Leaf-eating ladybird

This ugly little creature is the larva of the leaf-eating ladybird. Stressed plants in prolonged hot, dry conditions attract these pests. The larvae become almost black as they reach pupa stage. Both adults and larvae of leaf-eating ladybirds are particularly fond of the Solanum family (tomato, potato, eggplant) and the melon or squash family where they do a lot of damage to leaves.

The adult leaf-eating ladybird has 26 or 28 spots in rows across its wing covers. They are slow moving and drop to the ground when disturbed. In summer, if you see the adults on leaves in your garden, be sure to look under the leaves for their eggs. Remove small leaves containing eggs and, on large leaves, use a knife to scrape the eggs into a container. As I dislike spraying my garden, I just squash the adults and larva with a gloved hand.
不幸的是,这些瓢虫所造成的损失and their offspring have resulted in many gardeners spraying other species of ladybirds that are voracious pest predators. Both adults and larvae consume a considerable quantity of pests such as aphids, scale and mites, and one type of ladybird feeds on fungus. Peter Chew and his family have an excellent website,Brisbane Insects and Spiders,园丁可以轻松识别哪些生物对他们的花园有益,并且包括害虫,包括一个瓢虫场指南
下面的照片显示了28次斑点瓢虫的幼虫和蛹阶段。

黄叶 - 盆栽柑橘

irondeficiency

读者想知道在她盆栽的矮人柠檬树中引起新叶子的造成泛黄。从她通过电子邮件发送的照片,它看起来像这棵树有缺铁,因为黄生在幼叶中呈现。这可能是由许多条件引起的:


a) potting mix (or soil) that is too alkaline from excess bio-char or calcium in the mix or fertiliser containing a lot of poultry manure
b)冷和湿土壤或生长混合
c) if there is a build up of fertiliser salts from synthetic fertilisers, or
d) where there is an excess of potassium from synthetic fertilisers or over-use of seaweed liquid fertiliser.

要做的第一件事就是检查你的锅mple drainage. Large pots should not sit directly on a hard surface. While smaller pots usually have ample drainage holes around the sides at the base of the pots, large pots often have only one large hole in the base and this can easily become blocked resulting in poor aeration and/or a concentration of fertiliser salts if synthetic fertilisers have been used. Large pots should have pieces of tile placed under the pot to allow a small space between the base of the pot and the verandah or paving. If you notice crusting around the top of the soil line (fertiliser salts), flush the plant with clean water, once drainage has been improved.

The next step is to check the pH of the mix with a test kit. A suitable pH is important to all parts of your garden as the pH in soil or mix controls the availability of nutrients. Test kits are very economical to use and readily available from larger nurseries. If you find that the pH is above 7.2, you could repot the tree using an organic-registered potting mix as organic matter is an important source of iron. However, to do so may result in the loss of this crop of fruit.
The addition of flowers of sulphur (elemental sulphur) is the usual way to reduce pH in soils, but it is easy to overdo this in potted plants. You can apply iron chelates (the form of iron in organic compost) to the mix in the pot at the recommended rate. Citrus trees do not absorb iron chelates well through foliar spraying. Or, you can fertilise the tree with a weak solution of Multicrop’s Ecofish. This is an organic-registered liquid fertiliser that contains soluble iron and has a low pH, qhich will help to reduce the pH in the pot. Ecofish contains iron, manganese, sulphur and zinc (trace elements needed by citrus). Manganese deficiency is also caused by high pH or poorly-drained soil.

Red-shouldered beetles

OLYMPUS DIGITAL CAMERAThe warm, dry weather has enouraged this small native beetle (Monolepta australis)进入花园。他们共同的名字suggests, these yellow beetles have a bright red stripe across their shoulders and a red spot on their wings. They arrive in a large swarm and choose one or two stressed plants to feed on. We have noticed that they frequently choose plants with white flowers. Although these beetles are only 6mm long, their sheer numbers enable them to skeletonise small to medium shrubs in a very short time before moving on to another property. Monoleptas are difficult to control because sprays that will kill the beetles will also kill beneficial insects visiting plants at the same time.
如果攻击的植物不是太大,你可以通过使用棍子将它们敲入肥皂水容器中来摆脱这些甲虫。由于他们对彩色白色的喜爱,许多甲虫将淹没在一个充满水的白色容器中,留在目标灌木附近。(Don’t add soap to this water or it will kill bees that stop by for a drink.) The only way to protect your garden from attack by these beetles is to keep shrubs watered during dry spells, and keep the garden surface mulched to prevent moisture loss through evaporation.

