Chemigation for Control of Black Shank-Root-knot Complex and Weeds in Tobacco.

Tank mixes of a fungicide (metalaxyl) and a nematicide (fenamiphos) with herbicides (isopropalin or pendimethalin) and an insecticide (chlorpyrifos) were applied by soil incorporation or irrigation to control the black shank-root knot complex and weeds on four tobacco cultivars. The disease complex was more severe on cultivars McNair 944, NC-2326, and K-326 than on Speight G-70. The disease complex was reduced (P </= 0.05) on all cultivars with the pesticide combinations containing metalaxyl + fenamiphos. On most cultivars, percentage disease, disease index, root-gall index, yield, and weed control did not differ (P </= 0.05) between the tank mixes containing isopropalin or pendimethalin or among methods of application. Generally, the most effective method of treatment application for control of the disease complex and weeds was preplant incorporated followed by postplant irrigation and preplant irrigation.