Pest and disease problem

Inspect plants daily for pests and diseases problems can build up rapidly in a confined space. Remember to look under leaves, where many glasshouse pests tend to congregate. 

Herbs are easy plants to grow, beautiful to look at and, in many cases, free from pest and disease problems. Growing them yourself means that you can have fresh supplies available when you need them, and using organic methods means you can be sure they have not been treated with pesticides. 

Herbs are often recommended to the novice gardener because most are tough, vigorous, reliable plants that have been passed down in cultivation for centuries easy to grow, they rarely suffer from pest and disease problems. All of these gualities make herbs ideal candidates for the organic garden. 

Fussy fruit The blueberry needs damp but not waterlogged soil with high organic matter levels and a soil pH between 4 and 5.5. On the positive side, it can grow well in containers, in "ericaceous" potting mix, and pest and disease problems are rare. 

Jerusalem artichoke has relatively few pest and disease problems in the field. The main production losses, which are usually modest, arise due to bacterial and fungal pathogens late in the... 

A unique plant on many levels, the distinctive properties of the Jerusalem artichoke (Helianthus tuberosus L.) present novel answers to some of today s most pressing problems. Jerusalem artichoke is potentially a major source of inulin, a fructose polymer that provides dietary health benefits as a prebiotic that promotes intestinal health and as a low-calorie carbohydrate to combat obesity and diabetes. Inulin also has myriad industrial applications, including ethanol production — making Jerusalem artichoke a potential source of biofuel. With its ready cultivation and minimal pest and disease problems, Jerusalem artichoke is an underutilized resource that possesses the potential to meet major health and energy challenges. 

Pests and disease problems on apple trees are covered in the Apple entry beginning on page 21. Crab apples share many of the same problems, including fire blight, cedar-apple rust, powdery mildew, and apple scab. Ibr-tunately, disease-resistant cultivars are available. Some of the best include Adams , with reddish pink flowers Coral Cascade , with white flowers Prarifire , with purplish red flowers and Professor Sprenger , with white flowers. There are also many other resistant cultivars, so check with your local nursery owner or extension agent to learn about the best ones for your area. 

Although winter wheat is grown on more land than any other crop in England and Wales, it is not usually grown continuously, because of problems from pests and diseases. Break crops are grown to interrupt the build-up of these problems, so we need to look at the behaviour of nitrogen under these and other crops, but much less information is available than for winter wheat. 

Field beans grow well on clay soils and heavy loams, provided they are well-drained and limed (pH above 6). Winter beans are not frost hardy and so are risky to grow, north of the Midlands. In some rotations, beans replace the clover break and they are usually followed by wheat. Yields for spring and winter field beans are shown in Table 5.4. The problem with field beans is their variable yield, which is partly caused by adverse weather conditions and susceptibility to pests and diseases (winter beans get chocolate spot, spring beans are aphid prone), and partly due to the uncertain activity of the necessary insect crosspollinators. 

Langer, V. (1995). Pests and diseases in organically grown vegetables in Denmark A survey of problems and use of control methods , Biological Agriculture and Horticulture, 12 (2) 151-171. 

The spread of problems and the carryover of pests and diseases between seasons can be prevented with good housekeeping practices. 

Keeping plants growing well is the best defense against pests and diseases. Potbound plants in overcrowded pots, watered erratically, will be more prone to pests such as red spider mite and aphids, especially in hot and dry locations such as a sheltered patio. Deal with any problem as it arises check plants regularly and pick off pests or diseased shoots or leaves as you notice them. Remove sickly and badly infested plants. 

Lettuce is the most pest- and disease-prone member of the Asteraceae. Common pests include slugs, cutworm, leaf aphids, and root aphids. Linder cover, downy mildew and gray mold (botrytis) can be a problem, especially in cool, damp conditions. Cultivars with resistance to aphids, downy mildew, and various physiological disorders are available. For more advice and information, see the A-Z of Plant Problems ipp.320-341). 

Healthy, well-grown plants are more resistant to pest and disease attack. Pest- and disease-resistant cultivars should be used where problems are known to exist. Pests attack vegetables above and below soil. They range from large animal pests such as rabbits, which cause general damage, to microscopic nematodes that... 

Rotation of plant famihes (closely related plants) is yet another means of reducing insect and disease problems. Famihes of plants tend to be susceptible to mai of the same insect, disease and nematode problems. By grouping vegetable plants into famihes and moving each family to a different loeation within the garden every year, mai r insect and disease problems can be reduced. Table 1 lists several vegetable groups which can be rotated to help reduce pest problems. 

All crop production, except protected cropping (for example, glasshouse, plastic covered), is vulnerable to the weather. Measures to combat frost and drought are common to most kinds of crop production wind protection (by shelter belts and so on) is practised for only a few crops (e.g. top fruit). In general, apart from choice of location, little can be done about solar radiation, rainfall or temperature. Problems with weeds, pests and diseases are also common to all crops but the remedies available to organic producers are much more limited than for conventional farmers. 

Organic standards vary across the world, from very strict to non-existent, but those in force in the European Union (EEC, 1991) list the substances that may or may not be used if food produce is to be sold with the label organic in the UK (other EU countries have equivalent terms, such as biologique, ecologique ). Where there are common standards, there are considerable similarities in the nature of the problems, although the species and incidence of weeds, pests and disease-producing organisms may be quite different in different countries. 

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