Diseases and pests of cucumber, pumpkin, squash and squash
In our area, it is difficult to find a garden or a summer cottage where cucumbers, squash and pumpkins would not grow. As a rule, their cultivation is not a hassle and all agrotechnical measures have been known to the summer resident for a long time. But it may happen that once, before, a green bed of cucumbers begins to turn yellow, the leaves of the plants wither, wrinkle and the crop is in danger. In this case, most likely, the plants were attacked by pests, or affected by the disease. And they have enough cucumbers, pumpkins and zucchini. The pests of cucumber, pumpkin, squash and squash include, in addition to their own, pests that damage other crops.
Pests of cucumber, pumpkin, squash and squash
Especially harmful for the culture of cucumber in greenhouses and small-sized film shelters. The tick body is oval or oblong, 0.3-0.4 mm long. Spherical egg; recently deferred - greenish, transparent, further - unclear.
Ticks live and feed on the underside of the leaves, entwining them with a race of cobwebs. On the damaged leaves, first light dots appear, similar to pinpricks (especially noticeable from the top of the leaf). Subsequently, the leaf becomes spotty (marble), then turns yellow and dries; with severe damage, the death of the entire plant is possible.
Ticks and larvae, feeding on the cellular sap of cucumber plants and other plants from the pumpkin family, cause the falling of flowers, ovaries of fruits and leaves, which causes a significant decrease in yield.
In open ground, ticks appear from the second half of June. Here they breed greatly in hot, dry years. In normal years, ticks harm mainly in hotbeds and small-sized film shelters. The pest leaves for the winter in early August. Most often, an adult insect (females) hibernates under fallen leaves, plant debris, clods of earth, in crevices of buildings, greenhouses, in mats, greenhouse frames, or even in the surface soil layer at a depth of 30-60 mm.
In spring, at a temperature of 12 ... 13 ° C, fertilized females begin to lay eggs on the underside of weed leaves or vegetable plants 5-7 days after leaving the wintering places. After 5-7 days, larvae emerge from the eggs, which live and feed on the underside of the leaves. The tick develops continuously throughout the entire warm period. It takes 10-28 days to develop one generation.
The spider mite is ubiquitous.
Spider mite control measures
- regular spraying of beds with cucumbers with water during the day (in hot weather);
- spraying plants with infusion of onion or garlic scales (200 g of scales per 10 l of water);
- systematic weed control;
- spraying plants during the growing season when a tick appears with one of the drugs: celtan (chloroethanol), 20% ke. (20 g per 10 liters of water); in protected ground during the same period, isophene, 10% to. or 10% s. are used to control powdery mildew. item (60 g per 10 l of water) and ground sulfur (300 g per 100 m2);
- deep autumn digging of the soil with the destruction of post-harvest residues.
It is polyphagous, feeds on more than 46 plant species, and most often harms cucumbers and zucchini. The body of wingless females is oval, dark green, almost black, 1.25-2.1 mm long. Larvae are yellow or green, winged or wingless. Propagate asexually, giving in season 14-20 generations.
Mostly adult aphids overwinter, sometimes larvae. Reproduction in spring begins at a temperature of about 12 ° C. The optimum temperature for development is 16 ... 22 ° C. In the spring, the pest develops and feeds first on weeds, and then moves to cucumbers, zucchini and other pumpkin plants. Aphid colonies are located on the underside of the leaves, on shoots, ovaries and flowers. Damaged leaves curl, flowers and leaves fall off. Plant growth is delayed, sometimes plants die.
In open ground on aphid ridges, it appears on cucumbers in July - August, in greenhouses and small-sized film shelters - in the spring.
Measures to combat melon aphids
Spraying plants with the appearance of a pest during the growing season before flowering and after harvesting with one of the preparations: karbofos, 10% K. or 10% C. (60 g per 10 liters of water) in a protected ground, trichloromethaphosome-3 (triphosomes), 10% K. (50-100 g per 10 liters of water).
Damages the seedlings of all pumpkin crops. The fly is small, 5-7 mm long, gray with a dark longitudinal line on the abdomen. Larva white, narrowed in front, with denticles on end of body, up to 7 mm long.
