Diseases and insect pests are problems that cannot be avoided and urgently need to be solved in the growth and development of onions, and how to prevent and control under the premise of ensuring the harmless production of onions is a problem that growers are very concerned about. Today, FengJinghui's senior agricultural experts provide professional and technical guidance on different diseases of onions, hoping to help growers.
1. Purple spot disease
Spray 50% isobacterium urea wettable powder 1500 times liquid, or 50% Daisen manganese zinc wettable powder 600 times liquid, or 72% manganese zinc • frost urea wettable powder 600 times liquid, or 64% oxyholone • manganese zinc wettable powder 500 times liquid, etc., the above agents are used alternately, sprayed once every 7 days to 10 days, continuous prevention and control twice.
2. Rust
Spray 15% triazolone wettable powder 1500 times to 2000 times liquid, or 70% daisen manganese zinc wettable powder 1000 times liquid plus 15% triazolone wettable powder 2000 times liquid, or 40% fluosilazole emulsion 8000 times -10000 times liquid, etc., the above agents are used alternately, sprayed once every 10 days, and continuously prevented and controlled twice.
3. Downy mildew
Spray 72% manganese zinc • frost urea wettable powder 600 times liquid, or 64% oxyholster • manganese zinc wettable powder 600 times -800 times liquid, or 72.2% downy mildew water agent 700 times liquid, etc., spray once every 7 days to 10 days, the above agents are used alternately, continuous prevention and control 2 times - 3 times.
4. Gray mold disease
Spray 50% humus fungus wettable powder 1000 times liquid, or 50% more moldy wettable powder 1000 times liquid, or 40% permex moulder urea wettable powder 1000 times liquid, etc., the above agents are used alternately, sprayed once every 7 days to 10 days, continuous prevention and control 2 times - 3 times.
5. Viral diseases
Use 50% anti-aphid wettable powder 2000 times to 3000 times liquid to control aphids; or 10% imidacloprid wettable powder 2000 times -2500 times liquid, or 40% Lego emulsion 800 times -1000 times liquid to control aphids and allium thrips, reduce or eliminate the spread of viral diseases.
At the beginning of the disease, spray 20% virus A wettable powder 500 times liquid, or 20% morpholine guanidine and ethyl copper wettable powder 500 times liquid, spray once every 7 days to 10 days, and the above agents are used alternately, spraying 2 to 3 times continuously.
1. Onion thrips
At the peak of nymph occurrence, spray 10% imidacloprid wettable powder 2000 times to 2500 times liquid, spray once every 7 days to 10 days, and continuously control 2 times to 3 times.
2. Allium flies
Soak the roots of seedlings with 50% octylthion emulsion 1000-1500 times liquid, or 90% crystalline diphthiae 1000 times liquid, or 1.8% avermectin emulsion 5000 times liquid before colonization. At the beginning of the adult disease, spray with the above agents, spray once every 7 days, continuous prevention and control 2 times - 3 times. At the beginning of the larval occurrence, the roots are also irrigated with the above agents, but the water addition multiple is reduced to 60% when spraying.
3. Allium spotted fly divers
In the initial peak stage of adult occurrence and the peak stage of larval leaf potential, spray control with 1.8% avermectin emulsion 2000-3000 times liquid, spray control, spray once every 7 days to 10 days, continuous control 2 times - 3 times.
Some highly toxic pesticides are strictly prohibited, they are: 666, DDT, toxinfen, dibromochloropropane, insecticidal amidine, dibromoethane, herbicides, ashitrins, dieshikid, mercury preparations, arsenic, lead, dinoflus, fluoroacetamide, glycine, poison rat strong, sodium fluoroacetate, poisonous rat silicon, methyl amidophos, methyl parathion, dinophos, mutamol, phosphorus melal, methyl isotyphos, terbutythion, methyl thiophos, methyl thiophos, antiphosphate, inhaled phosphorus, Cabawe, nasal deter, line-killing phosphorus, thiocycline phosphorus, fly venom phosphorus, ground worm sulfur phosphorus, Chlorzophosphate, benzophosphate.