Before she began turning out best-sellers under the pen name Anne Frasier, Theresa Weir was an apple farmer's wife in Illinois, and her memoir about those years is equal parts moving love story and environmental warning. Weir was 21, her artistic dreams crumbling, when she found herself tending bar in her uncle's joint ''smack dab in the middle of bleak.'' After falling for Adrian, a handsome farmer whose local roots ran as deep as the century-old apple trees on his family's large spread, the two married. But the ominous soundtrack to their happy life was the drone of pesticide sprayers. The Orchard is ultimately Weir's disquieting cri de coeur about the consequences of dousing the food we eat with chemicals — and once you read it, you might never buy anything but organic again. B+