Pupa of flies overwinter in the soil on crops of vegetables, grain crops and clover. The fly flies in the spring in May, at the beginning of the flowering of birch; lays eggs in the second half of May under lumps of soil, preferring wetter soil with poorly manure. After 2-10 days, larvae appear that damage the swollen germinating seeds and seedlings of plants of various cultures. At the seedlings of the cucumber, they drill a submucosal knee and penetrate into the stalk. After eating, pupate in 12-16 days. During the season, 2-3 generations of sprout flies develop.
Sprout fly control measures
- conducting autumn digging of the soil with the introduction and careful incorporation of manure;
- sowing seeds at the optimal time (best for the area), the seeds should be planted shallowly, but carefully;
- collection and destruction of plant post-harvest residues.
Diseases of cucumber, pumpkin, squash and squash
The causative agent of the disease is a fungus. Squash, cucumber, pumpkin, squash are affected in various phases of development. In greenhouses and small-sized film shelters, the disease is widespread. Plants become infected during the entire growing season. Rounded, somewhat vague spots form on the leaves. Sometimes the spots, increasing, merge, covering a significant part of the leaf plate and giving it the appearance of a burned one. Then the leaves turn brown, dry, become brittle, crumble. On stems and lashes, spots are elongated, rather large, weeping. Mucous orange pads form on them, the located fruits are wrinkled and rot, becoming bitter. The harm from anthracnose is expressed in a decrease in the quantity and quality of the crop. The disease develops not only during plant vegetation, but also during harvesting.
The causative agent of anthracnose overwinter on infected plant debris, sometimes it is brought in with seeds extracted from diseased fruits.
Anthracnose Control Measures
- culling affected seedlings;
- removal of diseased plants during flowering;
- spraying plants during the growing season in a protected ground with gray colloidal, 35% paste (40-100 g per 10 l of water); Bordeaux mixture (100 g of copper sulfate and 100 g of lime per 10 liters of water) from the onset of the onset of the disease;
- disinfection of greenhouse frames and wooden parts of film shelters after harvesting with bleach (200 g per 10 l of water);
- collection and destruction of post-harvest residues.
Mushroom disease, manifested in the conditions of the non-chernozem zone on cucumber, zucchini, pumpkin, squash. The causative agent of the disease develops on plant tissues and affects pumpkin from the moment of plant growth, especially with frequent dew. Leaves and stems are affected. The disease is most harmful when humidity is high in conditions of insufficient watering.
At first, rounded white spots appear on the upper side of the older leaves. Then they increase in size and quantity, merge, appear on the lower surface of the leaves, the entire sheet is covered with a white powdery coating. Heavily affected leaves change their dark green color to light, yellow-green, then darken and shrink. Affected stems and young leaves become chlorotic, underdeveloped and can completely die out. Fruits on infected lashes ripen prematurely, have a poor taste and lack of sugar content, tied up late, often remain underdeveloped.
The mushroom hibernates on the remains of diseased plants, as well as on a number of herbaceous perennials susceptible to powdery mildew (thistle, plantain, etc.). In the spring, young leaves of pumpkin plants become infected. A very harmful disease, is ubiquitous. Cucumber plants in greenhouses and small-sized film shelters are more affected than in open ridges.
