No cultivars are available with resistance to the reniform nematode. Yield losses in these cultivars depend on the severity of the nematode problem. Under high root-knot pressure, significant yield losses can be expected. The cultivars Stoneville LA887 and Paymaster 1560 have the highest level of genetic resistance to root-knot of any of the popular cotton cultivars grown in Arkansas. Although the level of nematode resistance in these cultivars is moderate at best, field studies in Arkansas indicate that acceptable yield may be achieved under high root-knot nematode pressure with this cultivar in combination with relatively low rates of nematicide.
Crop rotation is the most effective and economical long-term management technique.
Resistant or non-host crops are very effective in lowering nematode populations. Decisions on the selection of rotation crops and how often to employ rotation must be based both on an accurate identification of the nematode problem, the population levels in a field, and the economics of the rotation program Care must be taken in selection of rotation crops because many commonly grown crops and cultivars are also susceptible. Table 3 contains a list of crops that are effective in lowering nematode populations and those that actually contribute to increased populations. Wheat and most small grains do not appear to have significant effects on populations of either root-knot or reniform nematodes because they are grown during the months when the nematodes are least active. Suggested rotation crops for management of cotton nematodes.