Lime Sulphur

yellrose1Agricultural lime or elemental sulphur are recommended to modify soil pH to a range that suits healthy growth of particular plants. A reader recently asked me if “Lime Sulphur” was suitable to use around roses in her organic garden.
‘Lime Sulphur’ or ‘Lime Sulfur’ is a fungicide/pesticide formed from reacting calcium hydroxide (made from adding water to quicklime) with sulphur. It is usually applied when roses are dormant as it can burn foliage.
水合石灰是非常有反应性的,不应在植物生长的情况下使用。石灰硫溶液非常碱性(pH1.1.5-11.5)和腐蚀性。手套,护目镜,面部面罩和防护服必须佩戴,因为农药对眼睛,皮肤和呼吸道的烦恼非常刺激。看看Material Safety Data Sheet对于这个产品。

当植物受到足够的元素(包括硫磺)时受疾病的影响,他们需要健康免疫系统,或者不合适的土壤pH(因为pH控制不同营养物的可用性)或土壤要么过于干燥,根部吸收营养素,或被涝,非常酸性。
Although some sources state that Lime Sulphur fulfils requirements of organic gardening groups, the ‘Australian Certified Organic Standard 2010'将石灰硫作为限制性产品,并指出它对有益昆虫产生潜在影响。
My advice is to maintain a moderate amount of well-made compost in your topsoil, where compost holds all nutrients (including sulphur) close to plant roots; adjust irrigation and soil pH, and provide suitable amounts of complete organic fertiliser. In the meantime, if your plants have a serious fungal problem, I suggest you use Organic Crop Protectants’ organic-registered ‘Eco-fungicide’. It won’t damage your plants or your soil, and it is kind to beneficial insects.

Cabbage butterfly update

cwbdecoy白菜白蝴蝶今年与我的西兰花度过了美好的时光。有几个条件使芸苔非常有吸引力,这些害虫和棕色白菜蛾。看到Cabbage white butterfly
我的问题是,我无意中向花园的那个区域添加了一些非常碱性的堆肥,(见最近的帖子Compost pH) and it is taking a while for the soil to get back to a neutral pH.

After spending a week or so removing eggs, squashing tiny caterpillars, or feeding larger ones to the chooks, I remembered a tip someone gave me long ago to deter these pests but have not needed to use before. The tip was to slip the plastic clips that seal loaves of sliced bread onto the edge of some of the Brassica leaves. White seals to deter the C W butterfly and beige ones for cabbage moth. The theory being that the adult butterflies and moths will “think” that eggs are already being laid on these plants and they look for another food source for their larvae.
My broccoli plants are looking healthier already and I have not found any more eggs under the leaves, but I don’t know if the seals are working or the pests are no longer present in our area. Has anyone else tried this tip?

Root knot nematodes

Nematodes that damage roots in the vege patch, are minute worm-like creatures, also known as eelworms. The female nematodes penetrate plant roots causing lumps to form on the roots, which affect the water-carrying ability of the roots. (These are not to be confused with the nitrogen–fixing lumps that form on the roots of legumes, seeFixing nitrogen)。在有机质中较低的土壤中更容易发生根结线虫,特别是在尚未实施适当的作物旋转的情况下。

Treatment
Each female nematode can lay up to 2000 eggs, and numbers can multiply quickly. Give affected plants a foliar feed of seaweed extract tea. Seaweed contains plenty of potassium that helps to strengthen cell walls and improves plants’ resistance to pests and promotes root growth. Remove all weeds. Some weeds are hosts to these pests and can transfer viruses to plants.
Affected plants must not be allowed to become water-stressed. Badly affected plants will have to be removed. Make sure the soil is damp so that soil clings to the roots. Place plants (with attached soil) into a garbage bag. Seal the bag, leave in hot sun for a few days, then place it in the garbage. Do not compost these plants. Once the crop is harvested, proceed with methods for prevention (see below).

