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Providing evidence to improve practice

Individual study: Integrated systems for managing potatoes in the Northeast

Published source details

Leach S.S., Fry W.E., Jones R.T., Loria R., Storch R.H., Sweet R.D., Tette J.P., White G.B. & Wright R.J. (1986) Integrated systems for managing potatoes in the Northeast. Technical Bulletin, Agricultural Experiment Station, University of Maine

This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Use pesticides only when pests or crop damage reach threshold levels Natural Pest Control

A study in 1982-1983 in arable land on Long Island, New York, USA (Leach et al. 1986) found potato Solanum tuberosum damage was similar for growers who sprayed insecticide according to threshold-based recommendations and growers who did not. Growers using a threshold-based spraying regime used an average of 1.4-2.6 fewer sprays/year for controlling Colorado potato beetle Leptinotarsa decemlineata and 0.4 fewer sprays/year for controlling aphids (Aphidoidea), compared to growers not using the regime. The threshold-based regime saved US$70-130/ha on Colorado potato beetle control and US$12/ha on aphid control. The trial included 30 growers, who were classified as having followed the recommendations if their practice matched recommendations 60% of the time. This included spraying within 72 hours of a recommendation to spray, and not spraying when not recommended. Growers used a variety of recommended insecticides including aldicarb, disulfoton, phosmet, fenvalerate, parathion and methamidophos. Effects on natural enemies were not presented.

Use crop rotation in potato farming systems Natural Pest Control

A paired sites study in 1982-1983 on Long Island, New York, USA (Leach et al. 1986) found that potatoes Solanum tuberosum in fields that had been rotated to barley Hordeum vulgare the previous season had 1.6 times more pest lesion nematodes Pratylenchus spp. per gram of root as fields that had grown potatoes in both seasons (395 nematodes/g potato root vs. 251 for non-rotated fields). Nematode soil populations were 1.4 times higher in rotated fields (376 nematodes/100 cm³ vs. 274 for unrotated fields). Data from the same experiment on Colorado potato beetle Leptinotarsa decemlineata numbers is described in Wright (1984). The experiment used pairs of rotated and non-rotated fields on four farms in 1982 and five in 1983. Fields averaged 8 ha in size and were up to 2 km apart.