Chemical and alternate pest control in the garden

article by: M Juckers, Tropics Kwekery, Simon Vermoootenway, Pretoria (translated)

Plants are healthy when they are able to accomplish all their normal physiological functions to the best of their abilities. Therefore garden plants have to be checked regularly for any damage by insects or disease (bacteria or fungi). The presence of insects does not necessarily mean you have to reach for your insecticide. In the homegarden, only a few insects, fungi and bacteria can be counted as pests, with the majority being natural inhabitants of the plants and your garden. Insecticides have the negative affect that they kill these natural inhabitants, as well as disrupting the ecological balance. The residual impact op the insecticide, the formula and the time of application all play a large role here.

The gardener has to apply preventive measures, whereby the occurence of infestations and disease, and so the use of chemical agents, can be minimised.
The next few points need to be taken into account:

• Plant healthy seeds and plants only
• Plants need to be spaced in such a way that they do not have to vie for space, a situation which creates an ideal microclimate for disease-causing fungi and bacteria. Plants that are planted too close together also have to compete for the same food and water. When this happens plants often injure each other, causing wounds which offer an ideal opportunity for disease-causing organisms. Irrigation must occur in the early morning, as opposed to the evening, since long wet periods, especially during the evening, may lead to rootrot.
• If the water does not drain away fast enough, the ground texture must be improved through the use of compost.
• Remove any weeds that may act as hosts for pests. Also remove any infected branches, plants and fruit.
• Pruning - Always seal the pruning scars with a woundsealer or lime. Disinfect the pruning shears with a household disinfectant and rinse, to prevent spreading pests or diseases between plants in this way.
• The ground has to be carefully prepared before planting. Use compost to improve ground texture and fertiliser to establish healthy plants. During the growing season, fertilisation should occur every six weeks.

• Plantlice and aphids can be removed using a strong jet of water (soapwater sometimes works easier)
• Larvae, snails and beetles can be removed by hand
• Mildew on plants (eg Roses and grapes) can be prevented by spraying the plants with baking soda on a regular basis.
• Rather use agents that use copper and sulphur, which aren't poisonous to birds and non-harmful organisms. Repeat application every 10 to 14 days for effective control.
• Follow instructions on the instruction leaflet that come with any agents you buy carefully. Overdoses can lead to burning and later death of plants

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