Deficiencies in essential nutrients can lead to specific symptoms that, if recognised early, can be addressed to maintain plant health. Below is a guide to common nutrient deficiencies in maize silage plants, their symptoms, and potential management strategies for maize growers in southern Australia.
Leaf sampling
Like a blood test, leaf tissue sampling provides a nutrient status of your maize silage crop, which can be assessed and potentially rectified. For micronutrients monitoring this leaf tissue information is critical.
Micronutrient deficiencies, like zinc (Zn) or boron (B), often go unnoticed but can significantly impact yield. A plant tissue sampling test can pinpoint these deficiencies, allowing for targeted applications in-crop and post-crop.
Quick guide to leaf nutrient symptoms
Healthy leaves shine with a rich dark green colour when adequately fed.
Phosphate shortage marks leaves with reddish-purple, particularly on young plants and especially on the undersides.
Potash deficiency appears as a firing or drying along the tips and edges of lowest leaves. Plants may have weak stalks, increasing susceptibility to lodging.
Nitrogen hunger sign is yellowing that starts at tip and moves along middle of leaf.
Magnesium deficiency causes whitish strips along the veins and often a purplish colour on the underside of the lower leaves. Interveinal chlorosis
Drought causes the corn to have a greyish-green colour and the leaves roll up nearly to the size of a pencil.
Disease blight, starts in small spots, gradually spreads across leaf.
Chemicals may sometimes burn tips edges of leaves and at other contracts. Tissue dies, leaf becomes whitecap.
Zinc deficiency with young leaves exhibiting white or yellow bands on either side of the midrib. Plants may show stunted growth with shortened internodes, resulting in a rosette appearance.
Immediate benefits for the Current Maize Silage Crop
Visual cues: By monitoring maize silage plants for these deficiency symptoms, its a quick way to identify any potential problems which need investigating.
Timely Corrections: Leaf tissue testing during critical growth stages (e.g., V6-V8 or VT-R1) can help identify nutrient deficiencies that are limiting yield potential. If deficiencies are identified early enough, corrective actions (e.g., foliar sprays, aerial spreading) can improve crop performance.
Targeted Nutrition: Maize has high nutrient demands, particularly for nitrogen (N), phosphorus (P), and potassium (K), during rapid vegetative growth and grain filling. Tissue testing can ensure these nutrients are available in the right proportions.
While this analysis can come too late to prevent deficiencies in the current crop, it can be useful for overcoming deficiencies and modifying the fertiliser programs for following crops. Always keep in mind late-season applications may not translate into substantial yield gains.
Long term benefits for subsequent crops in same paddock.
Soil Health Assessment: Leaf tissue tests provide a snapshot of what the crop is “experiencing,” reflecting soil nutrient availability and uptake efficiency. This data can highlight broader soil fertility issues that need addressing before the next crop.
Improved Fertiliser Planning: By combining tissue test results with soil test data, you can fine-tune fertiliser recommendations for the following crop, avoiding over- or under-application.