A note on the retention of water‐soluble dyes by cotton foliage

Abstract

The use of dyes in the physicochemical evaluation of sprayers and spray application methods assumes 100% recovery from targets. Using a red and yellow dye on cotton plants it was shown that a significant percentage of dye was actually retained by the plants. The amount differed for different‐coloured dyes.     

不同西瓜品种抗蚜性鉴定

为获得对蚜虫有抗性的西瓜品种，采用室内蚜量比值法和田间离中率方法对不同西瓜品种抗
蚜性进行了鉴定，鉴定出黑皮和绿美人2 个高抗品种，平均单株蚜量比值分别为0.16 和0.23，离中率分
别为0.16 和0.15；黑美人和惠兰2 个抗蚜品种，平均单株蚜量比值分别为0.32 和0.36，离中率分别为0.38
和0.39；甜美人和花绿2 个高感品种，平均单株蚜量比值分别为2.53 和2.68，离中率分别为1.09 和1.55。     

野生观果植物白棠子的驯化繁育研究

通过引种野生白棠子,对其进行驯化繁育,从生物学特性、繁殖方法、栽培技术等方面开展初步研究。结果表明:白棠子果实9月下旬至10月初开始变紫色,观果期从9月底至翌年1月,长达4个月,其中最佳观果期为10月下旬至11月中旬;采用200 mg/L GA3处理白棠子种子,萌芽率达到65.3%;白棠子扦插生根以皮部生根为主,采用500 mg/L NAA生根成活率达到83%;在不同立地条件下,白棠子移栽成活率均达到95%以上,均能当年开花结实,表现出良好的观赏性状,其中以平地沙壤土的生长表现更好;栽培管理上宜选择全光照或疏林环境栽培,5~8月份生长最旺盛,应在此期间加强肥水管理。白棠子观果性状突出,可应用于园林绿化、制作盆景和插花等。     

Study on the Insecticidal and Antifeedant Activity of Extracts from Portulaca oleracea L. on Aphis sp.

[Objective] The experiment studied on insecticidal and antifeedant action of on Portulaca oleracea L.to provide theoretical basis for developing a new botanical insecticide by taking Portulaca oleracea L.as a raw material.[Method] The insecticidal activities of the ethanol extracts and 5 kinds of extracts with petroleum ether,chloroform,ethyl acetate,n-butanol,water from Portulaca oleracea L..against Aphis sp.was studied;Leaves are using drug treatments of 5 extracts anti-feedant activity of Aphis sp.[Result] The results showed that 95% ethanol extract displayed high contact activity to Aphis sp.The corrected mortality after 48 h reached 95.4 % under the concentration of 50.00 mg·ml-1 and the insecticidal activities of 5 extracts against Aphis sp.was in the order that petroleum ether > chloroform > n-butanol > ethyl acetate >water.Five kinds of anti-feeding activity in the extract of the order for the water> ethyl acetate> n-butanol > chloroform >petroleum ether.[Conclusion] The extract from Portulaca oleracea L.has a strong contact toxicity of pesticide active on Aphis sp.substances and for a small polar compounds,the strong anti-feeding activity is a kind of larger polar compounds.     

The efficacy of a petroleum spray oil against Aphis gossypii Glover on cotton. Part 2: indirect effects of oil deposits

The primary mode of action of petroleum spray oils (PSOs) on pest insects is through direct contact. Indirect effects are, however, also possible, and deposits of the oils may influence pest populations by killing insects and/or by influencing their behaviour. The indirect effects of deposits of a new nC24 oil against the cotton aphid, Aphis gossypii Glover, were therefore determined. The effects of oil deposits on the acceptance of cotton as host plant by the aphids were assessed, as well as aphid mortality rates and their success in the establishment of colonies. The efficacy of deposits of a heavier oil (nC27) was also evaluated. Deposits of PSO were toxic to A. gossypii and remained effective until 8 days after spraying. Mortality decreased with time, so that, the older the deposit, the lower was the mortality. Significantly higher aphid mortalities were achieved on younger leaves than on mature ones. Thus, leaf age proved a significant factor in the efficacy of the deposits. Consecutive prophylactic applications (at 9 day intervals) did not have a cumulative effect, and their killing power proved to be independent of one another. Thus, applying the oil prior to aphid infestations would confer only minimal protection. The mortality inflicted by the deposits was not improved by increasing the molecular mass of the oil used (nC27 oil), but the toxic life of the oil deposit was increased. Oil deposits did not deter alates from landing on oil-sprayed plants. Oil deposits did, however, affect subsequent alate and nymphal survival, and thus the establishment of aphid colonies. The impact that the oils could have on the longer-term development of aphid populations in the field was thus demonstrated. First- and second-instar nymphs were the most susceptible life stages, with > 50% mortality compared with < 10% for the other stages. These nymphs did not show the typical signs of oil-induced mortality observed in aphids killed by direct oil applications, which suggests an alternative mode of action to that of the directly applied oil. Anoxia does not seem to be involved in either process, and alternative modes of action of the oil deposits are discussed. The implications of these findings for cotton aphid control are also considered, primarily in relation to the timing and frequency of oil application.     

