Effect of Forage and Grain Pearl Millet on Pratylenchus penetrans and Potato Yields in Quebec.

Rotation crop experiments were conducted from 1998 to 2000 to assess the impact of forage and grain pearl millet (Pennisetum glaucum) on Pratylenchus penetrans populations in three potato (Solanum tuberosum cv. Superior) fields in Quebec. These crops were compared to oats and(or) barley. Forage millet had a suppressive effect on P. penetrans populations after a 1 year rotation. The following year, marketable potato yields were negatively correlated with initial P. penetrans densities on two experimental sites (r = -0.454, P = 0.044; r = -0.426, P = 0.017). Average marketable and total yields were increased by 10% in plots previously grown in forage millet hybrid CFPM 101 when compared to oats (P = 0.017). Damage functions between preplant nematode density (Pi) and marketable yield (y = 42.0 -4.091 log [Pi + 1]) and total yield (y = 43.9 -4.039 log [Pi + 1]) of potato were established on pooled yield data. Forage pearl millet is an efficient and economically viable alternative for managing root-lesion nematodes and improving potato yields in Quebec.