动态第758页 - 绿手指 - 养花技巧、花生病了怎么办、花园打理和设计

2017年09月15日

Small silver patches and black dots on the leaves. Feeding thrips can also turn petals on flowers brown. New growth can be distorted, browning and curled.[图片]Plants affected Virtually all garden plants can be affected, from ornamental species, to fruit, vegetable, and cereal crops. Flowers and leaves of plants are most affected. About Thrips Thrips are sometimes known as thunderflies or thunderbugs. There are over 3000 recorded species worldwide, with over 150 in the UK. They are typically small, slender, dark-coloured insects about 2mm long or less and usually have two pairs of feather-like wings. Thrips rasp through upper leaf cells to feed on plant sap, causing a silvering appearance. Thrip droppings are minute black specks on the leaves.[图片]Thrips have six lifecycle stages including egg, larvae, pupa and adult. Larvae and pupae can be a lighter colour than adults. Females have a serrated tube for laying eggs into plant tissue. They are predominantly a summer pest, favouring warm temperatures and dry conditions. Thundery conditions trigger swarming. Some species can transmit viruses such as tomato spotted wilt virus. Treatment Chemical Products containing the following chemical ingredients are all effective on Thrips[图片]Pyrethrins Methiocarb Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments. Organic Release the predatory mite Amblyseius cucumeris, and predatory bug Orius laevigatus. Spray organic plant oils approved for use on plants. Remove and destroy infested leaves, particularly silvery areas where eggs are present.[图片]Prevention Thoroughly clean greenhouses at the end of the season to remove any over-wintering thrips. Use sticky traps to monitor the first appearance of thrips. Blue coloured traps are thought to be more effective than other colours. Netting and fleeces can be used as a barrier between plants.

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月15日

Leaves that become skeletonised or transparent with just their veins remaining tend to be the work of sawflies, which eat through the tissue of the leaf until it has almost completely disappeared. The larvae can often be seen around the edges of the leaves and most curl up into an S-shape when disturbed. Larvae will also bore into developing fruits causing them to become scarred and exude sticky liquid.[图片]Plants affected Sawflies affect a number of different plants but different types tend to affect different crops. Some of the most common are the apple sawfly (hoplocampa testudinae), the common gooseberry sawfly (Nematus ribesii), the turnip sawfly (Athalia rosae) the pear and cherry 'slugworm' (Caliroa cerasi), the rose slug sawfly (Endelomyia aethiops), also known as the rose 'skeletoniser'.[图片]About Sawflies Adult sawflies are usually inconspicuous flying insects with two pairs of wings and often dark coloured bodies and legs. They resemble flying ants but have no 'waist' between thorax and abdomen. They're often seen flying on warm sunny days in spring at blossom time when they usually feed on pollen and nectar. The adults live for about two weeks, during which time they mate before the females start laying eggs into plant tissue. Eggs are inserted into cuts on the leaf surfaces that the female makes with her saw-like ovipositor. Eggs hatch into larvae that resemble moth caterpillars, although they have more pairs of 'pro-legs' on their abdominal segments. The larvae usually feed in groups on leaves and fruit of plants.[图片]When disturbed, the larvae of most sawfly species adopt an S-shaped pose, often raising their rear ends and waving them about. At least 400 different species of sawfly have been recorded on plants in Britain. Larvae usually feed for about four to five weeks before pupating in the soil. Infestations of sawfly larvae often defoliate plants although infestations are usually localised and rarely devastating. Two or three adult generations may develop during the growing season with the third generation overwintering as pupae that emerge in the spring Treatment Chemical Products containing the following chemical ingredients are all effective on Sawflies[图片]Pyrethrum Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments. Organic Inspect bushes every week from April/May onwards for the signs of sawfly infestation then search for the larvae and remove by hand. Tell-tale signs include transparent patches on leaves where young larvae are feeding; seeping sap, where the insects have damaged plant tissue as they lay eggs; areas of defoliation or skeletonised leaves.[图片]Position susceptible plants in an open position where birds can easily feed on the larvae. Prevention Select varieties that are reported as less susceptible to attack, particularly roses and apples.

