Fertilizer application rates and recommendation for corn

In this macro stage, you need to pay attention to the germination of the seeds. Variety similarity at 60-80%, similarity of hybrids 92-98%. Factors such as the selection of high-quality seed, qualitatively prepared seed bed, seeding technique, seed treatment with micronutrients and favorable weather conditions have an impact on field similarity.

Germination is the beginning of plant development. Its duration starts from dormancy to the appearance of shoots, that is, until the sheath of the first leaf with a shoot appears on the soil surface. During seed germination, water is absorbed by the embryo, resulting in rehydration and cell expansion. Soon after water absorption or absorption begins, the respiration rate increases, and various metabolic processes that had been suspended or greatly reduced during the resting period are restored. These events are associated with structural changes in the organelles (membrane bodies responsible for metabolism) in the cells of the embryo. For the reason that spare materials are partially in an insoluble form, namely in the form of starch grains, protein granules, lipid droplets, etc., most of the early metabolism of seedlings is associated with the mobilization of these materials and the delivery or transfer of products to active sites.

Stocks outside the embryo are digested by enzymes secreted by the embryo, and in some cases also by special endosperm cells. Active embryo growth, except that resulting from swelling, usually begins with the emergence of a primary root, known as a seed root, although in some species (e.g., coconut) a shoot or perunus emerges first. Early growth depends mainly on cell expansion, but within a short time cell division begins in the root and young shoot, and then growth and subsequent organ formation (organogenesis) are based on the usual combination of increasing cell number and increasing individual cells.

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.