苹果渣替代麦麸饲喂雏鸡效果试验

选用400只商品代尼克红母雏,随机分为4组,每组100只,设5个重复,每个重复 20只。试验组日粮分别由基础日粮和用风干未发酵苹果渣粉、半干发酵苹果渣粉、膜发酵苹果 渣粉分别替代基础日粮中5％的麸皮。试期为6周。结果显示,添加半干发酵苹果渣粉组和膜 发酵苹果渣粉组试鸡6周龄平均体重及日增重显著高于喂基础日粮的对照组和风干未发酵苹 果渣粉组(P<0．05),喂基础日粮的对照组略高于风干未发酵苹果渣粉组,差异不显著 (P>0．05)。表明发酵苹果渣粉对雏鸡生长发育有显著的促进效果。     

Induced resistance: a tool for fungicide resistance management

Induced resistance to the apple scab fungus Venturia inaequalis was demonstrated in greenhouse tests with 12-day-old seedlings of the apple cultivar Golden Delicious treated with methyl 2,6-dichloro-isonicotinate or 3,5-dichlorosalicylic acid prior to inoculation with the causal fungus. Studies of the dose-response of flusilazole on induced resistant plants revealed synergistic effects between both crop protection principles. Therefore, the use of such resistance-inducing compounds in the field might allow a reduction in the number of fungicide applications, and possibly a reduction in dose, thus resulting in improved efficacy of fungicides. There was also evidence that induced resistance could prove to be a valid strategy for the treatment of pathogen populations with reduced sensitivity to a given fungicide. © 1998 SCI     

Erwinia amylovora populations resistant to oxolinic acid in Israel: prevalence, persistence and fitness

Oxolinic acid (OA) has been the only bactericide used against fire blight in pear and quince orchards in Israel since 1998. OA-resistant Erwinia amylovora strains (Ea-OA^R) were detected in several orchards in two restricted areas in the northern Galilee region during 1999–2001. In the following years, resistant strains could not be detected in some of these locations. Documenting the fate of Ea-OA^R strains in commercial orchards at eight sites in northern Israel during 2000/03 revealed that the resistant population appeared irrespective of the number of sprays applied and the severity of the disease. The persistence of the Ea-OA^R populations varied from site to site, ranging from 4 to 20 months; these differences could be attributed to the fire blight management activities of growers. Comparative studies on the fitness of Ea-OA^R and E. amylovora strains sensitive to OA (Ea-OA^S) were conducted in vitro and in planta using two strains of each group. In four of the six comparisons, disease incidence on detached blossoms inoculated with Ea-OA^S was significantly higher than that on blossoms inoculated with Ea-OA^R. In two experiments conducted on 8-year-old pear trees grown under netting, the colonization of Ea-OA^S in blossoms, annual shoots and perennial spurs was significantly higher than that of the Ea-OA^R. In two experiments conducted on 2-year-old trees grown under netting in an experimental station, the incidence of shoots exhibiting fire blight symptoms and the rate of symptom progress within the branches were significantly higher in trees inoculated with Ea-OA^S than in those inoculated with Ea-OA^R. The results of this study suggest that OA-resistant E. amylovora strains have lower fitness than wild-type strains. These findings may have implications for fire blight management.     

Response of broiler finishers to diets containing graded levels of processed castor oil bean (Ricinus communis L) meal

