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981.
Francis Mbuza Rosine Manishimwe Janvier Mahoro Thomas Simbankabo Kizito Nishimwe 《Tropical animal health and production》2017,49(1):71-77
A study was conducted on 37 randomly selected broiler poultry farmers in Rwanda to characterize the production system using pre-tested semi-structured questionnaires. The data were processed in SPSS and presented as means, percentages and ranges in tables and text. All respondents kept Cobb breed and young stock was mainly (73 %) imported from abroad. The majority of respondents were males (68 %) and most farmers had attended only primary level of education (40.5 %). Most of the farms were in the peri-urban (48.6 %) and urban (37.8 %) areas and hired male youth (62.2 %) mainly aged 19–35 years. The majority of respondents (68 %) kept less than 500 birds per batch. Recordkeeping was well practiced (91.9 %) and (62.6 %) had permanent poultry houses and all farmers used deep litter system. Purchased feedstuffs were reportedly (92 %) mixed at farm level as the main feed resource. Maize bran was reported (97.06 %) the main, basal feedstuff. The mortality rates of chick and growers were 12.3 and 9.4 %, respectively. The slaughter age was reportedly 60 days with an average dressing percentage of 75.67 %. The main challenges reported were scarcity and unaffordability of quality feeds (59.5 %), lack of market access (45 %) and lack of credit (21 %). The farmers had various views on improving broiler production in Rwanda ranging from establishing feed processing industries 62.2 %, improving marketing facilities 35.1 %, increasing availability of day-old chick and access credit 27 %, to intensification of farmer training 16.2 %. 相似文献
982.
On a global research expedition, over 500 bacterial strains inhibitory towards pathogenic bacteria were isolated. Three hundred of the antibacterial strains were assigned to the Vibrionaceae family. The purpose of the present study was to investigate the phylogeny and bioactivity of five Vibrionaceae strains with pronounced antibacterial activity. These were identified as Vibrio coralliilyticus (two strains), V. neptunius (two strains), and Photobacterium halotolerans (one strain) on the basis of housekeeping gene sequences. The two related V. coralliilyticus and V. neptunius strains were isolated from distant oceanic regions. Chemotyping by LC-UV/MS underlined genetic relationships by showing highly similar metabolite profiles for each of the two V. coralliilyticus and V. neptunius strains, respectively, but a unique profile for P. halotolerans. Bioassay-guided fractionation identified two known antibiotics as being responsible for the antibacterial activity; andrimid (from V. coralliilyticus) and holomycin (from P. halotolerans). Despite the isolation of already known antibiotics, our findings show that marine Vibrionaceae are a resource of antibacterial compounds and may have potential for future natural product discovery. 相似文献
983.
In this study dealing with the development of management strategies for P. ramorum in Rhododendron stands several plant protection and fertilizer products were tested for their suitability to control this pathogen on Rhododendron. Tests were conducted on young potted plants and abscised leaves, using the following products: phosphite (Nutri-Phite® PK), copper hydroxide (Cuprozin® liquid), Bacillus subtilis (Serenade®), a mycorrhizal preparation, and a product based on ‘effective microorganisms’ (EMa). Although transmission of the pathogen from infected to healthy plants was successfully inhibited by phosphite, Cu hydroxide and B. subtilis, subsequent tests showed that only phosphite and Cu hydroxide had a significant effect on disease development. All other preparations based on antagonistic or growth promoting microorganisms had no preventive or curative effect. While B. subtilis tended to increase disease symptoms, the remaining products caused a slight reduction of disease severity only. In contrast, phosphite and Cu hydroxide almost completely inhibited infection by P. ramorum. Therefore, in field situations, the use of the ecologically safe, systemic phosphite against P. ramorum in Rhododendron stands appears to be reasonable and advisable. Along with other supporting measures within the framework of a management strategy, this will allow to prevent or slow down further spread of the disease. 相似文献
984.
