Phlox pests can completely destroy all adult bushes of plants and seedlings. The main enemy is the nematode, which is ubiquitous. These are microscopic insects that can literally suck out all the juice from the stalks, leaves, buds and flowers of the plant. They winter well in the conditions of our country. The attack is usually inconspicuous at first. But gradually phloxes begin to wither and dry.
These phlox pests and control are described in detail in this material. You can clearly see what the nematode on phlox and a number of other dangerous pests of this culture look like.
Attacked by pests are most often exposed to weakened plants, the cultivation of which violated the rules of agricultural technology. Damage to phloxes by sucking pests is compounded by the fact that insects carry numerous infections of various origins.
The main pests of phlox
By the nature of the damage inflicted pests are varied. Some feed on the roots, others above-ground parts of plants, and some damage both.
In the fight against the main pests of phlox, the creation of unfavorable conditions for their existence is recommended - digging the soil with careful loosening (so that there are no cracks), weeding and other agrotechnical, as well as protective measures.
First of all, attention should be directed to:
Carrying viral and fungal diseases.
The fight should begin immediately after their detection, regardless of the number of pests. Recommended thorough weeding, digging the soil before winter, the destruction of plant debris. Effectively double spraying of affected plants with solutions of system insecticides Confidor or Aktar.
Weevil, wireworm, earworm, caterpillars are low-hazard pests.
Fighting them is not appropriate if the number of individuals is small. With a large number of pests, spray plants with insecticide solutions, for example, Denis, Aktellik, Iskra, or others that are similar in action. It is also possible to recommend double spraying of plants with Confidor or Aktar system insecticide solutions.
One of the important agrotechnical methods of fighting wireworms (the larva of the click beetle) consists in the destruction of weeds (especially crayfish), which serves as a source of nutrition for pests, as well as loosening the soil and all techniques aimed at improving the immunity of plants. The effectiveness of the mechanical treatment of the soil depends on how much the timing of their implementation coincides with the most vulnerable phases of pest development - egg laying (May – June) and pupation (July – August). Careful collection of larvae when digging the soil. Liming sour soil. Timely watering.
In the fight with earwig ordinary cleaning the site from debris, stones and plant residues, autumn digging of the soil is recommended. It is possible to lay out baits - shelters from boards, herbs for attracting the pest and their further destruction. With a large number of earwigs, the plants are sprayed with solutions of insecticides Detsis, Aktellik, Spark or others similar in action.
Very often, especially in rainy warm summer, bare slugs and various snails (or rather some of their species) cause considerable damage.
On the tender leaves of young phlox plants, they gnaw holes with jagged edges, leaving traces of mucus shining on their surface as the mucus dries and excrement dries out; damage the lower part of the shoots; can spoil the buds and flowers, sometimes eat the roots. Particularly harmful can be caused by bare slugs to young seedlings and cuttings on littered, poorly treated areas. In addition, they are carriers of plant diseases caused by various fungi, since the fungal spores, passing through the intestines of slugs, remain intact.
The number of bare slugs can be reduced if weeds are destroyed in a timely manner, the plants are thinned, in the summer to loosen the soil regularly and carefully (so that there are no cracks), and to dig it in the fall. In small areas, it is possible to collect slugs manually from under stones, fallen leaves, planks and other shelters, where they gather in the daytime, and destroy them.
You can catch slugs with the help of artificial shelters (the same boards, tin, bark of trees, wet rags). Effectively using bait traps (chopped carrots, potatoes, cabbage leaves).
At night, the areas where phlox grows are pollinated with a mixture of freshly erupted lime and tobacco dust (1: 1) or ground superphosphate. You can dust phlox and soil with ashes - this is useful for plants and creates unfavorable conditions for slugs. If the phlox bushes are surrounded by a narrow ribbon of superphosphate, ash, lime, this will close the access of the pest to the plants. In the fight against slugs, 5% Metaldehyde is also used - a granular drug of contact and intestinal action, or other drugs containing metaldehyde (Thunder, Thunder, etc.). Pellets scatter in the evening on a dry warm soil around the plants. Also spraying with broth of chilli pepper helps.
See what phlox pests look like and control them in the photo, where the main agrotechnical techniques are shown:
Nematode on phlox: photo and control measures
Plant nematodes on phlox are microscopic organisms that feed exclusively on living plant tissue. Nematodes are divided into root, stem and leaf. Nutrition and vital activity of nematodes causes plant disease - phytogilmintosis. Causative agent phlox disease - stem nematode Ditylenchus dipsaci var. phlo-xidis. Widespread and large economic damage caused by this type of agriculture ensured its inclusion in the list of quarantine organisms in many countries, however, the temperature regime favorable for the development and reproduction of stem nematodes is typical for a temperate climate zone. Currently, parasitic nematodes of the genus Ditylenchus have been identified in many regions of the Russian Federation. Timely measures to combat nematodes on phloxes can only reduce the number of pest populations. Constant monitoring is required.
Ditylenchus dipsaci has more than thirty races that cause plant diseases and occupy one of the main places among parasitic nematodes. Currently, about 480 species have been registered as host plant stem nematodes.
