AN IMPLEMENT FOR DISLODGING MAIZE ROOTS FROM THE SOIL FOR CORN-ROOTWORM (COLEOPTERA, CHRYSOMELIDAE) DAMAGE EVALUATIONS

Evaluation of damage to maize (Zea mays L.) roots caused by corn rootw orm (the western corn rootworm, Diabrotica virgifera virgifera LeConte , the northern corn rootworm, D. barberi Smith and Lawrence and the so uthern corn rootworm, D. undecimpunctata howardi Barber) infestations requires that the main root mass be dislodged from the soil, which can be quite labor intensive. A tractor-pulled implement was fabricated t hat would loosen the necessary components of the maize root system fro m the soil. The ''root digger'' implement did not mechanically detach roots required for corn rootworm damage assessment. In a nonscientific assessment of labor requirements, an average of 28.6 roots/hr per per son were removed from the field using heavy-duty garden forks compared to an average of 92.4 roots/hr per person using the ''root digger'' i mplement. The system will be useful for small-plot studies in which pl ant destruction is acceptable.