Downy mildew control
In June, it’s time to carry out preventive spraying of onions planted on a turnip from downy mildew with a 1% solution of Bordeaux liquid. For better stickiness, add 40 g of laundry soap or 1 liter of skim milk to a bucket of liquid. This treatment is repeated after 7-10 days. It is better not to process onions planted on greens with Bordeaux liquid, it can be protected by spraying with infusion of ash or a solution of baking soda (1 tablespoon per bucket of water). The use of ash and soda lowers the acidity of the soil, and this disease develops more strongly on acidic soils. In addition, ash is an excellent potash fertilizer that increases the resistance of plants to diseases. If the ashes are mixed with carrot seed powder, it will repel the onion fly.
Of great importance in the fight against downy mildew is the correct alternation of crops and planting them in sunny places. Joint plantings with carrots are good for onions. Often the soil is infected with a microscopic pest – an onion nematode. Planting around a ridge of undersized marigolds prevents the spread of the nematode.
The fly lays its eggs on the soil near the plants. The emerging larvae penetrate the bulbs, which then rot, and the plants turn yellow and dry out.
Female beetles gnaw holes in the leaves and lay their eggs through them. The emerging larvae live and feed inside the leaves, outside they are visible in the form of whitish stripes.
Downy mildew onion
Pale green blurry spots appear on the leaves, which gradually increase, and a light purple bloom forms on them. Affected leaves turn yellow and dry out. The infection penetrates the bulb, where it persists all winter.