A 4‐week feeding experiment was conducted to determine the effects of graded levels of dehulled and cooked castor oil bean (Ricinus communis L) meal on the performance of broiler finishers. Castor oil bean seeds were dehulled and detoxified by cooking in two stages at 100 °C for 50 min per cooking. Sixty 6‐week‐old broiler birds (Anak strain) were randomly divided into four groups of 15 birds each. The groups were fed four isocaloric (2.90 Mcal of metabolizable energy/kg) and isonitrogenous (21% crude protein) diets containing 0%, 10%, 15% and 20% dehulled and cooked castor oil bean meal (CBM) for 4 weeks. Results showed that there were significant (p < 0.05) differences among treatments in average daily feed intake, final body weight, average daily weight gain (ADWG), feed conversion ratio (FCR) and protein efficiency ratio (PER). Birds fed diets containing 0% and 10% CBM had significantly (p < 0.05) higher feed intake than birds on 15% and 20% CBM diets. The lowest feed intake was recorded at the 20% CBM inclusion level. The highest ADWG was observed in birds fed 0% CBM diet, but this was not significantly (p > 0.05) different from the ADWG of birds on 10% CBM diet. Birds fed diets containing10% and 15% levels of CBM had similar and non‐significant (p > 0.05) ADWG. Birds fed 20% CBM diet had the least (p < 0.05) ADWG. Birds fed 0%, 10% and 15% CBM diets had similar FCR and this was significantly (p < 0.05) lower and better than that of birds on 20% CBM diet. The least (p < 0.05) PER was observed in birds fed 20% CBM diet. Birds fed 20% CBM diet had significantly (p < 0.05) higher packed cell volume (PCV) than birds on 10% and 15% CBM diets. Birds fed 0%, 10% and 15% CBM diets had similar (p > 0.05) PCV values. Birds fed diets containing 0%, 10% and 15% levels of CBM had similar and significantly (p < 0.05) lower heamoglobin than birds fed 20% CBM diets. There were also significant (p < 0.05) differences among treatments in dry matter (DM), nitrogen, ether extract (EE) and nitrogen‐free extract (NFE) retention. Birds fed 0% CBM diet had significantly (p < 0.05) higher retention of DM, nitrogen and NFE than birds on 10%, 15% and 20% CBM diets. Birds fed 10% CBM diet had significantly (p < 0.05) higher DM, nitrogen and NFE retention than birds on 15% and 20% CBM diets. The lowest retention of DM, nitrogen and NFE was recorded at the 20% CBM inclusion level. Birds fed 0% CBM diet had significantly (p < 0.05) higher EE retention than birds on 15% and 20% CBM diets. The lowest EE retention was observed at the 20% CBM inclusion level. The results of the study indicate that up to 10% dehulled and cooked CBM can be included in broiler finisher rations for optimum performance.     

豫北地区苹果树干皮缝中越冬的节肢动物种类调查初报

通过２ａ的调查结果表明,豫北地区苹果树干皮缝中越冬的节肢动物数量大,且种类繁多,其中包括农林作物和果树害虫及其天敌。统计分析表明,害虫占总数的８．３４％,天敌占总数的９１．６６％,蜘蛛类占天敌总数的４５．４５％,传统的冬季刮老树皮防治果树害虫的方法,能消灭部害虫,也能杀伤大量的害虫天敌、建议尽量不要刮树干老皮。     

渭北苹果产业中影响果农产销效益的问题研究

采用问卷调查方法对渭北苹果产区中4个典型县进行了实地调研,在以简述设置问题为目的的基础上,就各选择项进行了统计分析,指出了影响该区果农产销效益的主要问题,并提出了针对性改进措施。     

Influence of host plant species on the development and reproduction of hawthorn spider mites

A leaf disc bioassay was employed to investigate the influence of host species of deciduous fruit trees, like apple, peach, plum, cherry and apricot, on the development and reproduction of the hawthorn spider mite Tetranychus viennensis Zacher in the laboratory under conditions of 25±1°C, 60±10% RH and a photoperiod of 16 h: 8 h light: dark. This was done by determining the duration of each life stage of the mites, the intrinsic rate of population increase (r _m ), mean generation time (T) and net reproductive rate (R ₀) of the spider mites on each of the host plant species. Differences in life table parameters of the spider mite among host plants were analyzed with the jack-knife method. The results indicated that plum might be the best suitable plant for the spider mite among the plants tested due to shorter developmental period and higher intrinsic rate of increase, whereas cherry and apricot were least suitable due to their long developmental duration and low intrinsic rates of increase. When the spider mites were transferred from apple to other fruit trees, negative effects on developmental duration, fecundity and life table parameters were found in the first generation, but the effects faded out in succeeding generations. When transferred onto plum and peach, the spider mite adapted to the new hosts in the second generation; however, on cherry and apricot, it adapted in the third generation. __________ Translated from Acta Ecologica Sinica, 2005, 27(7) [译自: 生态学报, 2005, 27(7)]