The plant-parasite broomrape belongs to the most numerous group of broomrape. This genus is distinguished by a large variety of species (known - 120, the most common - 40). It parasitizes on cultivated, weed and wild plants. The most dangerous species are those that infect fodder, melons, vegetables, ornamental crops and sunflowers.
The parasitic plant broomrape is classified as a consumer, as it feeds on ready-made organic substances.
Main species
Within our country today there are approximately 40 broomrape species, of which five parasitize cultivated plants. The following species are considered the most harmful:
- sunflower;
- branchy (hemp);
- Egyptian (melons);
- mutela;
- alfalfa.
Description
All types of parasitic broomrape are perennial and completely devoid of chlorophyll. Due to their unusual way of life, they have some features: they have a peculiar appearance, they do not have real roots. Instead, they are fleshy short fibers-suckers that stick to the roots of the host plant. The leaves of the plant are small, scaly, brownish, yellowish or purple.
Stem
The parasitic broomrape plant can have a brown, light yellow, blue or pink stem. It is upright, fleshy, not branching or branching, about 45-60 cm high. The stem is club-shaped at the base.
Flowers
The parasitic plant broomrape has five-membered axillary flowers with a two-lipped German with 4 stamens. The color depends on the species and is whitish, blue or purple. The Germans are collected by several dozen in a spike-shaped panicle or spike.
The plant is able to self-pollinate. Cross-pollination is carried out by broomrape flies and bumblebees.
Seeds
The fruit is in the form of a box with two or three wings. It contains over 2,000 seeds. They are very small, oblong or round, with a cellular surface. Color - dark brown, length - about 0.2-0.5 mm, width - about 0.16-0.25 mm.
Seeds are practically weightless, so they are very easily carried by the wind. They are also fastspread by animals and birds, carried along with soil sticking to shoes and tools, wheels of walk-behind tractors, wheelbarrows, cars, etc.
Seeds in the ground can be stored up to 12 years waiting for the carrier. They grow gradually. From the beginning of development to the formation of a flower, an average of 1.5-2 months passes.
Each of the parasitic broomrape species differs in appearance, parasitic specialization, shoot structure and is adapted to parasitize certain crops.
Sunflower broomrape
This species harms mainly sunflowers. From other plants, it can affect tomatoes, shag, tobacco, wormwood and others.
If there are a large number of sunflower broomrape flower stalks, the plant dies very quickly due to exhaustion and loss of water. Even if he manages to partially survive, the total volume of the crop will still decrease sharply. The broomrape not only takes away nutrients and water from the affected plants, but also poisons the seeds of the host with the products of its vital activity.
This species is characterized by a non-branching stem, the height of which is up to 30 cm and even more. Bracts acute, ovate, corolla 12-20 mm long. It is tubular, brown, strongly bent forward.
Egyptian (melon) broomrape
The plant harms potatoes, hemp, cabbage, tobacco, tomatoes, gourds, etc. The harm caused by this type of parasite lies in the fact that it sticks to the roots of the hostnutrient organs and absorbs beneficial nutrients, depleting it and causing death.
The stem of the plant is sprawling, there are a few ovate-lanceolate scales up to 30 cm long.
Branched (hemp) broomrape
This species infects many species of Asteraceae, Nightshade, Cabbage cucurbits, etc. It parasitizes mainly on hemp, tobacco, tomato, cabbage, carrots, melon, etc., consuming a large amount of nutrients and water. As a result, the stems of plants do not develop enough, and the cultures have an oppressed appearance. In addition, in the affected plants, the yield of fibers is greatly reduced and the strength decreases.
Branched broomrape is distinguished by a thin stem, up to 4-5 mm in the middle part, with sparse scales, up to 25 cm long. It is thickened at the base, there are a large number of lateral shoots. The flowers are smaller than those of the previously described species. Their diameter is up to 15 mm. This is what this parasitic broomrape plant looks like.
