Soybean Crinkle Leaf: A New Whitefly-Borne Disease of Soybean. Mitsuro Iwaki, Institute for Plant Virus Research, Tsukuba Science City, Yatabe, Ibaraki, 305 Japan. Pornpod Thongmeearkom, Division of Plant Pathology and Microbiology, Department of Agriculture, Bangkhen, Bangkok 9, Thailand; Yohachiro Honda, Institute for Plant Virus Research, Tsukuba Science City, Yatabe, Ibaraki, 305 Japan; and Nualchan Deema, Division of Plant Pathology and Microbiology, Department of Agriculture, Bangkhen, Bangkok 9, Thailand. Plant Dis. 67:546-548. Accepted for publication 21 December 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-546.

Soybean crinkle leaf disease occurred on soybean in many growing areas of Thailand. The disease agent was transmissible by the whitefly, Bemisia tabaci, in a persistent manner and by grafting but not by aphids, inoculations of sap, or through seeds of soybean. Single whiteflies did not transmit the disease agent and about 40 insects were necessary to achieve high transmission rates. Minimum acquisition and inoculation access times ranged from 30 to 60 min and from about 10 to 30 min, respectively. The latent period in the whitefly vector ranged between 8 and 10 hr, and the retention period in the vector lasted 9 days. The disease affected 11 plant species in three families (Compositae, Leguminosae, and Solanaceae).