To Measure Is To Know

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If Plants Could Talk...Nutrients



Critical Nutrient Problems Can Limit Yields.

Proper nutrient management is key to healthy plant growth, especially with high-value vegetable crops that have a short growing season. Maintaining the right amounts of nitrogen and potassium is essential for achieving crop yield and size requirements. However, too little or too much can cause problems. In fact, over-application can be just as detrimental as a deficiency. That's because excessive fertilizer impairs yield production, increases input costs and contributes to surface water runoff. The goal is to feed plants according to their physiological requirements. These can vary widely from field to field and throughout the growing season.


In-field Nutrient Measurement Allows Immediate Management Decisions.

While vegetable growers have used traditional petiole sap testing for years as a means for monitoring the nutrient concentrations in their crops, that old-school method has drawbacks. Petiole samples must be collected, dried and sent to a commercial laboratory for analysis. The process requires a lot of time, typically a week or more. A quicker approach is to use in-field measurement tools on a regular basis, every seven to 10 days, because nutrient levels can change rapidly. Nitrogen, in particular, is a very mobile and reactive element. These quick-test tools determine how much nitrogen or potassium is present and provide immediate readings – so there is no delay in waiting for a laboratory analysis. Growers can compare this instant information with general guidelines, such as the ones shown below, to make on-the-spot decisions concerning fertigation adjustments. This offers significant economic and environmental benefits. By applying the right amount of nutrients, you can save money, optimize yields and help safeguard the environment.




Put the Power of a Laboratory Right in Your Hands with Cardy Meters.

Perform fast, direct nutrient testing to analyze fertigation effectiveness! Cardy Meters bring microprocessor technology to the field for on-site nutrient measurement. The Cardy's unique, flat sensor allows you to conveniently and accurately measure small samples. Measurement readouts are shown on the LCD display. These meters are ideal for drip- and pivot-irrigated vegetable crops, including tomatoes, bell peppers, broccoli, celery, sweet corn, lettuce, watermelons and potatoes.


2305G Cardy Twin Nitrate Meter



Use this self-contained, waterproof, pocket-sized meter to measure samples as small as 0.3 mL.


  • Sensor stores dry and is field replaceable
  • Measures from 14 to 1,400 ppm
  • Accuracy correlates well with laboratory analysis
  • Includes batteries, case and calibration standards

2400G Cardy Potassium Meter



2400CardyKIonThis exceptionally small and portable digital meter delivers quick answers to potassium-level questions.

  • Sensor stores dry and is field replaceable
  • Automatic range switching from 0 to 9,900 ppm
  • Accuracy correlates well with laboratory analysis
  • Includes a carrying case, standards and accessories


Have questions?
Call us toll free: (800) 248-8873!



"Nitrogen (N) and Potassium (K) are vital building blocks for plant health. Ask your plants if they have the right amounts by performing in-the-field petiole sap testing."




Collect Samples Quickly, Easily with a Spectrum Sap Press

Handheld Plant Sap Press

Made of high quality, non-corrosive metal

Includes cleaning device


Hydraulic Plant Sap Press

Speed up collection of large or less succulent samples

Hydraulic press extracts sap into a collection vial