Powdery mildew control measures
- removal of tops of pumpkin and weed plants around film shelters and hotbeds;
- deep autumn digging of the soil;
- the return of cucumbers to their original place no earlier than 3-4 years;
- maintaining in greenhouses and small-sized film shelters an air temperature of 20 ... .25 ° C, normal soil moisture;
- spraying the plants when the first signs of powdery mildew appear with one of the preparations: gray colloid - 70% paste, 70% wettable, 80% s. item, 80% granular (20 g per 10 l of water in open ground and 40 g per 10 l of water in sheltered ground); gray colloid - 35% paste (sulfaride) (40-100 g per 10 liters of water in protected ground); ground gray (300 g per 100 m2); disubstituted sodium phosphate (50 g per 10 l of water); isophene, 10% to. and 10% with. (60 g per 10 l of water in protected ground);
- with focal disease, they cut and destroy the leaves or cauterize the leaves with ground sulfur (sulfur is applied to the affected areas with cotton wool);
- spraying with mullein infusion (1 kg of mullein is poured with 3 l of water and insisted for 3 days, then filtered and diluted 1 l of infusion in 3 l of water);
- evening spraying of hay infusion (1 kg of rotted hay is infused in 3 l of water for 3 days, then filtered and diluted with water 3 times) until a powdery coating appears, followed by repetition after 7-9 days;
- thorough washing of the treated fruits with warm water from the remnants of chemicals on the surface of the cucumbers;
- cultivation of resistant varieties with dark green leaves (Altai early 166, Hybrid Start 100, Elegant, etc.).
The causative agent of the disease is a fungus that affects the roots, the lower part of the stems, petioles of the leaves and fruits. A white flaky coating forms on the affected parts of the plant, on which black dots subsequently appear. The tissue areas on which the fungus develops become soft and mucilage, the plant withers, then dies. Zelentsy become infected very quickly in contact with a diseased area of the stem. With a strong development of the disease, the yield of cucumbers (greens) sharply decreases.
The development of the disease is promoted by low temperature with high humidity, thickening of plantings, untimely pruning of sick and dying leaves. During the growing season, plants become infected by caring for them through stomata and mechanical damage with pieces of mycelium. The causative agent of the disease is stored in the soil. Due to the fact that the disease strongly affects parsley, you can not grow cucumbers after parsley without first replacing or disinfecting the soil, since the infectious beginning of the fungus can be in it. White rot causes great harm to cucumber in greenhouses and small-sized film shelters.
White rot control measures
- the alternation of crops in greenhouses and ridges;
- rubbing with a piece of cotton wool or gauze sections of the stem with the initial signs of illness that appeared, followed by dusting with crushed coal or chalk; cutting out diseased tissue with the capture of part of the healthy;
- evening watering plants with warm water;
- application of foliar top dressing (1 g of zinc sulfate, 2 g of copper sulfate and 10 g of urea in 10 l of water);
- harvesting all plant debris with an upper 2-3 cm layer of soil;
- reduction of air humidity in the greenhouse by periodical ventilation in order to stop the development of the disease;
- cultivation of varieties resistant to the disease (Harvest 86) and with medium resistance (Intolerant 40).
The fungus, the causative agent of the disease, parasitizes on vegetating plants in greenhouses and small-sized film shelters, especially the flowers, ovaries and peduncles of the cucumber. In dry weather, the affected tissue turns brown and dies, and in wet weather a gray coating appears on them, the tissue mucilages. Black dots (sclerotia) form on the affected tissue. Rot spreads rapidly. Bees and other pollinating insects transfer fungal spores from diseased flowers to healthy ones throughout the growing season, causing damage to more and more new plants. Affected plants dramatically reduce fruit yield. The mushroom hibernates on the remains of affected plants, often on the stems of potatoes.
Measures to combat gray rot
- the alternation of cultures with the return of the cucumber to its former place in 2-3 years;
- replacement of contaminated soil in greenhouses;
- fertilizing with phosphorus fertilizers;
- timely removal of drying flowers and affected ovaries;
- Autumn digging of the soil.
A complex disease resulting from adverse growing conditions that weaken plants and thereby contribute to the attack of parasitic soil fungi on them. Distributed mainly in greenhouses and small-sized film shelters. The main signs of the onset of the disease are, first of all, the plant’s lagging in growth, underdevelopment of leaves, their yellowish color, falling of ovaries and underdeveloped fruits, and sometimes the death of the whole plant. The roots of the affected plant darken, become rotten, macerate; on larger roots, slightly indented dark spots are noticeable.
