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[[image:Food3.jpg|thumb|right|200px|Snails: a common pest]]
Part 4: Crop protection
Part 4: Crop protection


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* D. Weeds
* D. Weeds
These compete with the crop for water, nutrients, light and space.
These compete with the crop for water, nutrients, light and space.
Note that bacteria are usually a secundairy corruption (eg after a fungi attack) or with wounds (weakened plants)
virusses work through direct contact, they can not survive long without the host, several species, eg persistent species remain in the host, also if transferred


==A. Non-animal parasitic organisms==
==A. Non-animal parasitic organisms==
===Fungi===
===Fungi===
Fungi are categorised to the lower plants. They contain no chlorophyll and are dependent for their nutrition on dead and living organic matter. They consist of microscopic filaments (hyphae) which are sometimes packed together as a visible tissue (mycelium). Molds propogate mainly trough spores, which are very fine spheres that are dispersed by wind, water and also by animals. With sufficient moisture and warmth, the fungi develop rapidly. The damage that fungi cause is of major economic importance. We currently know some 3000 harmful fungi.
Fungi are an entirely separate group to plants, and, despite appearances, are in fact more closely related to animals. They contain no chlorophyll and are dependent for their nutrition on dead and living organic matter. They consist of microscopic filaments (hyphae) which are sometimes packed together as a visible tissue (mycelium). Molds propogate mainly through spores, which are very fine spheres that are dispersed by wind, water and also by animals. With sufficient moisture and warmth, the fungi develop rapidly. The damage that fungi cause is of major economic importance. We currently know some 3000 harmful fungi.
 
They usually have a full lifecycle on the course of a few days
Conditions: hot and moist weather
Weeds can be a host for fungi.


Commonly appearing on plants:
Commonly appearing on plants:
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====Botrytis====
====Botrytis====
This fungus manifests itself from the soil at humid weather and first targets the dying plant parts of a crop. Then it goes on to healthy plant parts. These will discolorate, and after this, they will exhibit a gray mold fluff, full of fresh spores for a new spreading.
This fungus manifests itself from the soil at humid weather and first targets the dying plant parts of a crop. The parasite also targets wounds, it is mostly saprofytic, note that wounds can also be cause by a heavy impact of rain (cellular damage). Then it goes on to healthy plant parts. These will discolorate, and after this, they will exhibit a gray mold fluff, full of fresh spores for a new spreading.


====Mildew====
====Mildew====
With "[http://en.wikipedia.org/wiki/Mildew Mildew]", 2 diseases are meant: powdery mildew and downy mildew. Powdery mildew usually appears around the middle of July as woolly spots on top of the leaves. Moments later they are covered with a flour-like layer. The fungus draws moisture from the leaf cells, which makes the leaf discolor brownish and makes it dry-out. With the downy mildew, the symptoms are pale-yellow discolored spots on top of the leaf and white, powdery fungal fluff at the bottom. The leaves discolorate brown afterwards.
With "[http://en.wikipedia.org/wiki/Mildew Mildew]", 2 diseases are meant: powdery mildew and downy mildew. Powdery mildew usually appears around the middle of July as woolly spots on top of the leaves. Moments later they are covered with a flour-like layer. The fungus draws moisture from the leaf cells, which makes the leaf discolor brownish and makes it dry-out. With the downy mildew, the symptoms are pale-yellow discolored spots on top of the leaf and white, powdery fungal fluff at the bottom. The leaves discolorate brown afterwards. Powdery_mildew occurs on dry, hot weather, the wooly fluff is everywhere, including the bottom of the leaf. Downy_mildew occurs with wet, hot weather


Prevention
Prevention
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===Nematodes===
===Nematodes===
Nematodes are always present in the soil. The colorless worms are less than 1 mm wide, and are not visible with the naked eye. Most species are decomposers of organic matter, only a few parasite on living plants and sucking their cells empty. The cyst-forming nematodes put their eggs in the soil in cysts (hard spheres filled with eggs, are observable with the naked eye). These cysts can survive years in the soil and awaken when a same vegetable species or a related one is grown. Such a nematode population can cause that a lot or a place fails, seemingly without any reason. We speak of soil fatigue. Infestation by nematodes is promoted by growing a same crop frequently in the same place, this is why we always apply a wide crop rotation. As a defense we can grow Tagetes (marigold). These plants secrete substances through their roots with a nematode-killing property and they are easy to use as a border planting or pre-cultivation.
Nematodes are always present in the soil. The colorless worms are less than 1 mm wide, and are not visible with the naked eye. Most species are decomposers of organic matter, only a few parasite on living plants and sucking their cells empty. The cyst-forming nematodes put their eggs in the soil in cysts (hard spheres filled with eggs, are observable with the naked eye). These cysts can survive years in the soil and awaken when a same vegetable species or a related one is grown. Such a nematode population can cause that a lot or a place fails, seemingly without any reason. We speak of soil fatigue. Infestation by nematodes is promoted by growing a same crop frequently in the same place, this is why we always apply a wide crop rotation. As a defense we can grow Tagetes (marigold). These plants secrete substances through their roots with a nematode-killing property and they are easy to use as a border planting or pre-cultivation.
====Eals====
[[Image:Agriculture manual_1_2_6_image_6.JPG|thumb|right|200px|Schematic of eal]]
Eals are a type of nematode. Eals exist in 2 varieties: parisitic and saprofytic (good-type) eals
Several eals: some live in the roots, near the roots, cyste-eals (latter can survive for 5-10 years in the soil)
Eals are the greatest cause of "soil fatigue". If [[crop rotation]] is used, this pest can be avoided.


