IN YOUR GARDEN
Question: What pests should I be on the lookout for in my summer vegie gardens, and how can I combat them? Answer: As the days start to get longer, the daytime temperatures heat up and the humidity increases, and so too do some pests and diseases in our
Of course, the most common pest of your fruiting vegies in summer is the Queensland fruit fly. It is the larvae or maggots of this pest that cause the damage, but to control them we need to reduce the population of the adults. The adult flies appear reddish brown with yellow markings, are approximately 7mm long, and lay their eggs into the fruit such as tomatoes.
To control them I have found the simplest way is to set up a trap. Fruit fly traps can be purchased commercially, but you can make one yourself. Take an empty two litre plastic soft drink bottle, wash it out thoroughly, and make a hole in the side of the bottle half way up (large enough for a fruit fly to crawl into).
Make up a mixture of three tablespoons of Vegemite with warm water, and a drop of dishwashing liquid. Pour this mixture into the bottle, replace the lid, and tie this trap with string to something close to your affected plants. You will need to empty the contents every week and replace it, but this is a cheap and easy way to reduce the population of these pests. For the best results you need to place these traps every two metres if you have a large vegie patch.
Powdery mildew is a cosmopolitan fungus that can attack a wide range of vegetables. The symptoms vary from plant to plant, however, commonly appear firstly as faint white spots on the leaves of your vegies. These spots gradually increase in size as the weather conditions become more favourable, and especially if you overhead water your vegies. Eventually the whole leaf will be covered in a white powder, and the buds, fruit and stems can also be affected.
Controls include reducing overhead watering and splash from sprinklers, thinning out plants to increase air flow, and of course
you can apply a chemical such as a fungicide. There are two main types of fungicides: pre-infection or protectant (e.g. Mancozeb), and post infection or eradicant types of fungicides (e.g. Rovral).
Don’t forget that when using any chemical ensure you wear all the appropriate PPE, especially when mixing, and always follow the manufacturer’s directions in relation to rates to be applied and when to apply each chemical. This way you will always get the best results and stay safe.
Another pest you may find in your vegie patch is the bean fly. These are glossy black flies around 2-3mm long. The adults lay their eggs on the leaves of bean plants, and the symptoms appear as small yellow spots. The larvae or grubs cause the damage by tunnelling into the main stem and leaf stalks and therefore are hard to see on the leaf surface. The stems and stalks will become swollen and cracked and may appear reddish in colour. If the plants attacked are very young they will wilt easily and fall over.
In older plants the parts infected will drop off easily. Overall you will notice a drop in your crop yield and quality of the beans.
Planting broad beans is one way of reducing the incidence of this pest as they are less affected than other varieties of beans.
Reducing the weeds around your vegie garden can also assist in reducing the incidence of this pest, especially the legume type weeds. Also you can use chemicals such as Rogor, however as said before, make sure to follow the manufacturer’s directions and always wear your PPE.
Being vigilant in your garden and monitoring any problems early at this time of year will ensure you have a bumper harvest throughout the summer months.
For more information about TAFE Queensland South West’s horticulture and landscaping offerings or for any other courses, please visit www.tafesouthwest.edu.au or call 1300 914 754.
Disclaimer: The comments provided in this article are general in nature only and are not a substitute for professional advice. The author accepts no responsibility for any action taken by a reader in relation to this article.
GROW: Horticulture teacher Darren Davidson (TAFE Queensland South West) is just one of the dedicated trainers ready to help you make great things grow.