Resistance of Populus deltoides clones to canker in field

【Objective】New Populus deltoids varieties with canker resistance were screened from 5-year natural hybrids of poplar.【Method】In middle July and late September when the emergence of Botryosphaeriacanker was high,number of lesions on stem 0.3-1.8meter high and diameter at breast height of each clone were measured.Then canker incidence and infection index of each clone were calculated.【Result】Clones with high canker resistance included 03-south-2-21,03-north-27-1and 03-north-3-1.Clones with low resistance included 03-south-5-11,03-south-1-13and 03-south-4-24.Clones those were susceptible to canker included 03-south-4-1,03-north-1-7,03-south-3-2and 03-north-1-15.【Conclusion】Clone 03-south-2-21was the best variety with high canker resistance for fast-growing.