Excellent black nightshade (Solanum nigrum L.), control is achieved with Staple, pyrithiobac sodium, when applied over the top of cotton in the one leaf stage with nightshade in the cotyledon to three leaf stage. Nightshade control ranged from 93 to 100 percent 50 days after application. There were no differences between broadcast and band applications. Cotton injury symptoms were evident with all treatments seven days after application, but nonexistent 50 days after treatment.

Staple adversely effected growth, development and yield of all rotational crops tested (barley, wheat, alfalfa, onions, sugar beets, tomatoes and corn). In general, reductions increased with increasing Staple rates and were greatest with broadcast treatments when compared to band treatments. Barley was more sensitive than wheat. Tomatoes and corn were more tolerant than most crops with onions and sugar beets being the most sensitive. There was no effect to cotton growth and development. When the same crops were planted two years after the initial Staple application, there were no adverse effects on growth, development and yield of all crops studied except onions and sugar beets.