Pickett Apple Orchard Improvement Pesticide Plan

Pickett’s modified spray program in Nova Scotia’s apple orchards offered a practical alternative to the cycle of increasingly intensive chemical treatment: it used natural controls wherever possible, applied the minimum effective doses at carefully chosen times, and sought to spare beneficial insects. The results were as good as those of intensive spraying, at substantially lower cost, and with less disturbance to the orchard’s ecological relationships.

Origins in a recurring failure

Dr. Pickett began his work some thirty-five years before the account in the apple orchards of the Annapolis Valley, Nova Scotia, then one of Canada’s most concentrated fruit-growing areas. The prevailing belief was that insecticides would solve the problem of insect control if fruit growers could simply be persuaded to follow recommended methods. At first these were inorganic chemicals; when insects persisted, new chemicals and improved spraying equipment were introduced, and the zeal for spraying increased. Yet the problem did not improve.

DDT seemed to promise an end to codling moth outbreaks, but its use brought an unprecedented scourge of mites instead. In this history, control did not eliminate difficulty so much as shift it: one pest crisis gave way to another. Pickett described the pattern as moving from crisis to crisis, trading one problem for the next. Rather than follow other entomologists in pursuit of ever more toxic chemicals, he and his associates chose a different course.

Working with natural controls

The program treated nature as an ally in pest control. Its governing principle was to make maximum use of natural controls and minimum use of insecticides. When chemicals were necessary, the objective was to use only enough to control the pest, while avoiding needless harm to beneficial species. The method therefore depended not only on which material was applied, but also on when it was used.

Timing could protect an important predator. Nicotine sulphate applied before the apple blossoms turned pink spared one such predator, probably because it was then still in the egg stage. The example shows how the program’s selectivity rested on attention to insect life cycles: a treatment aimed at a pest could be scheduled so that a beneficial species was less exposed.

Pickett also chose chemicals with care, favoring those that would do as little harm as possible to insect parasites and predators. He warned against making DDT, parathion, chlordane, and other new insecticides routine measures in the same way inorganic chemicals had been used. Such reliance, he argued, would leave entomologists interested in biological control with little purpose. In place of broad-spectrum insecticides, the program relied chiefly on ryania, derived from the ground stems of a tropical plant, nicotine sulphate, and lead arsenate.

Restricted use of stronger chemicals

The modified program did not rule out every modern insecticide. In particular situations it used very weak concentrations of DDT or malathion: one or two ounces per 100 gallons, rather than the usual one or two pounds per 100 gallons. Even these materials were treated as limited tools, not routine foundations of control. Although the account describes DDT and malathion as the least toxic of the modern insecticides, Pickett hoped further research would allow them to be replaced by safer and more selective materials.

This qualification matters to the program’s design. Its alternative to intensive spraying was not an absolute claim that orchards could never require chemical treatment. It was a change in priorities: preserve natural regulation where possible, minimize chemical use where it was not, and keep searching for materials that would do less collateral harm. The method’s restraint was built into its dosage, timing, and choice of treatment.

Results and significance

Nova Scotia orchardists following the modified spray program produced as high a proportion of first-grade fruit as growers using intensive chemical applications, and achieved equally good production. They did so at substantially lower cost: insecticide expenditure in the Nova Scotia orchards was only 10 to 20 percent of that in most other apple-growing areas. The comparison made the approach more than a theoretical appeal to ecological balance; it demonstrated that reduced spraying could meet commercial standards while spending far less on insecticides.

The account places the program among the few American examples comparable to integrated control work by some California entomologists, while emphasizing its development in Nova Scotia. Its wider importance lay in showing that pest management need not depend on escalating chemical force. The orchardists’ results supported a different understanding of control: natural populations and their relationships could limit organisms economically, sometimes more effectively than direct human intervention. The program was presented as a step toward changing the assumption of human superiority over natural environments and toward managing crops without doing violence to nature’s balance.