Methyl bromide fumigation for control of melon fly (Dacus cucurbitae Coquillett) in string beans
Tanaka, K.; Sunagawa, K.; Oda, Y.; Hokama, T.
Research Bulletin of the Plant Protection Service Japan 22: 67-78
1986
ISSN/ISBN: 0387-0707 Accession: 001408721
The efficacy of methyl bromide fumigation to control the tephritid Dacus cucurbitae in harvested string beans [Phaseolus vulgaris] was investigated in Japan. Various stages of D. cucurbitae from eggs to 3rd-instar larvae, were fumigated over a wide range to concentrations at 15 degrees C. Of all the stages tested, 1-day-old eggs were the most resistant to methyl bromide. A fumigation dose of 35 g/msuperscript 3 for 2.5 h at 20 degrees C resulted in 100% mortality at this stage. The effects of fumigation on the cultivars Kentucky-wonder, Sujinashi-F.S.-edogawa, America-ingen-shakugosun and Keystone-sujinashi were investigated. Kentucky-wonder and America-ingen-shakugosun were more susceptible and brownish patches developed on the outer skin of these cultivars when fumigated with 35 g/msuperscript 3 methyl bromide for 2.5 h at 20 degrees C. Smaller pods were more susceptible to the fumigant than larger ones. Beans stored at 10-15 degrees C after fumigation at 20 degrees C developed injury symptoms more readily than those stored at 20 degrees C after the same treatment. The load factor, brand of methyl bromide and time after harvest of beans had no significant effects on the susceptibility of the beans to the fumigant.