Beans

N is the nutrient absorbed in greater amounts by the common bean and approximately 50% of the absorbed N is exported to the grains. It is a constituent of the chlorophyll molecule and, therefore, essential for photosynthesis, which is responsible for promoting the vegetative growth of the common bean.

 The greater availability of N in the initial phase increases the production of dry matter by the common bean. 

Deficiency – Chlorosis in leaflets of older leaves, which fall off prematurely. The ribs become more prominent from the background. With the evolution of the deficiency, the chlorosis is accentuated, although small, punctate green spots, such as splashes, may remain. At this stage, whitish areas may appear in various parts of the leaf blade.

It has several functions throughout the plant cycle: it acts on respiration and energy production, on cell division, intensifying it; it enters the composition of some reserve substances, such as albuminoids and starch; provides strength and rigidity to cereal stems; facilitates flowering; increases fruiting; speeds up maturation; intensifies the resistance of plants to diseases; contributes to the development of the root system and the general health of the plant.

Deficiency – Young leaflets with a dull, bluish-green color and older leaflets with a lighter green color. The leaflets of older leaves may have chlorotic interveinal areas, with small dark punctuations. Stems shorter and thinner than normal, less plant development. Symptoms develop from bottom to top of the plant.

Participation in photosynthesis and activation of key enzymes for metabolic processes. Activator of several enzymes related to the processes of CO2 and nitrogen assimilation, it acts in the translocation and storage of carbohydrates.

This macronutrient acts in the activation of approximately 50 enzymes, highlighting the synthetases, oxidoreductases, dehydrogenases, transferases, kinases and aldolases. High concentrations of potassium (K) are necessary to induce conformational variations and optimize the degree of hydration of the enzymatic protein and, therefore, maximum enzyme activation.

Deficiency – Marginal chlorosis in the leaflets of older leaves, which develops between the veins. Brown or grayish stains, of different sizes, irregular, in the process of necrosis. The leaflets may be reduced, as well as the plant in general. In more developed leaves, in addition to necrosis, numerous small punctuations appear, very close to each other, causing the impression of a reticle. From the association of these spots, larger ones are formed, with a dark brown color. Smaller pods.

Important in preserving the absorption capacity of the roots by maintaining the integrity of the plasma membrane, as well as preventing the loss of solutes to the external solution, increasing the accumulation of nutrients by the plant. 

It has a structural role in plants, important in cell wall synthesis, pollen grain germination and pollen tube growth. Therefore, it is an essential nutrient for the fertilization of flowers, fixation of flower buds and formation of pods.

Deficiency – Stem, petioles and bud exhibit wilting, pods are deformed. The plant stops emitting new shoots. The lower leaves have small grayish spots, which are later affected by intense partial chlorosis, which starts at the base of the leaflet and progresses between the veins.

It directly participates in photosynthetic activity, constituting the chlorophyll molecule, participating in the activation of several enzymes, such as glutathione synthetase and PEP carboxylase, in the phosphorylation and translocation of photoassimilates. 

Deficiency – Weak, generalized chlorosis, with green veins, progressing from older to younger leaves. As the deficiency progresses, pale spots with irregular contours, almost whitish, appear on the leaf blade. 

Then, the spots darken in the central region, with necrosis occurring, which spreads to the periphery of the spot.

It is involved in enzymatic processes and oxidation-reduction reactions, it is a constituent of the amino acids cystine, cysteine ​​and methionine, which constitute about 90% of the total S of the plant.

Ferredoxins, proteins participating in photosynthesis, biological fixation of atmospheric nitrogen (N) and other electron transfer reactions, contain S in large quantities.  

Deficiency – Younger leaflets with generalized chlorosis. The symptoms can appear in the peripheral region of the leaflets, sometimes as isolated spots, of different sizes and contours, sometimes together, forming extensive yellow areas. The chlorotic leaflets are transparent, highlighting the veins, already somewhat clear, on the yellowish background.

It directly participates in the photosynthetic and respiratory process of the plant, in leaf growth and in nitrogen metabolism. 

Deficiency – At first, the limbus of the youngest leaflets becomes chlorotic, with the veins standing out. Then, the chlorosis is generalized, confusing the veins and the limbus. Brown spots appear that become necrotic.

It plays an important role in plant metabolism, acting in the activation processes of different enzymes, chlorophyll synthesis and photosynthesis.

Deficiency – Interveinal yellowing of younger leaves. Nerves and adjacent areas remain a deep green color. Later, red spots appear. In the case of toxicity, the plants present with dark spots on the median leaflets, which coalesce; wilting and leaf fall.

Its participation as a functional, structural or regulatory cofactor of a large number of enzymes is essential for the synthesis of tryptophan, which, in turn, is the precursor of indoleacetic acid.

It has an important role during seed germination and in the initial growth of seedlings, it is a structural, functional cofactor or that regulates the activity of many enzymes. Everything indicates that Zn participates in indole acetic acid (IAA) metabolism.

Deficiency – Severe reduction in plant size with compressed internodes. The leaves may become uniformly dark green in color, reduced in size and with spearhead-shaped leaflets.

Copper has unique importance for leguminous plants, as it helps the symbiotic fixation of N2, being required in the nodules for the full functioning of this process. 

Deficiency – The needy plants show a dark green color, with wrinkling of the edges and curving of the tip of the blade downwards. They also have reduced leaf area. Although the plants have almost normal development, the production of pods is reduced.

It is an essential element for plant growth, participating in various processes such as sugar transport, lignification, cell wall structure, carbohydrate metabolism, RNA metabolism, respiration, AIA metabolism, phenolic metabolism, ascorbate metabolism, in addition to having a in cell wall synthesis and plasma membrane integrity.

 It is an important nutrient in biological nitrogen fixation in beans. Although it has no direct action on this process, it is an element that activates the starch phosphorylase enzyme, responsible for the synthesis of starch, a reserve substance in seeds and roots.

 Deficiency – Initially the youngest leaflets turn dark green, progressing from the apex to the base. Then the leaves become twisted, thick, with the veins of a light green hue. After, necrotic spots and drying out of the growth spots appear. The terminal bud dies. The stem thickens and may show cracks. Deficient plants do not flower and root growth is seriously affected. Irrigation water containing 2 ppm boron is considered harmful to plant development.