In some cases, the lesion can ring-wrap around the root neck (neck rot), which leads to the death of the aerial part of the plant. Root rot occurs under unfavorable conditions for the growth and development of cucumber plants and can be a very harmful disease. Root rot is especially often found in the early cultivation of cucumbers. A sharp fluctuation in the temperature of the soil, watering plants with cold water (9 ... 11 ° C) negatively affects the development of the root system of the cucumber: it weakly develops, later soil fungi settle on it, which destroy it. Sharp fluctuations in the temperature of the soil, drying of the roots when untreated soil is added to them increase the susceptibility of plants to root rot.
Measures to combat root rot
- using only a mixture of fresh soddy soil and humus for growing cucumber with the addition of well-decomposed and weathered peat;
- watering plants with water at a temperature of at least 20 ° C;
- maintaining normal soil moisture (without overmoistening), and soil temperature during the entire period of growing cucumbers 20 ... 25 ° C;
- when the first signs of root rot appear, adding earth to the stems to form additional roots;
- carrying out rejuvenation of plants - the stem is lowered onto the soil and a little fresh soil is poured on it, just to cover the stem; after the appearance of new roots (after 10-15 days), additional soil is added; see also white rot control measures.
Seedlings root rot
A widespread disease of cucumber in greenhouses and small-sized film shelters. Mushrooms - the causative agents of this disease - affect only weakened plants. The disease is the result of sowing seeds in cold, very moist soil in cold weather. The development of the disease is promoted by unfavorable growth conditions (low air and soil temperatures due to waterlogging of the soil, irrigation with cold water).In this case, weak, slowly developing seedlings become susceptible to infection by soil fungi. In affected seedlings, the root neck and roots, cotyledons and young leaves are browned first, then the stem is thinned, which leads to death of the plant.
Measures to combat root rot seedlings
- creation of optimal conditions for the growth and development of plants (fairly fertile soil, soil temperature should be 20 ... 26 ° C);
- irrigation with lukewarm water (but not higher than 20 ° C);
- on days with cool weather, limiting the watering of cucumbers to exclude waterlogging of the soil, since even short-term (for several days) waterlogging is dangerous;
- the use of peat pots for growing seedlings.
The causative agent of the disease are various types of soil fungi. Plants are affected at any age. Mushrooms penetrate the root system of cucumber plants from the soil and grow in its conducting vessels. As a result, the cotyledons wither on the affected seedlings, the lower part of the stem decays, and mass death of seedlings in which the roots rot or dry out is often observed. The death of plants before their appearance on the surface of the soil is also possible. The disease is very harmful.
With the defeat of fully developed plants, the tops of the lashes wilt.
On the edges of the leaves, especially the lower tiers, spots form; leaf tissue between the veins begins to die; the leaves of the upper tiers lose turgor, become chlorotic. Then the whole plant gradually fades. On the transverse section of the stem of a diseased plant, a vasodilatation is clearly visible. Sometimes at the base of the stem you can find a white fluffy coating of mycelium. The roots and root neck rot, the plant breaks down. In dry years, a very strong manifestation of the disease can be observed, when within a few days all plants can die. In addition, the disease is able to switch to other pumpkin (pumpkin, squash, squash).
Fusarium wilting measures
- crop rotation;
- replacement of contaminated soil in greenhouses;
- systematic land addition to plants during the growing season in order to form additional roots.
The causative agent of the disease is a fungus that settles mainly on weakened plants. The disease occurs in greenhouses and small-sized film shelters. This disease affects the stem and leaves; first symptoms appear in the nodes of the stem, on the incompletely removed petioles of leaves or shoots, then spread up and down the stem. Gray spots with numerous black dots form in the affected areas.
At the time of mass fruiting of the fungus, leaf damage is noted. Leaf disease most often begins with the lower ones, which are most weakened and least illuminated. The defeat of the leaves begins from the edge in the form of large chlorotic spots with a large number of black mushroom pycnids. The leaves dry out quickly and the plant dies.
The defeat of the fruit begins from the stalk. Sick fruits lose their commercial qualities: first they dry out, then they turn black and decompose.
The spread of ascochitosis is facilitated by sharp changes in day and night temperatures, excessive humidity of air and soil, as well as plant thickening.