===Insects===
===Insects===
Insects belong to the arthropods. Insects have 3 pairs of legs and are usually winged. During their lifetimes, most insects undergo a transformation or a metamorphosis. This can happen through the phase of [http://en.wikipedia.org/wiki/Nymph_%28biology%29 nymph], where the young larvae already looks similar to the adult insect, but does not have wings yet (aphids, locusts, thrips). With a full metamorphosis the larvae does not yet look similar to the mature insect and a transition first occurs through the [http://en.wikipedia.org/wiki/Pupa pupal stage], often at a hidden place in a self-spun cocoon (moth, beetle). 70% of all known species, are insects, they have a hard skeleton, reproduce quickly and adapt to most environments. Many of these insects have specialized themselves in living on certain crops. With monocultures on large plots this may result in extensive pests. There are some insects that occur on various crops.
Insects belong to the arthropods. Insects have 3 pairs of legs and are usually winged. They usually also have antennas. During their lifetimes, most insects undergo a transformation or a metamorphosis. This can happen through the phase of [http://en.wikipedia.org/wiki/Nymph_%28biology%29 nymph], where the young larvae already looks similar to the adult insect, but does not have wings yet (aphids, locusts, thrips). With a full metamorphosis the larvae does not yet look similar to the mature insect and a transition first occurs through the [http://en.wikipedia.org/wiki/Pupa pupal stage], often at a hidden place in a self-spun cocoon (moth, beetle). 70% of all known species, are insects, they have a hard skeleton, reproduce quickly and adapt to most environments. Many of these insects have specialized themselves in living on certain crops. With monocultures on large plots this may result in extensive pests. There are some insects that occur on various crops.
 
2 types exist:
* with incomplete metamorphose (egg -nymphe-insect)
* with complete metamorphose (egg-larva-cocoon-nymph-insect)
The difference is that a nymphe looks like the insect, whereas a larva does not look like the insect (eg butterfly)
 
mites:generate honeydew -->formation of fungi can occur hereon
 
dry weather: mite
wet weather: fungi
daily checkups need to be done for both


===Aphids===
===Aphids===
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* The use of natural enemies such as Coccinellidae, parasitic wasps and Cecidomyiidae in greenhouses
* The use of natural enemies such as Coccinellidae, parasitic wasps and Cecidomyiidae in greenhouses


===[http://en.wikipedia.org/wiki/Leaf_beetle Leaf beetles]===
===Beetles===
Beetles usually disappear after a certain period of time
 
====[http://en.wikipedia.org/wiki/Leaf_beetle Leaf beetles]====
These are small (3 mm) beetles with long back legs that can jump high. They are best recognized by their metallic sheen. They eat out holes in the lower leaves of germinating plants. They are especially active in dry, crusty soils with cool and dry weather. One can expel them by pouring cold water over the plants during full sun. To catch them, one can use a glue board. A shelf is foreseen at the bottom with glue or wood tar. In the middle we place soft bristles that are bristled over the crop. The beetles will jump up and get stuck in the glue.
These are small (3 mm) beetles with long back legs that can jump high. They are best recognized by their metallic sheen. They eat out holes in the lower leaves of germinating plants. They are especially active in dry, crusty soils with cool and dry weather. One can expel them by pouring cold water over the plants during full sun. To catch them, one can use a glue board. A shelf is foreseen at the bottom with glue or wood tar. In the middle we place soft bristles that are bristled over the crop. The beetles will jump up and get stuck in the glue.


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===[http://en.wikipedia.org/wiki/Wireworm Wireworms]===
===[http://en.wikipedia.org/wiki/Wireworm Wireworms]===
These are copper colored, worm-shaped larvae of the skipjack. They are a typically a problem occuring on newly cleared land. They stay 3 to 5 years under the soilsurface and to grow up to 2 cm large. They mainly eat half decomposed vegetable matter and have a preference for root and tuber crops. They eat the plants roots and drill into the stems, the plants wither from this. Prevention can be done by keeping the soil free of weeds. Wireworms can be caught by cutting a potato in half and digging it in 5 cm deep into the soil with the cut part facing downwards.
These are copper colored, worm-shaped larvae of the skipjack. They are a typically a problem occuring on newly cleared land, and often occur with tuberous crops. They stay 3 to 5 years under the soilsurface and to grow up to 2 cm large. They mainly eat half decomposed vegetable matter and have a preference for root and tuber crops. They eat the plants roots and drill into the stems, the plants wither from this. Prevention can be done by keeping the soil free of weeds. Wireworms can be caught by cutting a potato in half and digging it in 5 cm deep into the soil with the cut part facing downwards.


