Efficiency impact of several important products of nematicide on Biological Control of Tea Root Lesion Nematode (Pratylenchus loosi)

Pratylenchus loosi, the root lesion nematode, is the most important cause agent damaging tea crop in Iran and the world. This research was carried out with the aim of evaluating the effectiveness of  nematicide organic  amendments at infected level with a population above the injury threshold, four treatments in three replications with a randomized complete block design was done at Fashalem tea station in Gilan province. The results showed that in the infected environment with a population higher than the damage threshold, only the moisture content index, treatment of tobacco waste with 71.93% was the best treatment. In quantitative indices such as nematode population in soil and roots in infected P. loosi environments, neemarin(neem extract) treatment was most effective. There was no significant  difference observed between the treatments in green leaf index, but the increase in yield was observed in comparison with the control. The results of this study showed that the use of neemarin and tobacco waste can improve the quality indices in addition to reducing the population of nematode in soil and root and as an important biological factor in controlling nematodes.