Photobiological Effects of Nano-TiO_2 Semiconductors Sol

Nano-TiO_2 semiconductors sol (NTSS) was synthesized through a sol-gel method,and its antibacterial abilities were identified by using bacterial pathogens of Pseudomonos syringae pv. lachrymans and Xanthornonasvesieatoria.Taking cucumber plants as experimental objects,the pho- tobiological effects of NTSS on preventing from plant bacterial/fungal diseases and promoting contents of photosynthetic pigments were primarily studied.Results show that crystal species of TiO_2 particles synthesized in experiments are in anatase phase with average size of about 30.6nm.NTSS possesses strong oxidizing power with over 99.9% antibacterial rate by forming continuous and stable antibacte- rial films on surfaces of substance.Lesion areas,disease incidences and disease indexes of leaves can be significantly reduced by spraying NTSS on cucumber leaves;however,content of chlorophyll and carotenoid in leaves can be significantly promoted.It is proved that NTSS can significantly prevent and control the development and pervasion of bacterial angular leaf spot of cucumber.The experimental results lay an important theoretical foundation and technical approach for developing and applying of biofuntional nanomaterials in agricultural areas.