施用竹炭对卷心菜叶绿素含量和荧光参数的影响

为探究人工施用竹炭对卷心菜叶绿素含量和荧光参数的影响,进而明确卷心菜的最适竹炭有机肥施用量,在田间试验条件下设置了无碳(CK)、中碳(MC)和高碳(SC)3个处理,对卷心菜莲座期和结球期的叶绿素含量及荧光参数进行测量研究.结果表明:(1)结球期的卷心菜叶绿素含量极显著高于莲座期(p0.01),且随着竹炭量的增加,两个时期的叶绿素含量变化趋势一致,从高到低依次为:MC,CK,SC.(2)结球期的卷心菜初始最小荧光Fo、初始最大荧光Fm、PSⅡ的最大光化学效率Fv/Fm,PSⅡ的潜在活性Fv/Fo、非光化学猝灭系数qN均低于莲座期,而PSⅡ实际光化学效率ΦPSⅡ、光化学猝灭系数qP高于莲座期,且随着竹炭量的增加,两个时期的这些参数均表现出一致的变化趋势,Fo和qN均呈"V"型变化,而Fm,Fv/Fm,Fv/Fo,ΦPSⅡ和qP均呈现倒"V"趋势,但对ΦPSⅡ和qP没有显著影响(p0.05).说明结球期的卷心菜光合作用高于莲座期;当竹炭量由CK增加到MC,有利于提高叶片叶绿素含量,增强光能利用率,减少植株热耗散,提高植株光合作用;但随着竹炭量进一步增加到SC,卷心菜叶片叶绿素含量降低,光能利用率减弱,热耗散增加,光合作用受到抑制,即中炭(MC)处理条件下,此卷心菜长势最优,表明中炭是该卷心菜生长的最适竹炭有机肥施用量.     

Automated sample cleanup for pesticide multiresidue analysis. Part II--Design and evaluation of column chromatography module

An automated, continuous flow system is described for Florisil column chromatography of pesticide residues from food extracts. Evaluation of the system using 5 common organochlorine and organophosphorus pesticides in 2 crop matrices demonstrates essentially no difference in recovery or precision between automated and currently used manual analyses. The automated procedure uses only 20% of the solvents and adsorbents used in the manual procedure and is 3 times faster.     

Mortality in calves, lambs and kids caused by severe infestation with the cat flea Ctenocephalides felis felis (Bouché, 1835) in Israel

Heavy infestation of calves, lambs and kids with the cat flea Ctenocephalides felis felis (Bouché, 1835), accompanied by severe anaemia and mortality, is described. Lambs and kids were affected more severely than calves. Flea infestation was more widespread in summer and autumn than in winter and spring. The clinical findings are discussed in the light of the pertinent literature.     

Mosquito collection in endemic areas of Japanese encephalitis in Hokkaido, Japan

A study was conducted during 1985 and 1986 to evaluate the roles of mosquito species as possible vectors of Japanese encephalitis (JE) virus in Hokkaido. The number of Culex tritaeniorhynchus was very low among the four pig farms where outbreaks of abortion caused by JE virus were observed in swine populations. At one farm near Sapporo, only one Cx. tritaeniorhynchus was found among a total of 510 mosquitoes collected during the survey period from July to October 1985, even when JE virus activity among sentinel pigs was revealed by seroconversion. At another farm in the south, no individuals of this mosquito species were found among 987 mosquitoes collected at the time of the outbreaks of abortion. Cx. pipiens pallens, Anopheles species, Aedes vexans nipponii, and Ae. japonicus were predominant over Cx. tritaeniorhynchus. Cx. tritaeniorhynchus, almost a solve vector species of JE virus in the southern part of Japan, is probably not a vector of the virus in Hokkaido. The collected mosquitoes (2,332 from 1985 and 1,403 from 1986) were processed for virus isolation but no JE virus was isolated. More extensive field studies are necessary to provide further information on the role of mosquito species other than Cx. tritaeniorhynchus in the transmission of JE virus in the northern limits of its range including Hokkaido.     

Myiasis caused by Wohlfahrtia magnifica (Schiner, 1862) in the Arabian camel (Camelus dromedarius) in the Peninsula of Sinai

Massive myiasis caused by Wohlfahrtia magnifica (Schiner, 1862) in camels in the Southern Mountainous zone of the Peninsula of Sinai is described. Wohlfahrtiosis seemed intimately related to the climatic and ecological conditions of the area, particularly altitude, precipitation, pasture, rodents and ticks. The clinical features resembled those described in sheep in Israel and in camels elsewhere. Treatment with diazinon and synergized pyrethrum in pine oil proved effective.