How to maintain wheat green leaf canopy
The key to achieving high wheat yields, having established the correct canopy structure, is to maintain the green area right through to the final grain filling period, capturing as much of the incident light as possible and converting it to yield.
Nitrogen, magnesium and sulphur are of particular importance in maintaining a green leaf canopy. Chlorophyll is a nitrogen and magnesium rich protein that gives the plant its green colour and is central to efficient photosynthesis. Sulphur is an important component of all proteins and is always required together with nitrogen for protein synthesis.
Nitrogen affects leaf canopy development and duration
The relationship between leaf chlorophyll content and nitrogen is well proven with more chlorophyll as leaf percentage of nitrogen increases.
Maintaining the level of nitrogen in the leaf through to GS 65 gives optimum yield.
Sulphur and magnesium help maintain leaf canopy
Magnesium is the central component of chlorophyll linked to four nitrogen molecules. The magnesium level is also therefore important in maintaining the green leaf canopy.
As well as the canopy greenness, it is also important to ensure that the structure and architecture is maintained further improving the efficiency of the crop to capture light and convert it to yield.
Potassium extends grain filling period
Potassium plays a very important role in maintaining cell turgidity and strength as well as nutrient movement around the plant.
Inadequate supplies of potassium can lead to premature wilting and a lodged canopy. Straw deficient in potassium is more brittle increasing the risk of lodging that dramatically reduces both yield and quality. The demand for potassium is higher than any other nutrient with the majority taken up in the spring. Between the beginning of tillering and end of tillering wheat will take up on average approximately 7.7 kg K20 / day. Applications should be targeted to meet this demand.
Recommended Yara fertilisers for wheat
Related articles
How to increase wheat leaf and tiller numbers
The number of leaves determines the size of the crop canopy and its photosynthetic potential. The number of shoots and how many of these survive through to harvest also determines the number of ears at harvest and so the potential yield.
How to increase wheat grain size and weight
Wheat grain size is strongly influenced by plant nutrition particularly during the important grain filling period. Nitrogen, phosphate, potassium, magnesium and zinc are particularly important.
How to increase wheat grain numbers
The grain number is itself a function of the number of fertile shoots per unit area and the number of grains per ear. The grower therefore needs to consider how nutrition can have an impact on the grain numbers per ear.