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月15日

If the shoots tips of rosemary and lavender are turning brown and dying back it could be the sign of an infestation of rosemary leaf beetle. These small beetles feed on the new shoot tips causing them to die back. They're easy to spot because they have metallic green and purple stripes across their backs. Their larvae, which are slug-like and pale grey in colour with a dark stripe down the side, also cause damage by feeding on the shoots as they grow.[图片]Plants affected Rosemary leaf beetles only feed on a small number of plant species which includes rosemary, lavender, sage and thyme. About Rosemary leaf beetle These attractive leaf beetles are an invasive species that first appeared in the UK in 1994. Since their introduction, they've been spreading steadily throughout the southern counties of England. The adult beetles are around 1cm long with metallic green and purple stripes down their wing cases. They're usually found in groups on stems, or feeding on the new growth of plants.[图片]The larvae are small slug-like grubs which are usually found on the underside of leaves. They are light grey with horizontal dark stripes along their body. Adult beetles are usually first seen in late spring, although they remain largely stationary on plants until later in the year. In late summer they'll begin to mate and lay eggs. Eggs are usually laid on the underside of leaves and are around 2mm in length. Larvae will hatch in about ten day's time and feed for a few weeks before dropping down to pupate below the soil surface. Adults may continue to mate during warmer winter periods, although this is rare.[图片]Treatment Chemical Products containing the following chemical ingredients are all effective on Rosemary leaf beetle Pyrethrum Natural fatty acids Surfactant-based products Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments. Organic Regular observation in late spring each year is essential to prevent infestations establishing. Removing adults and larvae by hand will help to reduce numbers. Shaking infested bushes over an old towel or sheet will enable large infestations to be collected and removed.[图片]Netting and fleeces can be used to stop adults moving between plants. There are currently no natural enemies commercially available to control rosemary leaf beetle. Prevention Check plants on a weekly basis for signs of infestation and deal with them as soon as they appear. Encourage insectivorous birds by hanging feeders in the winter and provide nesting boxes in the spring.

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月15日

Mottled, yellowing leaves with brown speckles are signs that these tiny pests have been feeding on plant leaf cells. Sometimes you can also see the fine silk webbing spun by adult spider mites, which they use to travel from one plant to another.[图片]Plants affected Spider mites feed on at least 200 different plants, including many common flowers, fruits and vegetables. About Red spider mite Spider mites are arachnids and are related to all spider species. These tiny, highly destructive pests are common in greenhouses and on house plants and can also be found on outdoor plants during the warmer summer months. Spider mites can feed on at least 200 different plants, including many common flowers, fruits and vegetables. They feed on the content of plant leaf cells by piercing them with their mouthparts. This results in a fine brown speckling effect on leaves where the cells have died.[图片]Adult mites also spin a fine silk webbing over leaf surfaces. With heavy infestations this can cover most of the plant. When active, the spider mites are light green with two dark spots on their back, but during their inactive periods they become dark orange or red. Spider mites emerge from hibernation during March and April and begin laying their minute, spherical eggs on suitable host plants. Adult females can lay up to a hundred eggs during their lifetime. Juveniles will hatch a few days later and begin feeding. They start life with six legs, but develop eight as they mature. The webbing provides a protective shield for the spider mite colony against predators and adverse environmental conditions. It also provides a means of spreading the colony to other areas of the plant. As autumn approaches, females stop laying eggs and begin to seek out places away from the plant to overwinter. They'll usually choose places, such as cracks in walls, fences and old plant material.[图片]Treatment Chemical Products containing the following chemical ingredients are all effective on Red spider mite Natural fatty acids Surfactant-based products Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments. Organic Inspect plants every week and deal with the first signs of mite infestation immediately. Where possible, remove infested leaves, buds and stems because this will initially reduce numbers. Spider mites prefer dry environments, so spraying the infested areas of a plant with water and damping the greenhouse floor areas will raise the humidity and hopefully slow the infestation rate.[图片]The predatory mite Phytosieulus persimilis feeds on Red spider mite, and reproduces much faster than its prey at temperatures above 18C (64F). This can be released on to infected areas and should quickly control infestations. Prevention Mites overwinter in cracks and crevices in greenhouses, as well as in any plant material left behind. So it's essential to clear away all debris once the growing season is over and thoroughly disinfect the greenhouse to keep pest numbers to a minimum.[图片]Keep the greenhouse atmosphere quite humid and damp by wetting the floor regularly. Mites hate damp conditions and this will help to discourage them from making a home here.

