Early invasion of overdrilled red clover seedlings by nematodes

Abstract

Root knot nematode (Meloidogyne hapla Chitwood), clover cyst nematode (Heterodera trifolii Goffart), and clover stem nematode (Ditylenchus dipsaci (Kuhn)), parasitised ‘Grasslands Pawera’; red clover (Trifolium pratense L.) within 3 weeks of overdrilling into mixed pasture containing white clover. Coating seed with oxamyl caused some reduction in nematode population densities in the seedlings during spring and increased seedling size. In the autumn, nematode densities in the seedlings were generally low. Oxamyl toxicity to seedlings was measured in the autumn sowing and in a laboratory experiment. The cost benefits of chemical control in this situation need to be established.

Keywords:

• root knot nematode
• Meloidogyne hapla
• clover cyst nematode
• Heterodera trifolii
• clover stem nematode
• Ditylenchus dipsaci
• red clover
• Trifolium pratense
• sowing
• overdrilling
• seedlings
• oxamyl
• phytotoxicity