===[http://en.wikipedia.org/wiki/Cutworm Cutworms]===
===[http://en.wikipedia.org/wiki/Cutworm Cutworms]===
This is the larva of a brown moth (Agrotis segetum, Agrotis ipsilon, Agrotis exclamationis). They are about 4 cm large. In peace or a danger to roll them in a spiral. They like warm, dry soils and light soils where they Eich daytime hiding. At night they go to raid also above the ground and eat young shoots off precisely at the separation of land and air. Prevention can occur through weeds and green already working in the winter. Since the larvae do not keep the moisture first weeks after planting enough casting. A good vehicle is a bait worms based on 25% of hardwood sawdust, wheat bran 25%, 50% syrup or molasses and water to this mix. Caterpillars come out, and remain the stuff hanging. Morning delivery as they are on the ground. At temperatures above 15 ° C can also work with Bacillus thuringiensis. The evening administration, the effect was only visible after a few days. Caterpillars have a hate sage, by this herb to be planted, they expelled.
This is the larva of a brown moth (Agrotis segetum, Agrotis ipsilon, Agrotis exclamationis). They are about 4 cm large. While resting or in danger they roll up in a spiral. They like warm, dry and light soils where they can hide at daytime. At night they hunt also above the soil and eat young shoots off, precisely at the separation of soil and air. Prevention can be done by already digging in weeds and greens in the winter. Since the larvae are not fond of moisture, the plants can be watered well the first weeks after planting. A good method is a caterpillar bait based on mixing 25% hardwood sawdust, 25% wheat brans, 50% syrup or molasses and water. Caterpillars eat from it, and get stuck in the stuff. In the morning, they are dead. At temperatures above 15°C, we can also work with Bacillus thuringiensis. Administer in the evening, the effect is only visible after a few days. Caterpillars also hate sage, if this herb is planted, they are also expelled.


===Mites===
===Spider mites===
Mites are not insects. They belong to the order of the spiders, 8 feet. This does damage to crops is the spider mite, and is mostly under glass. These suck juices from the plant which has white dots on the top of the leaves. Later, the entire leaf brown. Spider mites prefer to live in a dry climate. Regular spraying or Broeze is less likely to aantsating. Spider mites can fight with spirit soap. The conservatory can also use natural enemies such as predatory mites and predatory bug.
[http://en.wikipedia.org/wiki/Spider mites Spider mites] are not insects. They belong to the order of the spiders, having 8 feet. The one that does damage to crops is the [http://en.wikipedia.org/wiki/Tetranychus urticae red spider mite], and mostly spawns under glass. These spider mites suck juice from the plants causing white dots to appear on top of the leaves. Later-on, the entire leaf becomes brown. Spider mites prefer to live in a dry climate. Regular spraying with water makes the threat of infection smaller. Spider mites can also be fought with soapy ethanol. In the greenhouse , we can also use natural enemies such as predatory mites and [http://en.wikipedia.org/wiki/Assassin_bug assassin bugs].


===Mammals===
===Mammals===
Mice and rats
Mice and rats
All rats and mice eat do damage to crops. Only the shrew (dolleke) which is an insect eater, is useful in the garden. Mice can drive through to plant mint. You can catch them with traps and terminals or explaining poisoned bait.
All rats and mice do damage to crops. Only the [http://en.wikipedia.org/wiki/Shrew shrew], which is an insect eater, is useful in the garden. Mice can expelled by planting mint. You can catch them with traps or by laying down poisoned bait.


Mollen
Moles
The mole is a useful insects opruimer, but recovery from eating earthworms and creating seed beds in corridors and hope he is a gentleman unwanted in the garden. They gnaw not as sometimes thought to plant roots. To them one can exclude plants with a plant more resistant or more minor effect as imperial crown (1 to 8 meter around the garden) and cross-leaf spurge (about 10 plants per acre), a clove of garlic in the corridors, the mole scare . The most efficient for them to address his moll moll Enver clamps or hunters.
The mole is a useful insect eater, but because of the eating of the useful earthworms and by creating corridors in seed beds, it is an unwanted organism in the garden. They do not gnaw (as sometimes thought) on the plant roots. To fend them off, we can plant crops with a more or less mole-expelling effect such as [http://en.wikipedia.org/wiki/Fritillaria_imperialis Fritillaria imperialis] (place 1 every 8 meters completely around the garden) and [http://en.wikipedia.org/wiki/Euphorbia_lathyris paper spurge] (about 10 plants per are), also a clove of garlic in the corridors, would scare off the mole. The most efficient to expell them are mole traps or ultrasound devices.


Rabbits
Rabbits
These rodents do too much damage to crops. In nearby forests you best connect your garden with a dense mesh of 1 m high that most another 20 cm is buried in the ground. To protect young trees can these instrijken manure with lime. 3 parts pig manure, 1 part cow manure, 1 part lime and mix it with water to a string equivalent mixture.
These rodents also do much damage to crops. Near forests, it is best to protect your garden with a dense mesh of 1m high that is also (20 cm deep) dug into the soil. To protect young trees, we can cover them with lime manure. This is made from 3 parts pig manure, 1 part cow manure, and 1 part lime. The whole is mixed well with water, so that a semi-liquid mixture is attained.


