The salubrity of the roots of the sowing alfalfa (Medicago sativa L.) in dependence of tee numbers of Sitona humeralis (Steph.) larvae

In the pot experiment on the four-months plants of the sowing alfalfa were carried to the soil the Sitona humeralis (Steph.) larvae: object I - 340 larvae for pot (17 plants), object II - 680 larvae for pot (17 plants), inspection - without larvae. After three months they were stated that on the object I from formated root nodules 34.5% were damaged and 29.4% of main roots had the deep hurts. So on the object II the values were presenting as respectively: 51.8% and 80.4%. The damages gave the possibility of the very fast infection of the root system, especially the main root of the alfalfa by the pathogenic fungi: Fusarium, Rhizoctonia and Phoma.