Vegetable Production Guide

Corn
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Other Pests

This section was updated - 16 January 2019

Slugs

These slow-moving, soft-bodied slimy, legless creatures are found in various sizes up to 10 cm. They eat holes in leaves and leave a trail of mucus.

Control

See Table 2, Corn Insect Control.

Bird Control

Bird damage to corn can occur to newly emerged seedlings or to the ripening crop.

Newly sprouted seedlings may be pulled up by Canada geese, sandhill cranes (Interior), ring-necked pheasants or crows. The most effective control measure, especially for geese and cranes, is the propane exploder. However, exploders (as well as scarecrows) may have little effect on crows.

Shooting, either to frighten or kill crows, is effective but may be time-consuming. Crows, unlike the other bird species mentioned, are not a protected species and may be killed without a permit.

Propane exploders come in both stationary models and rotating models, mounted on a tripod. The latter are better because their movement, added to the sound, makes them more frightening. Propane exploders can be set to go off at varying time intervals; a five-minute interval for single shot devices is recommended. An external timer can shut the exploder off automatically at night. One 9 kg tank of propane should last at least a week.

Moving the exploders every few days will increase their effectiveness. However, birds can get used to exploders over a period of days or weeks, especially if their feeding pattern is well established. If this happens, shooting may be necessary to scare the birds off. Ordinary live ammunition, aimed to frighten but not kill birds, can be used. Even more effective are 12 gauge cracker shells, which explode about 75 to 100 m away.

If you plan to frighten waterfowl or cranes by shooting, you must obtain a “scare permit” from your District Conservation Officer, (Ministry of Environment) or from the R.C.M.P. Local municipalities also have restrictions on the discharge of firearms. If waterfowl damage is especially severe or persistent, kill permits are sometimes issued by Conservation Officers.

Most damage to ripening corn is caused by blackbirds, especially red-winged blackbirds. Corn fields adjacent to large marsh or wetland areas are most vulnerable to damage because these areas serve as nesting and roosting areas for the birds. Propane exploders are also effective deterrents to blackbirds.

Rotating exploders mounted on a tripod will protect 10 to 20 ha of corn. For further information, consult BCAGRI Audible Bird Scare Devices information.

Bird Repellents 

To reduce feeding damage to ripening sweet corn caused by birds including blackbirds, blue jays, finches, robins, sparrows, starlings and wrens apply, before damage by birds beginsAvian Control (methyl anthranilate) at the rate of 2.4 L/ha (1 L/acre) in 200 to 1000 L/ha (80 to 400 L/acre) of water using groundspray equipment.  Use with a non-ionic surfactant at 0.06 to 0.25% v/v.  Repeat using a 6 to 8 day application interval.  Do not make more than 5 applications per year.  Do not apply when cobs are wet.    

 

 

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