Influence of feeding sequence,light and colour on the performance of a self-grading system designed for turbot (Scophthalmus maximus)     

《Aquacultural Engineering》2017

Grading of cultured flatfish is essential to maintain even sizes and to avoid potential feeding dominance or cannibalism. Current hand-grading and forced mechanical grading methods result in labour costs and additional stress to animals, reducing their growth performance. This study tested a self-grading system allowing turbot (Scophthalmus maximus) to self-grade, based on size, between tank sections within 8000 L tanks designated as “Graded (G)” and “Non-Graded (NG)”. The grading success (percentage of graded animals/total gradable individuals) with stimuli (light, feeding sequence and colour of the grading device) and without stimuli was analyzed over 9 days. Mean grading success without stimuli was 38.1 ± 11.5%. Grading success was not improved by changes in feeding sequence (30.6 ± 10.2%) or altered colour of the grading device (30.9 ± 13.8%). Marked increases in grading success were obtained by adding a light source to the G section (52.9 ± 12.4%), and by combining the presence of a light source and the feeding sequence (57.9 ± 14.4%). The combination of light sources and changes to the colour of the self-grading device resulted in the highest mean grading success (72.1 ± 18.2%) overall. Light and colour stimuli combined yielded the highest self-grading maximum (88.36 ± 5.3%), achieved on day 6 after experimental onset. A three-parameter asymptotic exponential equation was fitted to the data from each stimulus and parameters describing the curves of all conditions are reported. The present results indicate that the tested self-grading systems for turbot can be highly efficient if used with the appropriate stimuli. Self-grading systems operating at the measured levels of success offer a viable alternative to stressful grading events, avoiding significant commercial disadvantages as well as improving animal welfare and performance.  相似文献   

Application strategies for an anthraquinone-based repellent to protect oilseed sunflower crops from pest blackbirds     

《Crop Protection》2014

Non-lethal alternatives are needed to manage the damage caused by wild birds to oilseed sunflower crops (Helianthus annuus Linnaeus). We evaluated field residues and experimental applications of an anthraquinone-based repellent (active ingredient 50% 9,10-anthraquinone) to minimize red-winged blackbird (Agelaius phoeniceus Linnaeus) depredation of oilseed sunflower. Chemical residues from experimental applications of the anthraquinone-based repellent (4.7 l/ha and 9.4 l/ha; low, high) in a ripening oilseed sunflower field were 481 ppm and 978 ppm anthraquinone at the beginning of blackbird damage, and 385 ppm and 952 ppm anthraquinone at the end of blackbird damage, respectively. Prior to harvest, we observed 402 ppm and 462 ppm anthraquinone in the oil, and 27 ppm and 165 ppm anthraquinone in the pomace from crushed sunflower achenes previously sprayed with the low and high applications, respectively. For the purpose of developing application strategies useful for avian repellents, we subsequently investigated blackbird feeding response to oilseed sunflower treated with the anthraquinone-based repellent and either a registered insecticide or a registered fungicide popularly used for ripening sunflower. We observed a positive concentration–response relationship among blackbirds exposed to anthraquinone and the insecticide (a.i. 8.4% esfenvalerate), or anthraquinone and the fungicide (a.i. 23.6% pyraclostrobin). Blackbirds reliably discriminated between untreated sunflower and that treated with 1810 ppm anthraquinone and 0.1% of the insecticide or 1700 ppm anthraquinone and 0.14% of the fungicide during our preference experiments. Given that ripening achenes are inverted from conventional pesticide applications throughout much of the period associated with blackbird depredation, we also evaluated blackbird repellency of the anthraquinone-based repellent applied to involucral bracts (i.e., the back of sunflower heads) of oilseed sunflower. Blackbirds did not discriminate between untreated involucral bracts and those treated with foliar applications comparable to 4.7 l/ha or 9.4 l/ha; blackbirds consumed more achenes from untreated sunflower heads than from those treated with 18.7 l/ha of the anthraquinone-based repellent. Supplemental repellent efficacy studies should investigate blackbird response to anthraquinone-based repellents (e.g., ≥4.7 l/ha) within 10–100 ha sunflower fields and include independent field replicates with predicted bird damage, repellent application strategies developed for protection of ripening crops, pre- and at-harvest repellent residues, and bird damage and crop yield measurements.  相似文献   

