The relationship between wildlife and agriculture often creates tension, particularly when native species like the white-tailed deer encroach upon cultivated fields. In cotton-growing regions, this common herbivore is frequently cited as a major source of crop loss. This damage represents a genuine economic concern, as the financial impact of wildlife damage on agricultural yields can be substantial. Understanding the specific feeding habits of these deer is the first step toward developing effective management strategies to protect valuable crops.
The Palatability of Cotton
Deer consume cotton plants, particularly when their preferred natural food sources become scarce. Deer are opportunistic feeders, and while cotton is not typically a favored browse, they will target it for its protein and water content. The most vulnerable parts of the cotton plant are the tender terminal buds and young seedlings, where the tissue is soft and easily digestible.
Cotton plants contain gossypol, a toxic yellow pigment, which can be harmful to monogastric animals; however, ruminants like white-tailed deer are less susceptible to its effects. Damage is most severe early in the season when young plants are establishing, or during periods of drought when other natural forage is low in quality.
Identifying Deer Damage
Confirming that deer are the source of damage requires careful field observation of the physical evidence. Deer lack upper incisor teeth, so they tear the plant material away, leaving a characteristic ragged, frayed edge on the remaining stems and leaves. This torn appearance contrasts sharply with the precise, clean cuts left by rabbits and other small rodents that possess sharp incisors.
Another sign is the height of the browse line, as deer can easily reach and damage foliage up to six feet from the ground, whereas rabbits primarily feed close to the soil surface. Growers can also look for secondary signs, such as large, oblong droppings or the distinct, heart-shaped impressions of cloven hooves in soft soil.
Effective Mitigation Strategies
Addressing deer consumption requires a combination of exclusion and deterrence methods to prevent them from establishing feeding patterns in the field.
Exclusion Methods
Exclusion is the most reliable method, typically involving the construction of high-tensile woven wire fences, which must be at least eight feet tall to prevent deer from jumping over. A less expensive, temporary option is the use of a baited electric fence, often constructed with highly visible polytape. This fence delivers a strong shock upon contact and teaches the deer to avoid the area.
Deterrence Techniques
Deterrence techniques work by making the cotton crop unpalatable or the environment unwelcoming. Chemical repellents, generally applied directly to the plants, include formulations based on putrescent whole egg solids, ammonium soaps, or organic fertilizers like Milorganite. Since deer can become accustomed to a single repellent, rotating between different types is recommended to maintain effectiveness. Growers can also employ scare devices, such as motion-activated lights or automated propane cannons. Cultural practices can involve planting a buffer or lure crop, such as sunn hemp or sesame, around the perimeter of the field to draw deer away from the more valuable cotton.