磷化氢熏蒸南洋臀纹粉蚧的效果及对火龙果品质的影响

本文在25℃条件下,利用磷化氢熏蒸南洋臀纹粉蚧以及越南进口红心、白心火龙果4 h,研究了磷化氢熏蒸处理对南洋臀纹粉蚧的杀灭效果以及对火龙果采后储藏品质的影响。耐受性比较试验结果表明,不同发育阶段的南洋臀纹粉蚧对磷化氢的耐受性为雌成虫>3龄若虫=2龄若虫>1龄若虫。毒力分析试验表明,使用1.70 mg/L磷化氢熏蒸雌成虫4 h可在95%置信区间下达到99.996 8%的死亡率。品质试验结果表明,使用0.55～2.21 mg/L磷化氢熏蒸处理对两种火龙果冷藏和货架期间的色泽、硬度、可溶性糖、酸度均无显著影响,但在熏蒸后短期内会提高呼吸强度,随着储存时间延长,呼吸强度恢复正常。这些结果显示,磷化氢熏蒸用于进口火龙果携带南洋臀纹粉蚧的检疫处理可达到理想效果,在25℃使用1.66～2.21 mg/L磷化氢熏蒸4 h可作为口岸检疫熏蒸的技术指标。

Effects of phosphine fumigation on the survival of Planococcus lilacius and postharvest quality of imported pitaya fruits

In order to study the effect of gaseous phosphine fumigation on the survival of Planococcus lilacius(Cockerell)and the storage quality of pitaya fruits,red and white Vietnam pitaya fruits were fumigated with various concentrations of gaseous phosphine at 25℃for four hours.Tolerance comparison results showed that the tolerance of different developmental stages of insects to phosphine from high to low was:female adult,the 3rd-instar nymph and the 2nd-instar nymph,and the 1st-instar nymph.Toxicity analysis results showed that 99.9968%mortality under 95%confidence level was achieved after female adults were fumigated with 1.70 mg/L phosphine for four hours.Quality test results showed that fumigation with 0.55-2.21 mg/L phosphine had no significant effect on the color,firmness,soluble sugar and total acidity of two kinds of pitaya fruits during cold and shelf-life storage,but the respiratory rate increased after fumigation,though it returned to normal with the extension of storage.Our results suggested that gaseous phosphine fumigation could be used for the phytosanitary treatment of imported P.lilacius pitaya fruits,and phosphine fumigation with the concentration of 1.66-2.21 mg/L at 25℃for four hours is recommended as the technical standard for port quarantine.