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Video: Diseases And Pests Of Cucumber, Pumpkin, Squash And Squash. Control Methods. Photo
In our area, it is difficult to find a vegetable garden or a summer cottage where cucumbers, zucchini 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 one day, before the green patch of cucumbers begins to turn yellow, the leaves of the plants wither, wrinkle and the crop is in trouble. In this case, most likely, the plants were attacked by pests, or affected by a disease. And cucumbers, pumpkins and zucchini have enough of them. 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
It is especially harmful for cucumber culture in greenhouses and small-sized film shelters. The body of the tick is oval or oblong, 0.3-0.4 mm long. The egg is spherical; recently delayed - greenish, transparent, later - unclear.
Ticks live and feed on the underside of leaves, braiding them in a race of cobwebs. On damaged leaves, light dots appear first, similar to pin pricks (especially noticeable on the upper side of the leaf). In the future, the leaf becomes spotty (marbled), then turns yellow and dries up; with severe damage, the entire plant may die.
Mites and larvae, feeding on the cell sap of cucumber plants and other plants from the pumpkin family, cause the flowers, ovaries of fruits and leaves to fall off, which is why the yield is significantly reduced.
In the open field, ticks appear from the second half of June. Here they multiply strongly in hot dry years. In normal years, ticks harm mainly greenhouses and small-sized film shelters. The pest hibernates in early August. Most often, an adult insect (females) hibernates under fallen leaves, plant debris, clods of earth, in the crevices of buildings, greenhouses, in mats, greenhouse frames or even in the surface layer of soil at a depth of 30-60 mm.
In spring, at a temperature of 12 … 13 ° C, fertilized females, 5-7 days after leaving their wintering grounds, begin to lay eggs on the underside of leaves of weeds or vegetable plants. After 5-7 days, larvae emerge from the eggs, which live and feed on the underside of the leaves. The mite develops continuously throughout the warm period. It takes 10-28 days to develop one generation.
Spider mites are ubiquitous.
Spider mite control measures
- spraying cucumber beds with water regularly during the day (in hot weather);
- spraying plants with an infusion of onion or garlic scales (200 g of scales per 10 liters of water);
- systematic weed control;
- spraying plants during the growing season with the appearance of a tick with one of the drugs: keltan (chloroethanol), 20% EC. (20 g per 10 l of water); in the conditions of protected ground in the same period, isophene, 10% EC, is used to combat powdery mildew. or 10% c. p. (60 g per 10 l of water) and ground sulfur (300 g per 100 m 2);
- deep autumn digging of the soil with the destruction of post-harvest residues.
Polyphagous, feeds on more than 46 species of plants, most often damages cucumbers and zucchini. Body of wingless females is oval, dark green, almost black, 1.25-2.1 mm long. The larvae are yellow or green, winged or wingless. They reproduce asexually, giving 14-20 generations in the season.
Mostly adult aphids, sometimes larvae, overwinter. Reproduction begins in spring at temperatures around 12 ° C. The optimum temperature for development is 16 … 22 ° С. In spring, the pest develops and feeds first on weeds, and then migrates to cucumbers, squash and other pumpkin plants. Aphid colonies are located on the underside of 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 ridges, aphids appear on cucumbers in July - August, in greenhouses and small-sized film shelters - in spring.
Melon aphid control measures
Spraying of plants with the appearance of a pest during the growing season before flowering and after harvesting with one of the drugs: karbofos, 10% EC. or 10% s. p. (60 g per 10 l of water) in protected ground conditions, trichlorometaphos-3 (triphos), 10% e. (50-100 g per 10 l of water).
Damages seedlings of all pumpkin crops. The fly is small, 5-7 mm long, gray with a dark longitudinal line on the abdomen. The larva is white, narrowed in front, with denticles at the end of the body, up to 7 mm long.
Pupae of flies overwinter in the soil on crops of vegetables, grain crops and clover. The fly flies out in spring in May, at the beginning of birch flowering; lays eggs in the second half of May under lumps of soil, preferring more moist soil with poorly sealed manure. After 2-10 days, larvae appear, which damage the swollen germinating seeds and seedlings of plants of various cultures. At seedlings of cucumber, they bore the hypocotyl knee and penetrate into the stalk. After finishing feeding, pupate after 12-16 days. During the season, 2-3 generations of a sprout fly develop.
