Micronutrients play an important role in increasing sugarcane yield and producing quality crops. Deficiencies and responses are related to a wide range of factors most notably soil type, pH and availability. Responses can be high in both the plant and the ratoon crop where foliar application helps encourage better growth. Plant crops – while higher yielding – usually have a greater soil supply of micronutrients.
There are numerous examples of positive responses in terms of growth and subsequent cane and sugar yield in the scientific literature. Figures 46, 47 and 48 highlight some of this research and indicate responses where micronutrients are in short supply.
There is, however, growing evidence that some micronutrient critical levels may not be high enough and that despite adequate macronutrient supply – particularly nitrogen – sugarcane crop performance may be restricted by micronutrients. In some countries, such as Brazil, researchers are revisiting the responses seen in the past on new, higher yielding varieties.
In independent research as well as Yara’s own trials, significant responses are being found from the use of boron and zinc applied in tandem to the planted setts and at early stages of regrowth in the ratoon crop as a foliar application.
At the same time, there is increasing evidence that molybdenum is also a key nutrient that is currently underestimated and under-used in sugarcane production, which could improve nitrogen responses in the crop.