Spanish Journal of Agricultural Research
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Cobweb, a serious pathology in mushroom crops: A review
No full textCobweb is a fungal disease of commercially cultivated mushrooms. Several members of the ascomycete genus Cladobotryum sp. have been reported as causal agents. White button mushroom is the most frequently cited host, but a wide range of cultivated edible mushrooms suffer cobweb. The pathology causes production losses and reduces the crop surface available. The parasite produces a great number of harmful conidia that can be released easily and distributed throughout the mushroom farm to generate secondary points of infection. To prevent initial outbreaks, hygiene is of primary importance within the facilities dedicated to mushroom cultivation, while additional measures must be implemented to control and reduce cobweb if there is an outbreak, including chemical and biological methods. This review summarizes and discusses the knowledge available on the historic occurrence of cobweb and its impact on commercial mushroom crops worldwide. Causal agents, disease ecology, including the primary source of infection and the dispersal of harmful conidia are also reviewed. Finally, control treatments to prevent the disease from breaking out are discussed
Global Malmquist indices of productivity change in Egyptian wheat production
No full textThis study aims to measure the total factor productivity of the main governorates of wheat production in Egypt during the time period 1990-2012 and decompose it into technical change, efficiency change and scale change. We used Global Malmquist TFP index as a non-parametric approach. The results indicated that the contribution of technical change component is more important than the efficiency change component. In fact technical change rose, 25.7%, while efficiency change presented a little decline, 3.7%. The decomposition of efficiency change indicated that the main problem of wheat production in Egypt was scale efficiency that worsened by 5.5%
Short communication: Evaluation of a model for predicting Avena fatua and Descurainia sophia seed emergence in winter rapeseed
No full textAvena fatua and Descurainia sophia are two important annual weeds throughout winter rapeseed (Brassica napus L.) production systems in the semiarid region of Iran. Timely and more accurate control of both species may be developed if there is a better understanding of its emergence patterns. Non-linear regression techniques are usually unable to accurately predict field emergence under such environmental conditions. The objectives of this research were to evaluate the emergence patterns of A. fatua and D. sophia and determine if emergence could be predicted using cumulative soil thermal time in degree days (CTT). In the present work, cumulative seedling emergence from a winter rapeseed field during 3 years data set was fitted to cumulative soil CTT using Weibull and Gompertz functions. The Weibull model provided a better fit, based on coefficient of determination (R2sqr), root mean square of error (RMSE) and Akaike index (AICd), compared to the Gompertz model between 2013 and 2016 seasons for both species. Maximum emergence of A. fatua occured 70-119 days after sowing or after equals 329-426 °Cd, while in D. sophia it occurred 119-134 days after sowing rapeseed equals 373-470 °Cd. Both models can aid in the future study of A. fatua and D. sophia emergence and assist growers and agricultural professionals with planning timely and more accurate A. fatua and D. sophia control
Short communication: Stability and integrity of classical swine fever virus RNA stored at room temperature
No full textWorldwide cooperation between laboratories working with classical swine fever virus (CSFV) requires exchange of virus isolates. For this purpose, shipment of CSFV RNA is a safe alternative to the exchange of infectious material. New techniques using desiccation have been developed to store RNA at room temperature and are reported as effective means of preserving RNA integrity. In this study, we evaluated the stability and integrity of dried CSFV RNA stored at room temperature. First, we determined the stability of CSFV RNA covering CSFV genome regions used typically for the detection of viral RNA in diagnostic samples by reverse transcription-polymerase chain reaction (RT-PCR). To this end, different concentrations of in vitro-transcribed RNAs of the 5’-untranslated region and of the NS5B gene were stored as dried RNA at 4, 20, and 37oC for two months. Aliquots were analyzed every week by CSFV-specific quantitative real-time RT-PCR. Neither the RNA concentration nor the storage temperature did affect CSFV RNA yields at any of the time evaluated until the end of the experiment. Furthermore, it was possible to recover infectious CSFV after transfection of SK-6 cells with dried viral RNA stored at room temperature for one week. The full-length E2 of CSFV was amplified from all the recovered viruses, and nucleotide sequence analysis revealed 100% identity with the corresponding sequence obtained from RNA of the original material. These results show that CSFV RNA stored as dried RNA at room temperature is stable, maintaining its integrity for downstream analyses and applications
Residual biomass potential in olive tree cultivation and olive oil industry in Spain: valorization proposal in a biorefinery context
No full textOlive crop and olive oil industry generates several residues, i.e., olive tree pruning biomass (OTPB), extracted olive pomace (EOP) and olive leaves (OL) that could be used to produce high-added value products in an integrated biorefinery. OTPB is generated in the field as a result of pruning operation to remove old branches; EOP is the main residue of the pomace olive oil extracting industry after extraction with hexane of residual oil contained in olive pomace; and OL comes from the olive cleaning process carried out at olive mills, where small branches and leaves are separated by density. In this work, an analysis of the potential of OTPB, EOP and OL residues was addressed by estimating the production volumes at national level and the spatial distribution of these residues using geographic information system software. Information provided by public institutions and personal surveys to the industries was evaluated. Moreover, chemical analysis of the residues was undertaken and the results used to make a first assessment of valorization into biofuels such as bioethanol and bio based chemicals. Results show that close to 4.2 million tons/year of EOP, OL and OTPB derived from olive oil industry and olive tree cultivation in Spain could be available as a raw material for biorefineries in Spain. The analysis of the chemical characteristics indicates the relevant potential of these feedstocks for the production of bioethanol and other compounds such as phenols based on suitable processing and conversion routes, although techno-economic evaluations must be tackled to refine this approach