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月15日

Rapid or gradual defoliation, where the lower leaves of the plant turn yellow and fall; wilting, drooping, spotted or stunted plants; or grey powdery mould round the stem, leaves or flowers. These symptoms can be indicative of other problems, but the presence of rotten roots as well would be a strong indication of water-logging.[图片]Plants affected Potentially all plants, but while drought damage occurs commonly in both outdoor and house-plants, over watering is relatively rare outdoors. It is probably the commonest cause of decline in house-plants, however, and much more serious than under watering. About over watering Plants vary hugely in the amount of water they need. It will depend very much on the type of plant, the season, the temperature and the climate. Over watering is more damaging to the plant than under-watering. The rate of evaporation of water from the leaves, and the rate of transpiration through the stem and roots both affect the exchange of oxygen and carbon dioxide in the plant. The presence of too much water prevents the diffusion of these gases.[图片]The commonest symptom is the yellowing of leaves. Lack of oxygen to roots causes general stunting and encourages the development of rotting organisms. Preventing further damage For house plants check carefully their water requirements and water accordingly. Not many flourish when standing permanently in dishes of water. Outdoors, check the soil condition: turning over heavy, loamy soils will aerate them and improve drainage. Water slowly to prevent soaking some areas and leaving others dry.[图片]Water in the morning when it is cool – during the day too much evaporation will occur and later in the evening humid conditions will cause fungal growth. Always allow the saucers of pot plants to dry fully between waterings. Make sure pots and plenty of drainage holes and fill bottom of pots with crocks, grit or gravel to prevent the holes becoming clogged.

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月15日

Yellowing or reddening of leaves, discoloured or aborting fruits and flowers, and poor plant growth. Fruits can become misshapen and display brown leathery patches.[图片]Plants affected All plants can be affected. About Nutrient deficiency In order to develop and complete their life-cycle without sustaining damage to new growth, flowers or fruit, plants require nutrients. To maximise efficiency, nutrient supply to plants should be balanced to meet individual needs. The main nutrients required are carbon, nitrogen, oxygen, hydrogen, phosphorous and potassium. In addition to these, a number of less essential nutrients known as secondary nutrients are used by a plant to optimise its growth. There are also many micro nutrients used in tiny amounts by specific plant species. Main nutrients contribute to production of chlorophyll, fruit set and yield, defence against adverse environmental conditions, leaf loss, and certain diseases. They also aid in the healthy growth of roots, leaves and flowers.[图片]Treatment Chemical Products containing the following chemical ingredients are all effective on Nutrient deficiency Nitrogen, potassium and phosphorous fertilisers. Calcium ammonium nitrate Ammonium nitrate Urea Potassium chloride Potassium sulphate Calcium carbonate[图片]Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments. Organic Incorporating farmyard manure, composted plant material, leaf mould and other natural sources of nutrients will ensure healthy plant growth. Prevention Establish a regular feeding programme for all potted and hanging basket plants, and those grown in a greenhouse. Apply a suitable liquid feed to your garden plants at regular intervals when watering. Apply a suitable granular feed to your lawn at seasonal intervals as indicated.[图片]Incorporate slow release fertiliser granules into all compost used for potting plants. Dig sources of plant nutrients such as garden compost or well-rotted manure into flower beds and vegetable patches, or place around the bases of existing plants. Scarify, top-dress, and aerate lawns at the beginning and end of growing seasons.

