Fumigants for postharvest control of insect pests of cut flowers.
Williams, P.; Muhunthan, M.;
Acta Horticulturae Year: 1998 Issue: No. 464 Pages: 291-296 Ref: 6 ref.
1998
บทคัดย่อ
One treatment currently used as an alternative to methyl bromide for fumigating cut flowers is a 2 h exposure period consisting of a 10 s burst of Pestigas (pyrethrum with carbon dioxide as a carrier gas) to agitate insects followed after 10 minutes by a 10 s burst of Insectigas (dichlorvos with carbon dioxide as a carrier gas) as the main killing agent. However, the current Pestigas/Insectigas schedule is not fully effective against all pests encountered in flowers. Extending the fumigation period from 2 h to 4-6 h and increasing the dosage of dichlorvos from 0.1 g/m3 to 1.7 g/m3 improved the range of pests controlled but did not kill all eggs of Tetranychus urticae and left some larvae of Epiphyas postvittana and Strepsicrates ejectana severely affected (making small twitching movements and unable to feed). Assessment of several alternatives identified phosphine as the most promising fumigant because of its effectiveness against insects and its low phytotoxicity. Large scale trials are being c
arried out in a commercial fumigation chamber using Pestigas followed by Phosfume (phosphine with carbon dioxide as a carrier gas). In tests so far, phosphine appears suitable for registration for fumigation of cut flowers. Results obtained in 6-h fumigations with 1.0-1.4 g phosphine/m3 were at least as good as those obtained in 6-h fumigations with 1.7 g dichlorvos/m3.