Host range of the ginger strain of Pseudomonas solanacearum in Queensland

Abstract

The host range of Pseudomonas solanacearum biotype 4, the strain responsible for a rapid wilt of ginger, was found to include tomato, potato, capsicum, egg plant, peanut, tobacco, Solanum nigrum, Physalis minima, P. peruviana, and Solanm mauritianum. During the summer months of 1967-68 and 1969-70, weeds growing in bacterial wilt affected ginger plantings were examined for the presence of P. solanacearum. Biotype 4 was isolated from S. nigrum, Crassocephalum crepidioides, S. mauritianum, P. minima, P. peruviana, and Ageratum houstonianum. Biotype 3, the strain commonly found in the ginger growing district of southern Queensland was isolated from S. nigrum, C. crepidioides, S. mauritianum, Xanthium pungens, Dodonaea lanceolata, Bidens pilosa, and Sida spinosa. These weeds were all collected from ginger fields. It appears from these results and previous observations that biotype 4 has a more restricted and slightly different host range from biotype 3. Consequently it has been suggested that in any crop rotation, ginger growers should eliminate known biotype 4 susceptible weeds. Both biotypes 4 and 3 survived, in the experimental plots, a 20-month period of severe drought during 1968-69. However, no attempt was made to control weed growth in the trial area.