Experience-altered oviposition responses to a neem-based product, Neemix, by the diamondback moth, Plutella xylostella     

Liu TX  Liu SS 《Pest management science》2006,62(1):38-45

The oviposition responses of the diamondback moth, Plutella xylostella L., to Neemix 4.5, a neem-based oviposition repellent/deterrent, with or without previous experience were studied in the laboratory on plain aluminum foil sheets, on aluminum foil sheets coated with cabbage juice, and on cabbage plants. In the plain aluminum foil sheet experiment, the females without prior experience of Neemix (inexperienced females) deposited more eggs (66.2%) on sections with untreated sheets than on sections with Neemix-treated sheets (33.8%), indicating that the inexperienced females were significantly repelled and/or deterred by Neemix. In contrast, the Neemix-experienced females deposited more eggs (69.2-69.7%) on sections with Neemix-treated sheets than on sections with untreated sheets (30.3-30.8%), implying that the females were not repelled and/or deterred by Neemix following an experience. In the tests using egg-laying sheets coated with cabbage juice or with cabbage juice plus Neemix, the inexperienced females deposited more eggs (63.8%) on the sections with sheets treated with cabbage juice only than on the sections with sheets coated with cabbage juice and Neemix (36.2%), indicating that inexperienced females were repelled and/or deterred by Neemix. Similarly, Neemix-experienced females deposited more eggs (62.2-65.6%) on the sections with sheets treated with cabbage juice plus Neemix than on the sections with sheets treated with juice only (34.4-37.8%), suggesting that the females were not repelled and/or deterred by Neemix following an experience. On cabbage plants, inexperienced females oviposited similar numbers of eggs on both Neemix-treated (50.8%) and untreated plants (49.2%). However, the Neemix-experienced females oviposited more eggs on the plants treated with Neemix (56.3%) than on untreated plants (43.7%), indicating that the females were attracted by Neemix-treated plants following an experience. The significance of this study for applications of insect repellents/deterrents in pest management is discussed.  相似文献   

非寄主蔬菜及其提取物对菜粉蝶的驱避作用   总被引：6，自引：0，他引：6  

吴利民  吕文彦  原国辉  徐艳聆  郭线茹  罗梅浩 《中国生态农业学报》2010,18(6):1311-1316

在室内和田间测定了番茄、茴香、荆芥、莴苣、香菜和丝瓜6种非寄主蔬菜对菜粉蝶的驱避作用。室内测定结果表明,用非寄主蔬菜粗提物处理甘蓝后,菜粉蝶成虫对甘蓝的选择反应率降低,尤其是交配雌蝶对荆芥、茴香、番茄和莴苣提取物处理的甘蓝的选择反应率最低,分别仅为3.67%、4.30%、5.27%和8.26%。在非寄主蔬菜粗提物处理过的甘蓝苗上,成虫的产卵量明显减少,其中以番茄、茴香和荆芥粗提物的驱避活性最强,处理后1d的非选择性产卵驱避率分别为91.04%、75.54%和71.67%,选择性产卵驱避率分别为94.64%、79.66%和78.96%。田间试验结果表明,甘蓝田套种番茄、茴香和荆芥后,可使田间落卵量分别减少68.80%、62.62%和55.09%,这3种非寄主蔬菜对菜粉蝶的有效驱避距离分别为4m、2m和2m左右。因此,可以通过在甘蓝田套种非寄主蔬菜或喷洒其粗提物驱避菜粉蝶,减少幼虫发生为害。  相似文献   

干湿循环对土壤斥水性的影响     

杨松  王磊  周明凯  马泽慧  李铭 《土壤》2019,51(6):1196-1201

处于地表的各类土壤总是处于不断的干湿循环过程,土壤性质也会因此而发生改变。本文通过试验对干湿循环过程中斥水性土壤的"斥水–亲水"特性展开研究,试验结果表明:干湿循环对斥水性土壤的接触角及斥水性有重要影响。在干湿循环过程中,增湿时的初始状态不同则其初始接触角会发生变化,土壤斥水性对初始状态的敏感性随着黏粒含量的增加而增大。干湿循环开始时,土壤越干则初始接触角越大。当黏土和黏壤土试样含水量减小时,增湿或脱湿过程中滴水穿透时间(waterdroppenetrationtime,WDPT)先增加后减小,在某一时刻达到峰值,试样含水量相同时,脱湿过程所对应的WDPT要明显小于增湿过程,两种类型的土样在干湿循环中均没有临界含水量。随着含水量的降低,壤质砂土的WDPT是不断增加的,且干湿循环过程中斥水性砂土并没有出现峰值,存在明显的临界含水量。  相似文献   

