Yield is a material thing, and without supplying plants with «building material» such high indicators should not be expected. Modern corn hybrids can use quite effectively the nutrients applied to the preceding crop, for example sugar beet, cereals or vegetable crops. Nitrogen fertilizers have the greatest effect on corn yield formation, so applying them before sowing and in feeding is a necessary agronomic practice. Doses, application dates and nitrogen forms are chosen based on specific conditions, taking into account the tillage method, temperature and other factors. Applying anhydrous ammonia in autumn, or in spring before sowing, gives excellent results. The dose of anhydrous ammonia is 1.2–1.5 c/ha. In at-sowing feeding, if possible, it is desirable to apply 0.5–0.7 c/ha of nitroammophoska to provide readily available mineral nutrients in the initial stages of plant growth. Potassium has an important place in forming the corn yield. In potassium removal corn is the record-holding crop in our country's farming, since potassium is important in forming the main reserve substance of the corn kernel, starch. That is why shortage of these two macroelements (nitrogen and potassium) most often has visual signs.
Photo 1. On the leaves, potassium deficiency is clearly visible as paling of the edges of the leaf blade.
Photo 2. A stronger manifestation of potassium deficiency shows as dying of the edges of the leaf blade, or complete dying of lower leaves. Dark spots on the stem are damage by the corn borer.
A visual sign
of phosphorus shortage is possible as a violet colour in the early stages of plant growth and development, which can be caused by low temperatures at this time. It is known that at low temperatures (at soil temperature below +13°C) phosphates are taken up very weakly by plant root systems. Insufficient phosphorus nutrition in the early stages delays root system growth, which in turn inhibits the development of the whole plant. The loss of several days of active plant vegetation definitely leads to reduced yield. A similar manifestation on corn plants, and a negative effect on yield, is observed after the preceding crop sugar beet: the «beet syndrome of corn» first described in the USA.
Photo 3. Visual signs of phosphorus shortage on corn plants.
To eliminate signs of phosphorus shortage in corn plants in the early stages of growth and development, 4–6 leaves, Ecoorganic offers several products. Ecoline Phosphite K – 1–2.0 l/ha; Ecoline Phosphite K-Amino – 1.5–2.0 l/ha, Ecoline Phosphite K - Zn – 1.5–2.5 l/ha. The choice of fertilizer and its dose depends on the level of manifestation of phosphorus, zinc or both elements' deficiency at the same time, the plant condition, the weather forecast for the next few days, and so on.
Microelements, in particular zinc and boron, have an important influence on corn growth and development. Zinc is extremely important in the period of the for
mation in plants of 4–6 leaves, when the generative organs of corn are laid down. It takes an active part in enzymatic and metabolic processes and in the synthesis of proteins, chlorophyll and vitamins B, P, C, influences growth and development processes and raises resistance to unfavorable conditions, in particular frosts. An increased content of phosphorus compounds in the soil leads to zinc shortage. With significant zinc deficiency, ears may fail to set on plants. Plant growth decreases because of shortened internode length. A sign of zinc shortage is yellow stripes on young leaves on both sides between the veins, as well as a yellow or white colour of the whole surface of young leaves.
Photo 4. Visual signs of zinc shortage on corn plants.
To prevent and/or overcome zinc deficiency we suggest using the most modern microfertilizers produced by Ecoorganic:
Ecoline Zinc Chelate , containing 85 g/l of zinc as 100% EDTA chelate. Application rate 0.5–1.0 l/ha. In cases when it is desirable to remove signs of phosphorus, potassium and zinc deficiency at the same time, we offer the unique composition Ecoline Phosphite K - Zn, which contains 320 g/l of phosphorus in phosphite form, 210 g/l of potassium, 35 g/l of zinc as 100% EDTA chelate and 8 g/l of organic boron. Application rate 1.5–2.5 l/ha.
Boron, which affects pollen viability, is needed by plants before tasselling. These microelements are also important in later periods of corn plant growth and development. In particular, the level of boron nutrition affects kernel set of the ear, and zinc affects growth and starch content, the main reserve substance in corn grain. To prevent boron deficiency, Ecoorganic suggests using the microfertilizer Ecoline Boron Organic at 0.5–1.0 l/ha. It should be noted that besides the highest possible concentration of boron in complex with monoethanolamine (155 g/l), this product has been certified under «Organic Standard» requirements, which allows this microfertilizer to be used in producing ecologically clean products.
In cases when the need for boron feeding coincides in time with signs of stress on corn plants, we suggest using a unique product from Ecoorganic, Ecoline Boron Premium. Besides 140 g/l of boron in organic form with monoethanolamine, this product contains 10 g/l of L-α-amino acids, which will help the plant overcome stress caused by weather conditions or crop protection products. The application rate of this microfertilizer is 0.5–1.0 l/ha. Corn is a high-yielding crop that forms a large vegetative mass. For such crops a fast growth phase is singled out, when in a short period of time, about two weeks, the vegetative mass of plants practically doubles. Accordingly, plant nutrient needs rise substantially. Very often these development stages fall in a dry period, when the root system cannot fully supply plants with all the necessary mineral nutrients. In this case, the most effective agronomic technique is applying special fertilizers containing a balanced composition of micro- and macroelements, intended to supply actively growing plants with the necessary nutrients. Our company offers exactly such a product, Ecoline Universal Growth Chelates. This microfertilizer contains all the necessary nutrients, and Mg, Fe, Mn, Zn, Cu in the foliar nutrition fertilizer Ecoline Universal Growth Chelates are 100% chelated with EDTA. Application rate 1.0–2.0 l/ha. When in the active growth stage plants are under stress from soil herbicides or weather conditions, the composition Ecoline Universal Growth Amino. is recommended for foliar feeding. This complex fertilizer, besides the set of micro- and macroelements the plant needs, contains 75 g/l of L-α-amino acids that help plants overcome stress situations. Application rate 1.0–2.0 l/ha.