Recommendations and fertilizer rates for cotton

During the development of the indicated macro stage, the differentiation of the main axis of the germinal inflorescence occurs. The actual number of flowers is determined. During the period of intensive development from the phase of formation of lateral shoots/bushing to the phase of flowering it is necessary to have enough of these types of reserves: macro-, meso- and microelements for the full development of all plant organs.

The shoots of most vascular plants branch out according to a sequential plan, with actually each new axis arising at an angle between the leaf and the stem, i.e. in the leaf axil. In some plants, buds may also be formed from older parts of the shoot or root distant from the main apices; these buds, called adventitious buds, do not follow the general plan. The apex of the lateral shoot begins on the sides of the main apex, but some distance below the point of emergence of the youngest leaf rudiment.

As in the origin of the leaf, usually the outer cell layers contribute to the surface tissues of the new apex, maintaining a consistent pattern of divisions. In some species, a sheath of more than one cell layer quickly forms, so that the new apex looks like a miniature version of the main one.

Alternatively, differentiation cannot become evident until a significant mass of the new initial state has been reached. In all cases, the new apex must reach a minimum volume before it can, in turn, begin to form its lateral rudiments and organize true axillary buds. When this size is reached, zoning occurs.

Like the beginning of the main apex, the formation of new rudiments is associated with the annular zone. From this point, the development of a lateral shoot is the same as the development of the main shoot, except that growth may not be as fast, because the main apex or leading bud dominates and absorbs most of the available nutrients.

Early axillary bud growth is quite vigorous until a certain number of leaf buds are formed; then the apex activity slows down. Cell division gradually ceases, and with it the associated syntheses; thus, there is no increase in DNA of meristem nuclei after the last division. The kidney essentially goes into a dormant state, even if external conditions for growth are favorable. This phenomenon is known as correlative bud oppression, because it is determined by the activity of the conducting bud of the shoot. If the main, i.e. leading bud is removed, the inhibited lateral buds restore growth, and with it all associated syntheses.

To disclose in detail this macro stage, it is necessary to indicate that here occurs the formation of second-order growth cones, the formation of the available number of flowers in the inflorescence with the laying down of flower covering organs, the formation of anthers (microsporogenesis) and stigmas (megasporogenesis), the formation of a larger number of synchronously developed productive stems. There is intensive growth of organs in length, formation of ovules and pollen grains.

Applying nitrogen and phosphorus fertilizers can increase the number of flowers in an inflorescence. Although the structural organization of the vascular plant is relatively loose, the development of different parts is well coordinated. Control depends on the movement of chemicals, including nutrients and hormones. An example of correlation is shoot and root growth. The increase in the aerial part is accompanied by an increased need for water, minerals and mechanical support, which are satisfied by the coordinated growth of the root system. Several factors seem to be involved in control, as the shoot and the root affect each other mutually. The root depends on the shoot for organic nutrients, just as the shoot depends on the root for water and inorganic nutrients, and thus the flow of ordinary nutrients must play a role. However, more specific control can be provided by supplying the nutrients needed in very small quantities.

The root depends on the shoot for certain vitamins, and changes in supply reflecting the metabolic state of the above-ground parts can also affect root growth. In addition, hormonal factors affecting cell division pass upward from the root to the stem; although the exact role of hormones has not yet been established with certainty, they may be one of the ways in which the root system can influence the activity of the shoot apex. Secondary thickening control is another important example of growth correlation. As the size of the shoot system increases, the need for both greater mechanical support and enhanced transport of water, minerals, and elements is met by increased coverage of the stem through the activity of the vascular cambium. As a rule, the cambium of trees in temperate zones is most active in spring, when buds are budding and shoots are sprouting, creating a need for nutrients.

Cell division begins on each shoot and then spreads out from it. The terminal bud stimulates the cambium to divide rapidly through the action of two groups of plant hormones: auxins and gibberellins.

Inhibition of lateral buds, another example of a correlated growth reaction, illustrates a reaction opposite to that occurring when controlling cambial activity. Lateral buds are generally depressed, as axillary shoots grow slower or do not grow at all, while the terminal bud is active. This so-called apical dominance is responsible for the characteristic unit of trunk growth observed in many conifers and herbaceous plants, such as the mallow. Weaker dominance leads to a form with multiple branching. This fact that the lateral or axillary buds become more active when the terminal bud is removed is evidence of hormonal control. The flow of auxin from the shoot apex is partially responsible for the inhibition of axillary buds.

The nutritional status of the plant also plays a role, as verticillium dominance is strong when mineral supply and light are insufficient. Since the axillary buds are released from inhibition by treatment with substances that stimulate cell division, also called cytokinins, it has been suggested that these substances are also involved in the regulation of bud’s activity.

In this macro stage, the processes of formation of all the organs of the flower inflorescence are completed, the development from the rudiments of the flowers to their opening takes place. The largest upper internode continues to grow.

Application of complex fertilizers with an emphasis on nitrogen and trace elements – zinc.

From the point of view of development, a flower can be considered as the axis of a shoot of deterministic growth, with the lateral members occupying areas of leaves that differentiate as floral organs — sepals, petals, stamens, and pistils. In transition to flowering, the stem apex undergoes characteristic changes, the most noticeable of which is the shape of the apical region, which is related to the type of structure to be formed, whether it is a single flower, as in a tulip, or a cluster of flowers (inflorescence), as in a lilac. The area of ​​cell division extends to the entire tip, and the RNA content of the terminal cells increases. As a single flower forms, lateral primordia appear higher and higher on the sides of the apical dome, and the entire apex is absorbed in the process, after which apical growth ceases.