Cereal Cyst Nematode and N Fertilization1

The effect of increasing amounts of nitrogen on the propagation of the cereal cyst nematode was studied. Nitrogen applications as nitro-chalk ranged 0–1,500 kg/ha (0–232.5 kg N/ha). Maximum propagation was obtained at about 46.5 kg N/ha. Increasing N doses reduced propagation to about 1/2 - 1/3 of the maximum. Two factors seem to be involved: 1) reduced fertility of females with increasing N application and 2) apparently fewer females developed with N applications greater than 46.5 kg/ha. Hatching in solution of calcium nitrate decreased with increasing concentration.