Abstract: This paper studied the effects of 0.3 mmol·L^-1 SNP on the antioxidant enzymes and reactive oxygen in pear leaves infected by Physalosproa piricola Nose. The results showed that compared with CK₁ (spraying leaves with water and infecting with P. piricola Nose), 0.3 mmol·L^-1 SNP could increase the activities of leaf POD, SOD, CAT and PPO and the contents of leaf ASA, GSH and proline by 39.41%, 21.11%, 41.61%, 13.04%, 44.45%, 48.32% and 33.80%, while decrease the contents of leaf MDA and H₂O₂ and the generating rate of O₂^- by 20.45%, 6.93% and 6.27%, respectively, indicating that lower concentration SNP could reduce the damage of P. piricola Nose to pear leaves.

Key words: wheat, supplemental irrigation period, photosynthetic characteristics, dry matter accumulation and allocation, water use efficiency