fertilizers
Fertilizers can not only accelerate plant growth, but also to a large extent optimize the phytosanitary state of potato plantings in relation to R. solani and improve the quality of the resulting tubers. The introduction of full mineral fertilizer under the crop reduces the development and prevalence of rhizoctoniosis on underground organs by 1,2-1,6 times, and also increases the yield of healthy tubers by 3-5 t/ha and reduces their population with sclerotia by 1,3-1,5 times.
Light tempering
Light, affecting the host plant, has its indirect effect on the pathogen. Light-hardening of tubers reduces the damage of sprouts by rhizoctonia by increasing their vital activity. The germination of tubers in the light leads to the formation of sprouts with a high content of dry matter and sucrose, a higher activity of oxidative enzymes, and the synthesis of complex inaccessible organic compounds, which makes them resistant to the disease.
Variety choice
The introduction of rhizoctoniosis-resistant potato varieties into production can be one of the most effective, environmentally safe and low-cost methods of crop protection from this disease. According to the results of the research, it was found that there are no varieties absolutely resistant to this disease, but with the proper set of agricultural practices, such varieties as Zhukovsky early, Lvovyanka, Tomich, Oredezhsky, Escort and Fresco have the properties of the greatest resistance and endurance to the Siberian population of the fungus R. solani.
Treatment of planting tubers
Even if all agrotechnical measures are observed, dressing of potato seed material remains an obligatory method, since at present there are practically no batches of planting tubers healthy, not affected by the fungus R. solani. The minimum level of occupancy of potato seed tubers is currently 20%. In addition, it is necessary to take into account the accumulated potential of the pathogen in the soil, which on average reaches 20 propagules per 100 g of soil. Based on the phytosanitary examination of seed material and soil, a decision is made on the need for preplant treatment of tubers. The range of preparations for dressing potato planting material currently includes biological preparations and fungicides of chemical origin.
Experimental data show that the use of the protectant Maxim 0,25 KS reduces plant losses from rhizoctoniosis, as well as the incidence of underground organs with the disease by 1,5 times. On average, the fungicide provides an increase in the yield of healthy tubers in the amount of 2,5 t/ha, but this value may vary depending on the crop preceding the potato.
Care of plantings
The soil crust, interfering with the heating of the soil, contributes to the defeat of the crop by rhizoctoniosis. Due to the fact that the causative agent of the disease affects not only cultivated plants, but also wild ones, many weeds (thistle thistle, white gauze, mountaineers, etc.) are a source of infection in agrocenosis. Therefore, the primary task in caring for planting potatoes is harrowing. Before the emergence of seedlings, it is necessary to carry out 2 harrowings and the third - for seedlings. Also, in the fight against weeds, herbicides can also be used, which allows not only to eliminate the reserves of the pathogen, but also to increase crop yields.
Use of growth regulators
To enhance growth processes, increase the resistance of potatoes to rhizoctoniosis and the quality of the products obtained, it is recommended to treat tubers before planting, plants in the budding phase - the beginning of flowering with growth regulators based on potassium or sodium salts of humic acids (Potassium or sodium humates, Beres-4, Gumostim), triterpene acids (Silk, Novosil, Verva), etc.
Cleaning
It is necessary to start harvesting no later than 7 days after the death or destruction of the tops, since the further presence of tubers in the soil leads to an increase in their colonization with sclerotia of the fungus.
List of used literature:
- Shaldyaeva E.M. Monitoring of rhizoctoniosis in potato agroecosystems in Western Siberia / E.M. Shaldyaeva, Yu.V. Pilipova, N.M. Konyaev. - Novosibirsk, 2006. - 196 p.
- Shaldyaeva E.M. Optimization of the phytosanitary state of potato plantations using spring rapeseed as a green manure crop / E.M. Shaldyaeva, Yu.V. Pilipova, M.P. Shatunova // Plant Protection in Siberia: Sat. scientific tr. teachers and graduate students of the Faculty of Plant Protection. - Novosibirsk, 2003. - S. 77-83.
- Cubeta MA Population biology of the Rhizoctonia solani complex / MA Cubeta, R. Vilgalys // Phytopathology. - 1997. - V. 87. - P. 480-484.
- Kronland WC Clean slide technique for the observation of anastomosis and nuclear condition of Rhizoctonia solani / WC Kronland, ME Stanghelllini // Phytopathology. - 1988. - V. 78. - Р.820-822.
- Ogoshi A. Ecology and pathogenicity of anastomosis and intraspecific groups of Rhizoctonia solani Kűhn / A. Ogoshi // Ann. Rev. Phytopathol. - 1987. - V. 25. - P. 125-143.
- Ogoshi A. Rhizoctonia species and anastomosis groups causing root rot of wheat and barley in the Pacific Nothwest / A. Ogoshi, RJ Cook, EH Bassett // Phytopathology. - 1990. - V. 80. - P. 784-788.
- Shaldiyeva EM Study of structure of Siberian soil population of Rhizoctonia spp. / EM Shaldiyeva, YV Pilipova // Abstracts of 4 International EFPP Symposium Diagnosis and Identification of Plant Pathogens. - Germany, Bonn, 1996. - P. 80.