The infection persists and accumulates in the soil on plant debris, is imported with manure containing infected pumpkin plant debris.
Ascochitosis Control Measures
- replacement of contaminated soil in greenhouses;
- during the growing season of plants, the exclusion of excess watering and the removal of dead affected plants;
- coating or dusting of the affected areas of the stem with copper-chalk powder (a 1: 1 mixture of copper sulfate and chalk) or crushed coal in order to dry the affected tissue and prevent the spread of infection;
- in the autumn, timely thorough cleaning of plant residues.
Brown, or olive spotting, or cladosporiosiosis of cucumber
A fungal disease that appears during low night temperatures and high humidity. The disease is widespread in unheated greenhouses and small-sized film shelters, where there are sharp changes in temperature and the presence of condensed moisture. Initially, single, then numerous rounded brownish spots appear on the leaves with a lighter center and a lighter border around the spot. This disease is different from anthracnose and bacteriosis. In addition, the disease manifests itself on the fruits, stems, petioles in the form of small watery spots that increase rapidly; the skin is cracked, and gelatinous drops appear on the surface. Then the spots are covered with dark velvety mold, ulcers form. The infection persists on post-harvest plant debris in the soil.
Measures to combat brown, or olive spotting, or cucumber cladosporiosiosis
- crop rotation;
- air humidity reduction by airing;
- if there are signs of the disease before fruiting, spraying with a 1% Bordeaux mixture (100 g of vitriol with the addition of 100 g of lime per 10 l of water) or copper chloroxide (40 g per 10 l of water) at the rate of 0.5 l of solution per 10 m2;
- collection and destruction of post-harvest crop residues.
The disease causes a mushroom. Powdery mildew appears on plants from the moment they grow in greenhouses and small-sized film shelters. It is noted not only on cucumbers, but also on a pumpkin. Rounded or angular brown-yellow spots appear on the upper side of the leaf, to which a gray-violet coating (mycelium of the causative agent of the disease) corresponds to the lower side of the leaf. With a strong development of the disease, the leaves dry out, the plants become weakened and give a low yield of fruits.
The infection persists on post-harvest plant debris, from which it is transmitted to healthy plants the next year.
Downy mildew control measures
- crop rotation;
- when the first signs of the disease appear, spraying with copper oxychloride, 90% s. (40 g per 10 l of water) or Bordeaux mixture (100 g of copper sulphate and 100 g of lime per 10 l of water at the rate of 0.4-0.5 l per 10 m2).
Mushroom disease manifests itself in the Leningrad, Pskov, Novgorod, Vologda regions of the northwestern zone when growing cucumbers in greenhouses and small-sized film shelters. Initially, on the waterlogged lower wooden parts of greenhouses, the vegetative body of the fungus appears, having the appearance of a yellowish thick mucus. If it enters a plant, it can cause damage to stems, petioles, leaves, fruits. Regardless of the place of manifestation of the disease, an outgrowth (fruiting body of the fungus) is first formed on the affected tissue. On top, the growth is painted in a lighter tone than its central part, which consists of a dark brown spore mass. The affected parts of the plant are deformed and die. The disease spreads by insects and when caring for plants.
Slime Control Measures
- collection and destruction of mucus growths;
- disinfection of the tissue of cucumber plants in places of damage with 1% solution of copper sulfate (10 g per 1 liter of water).
Bacteriosis, or angular spotting
The causative agent of the disease is a bacterium. The disease is widespread in cucumbers in greenhouse and small-sized film shelters. In wet and warm weather, the disease manifests itself from the moment of growth of plants, affects cotyledons, real leaves, flowers and fruits. Light browns appear on the cotyledons, oily angular spots appear on the leaves, which gradually darken and dry out. The affected tissue falls out. On stems, petioles, fruits, oily spots, drying up, form ulcers. Affected fruits become ugly, their quality deteriorates significantly. On the affected parts, the appearance of exudate is observed - adhesive droplets of a cloudy yellowish liquid. When dried, such droplets turn into a film. If pathogens of wet bacterial rot settle in ulcers, then the entire fetus rots.
