For more information on Sap sampling click here

Sap Analyses:

Short Test: NO₃, P, K, Ca, Mg, Zn
Full Test: NO₃, P, K, Ca, Mg, S, Zn, Cu, Mn, Fe, B
Additional Test: pH, Total N, Na, Cl, Si, Brix

Dried Tissue Testing

The conventional method of plant analysis is the analysis of dried tissue. This is essentially a measure of the total amount of the element in a particular plant part, including nutrients contained in non-metabolisable cellular tissue, metabolites already present and elements in the sap available to be metabolised.

Sap Testing

Sap testing, developed by Crop Tech in 1985, is a measure of the soluble elements in transport in the plant system which are available for metabolism, and thus is not only an indication of instantaneous nutrition, but can also be used as a measure of the rate of metabolism. The sap levels can be viewed as a set of diagnostic data that reflects the crop's reaction to the environmental and management influences.

Sap analysis has been used by researchers as a fast assessment of the levels of nitrate in a few crops for more than 30 years. In the last 19 years, Crop Tech have refined and developed sap testing into a comprehensive commercial nutrient monitoring system that is now being used in over 100 different crops in 12 countries.

Why use Sap Testing?

Because the analysis of plant sap mainly measures mobile nutrients in the plant system, it gives a different view of plant nutrition than the traditional dry tissue analysis, and it is more sensitive and able to detect minor or temporary deficiencies more easily. This enables more accurate diagnosis of plant stress, and therefore better management decisions to correct nutrient imbalances or deficiencies. Better selection of fertiliser products, rates, application types and timing of applications improves the efficiency of nutrient utilisation.

Software

Crop Tech's crop management software "Integrator" integrates the nutrition monitoring with soil moisture and environmental monitoring to make data analysis faster and more comprehensive by graphing nutrient changes against other parameters.

Benefits of Sap Testing

Regular monitoring of sap enables us to:

• Monitor plant stress as indicated by the dynamics of the nutrient levels.
• Determine the effect of management and environmental influences on nutrient levels.
• Monitor the effect of and response to fertiliser applications.
• Ensure deficiencies are detected before crop loss occurs.
• Ensure plant nutrients levels are optimal for maximum fruit growth and quality.
• Fill fruit evenly and improve internal quality by maintaining optimal K levels.
• Reduce effects of adverse weather on fruit by detecting temporary deficiencies.

As growers become accustomed to using sap testing, they can take more control of plant growth, crop production and fruit quality.

Nutrition Monitoring

Sap testing should be used as a monitoring tool, on a regular basis, with the frequency depending on the crop type and stage of growth. The objective is to record the dynamic changes over time, rather than using the analysis only as a one-off diagnostic test. This system ideally integrates crop observations, weather and irrigation management information and crop history. Nutrient deficiencies and toxicities can be diagnosed, and corrective measures recommended.

A fertigation or side-dress programme should be formulated from a Pre Plant Soil Test, and sap testing will then be used to increase, decrease, or add other elements to the programme, particularly where fruit set is abnormal, or weather conditions affect the crop requirement, or cause leaching.

Reports and Recommendations

As with any testing system, the interpretation of the results is an extremely important step, and the best results can only be obtained if the interpretations and recommendations are made by trained and experienced agronomists. This is even more important with sap and QuickSoil tests than with conventional soil and dried tissue tests, as the former are designed to monitor more variable and dynamic parameters. Because the changes in element level in sap and QuickSoil tests are highly sensitive to irrigation and environmental influences, the meaning of a high or low reading for any element does not necessarily translate to deficiency or toxicity. A pattern of element changes can be a strong indicator to certain type of stress within the plant.

The integration of irrigation and nutrition information is a key part of accurately monitoring crop performance. Crop Tech "Integrator" software has been designed to detect and identify these complex patterns. Crop Tech provides an interpretation and recommendation service (included in the price of the analysis) which utilises the software and experience gained from 19 years of interpretations. Crop Tech also provides training for consultants and growers to improve the understanding of interpretations and nutrient monitoring.

View example sap report - Recommendations are provided with reports, these are not show on this sample.

For more information on Sap sampling click here