We have often read about the 🤓 importance of zinc for corn 🌽, but rarely delved into the essence of why it is so important for this crop. Let’s try to understand this from an agronomic point of view and look at the specific processes that occur in the plant, particularly during the stages of ear and cob formation, as they determine our final yield.

🔸 3rd leaf stage – the growth cone is elongated. Formation of nodes and internodes of the stem’s embryonic meristem.

🔹 5th leaf – unfolding of the cotyledon leaves, segmentation of the growth cone, and formation of the ear axis embryo. Concurrently, leaf and tassel shoot development takes place.

🔸 7th leaf – segmentation of the cob glumes and the ear axis, laying down rows of grains. It is during this period that providing additional zinc nutrition is crucial, as it stimulates the formation of more rows in the cob.

🔹 9th leaf – formation and differentiation of tassel flowers, the beginning of pollen formation. Cob development and grain set in rows. This is another critical moment when additional zinc fertilization will promote the setting of a greater number of grains per row.

🔸 15th leaf – growth of the floral cover tissues of the tassel, differentiation of cob flowers, the formation of anthers and pistils. Supplementing with zinc improves the crop’s stress tolerance, while boron enhances pollination processes.

🔹 Emergence of the ear – appearance of the ear and formation of the embryo sac.

🔸 Tasseling – flowering of the ear and intensified growth of the silk and cob stalks.

🔹 Cob flowering – emergence of silks, pollination, and formation of kernels.

🔸 Milk stage – full maturity – encompassing the stages from embryo formation, endosperm and pericarp development, to endosperm differentiation, complex protein and carbohydrate synthesis.

⚠️ Therefore, there are 2 critical moments in the life of corn concerning zinc fertilization:

🔹🔸 6th-7th leaf stage – determining the number of rows in the cob;

🔹🔸 8th-9th leaf stage – determining the number of grains per row.

It is precisely before these development phases that the plant should be supplied with nutrients at 200% capacity.

So, keep your finger on the pulse of TerraTimes!