Christiane von der Ohe Victoria Gauthier Lily Tamburic-Ilincic Anita Brule-Babel W. G. Dilantha Fernando Randy Clear Todd J. Ward Thomas Miedaner 《European journal of plant pathology / European Foundation for Plant Pathology》2010,127(3):407-417
Twenty four isolates of Fusarium graminearum, half of which were 3-acetyldeoxynivalenol (3-ADON) and half 15-acetyldeoxynivalenol (15-ADON) chemotypes, were tested for
their ability to produce deoxynivalenol and to cause Fusarium head blight (FHB) in spring wheat cultivars. The objectives
of this study were to determine (1) whether 3-ADON isolates differ in aggressiveness, as measured by the FHB index, and DON
production from 15-ADON isolates under field conditions, and (2) whether the performance of resistant host cultivars was stable
across isolates. Field tests of all isolates were conducted with three replicates at each of two locations in Canada and Germany
in 2008 with three host genotypes differing in FHB resistance level. The resistant host genotype showed resistance regardless
of the chemotype or location. The differences between mean FHB indices of 3-ADON and 15-ADON isolates were not significant
for any wheat genotype. In contrast, average DON production by the 3-ADON isolates (10.44 mg kg−1) was significantly (P < 0.05) higher than for the 15-ADON isolates (6.95 mg kg−1) at three of the four locations where moderately resistant lines were tested, and at both locations where susceptible lines
were evaluated. These results indicate that 3-ADON isolates could pose a greater risk to food safety. However, as the mean
aggressiveness and DON production of 3-ADON and 15-ADON chemotypes was similar on highly resistant lines, breeding and use
of highly resistant lines is still the most effective measure of reducing the risks associated with DON in wheat. 相似文献
985.
Ntsikane Maine James Lowenberg-DeBoer Wilhelem Thomas Nell Zerihun Gudeta Alemu 《Precision Agriculture》2010,11(5):448-463
The response of maize (Zea mays) to banded variable-rate nitrogen (N) application over a period of 3 years (2002/3–2004/5) is analyzed. The experimental
design alternated variable-rate (VR) and single-rate (SR) applications of N. The yield monitor data were spatially autocorrelated
and therefore were analyzed with spatial regression methods. The baseline spatial regression model defined in this study showed
that the VR treatment, treatment by year and treatment by management zone were statistically significant. Sensitivity tests
were applied; the first showed that VR treatment had a yield advantage when soil depth was greater than the field average
of 174 cm. The second test showed that the VR N rates applied were close to those that would maximize profit. Partial budgeting
indicates that benefits from VR vary from year to year, but in this test VR was slightly more profitable than uniform rate
application. Economic sensitivity testing indicates that farm size and the price of maize are the key factors in the profitability
of VR N. 相似文献
986.
Georg Schirrmacher Thomas Skurk Hans Hauner Johanna Graßmann 《Plant foods for human nutrition (Dordrecht, Netherlands)》2010,65(1):71-76
Daily consumption of fruits and vegetables is frequently recommended to prevent several diseases. This health-promoting effect
is considered to be in part due to the antioxidant content of fruits and vegetables and their ability to decrease oxidative
stress. To investigate whether the ingestion of preparations from spinach or perilla, two carotenoid-rich leafy vegetables,
is followed by an increase in carotenoid concentration and/or affects parameters of oxidative stress in human blood plasma.
12 healthy volunteers ingested a perilla- or spinach preparation for 10 days (5 mg lutein/d). We quantified antioxidant levels
in plasma, kinetics of lipid peroxidation, MDA concentration, and total antioxidative capacity of plasma. We observed a significant
increase in lutein content and a moderate increase (n.s.) in β-carotene content in human blood plasma after consumption of
spinach or perilla. The markers of lipid peroxidation tended to decrease, but no influence on antioxidative capacity of plasma
could be detected. The high lutein content of perilla caused a more pronounced increase of lutein compared to spinach. Both
vegetables seem to be able to influence lipid peroxidation in a beneficial manner. 相似文献
987.
