Tillering

(stool out), the formation of aboveground shoots from a node located at the base of the principal shoot in grasses and some other plants. A tillering node consists of a number of short, neighboring internodes, from whose buds lateral shoots are formed. Daughter lateral shoots develop from the axillary buds of the sheath, which either remain inside the sheath (in-travaginal shoots) or pierce the sheath and emerge to the outside (extravaginal shoots). If the shoots grow at an angle to the main shoot, a loose shrub forms; if they grow vertically, a compact shrub develops. As a result of the development of numerous shoots from the tillering node, perennial plants form turf. Long shoots distributed horizontally form rootstocks when they are underground (for example, wheatgrass) or offshoots when they are aboveground, (for example, meadow grass and reed).

In annual plants, tillering occurs early in their life (in winter plants, during autumn and spring; in spring plants, during spring) and ends with their actual shooting. In perennial plants, tillering is interrupted only during flowering and fruit-bearing and continues until the end of the vegetative period. During tillering not all shoots flower and yield a harvest; some die off, not attaining full development.

A distinction is made between total frutescence (the total number of shoots in the bush) and productive frutescence (the number of fruit-bearing shoots). The productivity of a plant depends on the species, variety, germination conditions, and, in perennial plants, the age and ability to furnish reserve organic substances. The longer the tillering period, the greater the shoot formation. Tillering also depends on agricultural methods: the time and rate of sowing (early sowing usually causes greater tillering; in dense plantings there is less), seed quality (the larger the seed, the greater the tillering), depth of planting, and application of fertilizers. Intensified tillering, within certain limits, increases the harvest. Late-forming shoots (aftergrowth) do not yield a harvest and weaken the development of productive stems. In pastures and hay fields, tillering is regulated by applying fertilizers (mainly nitrogenous ones), changing the water regimen, and rotating crops.