| Popis: |
The article presents the results of studies of the quantitative and specific composition of soil micromycetes in potato cultivation, depending on the intensity of irrigation in the north-east of Kazakhstan. During their growth in the soil, plants actively interact with its microflora, while microorganisms can have both positive and negative effects. Micromycetes produce mycotoxins that accumulate in food and, when ingested, cause liver damage and cancer. Some mycotoxins persist in the ground for a long time, and with improper agricultural processing, they accumulate in it, and are also removed from it to adjacent environments (surface reservoirs). As a result of the conducted studies, indicators of the quantitative and specific composition of fungi were obtained, antagonist fungi and toxin-forming species were identified. According to the results of the mycological analysis of soil samples, 39 isolates were isolated. During the study, the accumulation of toxin-forming species was found to be 43−54 % in all the studied variants. In the soil, when using irrigation, there are both pathogenic (18.1-50.0%) and saprophytic (50.0-81.9%) species of micromycetes, as well as toxin-forming species of fungi (46.2-55.6%) , which can cause different effects on the resistance of plants to potato diseases. The greatest number of pathogenic fungi, as well as toxin-forming fungi, was found when using limited watering of potatoes. The greatest number of pathogenic fungal species was observed in the variants with moderate irrigation −38.5 % (genera Fusarium − 30.8 %, Penicillium − 7.7 %), as well as in the variant with maximum irrigation – 50.0 % (genus Fusarium – 39.0%, from the genera Gliocladium and Aspergillus − 5.5%). Thus, the use of crop rotations and repeated fungicidal treatments carried out when growing potatoes does not guarantee the absence of pathogenic microorganisms in the soil, and the use of intensive watering provokes a stronger development of pathogenic microflora. New approaches to integrated potato protection are required. |
