Abstract :
From the outset, a bottom-up, ecologically based approach to apple pest management was applied to a small commercial apple orchard in Conway, MA (USA). This approach was maintained throughout the first 20 years (1981–2000) of commercial production. It consisted of maximizing genetic-based resistance to pests through the planting of cultivars resistant to apple scab, designing the orchard and managing the surrounding habitat so as to be minimally conducive to influx of pests and maximally conducive to influx of natural enemies of pests, using behavioral and cultural pest management techniques where appropriate, and minimizing the use of pesticides. No insect pest caused damage to fruit that was greater in the fourth quartile of orchard operation (1996–2000) than in a preceding quartile, indicating no buildup of any damaging fruit insect pest across 20 years of essentially unvarying insect management tactics. Original management of surrounding habitat proved insufficient, however, for sustained suppression of pathogens causing summer diseases of apples. These built to unacceptable levels during the second quartile, were partially suppressed through additional habitat management during the third quartile, and were effectively suppressed using fungicide during the fourth quartile. During the fourth quartile, fruit of Conway orchard trees (which received two annual insecticide and two annual fungicide sprays) averaged 92% clean (free of any pest injury) compared with 0% clean fruit on unmanaged apple trees 200–250 m away from the orchard and 86% clean fruit on trees in large commercial apple orchards in Massachusetts that employed basic integrated pest management practices and annually received seven insecticide and nine fungicide sprays. No foliar pest of Conway orchard trees ever reached a threshold level requiring intervention with pesticide. Combined findings demonstrate long-term durability of a bottom-up, ecologically based approach to apple pest management suitable for small commercial orchards in northeastern North America.