Fatty acid profile as a tool to trace the origin of beef in pasture- and grain-fed young bulls of Retinta breed
No full textThis research explores the possibility of using the fatty acid profiles of intramuscular fat to authenticate the origin of Retinta breed meat according to different feeding regimes based on the combined use of concentrate and grass or forage (GP, grass pasture; MC, medium concentrate; HC, high concentrate). Young bulls from GP (n=30) were reared on grass pasture and supplement with concentrate in controlled feeders; MC (n=30) and HC (n=15) were reared in farm buildings using 40 and 80% concentrate of total dry matter from diet, respectively. The stepclass function in R was used to perform a stepwise linear discriminant analysis including thirty fatty acids from intramuscular fat. Two fatty acids, 9c18:1 and 22:5 n-3 were selected as discriminators of the meat origin. Meat from the GP and MC was characterized by higher 22:5 n-3 (p<0.05), while HC meat showed higher 9c18:1 (p<0.05). The use of 9c18:1 and 22:5 n-3 fatty acids from intramuscular fat resulted in a correct assignation of 100% of beef samples to each of the feeding regimes. Therefore, in addition to serving as an effective tool for discriminating between feeding regimes in the origin of the beef, the fatty acid profile of intramuscular fat could help companies to check the authenticity of the meat origin
Short communication: Morphological description and molecular detection of Pestalotiopsis sp. on hazelnut in Serbia
No full textIn autumn 2015, hazelnut plants with leaf blight symptoms were noticed in a commercial plantation in the Province of Vojvodina, Serbia. Symptomatic samples were collected and submitted to laboratory analysis. Based on morphological characterization, the fungus isolated from the material was initially identified as Pestalotiopsis sp. Pathogenicity tests showed that two selected isolates infected hazelnut leaves and fruits that developed symptoms after artificial inoculation. The pathogen was re-isolated from diseased leaves and fruits, confirming Koch’s postulates. Molecular identification was performed with sequence and phylogenetic analysis of ITS, EF1-α, and TUB genomic regions. Phylogenetic analysis confirmed the results of the morphological identification. The detection of Pestalotiopsis sp., a causal agent of leaf blight on hazelnut in Serbia, is one of a few reports of these pathogenic fungi on hazelnut
Holstein-Friesian milk performance in organic farming in North Spain: Comparison with other systems and breeds
No full textOrganic systems are highly dependent on the environment and require animals well adapted to local conditions. In Spain, organic dairy farmers are not satisfied with the productive performance of their herds and ask for technical advice to obtain suitable animals for organic systems. The milk productive performance (milk yield, nutritional composition, and somatic cell count) of Holstein-Friesian cows in organic farming in North Spain compared with conventional farms has been analysed. When breed diversity was present in the same organic farm, Holstein-Friesian milk performance was compared with other breeds and/or crosses. Holstein-Friesian cows in organic farming produce slightly less milk than grazing conventional cows, but milk was similar in composition and somatic cell count across systems. The limited data from organic farms where breed diversity exists indicate that Holstein-Friesian cows produce numerically more milk than other breeds and crosses but with statistically lower protein content. Considering that in Spain organic milk production is mostly used for liquid milk consumption and that the payment system is based only on milk volume, Holstein-Friesian cows would better fit the farmer interests than other breeds or crosses. However, in addition to productive performance, reproductive efficiency, animal health and consumer’s preferences should be fully considered when selecting a breed for organic production. If Holstein-Friesian was the selected breed, efforts should be made to identify cows within the breed that are best adapted to organic conditions. New productive, reproductive, nutritional and economic studies would be needed to develop a genetic merit index for organic systems
Assessment of combining ability for yield and quality components in hot pepper (Capsicum annuum L.)
No full textSix parental genotypes and their thirty F1 hybrids in a full diallel cross system with reciprocals, were used in the present study to estimate combining ability for five quantitative and five qualitative traits in hot pepper. The mean sum of squares due to general combining ability (GCA), specific combining ability (SCA) and reciprocal combining ability (RCA) were significant for all the characters which suggest that these parents could have performed differently in different combinations indicating interallelic interactions. All the traits studied exhibited greater SCA variance than GCA, suggesting that these traits are controlled by non-additive gene action. Analysis of the GCA effects of parents for various traits revealed that LCA625, K1 and PKM1 were the best general combiners for almost all the traits. Estimates of SCA effects showed that the hybrids LCA625 × K1, K1 × Arka LohitandPusa Jwala × PKM1were found to be the best combiners for yield and its attributes. The hybrid K1 × Arka Lohitwas the best reciprocal combiner for quality parameters based on its better mean performance and combining ability. These results suggest that commercial production of hot pepper hybrids and isolation of pure lines from these hybrids is a possible way to enhance the yield and fruit quality
Short communication: East-West European farm investment behaviour - The role of financial constraints and public support
No full textThe article investigated farm investment behaviour among East (Hungarian and Slovenian) and West (French) European Union farms using individual farm accountancy panel data for the 2003-2008 period. Despite differences in farm structures, except for the presence of capital market imperfections evidenced in the East, farms’ investment behaviour was not substantially different. Farm gross investment was positively associated with real sales’ growth. In addition, it was positively associated with public investment subsidies which can mitigate capital market imperfections in the short-term. On the long run, the farm’s ability to successfully compete in the output market by selling produce and securing a sufficient cash flow for investment is crucial