Protection of potatoes from pests and the Colorado potato beetle should be carried out throughout the season. Measures and control measures include both special methods of cultivating arable land and the chemical agents used to process planting tubers and seedlings.
Pest Colorado Potato Beetle
Currently, the Colorado potato beetle is widespread throughout Russia. Beetles and larvae are harmed by roughly eating leaves, petioles, and even stems, from seedlings to harvesting.
The greatest harm is done by the Colorado potato beetle in those areas where potatoes were planted too late, that is, the pest, “not wanting it,” appears too early in the phenophases on plants.
Also, the harm from the beetle and its larvae can be very noticeable both in areas with sparse plantings and in areas where a low agricultural background is noted. Almost everywhere, bushes are completely nibbled by this pest, because of which there are large crop losses.
Beetles winter in the soil at a depth of the arable horizon – up to 20-30 cm.
After warming the soil to 14 ° C, they begin to come out of the soil, but not simultaneously, but stretched.
Protecting Potatoes from the Colorado Potato Beetle
Effective protection against the Colorado potato beetle begins with a thorough harvest of tubers in the fall. Beetles immediately populate self-seeding (plants which have already sprouted from tubers not selected in the fall) of personal plots, planting of replacement, as well as plots close to last year’s fields and cultivation sites. In remote areas, the pest appears 2-3 weeks later. Soon, females begin to lay eggs, placing them 20-30 pieces on the back of the leaves. On average, the female lays 400-600 eggs, and individual individuals up to 2400 eggs. After 7-10 days, larvae emerge from the eggs, which live and harm for 15-20 days, during which time they pass 4 ages. The timing of their appearance depends on weather conditions, but usually, it happens in June.
After feeding, the larvae leave in the soil for pupation, and after 10-15 days new bugs appear. Due to the lengthy exit of the beetles from the wintering places in the fields, you can often meet simultaneously wintering beetles and newly appeared. At this time, special protection of potatoes from the Colorado potato beetle is needed.
Hot weather depresses the beetles, and some of the overwintered beetles fall into the summer for up to 30 days or more, the rest period. Due to poor food or lack thereof, beetles may have a temporary suspension of active life for a longer period, and for this reason, they are sometimes in the soil at a dormant stage for up to 3 years. With an average abundance on the field (20–40 larvae and beetles per bush), the leaves are usually destroyed by half, the yield is reduced by 2–3 times, When the leaves are fully eaten, the yield is reduced by 10 times, and what remains will be substandard have poor quality and poor keeping quality.
Methods and Means of Combating the Colorado Potato Beetle
The fight with the Colorado potato beetle should be carried out annually and in a timely manner (regardless of the appearance of the pest and the mass development):
- planting varieties of later ripening – Sotka, Zarevo, Temp, and others, as well as varieties that form a powerful top – Adretta, Nikita, Shurminsky and others;
- planting in optimally early periods on well-filled soils so that the plant “has time to escape” from the still “sleeping” beetle;
- repeated sealing of emerged seedlings with 3-5 cm soil (the bug does not gnaw them in the soil);
- high hilling of bushes with backfilling of lower leaves on which eggs are laid;
- loosening row-spacing 2-3 days after the mass departure of larvae to pupate in the soil;
- removing leaves before harvesting worsens the conditions for preparation for wintering;
- late and deep plowing of fields (2-3 cm below the arable horizon) from under the potato turns the beetles to the surface, where they can then die from the onset of frost.
When larvae of 1-2 age appear, when their number is more than 20 per bush and their population is more than 20% of the bushes, it is recommended to carry out focal or continuous spraying with one of the chemical preparations, which include the following means of combating the Colorado potato beetle:
- arrivo (ambush, sherpa), 25% ke. 1.5 ml per 10 liters of water, with a flow rate of 1–2 hundred parts;
- Sumy alpha, 5% ke – 5 ml per 10 l of water;
- decis, 2.5% ke – 2 ml per 10 l of water;
- kinmix, 5.0% ke – 2.5 ml per 10 liters of water and other drugs approved for use in small farms and the private sector, but not more than two sprayings.
Biological preparations are affordable methods of combating the Colorado potato beetle, they act somewhat more slowly, but they are safer for humans and the environment: Bicol is a new form of bitoxibacillin, consumption is less than 20 g per 10 l of water (instead of 30-50 g of bitoxibacillin); fit over, 0.2% ke. – 4 ml per 10 liters of water. A mixture of fit over 0.2% 4 ml + Bicol 10 g per 10 l of water, not inferior to decis inefficiency.
The first treatment with biological products is carried out at the beginning of the mass hatching of larvae, again after 7-8 days with a population of more than 5 larvae per bush. It is noted that phytoverm also destroys beetles.