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To get consistently high yields, you need to figure out who eats cucumber seedlings in the greenhouse. Pests are one of the main reasons for lower yields in greenhouse conditions.
The most famous pests in greenhouses
Gall nematodes
(Southern, Javanese, peanut and northern) – harmful phytophages, belong to a large group of roundworms. The southern gall nematode is more common.
The female is easily recognizable by the pear-shaped body of a milky white color, 0,5-1,9 mm long. Adults are located in the enlarged tissues of the injured root – in galls. They overwinter in the egg or larval phase. Penetration into the roots occurs during planting seedlings. Digestive enzymes of the pest provoke chaotic division of root cells. Nematodes develop in the formed galls. Galls create obstacles for the flow of water and nutrients into the vegetative organs of plants. Leaves turn yellow and fall off.
Meloydoginosis is the name given to diseases caused by nematodes. As a result of the destructive activity of worms, the plant is depleted, the yield is sharply reduced, and premature death of the crop may occur. Diseases penetrating through a damaged root (rot, fusarium wilt) develop due to a nematode infection. Positive results are obtained by growing hybrids that are resistant to damage.
Cucumber pests in the greenhouse – mites – represent an extensive group of phytophages.
Common spider mite
It breeds mainly on cucumbers. It settles on all vegetative organs of culture: leaves, stems, fruits, braiding them with cobwebs. Eating vegetable juice from cells causes irreversible changes in metabolism. Inhibition of plants leads to a significant decrease in yield. White spots on the leaves, at first single, eventually form a continuous marble pattern. Subsequently, the leaves dry up.
Tarsonemid mites
They rarely damage stems and roots, feeding mainly on leaves.
Melon Caviar
Tobacco and cucumber mosaic viruses are spread by aphids. Saprophytic fungi settle on its secretions. Cucumbers lag behind in growth and development, the quality of products is deteriorating. Photosynthesis is inhibited. With an ideal microclimate in a greenhouse – a temperature of + 22 … + 25 ° С, a relative humidity of 80% – the population increases dramatically: 20 generations grow per season. In auxiliary greenhouses, the pest is sprayed with Actellik or Phosbecid, Intravir, TAB.
In greenhouses, natural enemies are used – predators, including:
- gallica aphidimiza;
- parasitic ichneumons of lysiflebus;
- cuban ladybug cycloneda.
Greenhouse, or greenhouse whitefly
On cucumbers, the reproduction rate, fertility and survival rate are higher than on other crops. It infects the leaves with honeydew, which causes a shine to appear on them, and then a black, or sooty fungus. An adult is from 0,9 to 1,1 mm in size, yellowish in color. It has 2 pairs of wings covered in white powdery pollen. The larvae and nymphs have a flat, round, undivided body, covered with spines. Wintering females are able to tolerate temperatures down to -12°C. During the season, 10-15 generations are formed. Protective measures:
- prevention – destruction of weeds-reservoirs;
- disinfection of containers and seedlings;
- use in subsidiary greenhouses of Verticillin, Aktellik or Fosbecid, Inta-Vira, TAB.
Western flower or California thrips
Has a quarantine value. Imago with a narrow body 1,3-1,4 mm long. Color from light yellow to dark brown. 5 pairs of setae grow on anterior and posterior margins of pronotum. Has fringed wings. Adults overwinter on organic soil residues or in crevices of greenhouse structures. Appears after planting seedlings. Lays eggs in leaves and upper stems. Females feed on vegetable juice for a month. During this time, up to 300 eggs can be laid.
The vital activity of thrips causes the appearance of yellow necrotic spots and a significant weakening of the plants. There are torn holes on the sheet. The tops of the stems are twisted. Deformed fruits are tied on the flowers. Sterilization of the soil, disinfection of containers and tools, extermination of weeds give a positive result.
Nightsweeper
It harms cucumbers in spring. This is a fly with a black back, transparent wings, a yellow shield and light halteres. Body length – 1,5-2,3 mm. False cocoons overwinter in the soil surface. Flies out at the time of planting seedlings. Females, after mating, lay their eggs in leaf tissue. Then the larvae that appear gnaw through the passages, damaging the surface. Up to 5-7 generations can develop in a greenhouse. The function of photosynthesis is inhibited, the leaves turn yellow and fall off. Prevention – removal of weeds, soil disinfection. Actellik or Fosbecid, TAB, EC are used.
Cucumber Mosquito
3-5 mm long, gray in color, with large compound eyes. It has one pair of membranous wings. The larva is white, legless, worm-like. Penetrates into the greenhouse with humus. Imago populates on seedlings of cucumbers. Oviposition takes place in the soil. The larvae gnaw through passages at the base of the stems of seedlings and in the roots. The result of the nutrition of the larvae is the decay and soreness of the lower part of the stem. Turgor is broken, and the plant dies.
Indoor plant protection
The fight against phytophages begins with the aim of prevention:
- before planting, the greenhouse (its main structures) is disinfected by flame treatment;
- carry out heat treatment of the soil;
- eliminate old plant residues;
- wash glass and greenhouse structures with disinfectant solutions;
- whitewash the foundation of the greenhouse.
A complex of preventive measures leads to the death of the main number of phytophages.