Prevention
Allow 3 years between growing any member of the tomato/potato or melon/cucumber families in the same patch of soil. During this break, grow a green manure that is a ‘bio-fumigant’. ‘Bio-fumigants are green manures that release a gas that is toxic to nematodes. They are grown to knee height and chopped up and mixed through top soil, then covered with mulch.Green Harvest在控制线虫的情况下,对BQ覆盖物(在较冷的月份播种)和豇豆(播种)。印度或棕色芥末(Brassica Juncea)和非转基因油菜籽(Brassica Napus)也是有效的生物熏蒸剂。忘记万寿菊,他们对北半球线虫更有效。在3年的休息期间,如果花园空间有限,可以在经过有限的床上生长芸苔或玉米。
When preparing beds, add a 5 cm layer of organic compost to the bed surface and cover it with organic mulch. Beneficial organisms in compost are pest nematode predators, and mulch keeps compost damp to allow microorganisms to work on restoring soil to health.

Powdery mildew on zucchini

A reader has asked about powdery mildew on zucchini plants and fungus-eating ladybirds:
Hi. Wonder if you can sort this.
1。Most fungi need moisture and organic material. This seems to be supported by my zucchinis which seem to get worse powdery mildew when I get water on the leaves. I have read that they like dry weather. Is there evidence for either opinion?
2。Some people say that the ladybirds that feed on this mildew spread it by carrying spores, others reckon they are a controller, eating the fungus down. What is the evidence please for either of these? Many thanks, Barb


Powdery mildew is likely to occur on stressed plants in humid weather when temperatures are between 11-28° C. and, once established will continue to affect the plants even if weather becomes dry. Avoid wetting leaves whenever possible Barb. However, because they like low-humidity weather, it doesn’t mean that they are drought tolerant. Zucchini and some other members of the cucurbit family (melons and squash) produce a lot of foliage and need plenty of water and fertiliser. An efficient way to water this group of plants without wetting the leaves is to put a large drink container (with the base and cap removed) neck downwards near the roots so that all the water goes directly to the root area where it is needed, (see photo). Keep topping up the container until it empties slowly.
The yellowish ladybirds with 26 or 28 spots are the only pests of the ladybird family. They eat the leaves of stressed plants of cucurbits. The beneficial fungus-eating ladybird and larvae can be clearly distinguished from the pest in the photos below. From the far left is the ‘Fungus-eating ladybird’, then the leaf-eating ’26 spot Ladybird’ that damages plants. Next is the larva of the ‘Fungus-eating Ladybird’, which also eats fungus and, last of all is the prickly larva of the ’26 spot Ladybird.

Rather than blame the fungus-eating ladybird for spreading the disease, gardeners should check that their plants have sufficient water and nutrients to avoid stress, and the soil pH is suitable for them to absorb what they need for healthy, disease-resistant growth. Also seePowdery Mildewfor treatment of this disease.

Camellia leaf gall

If new leaves on Camellia plants become thick and very pale green or pink, and the underside of the leaf starts becoming white – the plant is suffering from ‘Camellia leaf gall’. This is a fungal disease that affects tender new growth ofCamellia sasanqua(and sometimesCamellia reticulata), especially in very humid or wet, shady conditions. Fungal diseases are a sign that growing conditions are stressing your plants and their immune system is compromised. There is no organic or chemical treatment for this disease. However, an application of seaweed extract tea will help to strengthen the cell walls of the affected plants and make them more resistant to disease.

但是,首先受影响的增长必须被移除,公关eferably before the undersides of leaves develop white spores. You will need a baked bean tin containing about 5 cm of methylated spirits to sterilize secateurs blades, and a large garbage bag for the prunings. Prune off all affected growth (swish the open secateurs in the spirits often while pruning) and place it directly into the garbage bag. Also collect in the bag any fallen leaves as they can harbour the fungal spores that will activate this disease again when conditions are suitable. Seal the bag and put it in the garbage if you are unable to burn the leaves. Do not compost them. Then give the soil around the plants a drink of seaweed extract at the recommended strength, and protect the soil surface with 3–5 cm of fresh mulch. Make sure your camellias are watered when the top centimetre of soil is dry, but afford watering the foliage. Also give the plants an annual application of compost or complete organic fertiliser and seaweed extract tea in late winter.

看到below, how affected new growth appears, and close-up of affected leaves.


Photos courtesy of A. Lavick.