===Snails===
===Gastropods===
The snail belongs to the molluscs. They just feel good in wet conditions and are especially active at night. The snails have low toxicity, especially the slugs are voracious. They eat not only grating holes in the leaves. Especially soft parts of plants and young seedlings must suffer. Preventive measures are moist places from which they operate isolate such weeds, grass strips brief, waste piles clean. Cm strips of wood ashes and some sharp sand to keep snails. Snails hate some plants such as nasturtiums, sage, hyssop, thyme and mustard. Even in the winter rye cover crop as snails seem to be divested. A slakkeval can make a jam that we're right on the edge digging into the ground, pour it for 1 / 3 beer, snails love it but drown in it.
The gastropods belongs to the order of the molluscs. They only feel good in wet conditions and are especially active at night. The [http://en.wikipedia.org/wiki/Gastropoda snails] (Gastropods with shell) do not do much damage, only the slugs are voracious. They do not eat, but grate holes in the leaves. Especially the soft parts of plants and young seedlings suffer. Preventive measures are to eliminate the moist places from which they operate, eg by removing weeds, by keeping the grass strips short, by cleaning up waste piles. Wood ash or sharp sand strips of a few cm wide stops gastropods. Gastropods hate some plants such as nasturtiums, sage, hyssop, thyme and mustard. Also, the use of rye as a green manure seems to be expell gastropods. A gastropod trap can be made with a jam pot that we dig into the soil, equal to the soil's edge. We pour in beer up to about 1/3 of the pot; gastropods love it but will drown in it. You can also breed your own nematodes which will kill the slugs [http://www.telegraph.co.uk/gardening/gardeningequipment/8675592/The-war-on-slugs-starts-at-home.html Nematode breeding with a bucket and some weeds]


==C. Non-parasitic causes (physio = disease gene)==
==C. Non-parasitic causes (physio = disease gene)==
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===Weather Influences===
===Weather Influences===
* Adverse temperature
* Unaduquate temperature
* Light defect
* Shortage of light
* Rain, hail
* Rain, hail
* Adverse humidity
* Unaduquate humidity
* Wind and storm
* Wind and storm


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* Acid rain
* Acid rain


==Weeds==
==Source==
Weeds are plants that grow in places where they are not wanted. They can damage because
This article is made using information from the coursebook:  
* The yield is less due to competition
Cultivation techniques </br>
* They transmit diseases and pests
Course from: 1st year of Herbalism</br>
* Because the crop can not illuminate and there is more chance of fungal attack
Course year: 2005 - 2006</br>
Weeds are wild plants that grow strongly and continue to grow crops soon. Weeds are also difficult to get away. Seed masses spreading weeds seeds that spread by the wind and 50 years in the soil are waiting for favorable conditions to germinate. In the weeds seeds we distinguish between the annuals that germinate in the spring and summer (chamomile, ragwort, knapweed) and two year olds that germinate in autumn and seeds are in the following years (daisy, dandelion). Furthermore, we know the remaining weeds that spread by rhizomes or underground stems that root is also called weeds (breeding, horsetail, thistle, nettle). Wall street and grass germinate and grow throughout the year.
Education center: Syntra, Asse-establisment</br>
 
Teacher: Leo Van Crombrugge
How to prevent weeds?
Field Hygiene: Remove all weed seeds in the will. Weeds on the compost heap will be just as dead in the hope the temperature is high enough (50 ° -60 ° C).
 
Fruit Variety: many weeds are linked to culture plants. By crop variety we shake the weed pattern together. Weed plants cover the ground completely inhibit or are so far apart that we can properly between heels. Weed species promoters do not have these qualities, and garlic chives.
 
Land cover: The cover of the soil prevented the hurry of weeds. When mulching, organic matter in thin layers between the plant made. The application of the mulchlaag can only happen when the seedlings are well above or if the plants are planted. Sow or plant in a mulchlaag is impossible. The mulchlaag not aanbregen frost sensitive plants in mid May By covering the soil with the cold nights will not be able to radiate heat so the danger of frost is greater.
 
<! - Burning is another possible solution, this should be indicated, another solution is steam ->
Teel Techniques
The interweaving of land were needlessly avoid because of the underlying strata many weed seeds to emerge. Sow in rows facilitates weed control. The first planting of cultivated plants will be ahead of the weeds. At first the weed seedlings to emerge, this away and then hoeing the ground for sowing was very superficial.
 
Fighting
Weeding: this is done in seed beds in the heel which can not be worked. Larger plants can best pull.
Hoeing and chopping: sets the cut weeds just below the ground. Scrape a hoe on the ground, you make a pushing movement with it as you get back. A heel is increasingly attracting to itself while forward steps. The best moment in dry sunny weather after a period of rain when the soil has dried sufficiently. The chopping and hoeing weeds is as small as possible. The larger the weed the harder. In dry and sunny weather the weeds remain. In wet weather, the weeds removed so they can not get regrowth.
 
Chemical
Root after the hoeing weeds or cut off just grow their underground root parts can fight with a systemic herbicide in the system of the plant is contained and transported to all parts, including the roots. The more active the growth of the plant, the faster and better the effect will be. Glyfosfaat is a historic (non-degradable organic) example. Degradable organic herbicides would this also should be used.
 