Sprout fly control measures
- carrying out autumn digging of the soil with the introduction and careful incorporation of manure;
- sowing seeds at the optimal time (the best for a given area), 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. Zucchini, cucumber, pumpkin, squash are affected in various stages 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 are formed on the leaves. Sometimes the spots, increasing, merge, covering a significant part of the leaf blade and giving it a burnt appearance. Then the leaves turn brown, dry, become brittle, crumble. On stems and lashes, spots are elongated, rather large, weeping. Slimy orange pads form on them, the located fruits wrinkle and rot, become bitter. The harm from anthracnose is expressed in a decrease in the quantity and quality of the crop. The disease develops not only during the growing season of plants, but also during harvesting.
The causative agent of anthracnose overwinters on infected plant debris, sometimes it is introduced with seeds extracted from diseased fruits.
Anthracnose control measures
- culling of 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 disease;
- disinfection of greenhouse frames and wooden parts of film shelters after harvesting with bleach (200 g per 10 liters of water);
- collection and destruction of post-harvest residues.
Fungal disease, manifested in the non-black earth zone on cucumber, zucchini, pumpkin, squash. The causative agent of the disease develops on plant tissues and affects pumpkin seeds from the moment the plants regrow, especially with frequent dew loss. Leaves and stems are affected. The greatest harm is caused by the disease with high humidity in conditions of insufficient watering.
Initially, 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 leaf is covered with a white powdery bloom. Severely affected leaves change their dark green color to light, yellow-green, then darken and wrinkle. Affected stems and young leaves become chlorotic, underdeveloped and may die off completely. Fruits on infected lashes ripen prematurely, have a bad taste and insufficient sugar content, set late, and often remain underdeveloped.
The fungus hibernates on the remains of diseased plants, as well as on a number of herbaceous perennials susceptible to powdery mildew (sow thistle, plantain, etc.). In spring, young leaves of pumpkin plants are infected. A very harmful disease, widespread. Cucumber plants in greenhouses and small-sized film shelters are more affected than in open ridges.
Powdery mildew control measures
- removal of pumpkin tops and weeds around film shelters and greenhouses;
- deep autumn digging of soil;
- return of cucumbers to their original place no earlier than after 3-4 years;
- maintaining in greenhouses and small-sized film shelters air temperature 20 ….25 ° С, normal soil moisture;
- spraying plants with the appearance of the first signs of powdery mildew with one of the preparations: gray colloidal - 70% paste, 70% wettable, 80% c. p., 80% granular (20 g per 10 l of water in the open field and 40 g per 10 l of water in the protected ground); gray colloidal - 35% paste (sulfaride) (40-100 g per 10 liters of water in protected ground); gray ground (300 g per 100 m 2); disubstituted sodium phosphate (50 g per 10 l of water); isophene, 10% e. and 10% c. p. (60 g per 10 liters of water in protected ground);
- in case of focal disease, the leaves are cut and destroyed or the leaves are cauterized with ground sulfur (sulfur is applied to the affected areas with a cotton swab);
- spraying with mullein infusion (1 kg of mullein is poured into 3 liters of water and infused for 3 days, then filtered and diluted with 1 liter of infusion in 3 liters of water);
- evening spraying with hay infusion (1 kg of rotted hay is infused in 3 liters of water for 3 days, then filtered and diluted with water 3 times) until a powdery bloom appears, followed by repetitions after 7-9 days;
- thorough rinsing of the processed fruits with warm water to remove chemical residues on the surface of the cucumbers;
- cultivation of resistant varieties with dark green leaves (Altai early 166, Hybrid Start 100, Graceful, etc.).
The causative agent of the disease is a fungus that infects roots, lower stems, leaf petioles and fruits. On the affected parts of the plant, a white flocculent bloom forms, on which black dots subsequently appear. The areas of tissue on which the fungus develops become soft and licky, the plant withers, then dies. Zelentsy become infected very quickly when in contact with the diseased part of the stem. With a strong development of the disease, the yield of cucumbers (zelents) is sharply reduced.
