Influence of fertility reproduction techniques of sod-podzolic sandy loamy soil on the phytosanitary condition of potato plantings and harvest

In a long-term stationary experiment on sod-podzolic sandy loamy soil in the Leningrad region, it was shown that the negative effect of soil fertility reproduction means on the phytosanitary condition of potato plantings and harvested crops was manifested only in an increase in the infestation of tubers with scab (1.5 times – the proportion of affected tubers, 1.3 times – the intensity of the lesion). As a result, there was an increasing need for measures to protect planting material from this disease. Positive changes in the phytosanitary parameters of the potato agrocenosis under the influence of soil cultivation were associated with a decrease in the damage to tubers by larvae of click beetles (by 1.2–1.3 times), with the introduction of a complete mineral fertilizer – with a decrease in the intensity of damage to potato plants by alternariasis (by 3.0–3.5 times), damage to plants and tubers by rhizoctoniosis (1.1–1.5 times and 1.2–2.1 times, respectively), damage to plants by larvae of the Colorado potato beetle (1.7–2.0 times). The defeat of tubers by scab and damage to tubers by larvae of click beetles depended more on the degree of cultivation of the soil (by 33.7–48.1 and 4.5–5.7%) than on the level of fertilization of potato plantings. Nevertheless, the contribution of fertilization was of decisive importance in the defeat of potato with alternariasis (76.9–77.7%) and rhizoctoniosis (8.9–18.0%), as well as damage by the Colorado potato beetle (7.0–10.4%). The influence of the studied means of reproduction of soil fertility in relation to damage to potato tubers by caterpillars of gnawing scoops was not sufficiently pronounced, which was not statistically confirmed.