Abstract
One-year-old shoot cuttings of Pinus densiflora were treated with various concentrations of benzoic acid, and then inoculated with the pine wood nematode. The cuttings were maintained hydroponically. Shoot cuttings treated with 300ppm benzoic acid solution did not become diseased and survived. The mean amount of benzoic acid absorbed by these cuttings was estimated at 3.1mg per g dry weight of wood. Shoot cuttings treated with lower concentrations died. When shoot cuttings were treated with 500ppm benzoic acid, they showed reddish-brown discoloration after 4 days of treatment and then died. The mean amount of benzoic acid absorbed by these cuttings was estimated at 4.4mg per g dry weight of wood. Pine wood nematode populations did not increase in shoot cuttings treated with 300ppm benzoic acid solution although living nematodes were found in healthy cuttings throughout the experimental period. Water uptake and moisture content were largest in shoot cuttings treated with 300ppm benzoic acid solution.
