Abstract

The impact of three levels of Meloidogyne incognita eggs, that is, 1000, 2000 and 3000 eggs/ plant on plant growth parameters of sugarbeet cv. Nejma and its development and reproduction under greenhouse conditions at 17 ± 5°C was studied. Results indicated that reduction percentage of sugarbeet growth parameters were greatly affected, where the marginal effect was more pronounced on roots than shoots. Moreover, as the inoculation level increased from 1000 up to 3000 eggs of M. incognita /plant, the percentage reduction of plant growth parameters increased, where the highest values were recorded to be 48.97 and 24.18% by 3000 eggs/ plant for shoot dry and whole plant fresh weights, whereas, their lowest values of 30.93 and 4.05% resulted by inoculation level of 1000 eggs/ plant for the same plant growth criteria, respectively. Moreover, the highest rate of nematode reproduction on sugarbeet plants cv. Nejma was recorded by the level of 2000 eggs per plant with value of 1.05 whereas the lowest ones of the same criterion resulted by the levels of 3000 or 1000 eggs per plant that were 0.85 or 0.84, respectively. M. incognita infection to sugar beet plants cv. Nejma at the three levels of egg inoculation obviously reduced N, P, K and total chlorophyll content on leaves of sugarbeet with values of 9.9% (N), 18.5% (P), 8.8% (K), 1.58% (chlorophyll) and 20.0% (N), 27.4% (P), 18.4% (K) and 5.9% (chlorophyll) by 1000 and 3000 eggs/ plant, respectively compared to the uninoculated plant.

Key words: Meloidogyne incognita, sugarbeet, inoculum levels.