橡胶籽提取物对新菠萝灰粉蚧的忌避作用     

张妮  陈泽坦  王发明 《农业科技通讯》2010,(7):76-78

就不同浓度的橡胶籽提取物对新菠萝灰粉蚧的选择性和非选择性忌避作用进行试验测定。选择性忌避试验结果表明：橡胶籽提取物300倍液（0.667ml/L）比其他浓度的忌避效果好,达到84.3%。非选择性忌避试验结果表明：以功夫3000倍液（0.008ml/L）作对照时,对新菠萝灰粉蚧的忌避率在900倍液（0.222ml/L）效果较好。  相似文献   

Tick repellents: Past, present, and future     

Brooke W. Bissinger 《Pesticide biochemistry and physiology》2010,96(2):63-79

Ticks are important vectors of human and animal diseases. One important protective measure against ticks is the use of personal arthropod repellents. Deet and the synthetic pyrethroid permethrin currently serve as the primary personal protective measures against ticks. Concern over the safety of deet and its low repellency against some tick species has led to a search for new user-approved, efficacious tick repellents. In this article, we review the history and efficacy of tick repellents, discovery of new repellents, and areas in need of attention such as assay methodology, repellent formulation, and the lack of information about the physiology of repellency.  相似文献   

蜱螨驱避药剂RB对柞蚕生产安全的试验研究     

赫英姿  宋策  刘孝良  于庭洪  左玲玲  赵翀 《北方蚕业》2013,34(1):19-21

柞蚕野外放养,人员遭受蜱螨危害严重。从对蚕以及使用人员的安全性考虑,进行了室内及野外蚕场蜱螨驱避剂对人和柞蚕的安全试验,结果表明:蜱螨驱避剂RB对柞蚕的生长发育没有不良影响,10%的RB水剂对人体安全。  相似文献   

根瘤菌对草地贪夜蛾的趋避作用     

任学祥  景茂峰  苏贤岩  迟雨  陈浩梁  钟永志  叶正和 《中国农学通报》2022,38(19):128-132

为明确大豆残留在土壤中的根瘤菌对草地贪夜蛾的趋避作用,以根瘤菌包衣玉米、小麦后,测定草地贪夜蛾对不同处理叶片取食量的差异性。试验发现,根瘤菌处理玉米、小麦种子后,草地贪夜蛾取食其叶片量明显少于对照处理。玉米叶片放置6、22、27 h,根瘤菌处理叶片质量平均减少0.1167、0.2622、0.3733 g,空白处理叶片质量平均减少0.1744、0.4211、0.5744 g;小麦叶片放置22 h,根瘤菌处理叶片质量平均减少0.3102 g,空白处理叶片质量平均减少0.3503 g。说明根瘤菌对草地贪夜蛾取食存在趋避作用。  相似文献   

不同方法提取驱蚊香草精油中化学成分的比较     

杨金  赵兴雷  易平  黄笃树  吴娜  闵勇  刘卫 《安徽农业科学》2012,40(32):15663-15665

[目的]比较不同方法提取的驱蚊香草精油的化学成分。[方法]应用GC/MS分别对2种方法提取的精油进行分离和检测。[结果]在水蒸气蒸馏法提取的精油中检测到23个成分,在有机溶剂法提取的精油中检测到49个成分;精油的主要成分为香茅醇、马兜铃烯、乙酸香茅酯、香叶醇、芳樟醇、异薄荷酮、β-波旁烯和香榧烯醇等。[结论]水蒸气蒸馏法使驱蚊香草精油化学成分大量损失,但对沸点高、相对难挥发的主要化学成分有很好地富集作用;有机溶剂提取法能很好地保留驱蚊香草精油的化学成分。  相似文献