Fungal disease suppression by inorganic salts: A review 总被引:1,自引:0,他引:1
This paper reviews the scientific literature on the topic of fungal disease suppression by applications of inorganic salts as alternatives to synthetic fungicides on a global scale for both protected and field crops. Where data were available, the comparative efficacy of inorganic salts with conventional fungicide products is discussed. In total, published evidence was found for 34 inorganic salts (mainly bicarbonates, phosphates, silicates, chlorides and phosphites) that were able to reduce the severity of 49 fungal diseases (of the foliage, stem, fruit, tuber, root and post-harvest) in 35 plant species (vegetables, cereals, fruit crops, root/tuber crops, ornamentals and native plants). The most studied and best controlled disease with inorganic salts was powdery mildew of cucurbits [Sphaerotheca fuliginea (Schltdl.) Pollacci 1913 or Erysiphe cichoracearum DC. 1805; up to 99% efficacy], wheat [Blumeria graminis (DC.) Speer 1975 (f. sp. tritici)] and grapes [Uncinula necator (Schwein.) Burrill 1892]. The next best evidence for disease control was for wheat septoria blotch (Septoria tritici Berk. & M.A. Curtis 1874), rice blast [Magnaporthe grisea (T.T. Hebert) M.E. Barr 1977], potato late blight [Phytophthora infestans (Mont.) de Bary 1876] and several other Phytophthora spp. The published evidence suggests that these 34 inorganic salts are generally less effective than conventional fungicides and could not fully replace them. However, their integration in a disease management strategy may enable a reduction in the number of conventional fungicide applications required. The potential for the inclusion of inorganic salts in fungal disease management programmes merits further investigation and greater regulatory innovation in the near future. 相似文献
988.
Topramezone is a new herbicide for post-emergence control of broadleaf and grass weeds in maize. Two field experiments were conducted in northern Greece in 2008 and 2009 to determine the response of grain maize to topramezone applied with the adjuvant DASH at 2–4, 4–6 and 6–8 maize leaf stage. In both years, plant height, cob number and yield were not differently affected with the use of herbicide at these growth stages, indicating no difference in selectivity and a similar response of maize to the three post-emergence applications of topramezone. Slight injury symptoms of leaf bleaching were observed in the second year, however, they were transient with no lasting injury on maize growth. 相似文献
989.
Jahangir Khajehali Thomas Van Leeuwen Maria Grispou Evangelia Morou Haoués Alout Mylène Weill Luc Tirry John Vontas Anastasia Tsagkarakou 《Pest management science》2010,66(2):220-228
BACKROUND: In Tetranychus urticae Koch, acetylcholinesterase insensitivity is often involved in organophosphate (OP) and carbamate (CARB) resistance. By combining toxicological, biochemical and molecular data from three reference laboratory and three OP selected strains (OP strains), the AChE1 mutations associated with resistance in T. urticae were characterised. RESULTS: The resistance ratios of the OP strains varied from 9 to 43 for pirimiphos‐methyl, from 78 to 586 for chlorpyrifos, from 8 to 333 for methomyl and from 137 to 4164 for dimethoate. The insecticide concentration needed to inhibit 50% of the AChE1 activity was, in the OP strains, at least 2.7, 55, 58 and 31 times higher for the OP pirimiphos‐methyl, chlorpyrifos oxon, paraoxon and omethoate respectively, and 87 times higher for the CARB carbaryl. By comparing the AChE1 sequence, four amino acid substitutions were detected in the OP strains: (1) F331W (Torpedo numbering) in all the three OP strains; (2) T280A found in the three OP strains but not in all clones; (3) G328A, found in two OP strains; (4) A201S found in only one OP strain. CONCLUSIONS: Four AChE1 mutations were found in resistant strains of T. urticae, and three of them, F331W, G328A and A201S, are possibly involved in resistance to OP and CARB insecticides. Among them, F331W is probably the most important and the most common in T. urticae. It can be easily detected by the diagnostic PCR‐RLFP assay developed in this study. Copyright © 2009 Society of Chemical Industry 相似文献
990.
Productivity of temperate broad-leaved forest stands differing in tree species diversity 总被引:1,自引:0,他引:1