Rots

Rots 

widespread pathological processes of decay and partial mineralization of organic intercellular tissue, cell walls, and cell substances in plants, caused by semiparasitic and saprophytic fungi and bacteria. In the process of rotting, tissue maceration and cell separation occur, the structure of the tissues is destroyed and their durability is reduced, and cell, tissue, and organ function is disturbed or destroyed. Juicy, woody, and rich nutrient-bearing parts of plants are subject to rots (fleshy leaves, flower buds, fruits, tuber and root crops, roots, and stems).

Various types of rots may be classified etiologically according to the pathogen of the rotting processes. Rots may also be grouped according to the infected plants and their organs (fruit, root, stem, or trunk rots) or according to the various types of plant material affected (wood, fiber, hay, and straw rots). These two systems of classification are used in scientific production practice. In addition, rots may be grouped according to characteristic symptoms and, in part, according to consistency (soft and dry rots) and color (black, white, gray, red, pink, blue, and dappled rots). Within the etiological classification the group of rots caused by polyphagous fungi and bacteria is particularly important for the number of types and the losses it causes. The group includes white rot, soft rot of tubers, root crops, bulbs, and head crops, storage rot of beets—one of the most serious diseases of beet root crops during storage—wood rot, and Texas root rot. Individual species or groups of related plant species are infected by root rots of grain ears, bean crops, and cotton, black rot of beets, dry rot of potatoes, ring rot of potatoes, fruit rot of pit- and seed-producing plants, blossom-end rot of tomatoes, and neck rot of onions.

Rots often cause premature plant death and great economic loss. Countermeasures include the elimination of conditions that reduce resistance to the pathogen and application of phytosanitary methods, such as destruction of infected plants and their parts, protection of plants from mechanical damage, and observation of accepted principles for harvest storage. Chemical methods such as fertilization and the use of pesticides are also indicated.

REFERENCES

Bondartsev, A. S. Trutovye griby Evropeiskoi chasti SSSR i Kavkaza. Moscow-Leningrad, 1953.
Vanin, S. I. Lesnaia fitopatologiia, 4th ed. Moscow-Leningrad, 1955.
Sveklovodstvo, 2nd ed., vol. 3, part 2: Bolezni sakharnoi svekly i mery bor’by s nimi, 2nd ed. Kiev, 1959.
Gerasimov, B. A., and E. A. Osnitskaia. Vrediteli i bolezni ovoshchnykh kul’tur, 4th ed. Moscow, 1961.
Dement’eva, M. I. Bolezni plodovykh kul’tur. Moscow, 1962.
Natal’ina, O. B. Bolezni iagodnikov. Moscow, 1963.
Slovar’-spravochnik fitopatologa. Edited by P. N. Golovin. Moscow-Leningrad, 1967.

M. S. DUNIN