Petrov Cross
This genus includes 5-7 species of plants that parasitize on the roots of shrubs and trees. Petrov's cross reaches a height of up to 30 cm. The stems of the plant are covered with fleshy white scales, which are modified leaves.
The root system attached to the roots of trees with suction cups is able to stretch over a long distance and connect with other mother plants.
During the first years the plant develops underground. After the rhizomes are developed, they will begin to appearinflorescences.
Plants-parasitic broomrape, petrov cross belong to the broomrape family.
Methods of struggle
A number of techniques are often used to protect against this parasitic plant. Basic broomrape control methods:
- Preventing the dispersion of the seeds of this plant to regions and farms where it is not found.
- Careful cleaning of broomrape seeds in infected areas.
- Systematic weeding and destruction of broomrape before the appearance of seeds and inflorescences in order to prevent a new contamination of the soil. In this case, the weeded plant must be taken out of the site, after which it is burned or buried deep.
- Introducing crop rotations that exclude crops affected by the parasite.
Because broomrape can infect various wild plants, it is very important to fight it. For this, scientists and breeders offer several options.
First of all, it is necessary to observe crop rotation. Plant control methods are divided into two areas, namely, genetic and chemical control. With genetic control, such resistant hybrids as NK Neoma, Tristan, NK Alego are bred.
Promising direction of chemical control - germination stimulants. As is known, sunflower root secretions are necessary for the germination of seeds of a parasitic plant. That is why their analogues are synthesized, and after the necessary treatment, broomrape seeds germinate and die immediately, since there is no host plant.
Good Enoughresults in pest control were shown by Clearfield technology. For this, a special herbicide is used that destroys all types of broomrape and weeds (including problematic sow thistle, ragweed and cocklebur). 4-7 leaves of sunflower hybrids specially created for this technology are processed. This herbicide is a water-soluble concentrate containing two active ingredients: imazapyr and imazamox. They are very quickly absorbed by the plant through the leaves and through the roots. Due to active active substances, the formation of amino acids and protein synthesis is blocked, resulting in the death of weeds.
Also quite an effective method of combating broomrape - provocative crops. In those places where there was a lot of broomrape in the previous year, sunflower is sown, which causes the mass growth of seeds of a parasitic plant. When a large number of flower stalks appear or at the very beginning of the flowering of the weed, the crop is harvested for silage.
Another provocative method of dealing with broomrape is growing corn. Unlike sunflower, it provokes the appearance of a weed, but does not allow it to develop and discard seeds.
Also, rapeseed, flax, and rapeseed provoke broomrape to germinate, but under these crops the parasite sprouts less than under corn.
Sunflower broomrape control
The fight against broomrape on sunflower is carried out as follows. A correct crop rotation is introduced, in which tobacco, sunflower and hemp are sown in their original place no earlier than after 6-8 years. ATas a result, the soil is cleared of broomrape seeds. At this time, crops not affected by it are sown - sugar beets, soybeans, cereals, castor beans, onions, lallemantsigo, peppers. Highly oily, broomrape-tolerant species are planted from sunflower varieties.
Provocative sowing cleans the soil well from parasite seeds.
Fight against cabbage broomrape
With broomrape cabbage methods of struggle are as follows. Early planting of cabbage shows good results. As well as provocative crops.
On cabbage, broomrape parasitizes near the stem, so it can only be destroyed manually. Weeding in all crops before flowering is required. After harvesting tomatoes, tobacco, gourds and cabbage, broomrape is harvested and must be burned.
Special attention should be paid to crops of plants whose roots stimulate germination, but they themselves are not affected by broomrape. For example, some varieties of clover and alfalfa.
Egyptian broomrape control
Since it is difficult for melons to observe crop rotation, pure fallows are introduced, while in the irrigation zone - "water vapors" that clean the soil well from the seeds of a parasitic plant, or transfer melons to new places. Autumn and winter watering also help clear the soil of weeds.