Increased humidity and air temperature, the presence of raindrops and dew on plants contribute to the development and spread of infection. Bacteria easily overwinter in undecomposed plant after-harvest residues, and quickly die in the soil. The infection is transmitted by post-harvest crop residues.
Bacteriosis - a widespread disease of cucumber, causes the death of seedlings, reduced yield and deterioration in the quality of the fruit.
Measures against bacteriosis, or angular spotting
- crop rotation (cucumbers are recommended to be returned to their original place no earlier than 3-4 years later);
- spraying the plants when the first signs of the disease appear on the cotyledon leaves with a 1% Bordeaux mixture (50 g of copper sulfate with the addition of 50 g of lime per 5 l of water), secondary treatment - when spots appear on real leaves, then every 10-12 days at the rate of flow of working fluid 4-5 liters per 100 m2 or copper chloride (40 g per 10 l of water) at the rate of 0.4-0.5 l per 10 m2 (spraying with Bordeaux mixture is completed 15 days before harvesting);
- removal from the site and instillation of diseased fruits with their sprinkling with bleach;
- post-harvest destruction of all plant debris.
Cucumber Viral Mosaic
The causative agent of the disease is a cucumber virus. In greenhouses and small-sized film shelters, the most common ordinary (field) and green mosaic. Sometimes there is a defeat of cucumber plants with a white mosaic. Signs of plant damage to the virus can be detected on young leaves a month after transplanting. A mosaic color appears on them - an alternation of green and light yellow spots. Plants are oppressed, internodes are shortened, leaves are small, gradually turn yellow and dry. The lashes turn yellow and become glassy. With a later infection, the lower leaves turn yellow, and the upper leaves become mosaic, yellowing and vitreous lashes are also observed. With a severe defeat, drying out and complete death of the entire plant occur. The fruits are deformed, their surface becomes tuberous with a characteristic mosaic color. Cucumber mosaic is one of the most dangerous diseases of pumpkin crops.
Green mosaic only young plants in greenhouses are affected. On the leaves there is a mosaic color - an alternation of dark and light green spots. Then the leaves become wrinkled with vesicular outgrowths. As the plants grow, the mosaic pattern on the leaves becomes less noticeable.
Mosaic plants lag behind in growth, are oppressed, the number of female flowers and fruits decreases. Fruits on infected lashes are deformed and may have a yellow-green mosaic color (often this symptom is absent).
White mosaic manifests itself primarily on young growing leaves, on which vein brightening is found, as well as characteristic star spots, rings that subsequently whiten, merge, and the entire leaf turns white. The growth of cucumber plants is suspended, the leaves are smaller. Fruits on heavily affected lashes are small, deformed, white, often with tuberous outgrowths. The development of the white mosaic is facilitated by sharp changes in air and soil temperature at night and day. Viruses are transmitted by juice from a diseased plant to a healthy one when taken care of. Overwinter in plant debris and transferred to cucumbers by aphids, especially melons and peaches. The source of infection is also the seeds collected from infected plants.
Measures to combat the viral mosaic of cucumber
- sowing with seeds obtained from healthy plants (preferably a 2-year or longer shelf life, with long-term storage, the seeds practically do not contain the virus);
- alternation by year of planting of cucumber and tomatoes in greenhouses and small-sized film shelters;
- the destruction of weeds in which the virus can persist;
- removal of the first appearing sick, strongly oppressed plants;
- spraying cucumbers to kill aphids - virus carriers - infusion of onion husks (200 g per 10 liters of water);
- use for garter new twine;
- disinfection of garden equipment in a 5% solution of potassium permanganate (50 g per 1 liter of water) by washing or immersing in a solution for 10-15 minutes;
- exclusion of sharp fluctuations in temperature in protected ground areas;
- watering plants with warm water;
- cultivation of resistant (Vanguard, Nezhinsky 12) or weakly susceptible (Far East 27) varieties;
- collection and destruction of post-harvest residues.
- Plant Protection in Home Gardens: Reference Book / A. A. Pearl, N.P. Stenin, V. Tarasova.