Phlox plants are especially harmed by the phlox race of stem nematodes Ditylenchus dipsaci var. phlo-xidis. It is a microscopic, invisible to the eye, thin thread-like worm. Females are distinguished by a rather slender body, strongly narrowed to the head and tail, the length of 1,1 is 1,8 mm. Males 1,0 long - 1,3 mm, the tip of the tail sharply narrowed. The entire life cycle of the nematode takes place inside the plant tissue. Worms are very mobile, easily rising from depth to 1,5 m, overcoming the distance in 10 cm in about 3 hours. During the growing season 4-6 generations develop. It is a parasite on plants from the family bluish, equally dangerous for all members of the Phlox genus.
In dry herbarium specimens stored in botanical collections, the nematode retains its vitality for up to 23 years. Under natural conditions, it survives in plant residues up to 6 -12 months. Egg-laying begins at 2-4 ° C, reaching optimum at 13 - 18 ° C, and ends at 35 ° C. The development cycle from egg to egg takes 19 - 23 of the day. The life span of a female 45 - 75 days, during this period she lays 200 - 400 eggs, an average of 8-10 eggs daily. Nematodes are preserved in hibernating plants (in the bases of shoots and rhizomes), as well as in dry plant debris.
Exterminus nematodes can completely destroy susceptible varieties of phlox paniculate. D. dipsaci var. phloxidis can also be found on the carnation of the Turkish, Canadian goldenrod, bellflower peach, primula, shizantus, enotere and some other ornamental cultures.
Most often it affects the buds, apical growth points, non-lignified stems, leaves and flowers. In addition, parasites can persist in the seeds.
Symptoms of damage caused by nematodes of the genus Ditylenchus are clearly visible to the naked eye and are very diverse, but in the early stages, when individuals are single, external signs are absent, and patients with phlox are no different from healthy ones. Depending on the degree of development of the disease, various metamorphoses of the aerial parts of the plant are noted — anomalous growth of damaged organs and tissues, accompanied by their destruction up to necrosis. Various deformations and deformities appear on the leaves of the affected plants.
The leaves shrivel, bend, curl inward at the edges; other pathologies are easily visible, the leaves become filiform, or, conversely, very broad, often curly. On sore leaves, swelling and yellowish translucent spots, resembling a mosaic, are often noticeable.
Stems thicken, bend, lag behind in growth and development, become either spindle-shaped and brittle with long internodes, or shortened, swollen, soft. Branching uncharacteristic for the variety may be observed. In newly infected plants, swelling is usually observed in the area of nodes and internodes. As the disease progresses, numerous small cracks appear on the lower part of the stems, peeling is noticeable. These signs are often accompanied by chlorosis. Such plants usually fall out at the beginning of flowering, and if they bloom, the inflorescences and flowers look ugly. The harm caused by nematodes is aggravated by the fact that they contribute to the spread of numerous fungal and some viral infections.
The most characteristic and typical sign of the presence of a nematode infection for phlox is the thinness of the leaves (phytogilmintosis).
Distribution of nematodes occurs with irrigation and rainwater, with the wind, with the help of tools and during vegetative propagation of plants. The number of stem nematodes sharply increases in monoculture conditions.
Penetration of nematodes into a plant is possible through mechanical damage or after overcoming the plant cell wall, which nematodes are able to destroy, releasing special enzymes.
In some cases, root (Pratylenchus penetrans, Rotylenchulus reni-formis, Meloidogyne hapla, M. javanica) and sheet nematodes (Aphelenchoides ritzemabosi, A. fragariae, A. subtenuis), as well as other races of the stalk, were found on the phlox plants, as well as other races of the stalk, and the other races of the stalkomatis, A. fragariae, A. ) - rye, beet, tulip and less often strawberry, alfalfa, narcissus and oatmeal.
See how the nematode on phloxes looks in the photo, illustrating its signs:
Treatment of phlox from nematodes
Early diagnosis helps control the spread of nematodes. In the spring when shoots appear, it is usually already possible to detect infected plants. At the slightest suspicion of nematode infection, it is necessary to carry out all anti-nematode measures, including the treatment of modern systemic nematicides from the group of carbofurans. Acceptable use of such drugs and for the treatment of planting material. When treating phlox from nematodes, watering the plants from above should be avoided in order to avoid intensive wetting of the aerial organs, which can lead to the rapid spread of the disease.
Effectively removing affected plants in the early stages of the disease (manual culling). The first such culling is carried out at the beginning of May, and plants are subsequently removed with deformed ones appearing (not only with threadlike leaves). For breeding varieties of phloxaffected by the stem nematode, carry out cuttings of healthy stems in late May - early June.
Before planting the cuttings are kept in a dark raspberry solution of potassium permanganate. Infected cuttings, as a rule, do not root. In some cases, regular and timely culling and reproduction with healthy cuttings allow you to completely get rid of phlox ditilenhoz within two to three years even with a strong initial infection.
Good results in the fight against stem nematode phlox gives the use of so-called trapping plants. These plants include marigold, pea, mustard, calendula, castor bean, cucumber, parsley, portulac, millet, ryegrass, asparagus, timothy, dill, chicory and some others.
These plants are especially susceptible to the nematode, some of which are traditionally used as siderats - soil improvers (plants used as green fertilizer). Farming crops are planted next to infected phloxes, then dug up and destroyed before the completion of the nematode development cycle.
As the nematode settles, feeds and multiplies on different types of weeds (dandelion, nettle, sow-thistle, mint, woodlouse and many others), systematic destruction of weeds is necessary. Weeds and various plant residues are an additional source of food and reservants for stem nematodes, as a result of which their numbers increase. Remove weeds should, if possible without damaging them. If conditions permit, surface treatment with organochlorine and phosphorus compounds can be recommended.