Annual weed seed can then confront with a total contact herbicide. For the 1-year germination of weed seeds to prevent soil can use herbicides, they are sprayed on a weed free soil and to prevent the germination of weeds.
 
==Control of plant==
Currently, we come to realize that a growing set of measures equilibria in nature as well as possible state must be kept. This enables the development of diseases and pests as much as possible to prevent and kill. Within this view is only room for limited use of chemicals. We call this integrated control, which can see through the use of biological control and cultural measures the use of chemicals to a minimum.
 
===A. Preventive measures cultivation===
1. Choosing the right plants in a soil culture and their suitability for our climate.
2. A fruit variety weloverdachte
3. Select varieties with resistance or still possess a high degree of resistance against diseases and pests.
4. Proper soil preparation
5. Healthy seeds and cultivation of a healthy young plants
6. Favorable sowing and planting times, which not only the state of the land and the requirements of the plant growing season and temperature to be determined, but that the magnitude of the risk of damage by parasitic and non-parasitic causes (frost) are involved.
7. One of the requirements of the plant-oriented fertilization (non-concentrated nitrogen)
8. Timely and professional system of cultivation measures (sowing depth, seed distance, climate in the greenhouse, weed control, ...)
 
===B. Mechanical plant===
This end we count all devices and objects that can be used to keep crops healthy.
* Weeding and hoeing
* Fences against damage caused by
* Horticultural Netting: this is an insect with very fine mesh of synthetic mesh (1 mm) where no insects can pass
 
===C. Biological control===
This is use of natural enemies against pests and diseases are bred for that purpose. The natural enemies are as follows:
* They suck the plague organism empty as the larva of the lacewing and the gall midge and the predatory mite
* They lay one egg in the plague organism as the parasitic wasp.
* They eat the pests in the larvae and as the image of the ladybug and the predatory bug
* They separate toxic emissions in the plague organism or pest organism make it otherwise ill as nematodes and bacteria
 
Natural Pest enemy
aphid parasitic wasp, ladybird, gall midge
mineervlieg parasitoid
predatory mite, predatory bug
whitefly parasitic wasp, predatory bug, fungus
spider mites, gall midge
caterpillar parasitoid, bacterial
Varenrouwmug predatory mites, nematodes
mealybugs parasitic wasp, predatory beetle
vine weevil nematodes
 
===D. Allowable biological crop protection products===
Plant Infusions
This means plants in cold or warm water steeped for a time. The liquid will then be seven by a linen cloth and then on the crop or soil spray or squirt. Most funds contain trace elements and plant hormones the cell walls strengthen and reinforce the defense of plants. Some also contain substances that kill or inhibit the endorsed organism. Treatment should be repeated so often since the start of cultivation.
 
-Wormwood absinthe: the poisonous plant contains bitter substances that make the plant unpalatable for insects. Effective against aphids and mites. Stock: 200-300 g of dried wormwood to pour boiling water over. 1 days after dilution to 10 liter. Seven of the plant and spraying.
 
Tansy: animals find and taste unpleasant odor of this plant and not eat there. Against various insects. Extract: 300g fresh plant parts to 10 liter of water. First, cook briefly and then 24 hours rest. Seven and syringes.
 
Nettle: the active substance is formic acid. It is the softest known cure for aphids, not against other insects. Stock: 1kg fresh nettles in cold water for 10 liter. After seven and maximum of 24 hours undiluted. Gier: the mixture about 5 days leave. Add flour and stir regularly rock. Ten times dilution and pour on the ground. The slurry is used as reinforcing fertilizer.
 
Horsetail: This herb contains much silica that would strengthen the cell walls. An extract of horsetail has a good reputation against fungal diseases. Stock: 1 kg 150 g fresh or dried horsetail fifteen minutes to boil water in 10 liter. A few hours to draw, seven, and 5 to 10 times dilution for spraying.
 
Seaweed Extract: extracts of brown and green algae contain much potassium, a high content of trace elements and magnesium. Their growth-promoting value it writes to the vitamins, plant hormones and enzymes. It strengthens resistance to disease and promotes growth.
 
Derris and kwassia: harmless to humans but is less effective as insecticide
 
Rock Flour
Seaweed Calcium, basalt lava and flour have a crop protective function. They increase the acidity which impairs development. The fine work gesteentemelen drying and damage the wax of many insects. By Dusting or spraying the plants covered with a thin layer of dust. Treatment evening run and it should not rain 12 hours (up to 2 times per month) dose 250g/are.
 
Commercial Preparations
Soap: a solution (hot water) from 1 to 3% (10-30g/liter) soft soap (green or brown) has moderate activity against aphids and some other insects. The insects must be properly concerned with the soap solution.
 
Soap Spiritus: ditto above but add 50 ml spirits in 1 liter of water
 
Sulfur: one injection of pure sulfur Atomizes against many fungi (mildew and scab). Is harmless to humans and animals.
 
Bordease Dad: A mixture of copper sulphate and slaked lime in prevention of scab. It is a very old way. The copper ions in the magazine prevent the germination of fungal spores and the calcium also increases the pH.
 
