Cotton can be negatively affected by diseases and nematodes. Primarily nematodes and diseases are early-season pests of cotton, but their effects are often seen season long. Cotton has a notoriously weak seedling that emerges slowly. Protection from diseases and nematodes at planting and early in the season is important for establishing a stand in all regions of the US cotton belt.
Cool, wet conditions that slow cotton emergence and growth are typically more favorable for development of infection from pathogens. Common pathogens include rhizoctonia and pythium. Several fungicides are available for control of these diseases, although they are not used in all planting situations. The amount of protection needed is a function of how quickly seeds will germinate, emerge, and grow off. Therefore, growers may elect to use a fungicide early in the planting season and save the expense later.
Nematodes are microscopic organisms that live in the soil and feed on plant root systems. Common troublesome nematodes in cotton are root-knot and reniform nematode. High populations of these nematodes can inhibit the cotton root system’s ability to take up nutrients and water needed for plant growth. The general result is stunted plants with smaller, shallower root systems. Plants may be deficient of some nutrients and lack drought tolerance. Nematodes often can magnify other soil fertility related problems. Sampling for nematode populations is critical. Economical control measures are lacking; however, crop rotation can help alleviate nematode pressures in infested fields over time.
