Abstract Crops were grown in field plots under plastic-covered greenhouses for 3 years under ambient, charcoal-filtered, and charcoal-filtered with 2,4-D added atmospheres. No differences in market quality were found with green beans and raspberries. Deformed fruit in strawberries, uneven berry ripening in grapes, and blotchy ripening and deformed fruit in tomatoes occurred in “2,4-D added” treatment but not in “charcoal-filtered” treatment, while “ambient” was generally intermediate. The amount of 2,4–D in the atmosphere also influenced yields of grapes and strawberries.