4. Organic vegetable production

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used, with reported excellent results. Some substances listed as permissible are not registered as veterinary treatments, and the Organic Industry Export Consultative Committee, which is responsible for approving changes to the National Standard for Organic and Biodynamic Produce, has been asked to explore the legality of using these unregistered substances. Alternative management practices aim to disrupt a parasite’s life cycle. Temperature and moisture favour the development of internal parasites, so after rainfall or irrigation livestock are moved to a clean pasture; alternatively, pastures can be harrowed following grazing to expose the eggs and larvae to sunlight and heat. The New Zealand Agroecology Program found pastures such as chicory and lucerne to be least conducive to parasite larvae intake. Resistance to internal parasites increases with age because immunity develops through previous exposure. Sheep reach a higher level of resistance at about nine months, whereas cattle reach this stage at about 18 months. Late pregnancy, lambing and weaning are critical periods for infection because resistance drops with increased stress and as feed intake increases, so it is critical to provide clean pasture at these times. Good nutrition and grazing rotations assist in developing and maintaining resistance. Grazing management is very important in managing parasites. Spelling paddocks can control worm populations, as can alternate grazing. This latter method can involve older, less susceptible stock grazing wormier pastures before young stock or having a higher number of less susceptible stock together with young stock. Another form of alternate grazing is to graze alternately with different species— for example, cattle before sheep because cross-infection does not occur to any great extent—or with different species together. This also offers benefits in terms of weeds: different grazing habits will prevent the domination of a particular weed species. Strip grazing involves back-fencing stock to match larvae development so that the stock do not contaminate their pasture. Most organic farmers prefer low stocking rates and relatively intensive rotations. Cultivation and intermediate cropping allow for a break in the build-up of insects, parasites and disease and therefore a clean pasture. Sowing mustard and ploughing it in as a green manure has been shown to clean a pasture (Belstead & Belstead 1992). In summary, maintaining good health and reducing the risk of parasites involves the following: • maintaining a high plane of nutrition and minimum stress • grazing management that reduces exposure to parasites • eliminating herd drenching and drenching individual stock only when infection is sighted—close observation is crucial here • after the system is established, culling of animals that show signs of heavy infestation. 2.3 Plant pest and disease management Organic systems are designed to re-create natural systems, which support several competing species, so that no single species has a consistent advantage. This is contrary to the main objective of modern agricultural systems, where the enterprise must maintain permanent control in order to be viable. Organic producers also believe that, by maintaining a vigorous and healthy crop through the adoption of sound cultural practices, plants are better able to withstand attack from pests and disease. Predicting potential problems and developing strategies to prevent the problems from occurring is the key to successful organic pest and disease management. Organic farmers take an ‘integrated pest and disease management’ approach. Such an approach is sometimes called ‘ecological pest management’ in the case of organic farming, to differentiate it from integrated pest and disease management in conventional farming, which includes the use of pesticides. Pesticides are generally not available to organic farmers, although some substances that are derived naturally are allowed for restricted use—for example, natural pyrethrum and Bacillus thuringiensis). In organic systems integrated pest and disease management makes use of a range of non-chemical techniques: • cultural controls such as crop rotation, cultivation and crop manipulation—for example, varying the crop spacing and the planting time—and crop hygiene • manipulation of species diversity—for example, increasing the number of plant Biological pest control is encouraged in organic systems. Predatory shield bug parasitises Heliothis caterpillar in a pigeon pea trap crop. Photo: R Neeson 10