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月15日

Wilted, stunted and dehydrated plants which may also be losing leaves. Foliage becomes covered in a sticky honeydew residue which in turn can lead to the development of dark sooty mould. You may be able to spot colonies of mealybugs on the undersides of leaves and in the leaf joints of plants. They're usually pinkish in colour and protect themselves with a layer of white waxy coating. Mealy bugs can also attack the roots of plants, but are much more difficult to identify.[图片]Plants affected Mealy bugs usually infest greenhouse and houseplants, although the phormium mealy bug, imported on New Zealand flax, will survive on outdoor plants in southern Britain. About Mealy bugs Mealy bugs are small, sap-sucking insects that produce large quantities of wax. Most UK mealy bug species are thought to have originated in the tropics. Males are winged and relatively few in number. Females are wingless and have flattened, soft, oval-shaped bodies up to 4mm in length. They're pink in colour, but appear white because of the waxy powder that covers their bodies and the long wax filaments that they also secrete. Development from egg to adult takes about three weeks.[图片]Breeding can continue throughout the year on plants in heated greenhouses and indoors. Colonies develop on leaves, stems, flowers and fruits of plants, and consist of egg masses, juveniles and adults clustered together and protected within a mass of wax filaments produced by adult mealy bugs. Treatment Chemical Products containing the following chemical ingredients are all effective on Mealy bugs Natural Fatty Acids Surfactant based products Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.[图片]Organic Check susceptible plants every few weeks and deal with the first signs of infestation immediately. Remove as many mealy bugs as you can by hand or, if possible, cut off infested shoots and stems. Use natural enemies such as the parasitic wasp Leptomastix dactylopii and predatory beetle Cryptolaemus montrouzieri, which are both commercially available for mealy bug control.[图片]Prevention Inspect new plants thoroughly and, if possible, quarantine them for a month or so before introducing them to the greenhouse. Destroy all infested material since mealy bugs are fairly mobile. Remove dead leaves and prunings from the glasshouse because these may harbour adults or eggs. Wash vines and citrus trees with a recommended plant wash or surfactant-based product during the early winter when they're dormant.

...显示更多

1

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月15日

These bright red beetles are very distinctive and therefore quite easy to spot on affected plants. Also, look for holes in leaves, stems and flowers, left by the small slimy black larvae.[图片]Plants affected They're highly destructive to lilies (Lilium), and fritillaries (Fritillaria). About Scarlet lily beetle These bright red beetles, with distinctive black legs and antennae, are an invasive species which was first recorded in the UK during the 1940s. They're also known as red lily beetles and are now commonly found across the south-east of England, and have recently been reported in parts of Scotland, Wales and Ireland.[图片]When disturbed, adults emit a high pitch squeak, perhaps as a warning to other beetles. Adults overwinter in the soil and emerge in late-March to early April. Adults will continue to mate and feed from spring until autumn. After mating, females will lay small groups of bright orange eggs on the underside of leaves. Larvae hatch a few days later as red or orange-coloured grubs with black heads and three pairs of legs on their upper body. As they feed, the larvae cover themselves in their own sticky black excrement. Lily beetle larvae are usually found on the underside of leaves where they feed from the tip and work back to the stem. Any larvae which survive to become adults will drop to the soil in late autumn to overwinter, and emerge again the next spring.[图片]Treatment Chemical Products containing the following chemical ingredients are all effective on Scarlet lily beetle Pyrethrum Natural fatty acids Surfactant-based products Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments. Organic Inspect plants carefully in early spring and remove any adults and larvae by hand to prevent infestations becoming established. Use netting and fleece to contain the pests and stop adults moving between plants. Replant pot-grown lilies and fritillarias using fresh compost in early spring before the overwintering adult beetles emerge from the soil.[图片]There are no biological controls commercially available, although a range of native parasites and predators will feed on both adult and larval stages. So encourage these by establishing a natural balance of wildlife in your garden and avoid using chemicals. Prevention Check plants regularly for signs of infestation and deal with them as soon as they appear. Encourage insect-eating birds by putting up feeders in winter and provide nesting boxes in spring.

