quality in nutritional, physical and sensory traits in chickpea. Genotypes with good seed sensory quality should be selected in the final stages of the breeding program, because it is not feasible to evaluate very large numbers of samples. However, in some cases, moderate correlations were found between sensory and either nutritional or physical traits. Therefore, indirect selection to increase the frequency of genes for sensory traits in an early stage should be considered.