陕西棉蚜抗药性监测

１９９０￣１９９５年测定了陕西棉花伏蚜对１３种杀虫剂的抗药性。结果表明，陕西棉蚜对溴氰菊酯、氰戊菊酯、三氟氯氰菊酯、氯氰菊酯产生了极高水平抗药性；除对久效磷产生５．２￣９．８倍的低水平抗性外，对其它供试的有机磷杀虫剂均处于敏感或敏感性降低阶段。     

35%双扑乳油对菜青虫和棉蚜的毒力及作用机理研究

以棉蚜和菜青虫为试虫,采用ＦＡＯ推荐的浸渍法和点滴法,测定了３５％“双扑”乳油及各组成单剂对其毒力。并对菜青虫的乙酰胆碱酯酶活性进行了测定,了探讨了“双扑”的作用机理。结果表明：“双扑”及单剂Ａ、Ｂ、Ｃ对棉蚜的ＬＣ５０分别为８．８３ｐｐｍ、５．２９ｐｐｍ、３２．１３ｐｐｍ、２９．７８ｐｐｍ,对菜青虫的ＬＣ５０分别为６．８８ｐｐｍ、１９．２６ｐｐｍ、４７．９２ｐｐｍ、１２３．５８ｐｐｍ。对两种试虫的     

植物源杀虫剂对棉蚜毒力及多异瓢虫的安全性评价

【目的】评价苦参碱、藜芦碱、印楝素对棉蚜的毒力和不同虫态多异瓢虫(卵、1龄幼虫、3龄幼虫、成虫)的毒性,为科学使用植物源杀虫剂提供参考依据。【方法】利用喷雾塔进行室内定量喷雾,测定苦参碱、藜芦碱、印楝素处理后棉蚜、多异瓢虫的死亡率。【结果】在2 000 mg/L处理下,苦参碱对棉蚜的毒力最高、校正死亡率为89.3%,高于藜芦碱的61.7%和印楝素的57.6%。这3种植物源杀虫剂对多异瓢虫毒力均较低,2 000 mg/L处理96 h后多异瓢虫卵死亡率分别为16.5%、20.9%和20.9%;处理24 h后,1龄幼虫死亡率分别为29.6%、38.9%和42.6%,3龄幼虫死亡率分别为1.7%、8.3%和5.0%,成虫死亡率均不超过20%。3种植物源杀虫剂处理下的多异瓢虫各虫态死亡率均显著低于100 mg/L吡虫啉。【结论】苦参碱、藜芦碱、印楝素对多异瓢虫安全性较高,其中苦参碱对棉蚜毒力高于其他2种,适合在新疆棉田棉蚜防治中使用。     

氟啶虫酰胺亚致死浓度处理棉蚜对十一星瓢虫捕食功能反应的影响

【目的】研究氟啶虫酰胺亚致死浓度处理棉蚜对十一星瓢虫捕食功能反应的影响,为合理使用杀虫剂和协同生物防治防控棉蚜提供科学依据。【方法】测定氟啶虫酰胺对棉蚜的毒力,以供试药剂的LC₂₅、LC₅₀为处理浓度,采用浸叶法处理棉蚜,选取活体棉蚜作为十一星瓢虫的食物,分析对其捕食功能反应的影响。【结果】饲喂氟啶虫酰胺不同亚致死浓度处理棉蚜后,十一星瓢虫捕食功能反应等参数及寻找效应均有一定影响,且随药剂浓度增加,对其捕食能力影响越大。饲喂氟啶虫酰胺LC₅₀处理的棉蚜后,十一星瓢虫日捕食量及搜寻能力显著降低,与对照相比,十一星瓢虫1、2、3、4龄幼虫和成虫的瞬时攻击率分别下降0.38%、7.18%、2.19%、16.83%、1.41%,处理一头棉蚜所用的时间分别延长0.002 4 d、0.001 6 d、0.000 6 d、0.000 5 d、0.000 1 d,日最大捕食量分别下降0.72、2.52、7.76、7.01、1.17头/皿。【结论】饲喂氟啶虫酰胺亚致死浓度处理棉蚜对十一星瓢虫1~4龄幼虫及成虫的瞬时攻击率降低,处理棉蚜所用时间延长,日最大捕食量下降。其中饲喂氟啶虫酰胺LC₅₀处理棉蚜对十一星瓢虫各虫态捕食功能有显著影响。     

0.3%苦豆子总碱防治枸杞蚜虫田间药效试验

以0.3%苦豆子总碱水剂为试药,在三个地区的枸杞蚜虫上进行田间防效试验。结果表明:稀释800倍药液防效好于1000倍,药后7d三地防效均达90%以上,持效期长达15d。与对照相比,不产生药害,且有一定的增产作用,是理想的防治枸杞蚜的无公害药剂。