PEST CONTROL
TIPS FOR ANDERSON SITE
Prepared by Fleurette Huneault, October 31, 2007
DEER
At Anderson in 2007, deer ate many vegetables that they didn’t eat in
the past, e.g. zucchini, squash and water melon, lettuce and
parsley. They of course ate all types of beans which seem to be
their preferred food.
I experimented with floating row covers on the beans. It kept the
deer away and was especially beneficial on climbing beans because I was
able to wrap the cloth around the tepees leaving the top open for light
penetration. It was also effective when applied as a fence around
fava beans, once again leaving the top open for light
penetration. It also prevented deer damage on bush beans however
those beans didn’t grow as well under the cloth and also I am told that
deer will walk/run across this cloth once they get used to its presence
if it is close to the ground. The deer didn’t touch the tomatoes,
potatoes, turnips, Brussels sprouts and parsnip.
GROUND HOGS AND RABBITS
To deter groundhogs and rabbits, I have successfully used a light
sprinkling of blood meal around the perimeter of the garden plot and
around the plants that are most susceptible to damage from these
pests. The product must be reapplied once a month or more often
if it rains. In trials this year, it did not deter racoons from eating
the corn.
INSECTS
This year the Anderson site was infested with Colorado Potato Beetles
and Striped Cucumber Beetles. There are several ways of
controlling these beetles organically.
Floating Row Covers
Not only are row covers effective in deterring animals such as deer,
ground hogs and rabbits, they are used extensively by organic growers
to control insects thereby reducing the need for insecticides.
Row covers are spun bonded polypropylene fabrics known by their
registered trade names e.g. Reemay, Agribon, Argyl P17, etc. They
allow air, light and water to pass through and come in various widths
and lengths. They also come in different weights: super-light,
light (floating), and heavy. Super-light cloth lets 95% of the
light through, light cloth lets 85% of the light through and heavy
weight cloth lets less than 50 % light through to the plant. All
weights form an effective insect barrier however the heavy gauges are
used mostly for frost protection at night because of the significant
reduction in light transmission.
Row covers can stop crop damage from Mexican bean beetles,
cabbageworms, cabbage maggots, carrot weevils, Colorado potato beetles,
cucumber beetles, flea beetles, leafhoppers, leafminers, squash bugs,
squash vine borers and other pests. For row covers to be
effective, crop rotation is important. Many insect pests and their eggs
over-winter in the soil to emerge in the spring and early summer.
If you plant the same crop in the same space for two successive years
the insects will emerge under the row cover and will quickly decimate
your crop. If you use row covers, remember to remove them from
plants that require pollination at least one week before the plants
bloom OR hand pollinate. Several websites are advertising the
sale of row covers. Prices and sizes vary. For example, one
site has super-light cloth measuring 8 ft x 20 ft for $8.95 and another
size 8 ft x 96 ft for 24.95.
Organic Pest Control
Because some pests have not been controlled for many years at the
Anderson site, the use of row covers in 2008 is strongly recommended
and the row covers may need to be supplemented with organic pest
control methods. Before applying pesticides, gardeners should be
aware that even organic pesticides can harm beneficial insects.
To properly control an insect pest it is therefore important to first
identify it and then target it with as little secondary damage as
possible.
Colorado Potato Beetle
The Colorado potato beetle attacks all plants in the Solanaceae family,
i.e. potatoes, tomatoes, eggplant and peppers. Cucumber beetles
attack all plants in the Cucurbitaceae family, i.e. cucumber, summer
squash, winter squash, pumpkins, gourds and melons. These plants make
up a large portion of our gardens and an effort should be made in 2008
to control these beetles. This beetle over-winters in the soil
and emerges in the spring to feed on young plants. Both the adult
and larvae chew leaves of all Solanaceae family plants and this can
greatly reduce the yield. The following organic methods can be
used to control this beetle.
- If the gardener goes to the plot regularly (every two to three days)
one of the best methods of control is to hand pick this beetle and
destroy it as well as its bright yellow coloured eggs which can be
found in clusters on the underside of leaves.
- Another effective control is to apply thick straw mulch. This
helps break the path used by larvae to go to the soil to pupate.
It also helps isolate the plant so that the insect cannot move as
easily from plant to plant.
- Floating row covers can be used until mid-season if plant rotation is
practiced. If these methods fail, the following organic
insecticides can be used in organic gardens.
- Pyrethrin is an effective control but be aware that this insecticide
will kill lady beetles.
- BTSD (Bacillus thuringiensis San Diego) BT is a microbial biological
control pesticide but it may infect butterfly larvae.
Striped Cucumber Beetle
This beetle attacks mostly plants in the Cucurbitaceae family but can
also feed on beans, corn and peas. It swarms on seedlings often
killing the plant. It also attacks stems and flowers of older
plants and eats holes in the fruit. It transmits wilt and mosaic
viruses. As well, the larvae feed on roots of squash family
plants killing or stunting the plants. Adults overwinter in the
soil emerging in April to early June. They lay their eggs in the
soil at the base of plants. The following organic methods can be
used to control this beetle.
- Row covers should be the first line of defence but for this to be
effective, rotation planting must be practiced. If you do use row
covers, the Cucurbitaceae family plants will have to be hand
pollinated. Or remove the cloth one week before the plants bloom
and control by spraying the beetles with Pyrethrin when it is seen
feeding on pollen in flowers. Pyrethrin will not kill bees.
- Apply thick straw mulch around the base of the plants to prevent the
beetles from moving from plant to plant. This helps to isolate
the pest.