How to prevent and control pests and diseases in Panax notoginseng? Detailed explanation of methods and technical key points

    1. Diseases     1.1 Black spot disease Mostly occurs in the high-temperature and high-humidity season from June to July, causing plants to twist, break and die. The control method is to adjust the shade shed light transmittance to below 20%, and spray with 1.5% polyoxin 150-fold solution or 70% chlorothalonil wettable powder 600-800-fold solution.     1.2 Phytophthora blight It is a devastating disease of Panax notoginseng at the seedling stage. It mostly occurs from June to July and harms leaves and petioles. The control method is to strengthen field management, reduce temperature and humidity; remove residues promptly and burn them in a centralized manner, and spray with 65% zineb wettable powder 500-fold solution for treatment.     1.3 Damping-off Mostly occurs in the high-humidity and low-temperature season from April to May and harms the base of seedlings. The control method is to drench the roots and spray with 70% dexon wettable powder 500-800-fold solution.     1.4 Root rot It is the main root disease of Panax notoginseng. It mostly occurs from late April to early July. The control method is to drench the roots with 58% metalaxyl wettable powder or 50% carbendazim wettable powder 300-500-fold solution.     2. Pests     2.1 Slug (snail without shell) The control method is to spray lime powder on the bed surface on clear evenings.     2.2 Red spider mite The control method is to spray with 40% dimethoate emulsifiable concentrate 1000-fold solution.     2.3 Black cutworm The control method is to use 90% trichlorfon crystal mixed with poison bait for trapping and killing, or drench with a 1000-1500-fold solution.