Effect of Heterodera Ciceri On Yield of Chickpea and Lentil and Development of This Nematode On Chickpea in Syria

Abstract

Experiments were undertaken in 1984-1986 to assess losses caused by Heterodera ciceri to chickpea and lentil and to investigate the development of the nematode in Syria. Pots containing 5.5 dm 3 of soil were sown to spring chickpea in 1985 and microplots containing 34 dm 3 of soil sown to winter chickpea or lentil in 1985-1986. There were nine pots or ten microplots for each plant species and population density levels (0, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64 and 128 eggs of H. ciceri/cm 3 soil). Sixteen more microplots were sown to winter chickpea and 14 to spring chickpea, to investigate the development of the nematode. When plant size was considered, tolerance limits (T) to H. ciceri were 0.22 and 0.6 eggs/cm 3 soil and minimum relative plant sizes 0.6 and 0.47 for winter sown chickpea and lentil, respectively. Tolerance limits of 1, 1.15, and 2.51 eggs/cm 3 soil for spring and winter chickpea and lentil, respectively, and relative minimum yields of 0 for chickpea and 0.5 for lentil were instead estimated for grain and total plant weights. Seed protein content was also negatively affected by the nematode. Second stage juveniles of the nematode had invaded roots of both winter and spring chickpea by the time of emergence of the plants. Females appeared on 13 March and 10 April on the roots of winter and spring chickpea, and cysts 14 and 6 days later, respectively, when 212-227 day degrees had accumulated. Maximum reproduction rates of H. ciceri at very small initial population densities were large (249-297) and about the same on winter chickpea and lentil and 4.5 on spring chickpea.