Occurrence of Major Diseases and Insect Pests in Medium-term Growth Period of Sugarcane and The Diseases Resistance Evaluation in Guangxi

To figure out major diseases and insect pests of sugarcane and sugarcane resistance to diseases,the occurrence of major diseases and insect pests on 11 main sugarcane varieties in eight sugarcane producing areas of Guangxi was investigated during the medium-term growth period of sugarcane in 2015,and field resistance to smut and mosaic diseases was evaluated. The results showed that the dead heart rate( DHR) ranged from 0. 00% to 38. 55%; new-planting sugarcane of Guiliu 2 and ratoon sugarcane of Liucheng 05-136 suffered the most severe damage in Beihai city,and the DHR were 38. 55% and 37. 66%,respectively. The incidence rate of smut disease ranged from 0. 00% to 24. 89%. Ratoon sugarcane was more susceptible to smut than new-planting sugarcane among all investigated varieties. Variety ROC22 was most susceptible to smut,and performed moderate susceptibility. Guiliu 2 was the second susceptible and performed resistance,with the incidence rate of 7. 45%. The rest nine varieties had high resistance. Sugarcane mosaic disease occurred mildly in Guangxi,and the incidence rate ranged from 0. 39% to 7. 73%. ROC22,Guitang 42 and Guiliu 2 expressed moderate resistance and the rests exhibited resistance. Sugarcane in Nanning and Beihai suffered more severe damage than those in other producing areas. The field evaluation system of sugarcane resistance to borers was expected to be constructed. ROC22 was most susceptible to smut,compared with other main varieties. Mosaic diseases occurred lightly in Guangxi. Multi-location and multi-year observation are necessary for accurate evaluation of sugarcane resistance to smut and mosaic diseases.