species that act as a barrier to a pest or that provide an alternative (preferred) host • crop resistance or other physical attributes of the crop—such as spines or hairs—that deter pests • natural and biological controls— for example, encouraging the natural enemies (parasites, predators and disease organisms) of a pest species by providing a favourable habitat or food source • mechanical controls to trap or kill pests or physically prevent them from gaining access to crops • modification of the physical environment—for example, using light traps and sticky traps (to trap and monitor insect pests), laying down clear plastic to control weeds (solarisation), planting a crop such as canola that inhibits certain pest species (known as bio-fumigation), or planting antagonistic species (known as allelopathy) for weed control use of livestock—for example, using ducks and geese to reduce populations of snails and maintain hygiene by consuming crop refuse. 2.4 Weed management Economic weed control—without the assistance of synthetic herbicides—remains one of the most difficult aspects of successful organic production. A well-managed organic system should not develop a significant weed problem. A primary objective for organic farming is to change the composition of the weed community, so that the farming system gains maximum benefit. Sometimes, however, one weed species might dominate or a noxious weed (one that, by law, must be controlled) might be present and this situation must be managed. Whereas most conventional farmers see a weed as something that grows where it is not wanted, organic farmers see it as a sign that something in the farming system needs attention. Weeds are also seen as having an important ecological role: for example, some deep-rooted species will recycle nutrients from deep down in the soil profile, making them available to shallowrooted species. In order to develop an integrated strategy for suppressing weeds without using chemicals, organic farmers need to have a good understanding of weeds’ behaviour, their growth characteristics, and the conditions that favour their Organic farmers use a range of innovative techniques to manage weeds. Pictured is a tractor-mounted hot-air weed steamer. Photo: R Neeson. 11
Page 1 and 2: Going Organic Organic Vegetable Pro
Page 3: Going Organic Organic Vegetable Pro
Page 6 and 7: Contents Foreword v Executive summa
Page 8 and 9: 7. Regulatory considerations 87 7.1
Page 11 and 12: 1. Introduction to organic farming
Page 13 and 14: 1.2 Market potential for organic ve
Page 15 and 16: 2. Organic production principles: a
Page 17 and 18: Organic farming starts with the soi
Page 19: not result in loss of organic or bi
Page 23 and 24: Do I understand what organic means?
Page 25 and 26: management plan, the following ques
Page 27 and 28: No label is issued during the prece
Page 29 and 30: 4. Organic vegetable production 4.1
Page 31 and 32: 4.1.8 Monitoring performance Record
Page 33 and 34: can influence the occurrence and di
Page 35 and 36: The maintenance phase Research has
Page 37 and 38: Compost—a primary source of organ
Page 39 and 40: or crops rich in organic matter are
Page 41 and 42: anded in the crop row. The time of
Page 43 and 44: • Planning should aim to prevent
Page 45 and 46: herbicides. The certifier’s appro
Page 47 and 48: effective, so solarisation in narro
Page 49 and 50: The first step in an integrated pes
Page 51 and 52: Site selection Some sites will be m
Page 53 and 54: RIRDC Pub. No. 07/153; $15. mobile,
Page 55 and 56: lettuce varieties. Varieties can al
Page 57 and 58: Table 4.3 Indicative gross margin b
Page 59 and 60: 5. Organic vegetable case studies T
Page 61 and 62: The soil should be analysed for its
Page 63 and 64: An alternative cover cropping syste
Page 65 and 66: 5.2 Organic production of pumpkin I
Page 67 and 68: Powdery mildew first appears as whi
Page 69 and 70: 5.3 Organic production of processin
Page 71 and 72:
not growing your own) at least 6 mo
Page 73 and 74:
C.A., Multiple cropping systems, 19
Page 75 and 76:
Organically acceptable insecticides
Page 77 and 78:
Maintaining the proper balance of p
Page 79 and 80:
6. Post-harvest management and mark
Page 81 and 82:
Forces driving change in agricultur
Page 83 and 84:
communicate its expectations of qua
Page 85 and 86:
organisational structure, responsib
Page 87 and 88:
all those elements but, to gain org
Page 89 and 90:
Further processing (valueadding) As
Page 91 and 92:
year. Your participation not only g
Page 93 and 94:
field days, and so on. Select dates
Page 95 and 96:
are held throughout the world each
Page 97 and 98:
7. Regulatory considerations 7.1 Ex
Page 99 and 100:
All chemicals used for pest and dis
Page 101 and 102:
Appendices Appendix A Sources of in
Page 103 and 104:
• Department of Natural Resources
Page 105 and 106:
Phone: 03 5781 0033 Fax: 03 5781 00
Page 107 and 108:
Appendix B Farming inputs The follo
Page 109 and 110:
Plant disease control Substances Ay
Page 111 and 112:
Bibliography ABARE 2003, Australian
Page 113 and 114:
Hely, PC, Pasfield, G & Gellatley,
Page 115 and 116:
Pfeiffer, E 1983, Soil Fertility, R
Page 118:
Going Organic Organic Vegetable Pro
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4. Organic vegetable production

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