The development of the disease is facilitated by a low temperature with high humidity, thickening of plantings, untimely pruning of diseased and dying leaves. During the growing season, plants are infected when caring for them through the stomata and mechanical damage by pieces of mycelium. The causative agent of the disease persists in the soil. Due to the fact that the disease strongly affects parsley, it is impossible to grow cucumbers after parsley without first replacing or disinfecting the soil, since it may contain the infectious origin of the fungus. White rot causes great harm to cucumbers in greenhouses and small-sized film shelters.
Measures to combat white rot
- alternation of crops in greenhouses and on ridges;
- wiping with a piece of cotton wool or gauze sections of the stem with the initial signs of the disease appeared, followed by dusting with crushed coal or chalk; cutting out diseased tissue with the capture of a part of healthy tissue;
- evening watering of plants with warm water;
- the use of foliar dressings (1 g of zinc sulfate, 2 g of copper sulfate and 10 g of urea per 10 liters of water);
- cleaning of all plant residues with an upper 2-3 cm layer of soil;
- reduction of air humidity in the greenhouse by periodic ventilation in order to stop the development of the disease;
- cultivation of varieties resistant to the disease (Yielding 86) and with medium resistance (Irrelevant 40).
The fungus, the causative agent of the disease, parasitizes on vegetative plants in greenhouses and small-sized film shelters, flowers, ovaries and peduncles of cucumber are especially strongly affected. In dry weather, the affected tissues turn brown and die off, and in wet weather a gray coating appears on them, the tissue becomes licky. Black dots (sclerotia) form on the affected tissue. The rot spreads quickly. 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 sharply reduce the fruit yield. The fungus overwinters on the remains of affected plants, often on potato stalks.
Gray mold control measures
- alternation of crops with the return of the cucumber to its original place in 2-3 years;
- replacing contaminated soil in greenhouses;
- feeding with phosphorus fertilizers;
- timely removal of drying flowers and affected ovaries;
- autumn digging of soil.
A complex disease resulting from unfavorable growing conditions that weaken plants and thereby contribute to the attack on them by parasitic soil fungi. Distributed mainly in greenhouses and small-sized film shelters. The main signs of the onset of the disease are, first of all, a plant lag in growth, underdevelopment of leaves, their yellowish color, abscission of ovaries and underdeveloped fruits, and sometimes the death of the entire plant. The roots of the affected plant darken, become rotten, milled; slightly depressed dark spots are visible on larger roots.
In some cases, the lesion can encircle the root collar in an annular fashion (cervical rot), which leads to the death of the aerial part of the plant. Root rot occurs when conditions are unfavorable for the growth and development of cucumber plants and can be a very harmful disease. Root rot is especially common when growing cucumbers early. A sharp fluctuation in soil temperature, watering plants with cold water (9 … 11 ° C) negatively affects the development of the cucumber root system: it develops poorly, later on it is settled by soil fungi that destroy it. Sharp fluctuations in soil temperature, drying of roots with untimely adding soil to them increase the susceptibility of plants to root rot.
The sources of the disease are affected post-harvest residues.
Root Rot Control Measures
- using only a mixture of fresh turf soil and humus for growing cucumber with the addition of well-decomposed and weathered peat;
- watering plants with water at a temperature not lower than 20 ° С;
- maintaining normal soil moisture (without waterlogging), and soil temperature during the entire growing period of cucumber 20 … 25 ° C;
- when the first signs of root rot appear, add earth to the stems to form additional roots;
- carrying out the rejuvenation of plants - the stem is lowered onto the soil and a little fresh soil is poured onto 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.
Root rot of seedlings
Widespread cucumber disease in greenhouses and small-sized film shelters. Mushrooms, the causative agents of this disease, affect only weakened plants. The disease is a consequence of sowing seeds in cold, very moist soil in cold weather. The development of the disease is facilitated by unfavorable growth conditions (low air and soil temperatures with waterlogging of the soil, irrigation with cold water). In this case, weak, slowly developing seedlings become susceptible to infestation by soil fungi. In the affected seedlings, first the browning of the root collar and roots, cotyledonous and young leaves is observed, then the thinning of the stem, which leads the plant to death.
Seedling root rot control measures
- creation of optimal conditions for plant growth and development (sufficiently fertile soil, soil temperature should be 20 … 26 ° С);
- watering with lukewarm water (but not higher than 20 ° C);
- on days with cool weather, limiting watering of cucumbers in order to exclude waterlogging of the soil, since even short-term (over several days) waterlogging is dangerous;
- the use of peat pots for growing seedlings.