Pyrethrum: plant based insecticide for all cold blooded creatures a strong neurotoxin. Is virtually harmless to warm-blooded. Pyrethrum breaks down within 48 hours. Other vegetable insecticide Rotenone and Koppert Koppert Plant Clean.
 
 
Growing Combination
Just as it is difficult for people of different nature to live side by side, plants also have this problem. Plant roots separated from the different growth inhibitors and off, making a different kind of worse or better can grow. This is called a reciprocal negative to positive influence. The insights obtained from this basic principle was the so-called mix or combination cultivation. They plant different vegetables, herbs, and groentbemesters together or close together, which should be sought that the earth is covered throughout the year. This method of gardening are striking results. Except for reasons of pest and disease prevention are also often motivated others, such as more efficient space utilization, higher yields, better utilization of nutrients in the soil, improving the taste to harvest products, wind shelter, etc. For those who feel attracted to this end, the winter months particularly suitable for this purpose the necessary knowledge. By reading literature or knowledge with other gardeners can crop combinations for the upcoming season is already down. Who is this deal going, will soon discover that the good neighbor next crop plants are also bad neighbor.
 
Crop rotation
The aim of rotation is to try the harmful effects of the continuous cultivation of same crop reduction. Especially in the vegetable should be washed regularly other on the same plot to cultivate. The proceeds will thus increase. For small gardens rotation seems a pious wish, but where possible, one must try January 1 to 3 and preferably 4 to January 1 system to introduce. This means that with a given crop within three years on the same site should come back. To some this administration does not escape. The benefit of rotation in the vegetable garden that certain parasitic organisms this heavy infection pressure can build. Examples are: cabbage and turnip feet in some soil dwelling nematodes.
 
List of possible plant combinations
-> To be added


[[Category:Agriculture_manual]]
[[Category:Agriculture_manual]]
[[Category:Pest control]]

Revision as of 04:40, 4 December 2014

Snails: a common pest

Part 4: Crop protection

  • Causers of diseases and pests

Deviations in the crop can be caused by:

  • A. Non-animal parasitic organisms
    • Fungi
    • Bacteria

If an infection is caused by non-animal parasitic organisms, they are called diseases.

  • B. Animal parasitic organisms
    • Nematodes
    • Insects
    • Mites
    • Mammals
    • Birds

If an infection is caused by animal parasitic organisms, they are called pests.

  • C. Non-parasitic causes
    • Soil influences
    • Weather influences
    • Air pollution

These disrupt the physiology of the crop. We talk of physiogenic diseases.

  • D. Weeds

These compete with the crop for water, nutrients, light and space.

Note that bacteria are usually a secundairy corruption (eg after a fungi attack) or with wounds (weakened plants)

virusses work through direct contact, they can not survive long without the host, several species, eg persistent species remain in the host, also if transferred

A. Non-animal parasitic organisms

Fungi

Fungi are an entirely separate group to plants, and, despite appearances, are in fact more closely related to animals. They contain no chlorophyll and are dependent for their nutrition on dead and living organic matter. They consist of microscopic filaments (hyphae) which are sometimes packed together as a visible tissue (mycelium). Molds propogate mainly through spores, which are very fine spheres that are dispersed by wind, water and also by animals. With sufficient moisture and warmth, the fungi develop rapidly. The damage that fungi cause is of major economic importance. We currently know some 3000 harmful fungi.

They usually have a full lifecycle on the course of a few days Conditions: hot and moist weather Weeds can be a host for fungi.

Commonly appearing on plants:

Germing fungi

These can infect the seedlings in the nursery. The disease is also called smoldering. The young seedlings start to melt or fall over. Sometimes the plants don't rise above the soilsurface because the fungus has already struck them at the germination. It is best to hold off with sowing until the soil has warmed and dried enough. Also, do not sow too deep in the soil, nor too close together.

Botrytis

This fungus manifests itself from the soil at humid weather and first targets the dying plant parts of a crop. The parasite also targets wounds, it is mostly saprofytic, note that wounds can also be cause by a heavy impact of rain (cellular damage). Then it goes on to healthy plant parts. These will discolorate, and after this, they will exhibit a gray mold fluff, full of fresh spores for a new spreading.

Mildew

With "Mildew", 2 diseases are meant: powdery mildew and downy mildew. Powdery mildew usually appears around the middle of July as woolly spots on top of the leaves. Moments later they are covered with a flour-like layer. The fungus draws moisture from the leaf cells, which makes the leaf discolor brownish and makes it dry-out. With the downy mildew, the symptoms are pale-yellow discolored spots on top of the leaf and white, powdery fungal fluff at the bottom. The leaves discolorate brown afterwards. Powdery_mildew occurs on dry, hot weather, the wooly fluff is everywhere, including the bottom of the leaf. Downy_mildew occurs with wet, hot weather

Prevention All measures aimed to let the crop dry-up faster, have a preventive effect on fungi. We can provide a wide spacing, a windy and weed-free place and adequate ventilation in the greenhouse. Both stressed plants (by supplying too much N) and crops with a growth arrest fall prey to fungi. Besides the essantial crop rotation, sprayings with rock meal are also possible. Sprayings with Equisetum arvense extract or pure sulfur are considered effective. At a beginning infestation, we remove the infected plants and burn them. Once the mold has well infected our crops, there really isn't much to do about it anymore without the use of chemical agents.

