Effect of Inhibition of Fusarium Species Associated with Maple Seedling Roots on Root-Lesion Nematode in Behshahre Area of Mazandaran Province, Iran

One of the most important factors in developing forests is Production of seedlings Free of Pests and
diseases to be transplanted in the forest. Among softwood and hardwood trees, Acer velutinum is the
most useful species because of its easy planting, rapid growth and good wood quality. Pests and
diseases are important factors affecting plant growth and development in the nurseries. Nematodes
constitute one group of these agents that have not so far been studied in forest nurseries in Iran. In a
survey of maple seedlings in the forest nurseries with student growth, chlorosis and weakness,
Pratylenchus vulnus, Fusarium solani and F oxysporum were isolated. The interaction of these fungi
and the nematode were studied in randomized complete block design with four a replications and six
treatments. In treatment with F. oxysporum the average height of seedlings were 28 & 30 after 4 & 7
months; in treatment with F solani, the averages were 27 & 25.75 cm, and in control they were 28.5 &
30.5 cm, respectively. The seedlings were not truly infected with these two fungi. But in treatment
with nematode alone 75% of the seedlings died. In the treatments with nematode and fungi combined,
the population of nematodes decreased and the growth of the seedlings increased (in comparison with
nematode alone), F oxysporum showed a more antagonistic effect than F solani on the nematode.
Therefore, the nematode alone was more destructtive on the roots of maple seedlings than when
combined with the fungi. F oxysporum was less in urious than the other and decreased the nematode
population as well, although the infection due to either of these fungi on the roots of seedlings were
not so severe.