The “Big Three” are where the main focus of most fertility programs are, but there are at least 17 essential elements and especially as we enter into higher yielding environments, there are others besides the N,P, and K we need to concentrate on. Calcium is often overlooked, however, it is critically important because it is needed to form cell membranes.
It is especially important during the early reproductive stage. Why? Because this is when potential grain size is being determined. At this stage, the cells in the embryo are rapidly dividing exponentially. This will occur for about 10-14 days immediately following pollination. After this period, the cells will be expanding in size, but not number. If the grain has more cells, it can expand to a much larger size.
To produce exceptional yields you must ensure that you have available calcium at this peak period. We apply gypsum and/or lime to our soils to increase the quantity of available calcium. However, other factors can also affect the availability of calcium in the soil. Poor uptake of calcium can be due to dry soils, excessive potassium levels, high sodium levels, low boron or low manganese availability. For this reason, in addition to soil applications of calcium we recommend calcium, manganese and boron be foliar applied prior to pollination. To increase the absorption of calcium at this critical time. Also, Calcium and boron are not very mobile in the plant meaning that it must be taken in at the time it is needed and won’t translocate from another part of the plant to where it is needed (ie. Cells rapily dividing). Remember the 5Rs. Right Rate, Right Form, Right Time, Right Place, Right Product.