The causative agent of the disease is 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 rots, and often there is a massive death of seedlings, in which the roots rot or dry out. It is also possible that plants die before they appear on the soil surface. The disease is very harmful.
When fully developed plants are affected, the tops of the lashes wither.
On the edges of the leaves, especially the lower tiers, spots are formed; leaf tissue between the veins begins to die off; the leaves of the upper tiers lose turgor and become chlorotic. Then the whole plant gradually fades. On the cross section of the stem of a diseased plant, the browning of the vessels is clearly visible. Sometimes at the base of the stem you can find a white fluffy bloom of mycelium. The roots and root collar rot, the plant breaks. In dry years, a very strong manifestation of the disease can be observed, when all plants can die within a few days. In addition, the disease can spread to other pumpkin seeds (pumpkin, zucchini, squash).
Fusarium wilt control measures
- alternation of cultures;
- replacement of contaminated soil in greenhouses;
- systematic bedding of soil 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; symptoms first appear in the nodes of the stem, on not completely removed petioles of leaves or shoots, then spread up and down the stem. Grayish spots with numerous black dots form on 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. Leaf lesion begins at the edge in the form of large chlorotic spots with a large amount of black pycnidia of the fungus. The leaves dry out quickly and the plant dies.
Fruit damage starts from the stalk. Sick fruits lose their commercial qualities: first they dry out, then turn black and decompose.
The spread of ascochitis is facilitated by sharp changes in day and night temperatures, excessive humidity in the air and soil, as well as thickening of plants.
The infection persists and accumulates in the soil on plant debris, is brought in with manure containing infected pumpkin plant residues.
Measures to combat ascochitis
- replacement of contaminated soil in greenhouses;
- during the growing season of plants, the exclusion of excessive watering and the removal of dead affected plants;
- coating or dusting the affected areas of the stem with copper-chalk powder (a mixture of copper sulfate and chalk 1: 1) 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 spot, or cucumber cladosporiosis
A fungal disease that appears during the period of 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, and then numerous, rounded brownish spots with a lighter center and a light border around the spot appear on the leaves. This disease differs from anthracnose and bacteriosis. In addition, the disease manifests itself on fruits, stems, petioles in the form of small watery spots that rapidly increase; the skin is cracked and gelatinous drops appear on the surface. Then the spots become covered with a dark velvety mold, ulcers are formed. The infection persists on post-harvest plant debris in the soil.
Control measures for brown or olive spot or cucumber cladosporiosis
- alternation of cultures;
- reduction of air humidity by ventilation;
- when signs of a disease appear before the start of fruiting, spraying with 1% Bordeaux mixture (100 g of copper sulfate with the addition of 100 g of lime per 10 l of water) or copper oxychloride (40 g per 10 l of water) at the rate of 0.5 l of solution per 10 m 2;
- collection and destruction of post-harvest plant residues.
The disease is caused by a fungus. Downy mildew appears on plants from the moment they grow back in greenhouses and small-sized film shelters. It was noted not only on cucumbers, but also on pumpkin. On the upper side of the leaf, rounded or angular brown-yellow spots appear, which correspond to a gray-violet bloom on the underside of the leaf (the mycelium of the causative agent of the disease). 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
- alternation of cultures;
- when the first signs of the disease appear, spraying with copper oxychloride, 90% c. p. (40 g per 10 l of water) or Bordeaux mixture (100 g of copper sulfate and 100 g of lime per 10 l of water at the rate of 0.4-0.5 l per 10 m 2).
Slime mold disease
Fungal disease manifests itself in the Leningrad, Pskov, Novgorod, Vologda regions of the north-western zone when growing cucumber in greenhouses and small-sized film shelters. First, a vegetative body of the fungus appears on the waterlogged lower wooden parts of the greenhouses, which looks like a yellowish thick mucus. Upon contact with the plant, it can cause damage to stems, petioles, leaves, fruits. Regardless of the place of manifestation of the disease on the affected tissue, an outgrowth is first formed (fruiting body of the fungus). From above, the growth is colored 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 off. Insect disease is also spreading when caring for plants.
