How to tissue sample

How to tissue sample

The last 30 years have experienced a tremendous increase in plant testing as a management tool. The major purpose of plant testing is to evaluate the nutritional status of the plant and add the necessary elements in water or on the leaves in order to obtain maximum profits for the grower. Plant analysis is not a substitute for soil analysis, but compliments soil testing and makes overall fertilization more efficient and effective.


  1. Confirms deficiency symptoms
  2. Identifies hidden hunger
  3. Detects under-fertilization
  4. Detects improper fertilizer placement
  5. Used for monitoring crops throughout season
  6. Helps increase sucrose content of sugar beets
  7. Helps decrease diseases in potatoes
  8. Increases yield and protein in small grain
  9. Determines feed value in alfalfa
  10. Helps increase yield and quality of all crops

How to sample

  1. Obtain tissue samples from areas representing the field.
  2. Collect a sufficient number of samples as described in the following pages
  3. When normal and abnormal plants are being analyzed, a sample of both types should be taken for separate analysis
  4. Do not include diseased and insect damaged plants.
  5. Avoid dusty or contaminated plant parts

Handling and Packaging

  1. Place sample in paper bags provided and send to our laboratory within two days of when the samples were taken. DO NOT place in plastic bags.
  2. If applicable, indicate stage of growth on the bag for each sample. Recommendations can be affected depending on the stage of growth.
  3. If samples are sent through the United States Postal service send to: PO Box 353 Twin Falls ID 83303.
  4. If samples are sent through UPS or FEDEX, send to: 2924 Addison Ave E Twin Falls, ID 83301



  1. Take the first recently mature leaf, it is generally the 3rd-5th leaf from the top of the plant, not counting the very small cluster of new leaves at the growing point.
  2. Once you have picked the 3rd, 4th or 5th leaf, you should immediately strip all of the leaflets off the petiole (small stem). Just submit the petioles from the potatoes, not the leaflets.
  3. It is important to get a sufficient number of petioles to show the average of the field; usually 30-40 petioles, Laboratory analyses are more accurate when we receive a larger sample.


For Nitrates only: Take 15 petioles from fully matured leaves midway between the younger center leaves and older leaves

For complete analysis: Take 15 petioles and leaf blades from fully matured leaves midway between the younger center leaves and older outer leaves.


Take entire stem above mower height from 50 plants.


Until the LATE BOOT stage of growth when the FLAG LEAF is visible, sample the entire plant down to the white area of the stem above the roots. AFTER LATE BOOT STAGE, sample the FLAG LEAF only. Sample at least 50 plants from 20-25 locations in the field.


Prior to silking, take 3rd leaf from the top. Between silking and tasseling take entire leaf opposite and below lower ear. Collect 15-20 leaves.


Take 50 uppermost mature leaf blades with petioles at or near early bloom stage.


Sample 40-50 leaves and petioles at about head height during early to mid-season.


Take 25 petioles and leaflets from the 3rd node down from the top of the plant before and during initial flowering.


Sample 20-25 first fully expanded mature leaves at mid-growth or when root begins to enlarge.


Sample 25-30 leaves midway between old and new leaves at bulb stage.


Sample 30-35 first fully expanded mature leaves midway between younger new growth and outer older growth.


Sample 20-25 first fully expanded mature leaves located 3-5 leaves from the growing point.


Sample 50-60 blades from the 4 upper most leaves


Sample 50-70 of the youngest fully expanded mature leaves at mid-season.


Sample 40-50 leaves from the first fully mature leaves below the growing point.


Take mature leaves and petioles from each tee at waist to shoulder height, removing only 1 leaf per spur or shoot. Sample 4-8 leaves per tree and sample should contain 100 leave. Sample from June 1st to August 1st.


Same as apples, but sample leaves from July 1st to July 15th.


Same as apples, except take mature leaves from mid-portion of current season terminal growth 12 to 14 days after full bloom.


Same as Cherry

2924 Addison Ave E Twin Falls, ID 83301
208-734-3050 * 208-734-3919 (fax)