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月15日

Narrow brown, white or opaque snaking trails in leaves often with round blistered patches. There may be clusters of white dots on leaves where the adults have been feeding.[图片]Plants affected A wide range of vegetable crops growing indoors or outdoors, especially tomatoes and peppers. About Leaf miner flies There are many species of leaf miner flies in the UK. Adults are usually small, dark-coloured flies around 5mm long. Some of the more destructive species have a characteristic yellow spot on their backs, and others have dark-patterned wings. Eggs are laid on or into the upper or lower surfaces of leaves and hatch about a week later. Larvae are grubs about 1cm long, usually white in colour, and feed on the tissue between the leaf surfaces. This creates the distinctive mined trails across the leaf surface.[图片]As larvae grow the mined trails become wider. Larvae feed for two to three weeks before pupating. Pupation sites vary with species, either within or on leaves, or in the soil. Some species over-winter as pupae whereas others feed continuously until spring. There may be one or many generations per year depending on the species.[图片]Treatment Chemical Products containing the following chemical ingredients are all effective on Leaf miner flies Methiocarb Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments. Organic Regularly inspect plants all year round. Remove and destroy infested leaves. Crush larvae at the end of tunnels in leaves by hand. In greenhouses, release the parasitic wasps Dacnusa sibirica and Diglyphus isaea.[图片]Prevention Remove any heavily infested plants. Hang yellow sticky traps to monitor the fist sign of the flies. Encourage insectivorous birds by hanging bird boxes and feeders. Keep weeds under control, particularly groundsel and sowthistle as these are wild hosts.

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月15日

Numerous symptoms are related to herbicide damage, depending on the active ingredients and modes of action of the products used, and all parts of a plant may be affected. Leaves may exhibit distortion, cupping, rolling, yellowing, browning or spotting. Stems may bend, twist, split or swell. Flowers may change size or shape and roots swell and shorten.[图片]Plants affected All plants – but some are more susceptible than others, for instance, tomatoes and brassicas are prone to damage by hormone or growth-regulating herbicides. Damaged food crops should not be eaten. Some herbicides remain active despite composting or stacking so unless you are sure of the contaminant, you should burn the affected material.[图片]About herbicide damage Plants can be exposed to herbicides in a number of ways: From drift when spray herbicide is applied during windy conditions. Using a contaminated , poorly rinsed sprayer to apply pesticide. Leaching of herbicides through water in the soil may result in the root structure of nearby plants being affected. Garden materials such as compost, manure or mulch may be contaminated with a herbicide, causing damage to nearby plants. Herbicide residue in manure has been an increasing problem in recent years. Try to avoid using bought in manure unless you know where it has come from and how it has been treated.[图片]Soil sterilants are long-lasting herbicides that can persist for years. Paths often acquire weeds and foliar sprays are available that may cause yellowing on sensitive plants next to the path. Herbicide applied to a patio may affect tree roots growing under the paving. Plants vary how they recover from herbicide damage, depending on their vigour and the amount of chemical they have received.[图片]Preventing further damage Read and follow instructions on the labels of herbicides, using recommended application rates. Apply liquid sprays very carefully as they can drift in the slightest breeze. Drift may be reduced by lowering spray pressure and spraying close to the target. Be aware of possible leaching and water runoff when using systemic herbicides.[图片]Avoid the use of soil sterilants as these are active for long periods, and soil contaminated with them may need to be replaced. Try to use other forms of weed-control, including mulches, hand-weeding or a flame weeder.

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px