Bacteria

These microscopicly small organisms can also cause damage to plants (Erwinia and Pseudomona). It are these that cause root rot with tuber and bulb crops and various spot diseases or wilting in other plants. Against bacterial diseases, there are no effective pesticides. Modern varieties are often resistant and a crop rotation prevents damage.

Viruses

Even under a regular microscope, these minuscule organisms are unobservable. In addition, viruses are so primitive that they live can not live outside of their hosts. Yet they are able to cause persistent diseases with symptoms such as growth inhibition and malformations. Viruses can be transferred at dozens of ways such as through aphids, fungi, touching, contaminated irrigation water, ... Viruses are almost impossible to combat. Preventative, one might think of few precautions to help prevent an infection such as:

  • Burning diseased plants
  • Buying healthy seeds/plants
  • Growing varieties that are not susceptible to viruses
  • Carefully combat weeds
  • Effectively combat aphids

Also, we never put young plants or seed beds next to older plants or plants that already bear seeds. Modern varieties are usually resistant to viruses or at least tolerant.

B. Animal parasitic organisms

Nematodes

Nematodes are always present in the soil. The colorless worms are less than 1 mm wide, and are not visible with the naked eye. Most species are decomposers of organic matter, only a few parasite on living plants and sucking their cells empty. The cyst-forming nematodes put their eggs in the soil in cysts (hard spheres filled with eggs, are observable with the naked eye). These cysts can survive years in the soil and awaken when a same vegetable species or a related one is grown. Such a nematode population can cause that a lot or a place fails, seemingly without any reason. We speak of soil fatigue. Infestation by nematodes is promoted by growing a same crop frequently in the same place, this is why we always apply a wide crop rotation. As a defense we can grow Tagetes (marigold). These plants secrete substances through their roots with a nematode-killing property and they are easy to use as a border planting or pre-cultivation.

Eals

Schematic of eal

Eals are a type of nematode. Eals exist in 2 varieties: parisitic and saprofytic (good-type) eals Several eals: some live in the roots, near the roots, cyste-eals (latter can survive for 5-10 years in the soil)

Eals are the greatest cause of "soil fatigue". If crop rotation is used, this pest can be avoided.

Insects

Insects belong to the arthropods. Insects have 3 pairs of legs and are usually winged. They usually also have antennas. During their lifetimes, most insects undergo a transformation or a metamorphosis. This can happen through the phase of nymph, where the young larvae already looks similar to the adult insect, but does not have wings yet (aphids, locusts, thrips). With a full metamorphosis the larvae does not yet look similar to the mature insect and a transition first occurs through the pupal stage, often at a hidden place in a self-spun cocoon (moth, beetle). 70% of all known species, are insects, they have a hard skeleton, reproduce quickly and adapt to most environments. Many of these insects have specialized themselves in living on certain crops. With monocultures on large plots this may result in extensive pests. There are some insects that occur on various crops.

2 types exist:

  • with incomplete metamorphose (egg -nymphe-insect)
  • with complete metamorphose (egg-larva-cocoon-nymph-insect)

The difference is that a nymphe looks like the insect, whereas a larva does not look like the insect (eg butterfly)

mites:generate honeydew -->formation of fungi can occur hereon

dry weather: mite wet weather: fungi daily checkups need to be done for both

Aphids

An aphid is a parasite that appears in the garden from March. They are small(2-3mm),oval, black, gray or green insects, and belong to the order of the lice (Phthiraptera). They carry on their abdomen, two tubular wax glands from which they secrete sugars in the form of a sticky substance which is called honeydew. Ants love it and stay close to aphids. Best known is the green peach aphid and the black bean aphid. Especially in hot weather, the aphids multiply rapidly as they reproduce Parthenocarp and vivipare (without fertilization and viviparous) in the summer. They spawn on the underside of the leaf. Lice are sucking insects that feed on plant saps. We can observe this by the curling and wilting of the leaves and shoots on which they sit (youngest leaves). The damage manifests itself by:

  • Growth inhibition and growth arrest
  • Formation of Dematiaceae, a black fungus on the honeydew
  • Transmission of viruses

Weak or imbalanced plants are first affected. We will thus preventively make sure of

  • A healthy and strong plant (balanced diet and certainly not too much nitrogen)
  • Plant strengthening substances such as nettle manure, seaweed extracts, fertilization with rock flour, sowing of nasturtium catch crops

When infected, we can spray with:

  • A solution of brown soap or an ethanol-soap mixture
  • Organic insecticides such as pyrethrum, or derris, or kwassia (bitter wood)
  • The use of natural enemies such as Coccinellidae, parasitic wasps and Cecidomyiidae in greenhouses

Beetles

Beetles usually disappear after a certain period of time

Leaf beetles

These are small (3 mm) beetles with long back legs that can jump high. They are best recognized by their metallic sheen. They eat out holes in the lower leaves of germinating plants. They are especially active in dry, crusty soils with cool and dry weather. One can expel them by pouring cold water over the plants during full sun. To catch them, one can use a glue board. A shelf is foreseen at the bottom with glue or wood tar. In the middle we place soft bristles that are bristled over the crop. The beetles will jump up and get stuck in the glue.

