In certain cases, eastern black nightshade contaminates the harvested crop resulting in either a lower market value or perhaps rejection. For example, nightshade fruits harvested with peas, snap beans and soybeans are impossible to remove mechanically from the harvested crop. Ripe fruits are often crushed during harvest which stain the crop seed. Green and ripe fruits contain a sticky, saponin-rich juice that adheres to harvest equipment and increases the likelihood of plugging the machine as dust and plant debris coat the internal parts. This juice also coats soybean seed, allowing foreign matter to stick to it, thereby increasing the grain moisture content.
Poisonous plants are among the important causes of economic loss to the livestock industry.
In addition to these obvious losses, poisonous plants can also result in loss of forage, increased labor and management costs, and frequently, interference with proper harvesting of forage. In most cases, animals are affected only when they consume too much of the poisonous plant. It is important to note that definitive diagnosis of suspect plant poisonings is difficult. In general, diagnosis of plant poisoning is based on availability, grazing evidence, presence in the hay and existence of plant parts in the rumen contents. Diagnostic lesions are usually lacking and analytic methods to identify toxic components are severely limited.