Plan to graze corn stalks or bean stubble? How about feeding some weedy seedling alfalfa hay? If any of these feed resources has black nightshade, be careful, it might be toxic.

Terry Gompert, UNL Extension educator in Knox County, says that black nightshade is common in many corn and bean fields as well as in new alfalfa. It usually isn't a problem, but if the population gets high it can poison livestock grazing the plant or consuming hay with nightshade in it. Almost all livestock, including cattle, sheep, swine, horses, and poultry are susceptible.

All plant parts contain some of the poison and the concentration increases as plants mature, except in the berries. Drying as hay or after a freeze will not reduce the toxicity and neither will fermenting it as silage, Gompert says.

It's very difficult to determine how much black nightshade is risky. Guidelines say that a 1,000-pound animal that eats 1 to 3 pounds of fresh black nightshade is at risk of being poisoned.

How will you know if your animals will eat that much? In a stalk or stubble field, a few green plants of nightshade might be very tempting to a grazing animal, especially if there is little grain to select. In hay, the nightshade may be sparse through most of the field but in a few areas it could be quite thick. Animals offered hay from those thick areas could be at risk.

Common sense and good observation must be your guide, according to Gompert. If cattle selectively graze green plants in stalk or stubble fields, pull them out and wait for a hard freeze before trying again. Keep track of bales from heavily infested areas. Either don't feed these bales or grind and mix them with other feeds to dilute the problem. If still unsure, expose only a few animals at a time to risky feed.