Feeding rapid growth in the early stages of establishment

Feeding rapid growth in the early stages of establishment

During the early stages of germination plants, especially Oilseed rape (OSR), in autumn and early spring require a quick uptake of nitrogen to fuel the rapid cellular division that is taking place.  The importance of Nitrogen in this process is never in question and every effort is made to ensure that there is plenty available. However, the effective uptake and efficient use of Nitrogen could be limited by the lack of Boron available from the soil.

Boron was either contained in the rocks that weathered down to create the soil in your field or it wasn’t. There are some fields that will always have absent or low Boron levels; this is readily established by routine soil analysis.

In all crops Boron is vital in the early stages of growth for the conversion of carbohydrates into proteins to enable energy generating reactions, intracellular structure and membrane transport to take place within the plant.  During germination this will contribute to successful root establishment and growth.

Boron deficiencies will reduce the physical robustness of plants. It has often been referred to as the “glue” helping hold cellular structures together. Hence a deficiency in root crops will lead to cracking and the crown opening to cause crown-rot. De-lamination in allium species can also be a symptom of Boron shortage.

Ideally your soil should have 10-100kg of Boron per hectare, which roughly translates into between 1-10kg/ha of available Boron for the plant to use. The levels of plant available Boron in the soil can be affected by a number of factors such as, pH level, drought, low organic matter and excessive liming.  

Boron availability levels start to decline in soils with a pH level between 5.5 and 7.5, which is the pH range that favours the major nutrients. In France rather higher rates of Boron are used in many crops than is common in the UK, mostly because they have less Boron in the soil. However, it is worth noting that their OSR yields are consistently higher than ours, perhaps down to a Boron response?

Boron can go through the crop sprayer for foliar application in many forms. The Disodium Octaborate Tetrahydrate (DOT) powder was the standard treatment for many years and it is the most soluble form of any dissolvable Boron Salt. The hang-up with DOT is that it dissolves very slowly and creates an alkaline spray solution which antagonises pesticides reducing their efficacy dramatically. There’s not much point getting a cost effective Boron product if it requires a separate pass through the crop to apply it.

BroadAcre Boron is the same DOT material, but in a fast-dissolving ACIDplex formulation which CAN be tank-mixed and creates an acidified spray solution; improving uptake and activity as well as preventing it interfering with fungicide and insecticide efficacy.

There is a considerable weight of evidence that Boron and Molybdenum applied together have the most beneficial effect on Nitrogen metabolism efficiency, hence products like Borimol which is based on Boron (BE) Ethanolamine, but with a complementary micro-element Molybdenum content. The liquid BE formulation has become more popular in recent years and is readily absorbed by the leaf, but sometimes does not seem to generate as high a tissue Boron level as equivalent elemental quantities of DOT, and unfortunately also generates alkaline spray water.

The traditional crops that require Boron supplements, sugar beet, OSR and brassicas, are now being joined by carrots, potatoes and even cereals in responding to foliar Boron.