INFLUENCE OF EDAPHICAL PARAMETER ON INFESTATION RATE OF CYSTIC NEMATODE OF CEREALS HETERODERA AVENAE IN THE REGION OF TIARET (ALGERIA)

Infestation states of Heterodera avenae at the level of cultivated cereals plots are varying going from absence to presence which widely overtakes the harmfulness threshold. To study influence of the ground nature on levels of nematode, we have tested granulometer (rate of clay, silt and sand); rate of organic material of total limestone and active limestone and so on dampness rate to see at last correlation between level of infestation and ground nature. The muddy and sandy texture enriched with organical matter and limestone favours developing and proliferation of nematode. Even though clayey texture (heavy grounds) poor in organic material is marked by absence of nematode in the plots. Dampness is negatively closely connected with infestations; the good development of nematode is marked by the low temperature influence which favours the hatching. Organic material favours structural stability of the grounds and so the growing of nematode, the total limestone grows friableness of the grounds. While active limestone impoverishes the ground in (phosphor, potassium and iron) cultivated plants are favourable guests for Heterodera avenae.