Maintaining Barley Leaf Canopy

To achieve high barley yields, having established the correct canopy structure, it is important to maintain the green leaf area right through to the final grain filling period, capturing as much of the incident light as possible and converting it to yield.

Nitrogen, potassium and magnesium 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. The relationship between leaf chlorophyll content and nitrogen is well proven with more chlorophyll as the leaf percentage of nitrogen increases.

Nitrogen directly affects leaf chlorophyll content

 

Correlation between nitrogen supply and flag leaf

Correlation between nitrogen supply and flag leaf N%

 

The correlation between leaf chlorophyll content and the Yara N-Tester measurements

The correlation between wheat leaf chlorophyll content and N-Tester measurements

 

The correlation between leaf nitrogen content and the Yara N-Tester measurements

The correlation between wheat leaf nitrogen content and N-Tester measurements

 

Magnesium helps keep the leaf canopy greener for longer

Magnesium is the central component of chlorophyll linked to four nitrogen molecules. The magnesium level is therefore important in maintaining the green leaf canopy.

Chlorophyll molecule

Potassium maintains straw stiffness and reduces lodging

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. The more, larger cells produced by the nitrogen means more water in the plant which then requires more potassium. 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 / brackling that dramatically reduces both yield and quality.