Bean Mosaic

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

Bean Mosaic - The attack is serious enough. As a rule, it affects the whole plants, although, of course, the bean leaves are most affected. Severely affected bushes become dwarf, stop blooming and do not bear fruit at all, respectively, there is no need to dream of a good harvest in this case. A particularly severe manifestation of the symptoms of the ill-fated illness is observed with dry air and a sufficiently high temperature (from 22 to 28 degrees or more). In addition to beans, the virus that causes this type of mosaic can also infect clover, beans and lupine with peas

A few words about the disease

The bean leaves struck by the mosaic are distinguished by mosaic variegated colors. At the same time, the tissues near the leaf veins have a more saturated green color. In most cases, the leaves are characterized by deformation of the leaf blades and uneven development. The edges of the leaves curl downward, and in some areas of the leaf blades, bubble-like swellings can be seen. Infected leaves are characterized by shortened petioles, become stiff and quickly droop.

The root system of the bean attacked by the mosaic is characterized by a rather weak development (not only its mass decreases, but also its length), and in general the plants begin to lag behind in growth. And flowers with beans are almost always deformed quickly.

A bean mosaic is caused by a virus called Phas. virus 1 (bean mosaic virus), which is characterized by unprecedented resistance. Often this virus persists on the seeds of infected crops. And the carrier of this pathogen from one plant to another is often aphid, and the most diverse species - black legume, peach, potato, etc. Inoculation of juice also plays an important role in the spread of the pathogen. Infection was also noted through the pollen of diseased plants.

Depending on the type of beans, the first symptoms of infection in most cases can be observed after 6 to 16 days.

Bean mosaic is especially widespread in the central regions and in the southern regions (Ukraine, Krasnodar Territory, etc.).

How to fight

Seeds for planting beans should be taken exclusively from healthy specimens. At least outwardly, they should all look healthy. If beans are planned to be grown in zones of mass destruction by mosaics, it is necessary to shift the dates of their sowing to earlier ones. This is especially true for plants that will be used for seeds. Subject to this rule, the beans will finish blooming before the start of the mass reproduction of aphids. In addition, early sowing dates greatly contribute to healthier crops. By the way, you should always try to isolate the crops of beans from the crops of perennial legumes.

The cultivation of lightly attacked and resistant bean varieties will also do a good job. Among the poorly affected varieties, the best known is Robust improved. Such varieties as Greenfinned Dwarf, Corbett and Sugar Triumph 764 also show themselves well. Before sowing, it is advisable to pickle seeds with Fentiuram or with the help of TMTD. Calibrating the seeds will not hurt either.

Before flowering beans, it is recommended to carry out antiviral cleaning of seed crops. And throughout the entire period from the appearance of tiny shoots to flowering, it is necessary to conduct a systematic examination of the bean crops and remove infected specimens. Weeds also need to be constantly eliminated from the site, and you should especially carefully deal with white and yellow melilot, as well as meadow and hybrid clover.

An extremely important preventive measure is the constant fight against aphids, which are the main carrier of the ill-fated virus. In order to get rid of these parasites, bean crops are sprayed with Sayfos, Trichlormetaphos or Karbofos.