PESTS AND DISEASES OF FRUIT

Most gardeners want to harvest good crops relatively free of pests and diseases, grown in a safe, environmentally sustainable manner. This article recommends only low toxicity environmentally friendly products, both synthetic and natural, and guides the home gardener to methods of pest and disease control that best suit their needs considering

1.   good yields, relatively free of pests and diseases

2.   using best garden practices to minimise pests and diseases

3.   using only safe environmentally friendly products

4.  using products that are commonly available in home garden size packs and are legally registered and approved.

 Minimising pest & diseases

Using good basic gardening practices to minimise pests and diseases is common to all gardeners whether conventional or organic. In simple terms, providing the best growing conditions to ensure a strong healthy crop. The following are the simple basics:

·       in clay soils raise the planting area above the surrounding soil to ensure good drainage.

·       add lots of compost and work into the soil.

·       grow fruits suitable to the area and choose disease resistant varieties.

·       provide adequate balanced feeding—we recommend ican Slow Food as a base fertiliser when planting.

·       water in dry periods, but avoid overhead watering

·       practice good garden hygiene by removing all diseased leaves and plants.

‍Using disease resistant varieties

Whilst a few ‘Heritage’ varieties may have disease resistance, modern varieties are more likely to be better. Using disease resistant varieties will ensure better crops, greatly minimising the need to use fungicides. Modern varieties are also likely to yield more and taste better. This is especially true of apples.

 Using pesticides

If good gardening practices are followed and disease resistant varieties used, use of pesticides can be minimised. There are a range of very low toxicity, environmentally friendly pesticides available to home gardeners.

‍Synthetic Pesticides - enviro-friendly garden pesticides are Mavrik, Success Ultra, Fungus Fighter.

Natural Organic Pesticides - some natural organic pesticides are very safe e.g. Enspray 99, FreeFlo Copper, BioNeem—all BioGro certified organic from Grosafe.

 Some natural pesticides are more toxic than synthetic pesticides e.g. some Neem products, Derris Dust, Pyrethrum. Only use pesticides registered with MPI under the Agricultural Compounds and Veterinary Medicines (ACVM) Act 1997

 Prevention is better than cure

Once you have gained experience and are aware of what pests and diseases attack which crops, you will be able to anticipate, and spray at the first sign, which is more effective, and minimises pesticide use.

Black spot, brown rot and codling moth are three good examples of where early treatment at first sign is effective, but if left until the problem builds up, pesticide use becomes ineffective.

 What to use

 1.   Birds and animals - the only effective measure is to cover with netting.

2.   Insects
      Yates Mavrik is a very environmentally friendly product, and safe to bees. It controls many insects commonly found on fruits and is registered for such use. It is        generally used early in fruit development and the life cycle of insects to maximise effectiveness and minimise residues.

      Yates Success Ultra is an environmentally friendly product (an extract from a soil bacteria). Controls caterpillars, leaf roller and codling moth.  

      Grosafe Enspray 99 a natural mineral oil, BioGro certified organic, which kills small soft insects such as aphids, white fly, thrips, mealy bugs, mites, scale and       insect eggs, by smothering. High quality oil which can be used on all plants.

      Gosafe BioNeem is a broad-spectrum insecticide derived from the neem tree. It effectively controls the economically important pests such as whitefly, aphids,       thrips, mealy bugs, leaf-mining flies and scale in a wide range of crops. It is usually safe to beneficial insects when applied correctly. BioGro certified organic.

The withholding period between spraying and harvest varies between fruits, so check the label.  For control of insects close to or during harvest, use Grosafe Enspray 99. Add Success Ultra if caterpillars are present.

3.   Diseases - spots, mildews, and rots.

       Yates Fungus Fighter is the only registered fungicide for black spot and powdery mildew in apples. Also effective for brown rot of stone fruit.

       Grosafe FreeFlo Copper Fruit & Vegies is an ultra-fine copper spray effective for a number of diseases. Very effective as a clean-up and preventative spray in winter        and early spring. BioGro certified organic.

Common pests and diseases of stone fruit (apricots, cherries, peaches, nectarines, plums)

• Pests - aphids, cherry pear slug, leaf roller caterpillar, Oriental fruit moth, scale insects, thrips
• Diseases - brown rot, leaf curl, bladder plum, shot hole, rust

‍

Common pests and diseases of pip fruit (apples, pears, quinces, nashi)

• Pests - aphids, cherry pear slug, codling moth, leaf roller caterpillar, mealy bug, mites and blister mites, scale insects
• Diseases - black spot, European canker, powdery mildew

‍

Common pests and diseases of citrus (lemons, limes, mandarins, oranges, tangelos, grapefruit)

• Pests - aphids, leaf roller caterpillar, mealy bug, mites, scale insects, whitefly, thrips, lemon tree borer
• Diseases - brown rot, blue-green mould, verrucosis

‍

Common pests and diseases of brambles (raspberries, blackberries, boysenberries)

• Pests - raspberry bud moth, passion vine hopper, soft rose scale, leaf roller caterpillar
• Diseases - dryberry (downy mildew), botrytis (grey mould)

‍

Common pests and diseases of blueberries, feijoas, grapes, passionfruit, strawberries

• Pests - aphids, passion vine hopper, leaf roller caterpillar, mealy bug, mites, scale insects, thrips, grass grub beetles
• Diseases - downy mildew, botrytis (grey mould), leaf spots, powdery mildew

‍

For comprehensive information, identification and advice, refer to 'Garden Pest & Disease Control' by Bill Brett.