Leatherjackets

This is the larva of the Crane fly, it is around 5 cm long and gray in color. Leatherjackets occur on wet soils overgrown with weeds or where green parts (grass) are dug into the soil. They eat the roots and stems of virtually all crops and can cause major damage. Prevention is done by keeping the ground free of weeds and by not digging grasses under. Leatherjackets can be caught by searching the soil surface on a hot day. We can also use chickens to do this work.

Wireworms

These are copper colored, worm-shaped larvae of the skipjack. They are a typically a problem occuring on newly cleared land, and often occur with tuberous crops. They stay 3 to 5 years under the soilsurface and to grow up to 2 cm large. They mainly eat half decomposed vegetable matter and have a preference for root and tuber crops. They eat the plants roots and drill into the stems, the plants wither from this. Prevention can be done by keeping the soil free of weeds. Wireworms can be caught by cutting a potato in half and digging it in 5 cm deep into the soil with the cut part facing downwards.

Cutworms

This is the larva of a brown moth (Agrotis segetum, Agrotis ipsilon, Agrotis exclamationis). They are about 4 cm large. While resting or in danger they roll up in a spiral. They like warm, dry and light soils where they can hide at daytime. At night they hunt also above the soil and eat young shoots off, precisely at the separation of soil and air. Prevention can be done by already digging in weeds and greens in the winter. Since the larvae are not fond of moisture, the plants can be watered well the first weeks after planting. A good method is a caterpillar bait based on mixing 25% hardwood sawdust, 25% wheat brans, 50% syrup or molasses and water. Caterpillars eat from it, and get stuck in the stuff. In the morning, they are dead. At temperatures above 15°C, we can also work with Bacillus thuringiensis. Administer in the evening, the effect is only visible after a few days. Caterpillars also hate sage, if this herb is planted, they are also expelled.

Spider mites

mites Spider mites are not insects. They belong to the order of the spiders, having 8 feet. The one that does damage to crops is the urticae red spider mite, and mostly spawns under glass. These spider mites suck juice from the plants causing white dots to appear on top of the leaves. Later-on, the entire leaf becomes brown. Spider mites prefer to live in a dry climate. Regular spraying with water makes the threat of infection smaller. Spider mites can also be fought with soapy ethanol. In the greenhouse , we can also use natural enemies such as predatory mites and assassin bugs.

Mammals

Mice and rats All rats and mice do damage to crops. Only the shrew, which is an insect eater, is useful in the garden. Mice can expelled by planting mint. You can catch them with traps or by laying down poisoned bait.

Moles The mole is a useful insect eater, but because of the eating of the useful earthworms and by creating corridors in seed beds, it is an unwanted organism in the garden. They do not gnaw (as sometimes thought) on the plant roots. To fend them off, we can plant crops with a more or less mole-expelling effect such as Fritillaria imperialis (place 1 every 8 meters completely around the garden) and paper spurge (about 10 plants per are), also a clove of garlic in the corridors, would scare off the mole. The most efficient to expell them are mole traps or ultrasound devices.

Rabbits These rodents also do much damage to crops. Near forests, it is best to protect your garden with a dense mesh of 1m high that is also (20 cm deep) dug into the soil. To protect young trees, we can cover them with lime manure. This is made from 3 parts pig manure, 1 part cow manure, and 1 part lime. The whole is mixed well with water, so that a semi-liquid mixture is attained.

Gastropods

The gastropods belongs to the order of the molluscs. They only feel good in wet conditions and are especially active at night. The snails (Gastropods with shell) do not do much damage, only the slugs are voracious. They do not eat, but grate holes in the leaves. Especially the soft parts of plants and young seedlings suffer. Preventive measures are to eliminate the moist places from which they operate, eg by removing weeds, by keeping the grass strips short, by cleaning up waste piles. Wood ash or sharp sand strips of a few cm wide stops gastropods. Gastropods hate some plants such as nasturtiums, sage, hyssop, thyme and mustard. Also, the use of rye as a green manure seems to be expell gastropods. A gastropod trap can be made with a jam pot that we dig into the soil, equal to the soil's edge. We pour in beer up to about 1/3 of the pot; gastropods love it but will drown in it. You can also breed your own nematodes which will kill the slugs Nematode breeding with a bucket and some weeds

C. Non-parasitic causes (physio = disease gene)

Soil Influences

  • Lack or excess nutrients
  • Too much or too little water
  • Poor structure
  • Adverse pH
  • To high salinity

Weather Influences

  • Unaduquate temperature
  • Shortage of light
  • Rain, hail
  • Unaduquate humidity
  • Wind and storm

Air pollution

  • Acid rain

Source

This article is made using information from the coursebook: Cultivation techniques
Course from: 1st year of Herbalism
Course year: 2005 - 2006
Education center: Syntra, Asse-establisment
Teacher: Leo Van Crombrugge

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