Abstract:
The effect of infection was studied with five levels of the infectious inoculum for the root-knot nematode, Meloidogyne incognita. They are (A = 0, B = 1000, C = 2000, D = 4000, E = 8000) egg/pot on the yield of tomato varieties (Oula, Noor, Arwa, New Malaka, Super Red), under field conditions in Aleppo (Azaz).
It was found that the root-knot nematode Meloidogyne incognita caused a decrease in the mean yield and weight of the fruit in all the tested cultivars, where there was a positive correlation between the levels of primary infection with the nematode and the percentage of the decrease in the yield and the weight of the fruit in the infectious plant. On the other hand, there was a variation in the percentage decrease in yield and fruit weight between varieties as a result of nematode infection arranged in ascending order as follows:
Lower yields: Super Red, Noor, Oula, New Maleka , Arwa.
Low weight of the fruit: Super Red, Noor, New Maleka , Oula, Arwa.
Key words: Lycopersicon esculentum, yield, fruit weight, root- knot nematode