Petiole testing can provide a snapshot of the nutrient status of the vine. Obtaining quantitative information on nutrient levels can assist in determining the effectiveness of fertiliser applications and also help identify the cause of any specific vine problems.
The following table outlines nutrient guidelines for the full list of parameters tested in our Petiole Analysis Bundle.
|Nitrate Nitrogen (%)||<340||340-499||500-1200||>1200|
|Chloride (%)||<1.0||1.0-1.5||>1.0 or 1.5|
From Iland et al, 2011: The Grapevine from the science to the practice of growing vines for wine. Patrick Iland Wine Promotions Pty Ltd.
The results from your petiole analysis can be compared with the developed standards in the above table, which relate to vegetative and reproductive performance. The standards have been developed in Australia for petiole samples collected at full flowering (80% cap-fall).
It is important to consider other factors when interpreting your petiole analysis results, such as hoot vigour and overall vine health and performance. We recommend contacting an agronomist or vineyard specialist for further advice.
- It is recommended that sampling take place at full flowering or when approximately 80% of the flower caps have fallen off.
- Using clean hands and the gloves provided, collect a petiole (leaf stalk) of a basal leaf opposite a flowering cluster. One petiole from each of 100 vines throughout a planting is required.
- Sample from vines in a zigzag pattern to obtain a representative sample.
- Miss the first three vines in each row if there is an access road adjacent. Avoid sampling vines growing within areas with unusual features, such as rocky areas, poor drainage, near fences, trees, water troughs or fertilizer depots to minimise the risk of contaminated or skewed results. Avoid soiled, diseased or damaged plants. Do not sample petioles touching trellis wires, or plants that are under water or temperature stress.
- Preferably sample in the cool of the morning, before any moisture stress may occur.
- Petioles should be placed in the brown paper bags provided and labels attached with the following information:
- Company Name
- Contact Name
- Sample ID
- Date Sampled
- Maintain samples in a cool environment prior to and during transportation. Do not seal samples in plastic bags or on unprotected ice – use newspaper or cardboard to keep separate.
- Samples should be dispatched to the nearest Vintessential laboratory as soon as possible through the post using the provided Reply Paid sticker. Alternatively, samples can be couriered direct to the laboratory – refer to the street addresses on our contacts page.
- Please ensure that transfer of the samples complies with quarantine regulations. A permit may be required for samples sent from outside of a Phylloxera Exclusion Zone (PEZ).
Download the Grapevine Petiole Analysis Fact Sheet as a PDF
Copyright © 2018 Vintessential Laboratories. No part of this publication may be reproduced in any form or by any means without the permission in writing from the copyright owner