生锈疾病

There are hundreds of types of fungi that cause ‘rust’ on plants but each type has a limited number of host plants so that your whole garden is not likely to be overrun by rust.
Rust can occur in various seasons but it does need moisture to grow. It typically causes yellow or brown markings on upper surface of leaves, and small yellow or brown powdery growths on the underside of leaves. The powdery substance consists of fungal spores that can be blown about by wind, infecting other plants that are susceptible to that type of rust fungus.
下面,在左边,如果赤素馨花叶和典型的生锈符号在草地上的典型标志,是底面的锈迹。一些叶标记可以与真菌疾病混淆。在右边是蕨类植物骨折上侧面和孢子上的冰雹伤害的照片 - 这是蕨类植物的繁殖。

Treatment
Basically, rust diseases are a sign of malnutrition that produces an unsuitable pH on the leaf surface. Plants, like humans and animals, are more prone to diseases when they have a poor diet, and rust diseases can be avoided by keeping plants growing vigorously – but this is not always possible in extreme weather conditions. Sulphur or copper are the usual treatments for rust. Both of these are nutritional elements that can be supplied by various fertilisers, including seaweed extracts. Seaweed also contains plenty of potassium that strengthens cell walls, sulphur, and trace elements (including copper) that boost plants’ immune systems.
对于轻度锈病,消除受影响植物的受损部分,并将它们烧掉或在密封的塑料袋中烧掉它们。不要堆肥它们,因为孢子可能不会被杀死。然后给植物饲养海藻提取茶的叶面饲料,并将一些物水进入根部区域。使用完整的有机肥改善您的肥料计划。
For deciduous plants, rake up and dispose of dropped leaves to avoid reinfecting the plant. Apply the seaweed tea at bud swell.
对于更严重的情况,在去除受损的叶子后,植物可以用元素硫磺(硫的花朵。然而,随着孢子在叶片下,灰尘可能难以涂抹,可能会用凉爽的天气喷涂受影响的植物只有,当温度超过24摄氏度时,硫磺将损坏植物。请注意,硫也会杀死害虫捕食者。如果这些存在于受影响的植物上,请将洋甘菊茶(一个茶袋为500ml水)涂抹。

霜霉病

Many parts of Australia are experiencing flooding, while West Australia is experiencing extremely hot weather with bushfires in the south, so looking after the garden is the least of their problems. My sincere sympathy to all those affected by these extreme weather events, many of whom are facing heart-breaking work to rebuild their lives.

For those of us who are fortunate enough to still have gardens, the prolonged wet conditions provide the perfect conditions for downy mildew to flourish. A set of three conditions (10:10:24) is necessary for downy mildew to establish – a minimum of 10 mm of rain, a temperature higher than 10 degrees Celsius, and foliage that stays wet for more than 24 hours. It is also more likely to affect plants that are stressed for some reason, and where there is poor air circulation. This group of fungal diseases produce pale green or yellow spots on the upper side of leaves, and white-grey furry patches on the underside of leaves of a wide range of plants, including cucurbits, the cabbage family, lettuce, onions, peas and grapes (starts as oily spots). Different species of the fungi infect different varieties of plants, so that downy mildew on your cauliflowers does not mean that other vegetables in your garden will be affected.

The best thing you can do is remove badly damaged foliage and dispose of it in a sealed plastic bag – compost it! Then give soil around affected plants a drink of seaweed extract tea at the strength advised on the label. A good potassium content in seaweeds strengthens plants cell walls helping plants to build resistance to diseases.
Spray remaining leaves with 100 mls milk in 900 mls water (to make 1 litre of spray), and add a good pinch of bi-carbonate of soda (baking soda) for every litre of spray. Full cream milk works best because the fat content helps the spray stick to the leaves, and full cream, organic milk is even better (according to some gardening gurus) – if you can spare it. Milk and bi-carb are not fungicides, but they produce unsuitable conditions on leaf surfaces for the fungi’s survival. Spray leaves early in the day, and repeat every four or five days until mildew clears.
霜霉病tends to disappear as weather becomes drier because it needs constant humidity. However, powdery mildew needs high humidity, but not wet weather, to establish and will continue to flourish after weather becomes drier. Powdery mildew is caused by an entirely different genus of fungus and treatment for that disease can be foundhere

P.S. When spraying – be careful to avoid these tiny fellows below – the adult and larva of the Fungus-eating Ladybird.

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