Causes and control techniques for continuous cropping obstacles of lily：A review

Lily is an important cash crop with high edible， medicinal， and ornamental values， however， there are often serious continuous cropping obstacles（CRO）in lily cultivation， which threaten the yield and quality of lily harvest. Green and effective preventing techniques of CRO can reduce the production cost of lily and ensure the safe use of lily products. Therefore， it is very necessary to deeply understand the causes of CRO of lily and develop corresponding prevention and control technologies. Herein，the recent domestic and foreign studies on CRO of lily were reviewed. Results showed that the degradation in soil properties， soil pathogenic microorganisms increase， and the gradual accumulation of autotoxic substances were the main causes of CRO of lily. At present， the methods to deal with CRO of lily mainly involved the selection of CRO-resistant lily varieties， crop rotation and intercropping， soil fumigation and disinfection， reductive soil disinfestation， application of microbial preparations， and other green soil conditioning agents. However， the CRO-resistant lily varieties are severely lacking in China， and the various new preventing techniques of CRO still need to further verify the safety， improve the effectiveness and reduce the cost，and at present，lily cultivation is still restrained heavily by the lack of cultivated land resources. Aiming at such problems，the main research direction should be cultivating CRO-resistant lily varieties， improving the performance of preventing techniques of CRO， reducing the related cost， and realizing the safety and harmless management technologies in the future.