Slime mold control measures
- collection and destruction of slime mold growth;
- disinfection of tissue of cucumber plants in the affected areas with a 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 on cucumber in greenhouse and small-sized film shelters. In humid and warm weather, the disease manifests itself from the moment of regrowth of plants, affects the cotyledons, true leaves, flowers and fruits. Light brown spots appear on the cotyledons, and oily angular spots appear on the leaves, which gradually darken and dry out. The affected tissue falls out. On the stems, petioles, fruits, oily spots, drying out, form ulcers. The affected fruits become ugly, their quality deteriorates significantly. On the affected parts, exudate appears - sticky droplets of a cloudy yellowish liquid. When dried, such droplets turn into a film. If pathogens of wet bacterial rot settle in the ulcers, then the entire fruit rot.
High humidity and air temperature, presence of rain and dew droplets on plants contribute to the development and spread of infection. Bacteria easily overwinter in undecomposed plant post-harvest residues, and quickly die in the soil. The infection is transmitted by post-harvest plant debris.
Bacteriosis is a widespread disease of cucumber, which causes seedling death, reduced yield and deterioration of fruit quality.
Control measures for bacteriosis, or angular spotting
- compliance with crop rotation (it is recommended to return cucumbers to their original place no earlier than after 3-4 years);
- spraying plants when the first signs of a disease appear on 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 when the consumption rate of the working fluid is 4-5 liters per 100 m 2 or copper oxychloride (40 g per 10 liters of water) at the rate of 0.4-0.5 liters per 10 m 2 (spraying with Bordeaux mixture is completed 15 days before harvesting);
- removal of diseased fruits from the site and burying them with bleach;
- post-harvest destruction of all plant residues.
Cucumber viral mosaic
The causative agent of the disease is the cucumber virus. In greenhouses and small-sized film shelters, ordinary (field)and green mosaics. Sometimes, the defeat of cucumber plants is also observed with white mosaic. Signs of virus damage to plants can be found on young leaves as early as a month after planting seedlings. Mosaic colors appear on them - alternating green and light yellow spots. Plants are depressed, internodes are shortened, leaves are small, gradually turn yellow and dry out. The scourges turn yellow and become vitreous. With a later infection, the lower leaves turn yellow, and the upper leaves become mosaic, yellowing and glassiness of the lashes are also observed. With a strong defeat, the whole plant dries up and completely die. The fruits are deformed, their surface becomes lumpy with a characteristic mosaic color. Cucumber mosaic is one of the most dangerous diseases of pumpkin crops.
Green mosaic affects only young plants in greenhouses. Mosaic color is observed on the leaves - alternating dark and light green spots. Then the leaves become wrinkled with blister-like outgrowths. As the plants grow, the mosaic pattern on the leaves becomes less noticeable.
Mosaic plants are stunted, depressed, the number of female flowers and fruits decreases. Fruits on infected stalks are deformed and may have a yellow-green mosaic color (this feature is often absent).
White mosaic appears primarily on young growing leaves, on which vein lightening is found, as well as characteristic star-shaped spots, rings, which later turn white, merge, and the entire leaf becomes white. The growth of cucumber plants is suspended, the leaves become smaller. Fruits on severely affected lashes are small, deformed, white, often with bumpy outgrowths. The development of white mosaics is facilitated by sharp changes in air and soil temperatures at night and during the day. Viruses are transmitted by sap from a diseased plant to a healthy one during care. They overwinter in plant residues and are transferred to cucumbers by aphids, primarily melons and peach greens. Seeds harvested from infected plants are also a source of infection.
Measures to control viral mosaic of cucumber
- sowing with seeds obtained from healthy plants (preferably a 2-year or more shelf life, with long-term storage, the seeds practically do not contain the virus);
- alternation of planting cucumber and tomatoes in greenhouses and small-sized film shelters by years;
- killing weeds in which the virus can persist;
- removal of the first diseased, strongly oppressed plants that appeared;
- spraying cucumbers to destroy aphids - carriers of viruses - with onion peel infusion (200 g per 10 liters of water);
- use of a new twine for tying;
- disinfection of garden equipment in a 5% solution of potassium permanganate (50 g per 1 liter of water) by rinsing or immersion in the solution for 10-15 minutes;
- exclusion of sharp temperature fluctuations in protected ground areas;
- watering plants with warm water;
- cultivation of resistant (Avangard, Nezhinsky 12) or poorly receptive (Far Eastern 27) varieties;
- collection and destruction of post-harvest residues.