Sample Collection & Preparation for Perennial Fruit Crops
Tissue samples for perennial fruit crops are typically taken when nutrient levels in leaves are relatively stable. All leaves for a sample should be collected from the same cultivar. The sampling procedure should be as random as possible. It is best NOT to take multiple leaves from the same bush or tree but rather collect from a wide selection of plants throughout the block you are sampling. Refer to NM-5 “Nutrient Management for Tree Fruits and Small Fruits” for more information on tissue sampling.
Consult Table 1 to determine the appropriate time to sample, the number of samples/plant part, and the location on the plant for each fruit crop. Figure 1 has additional information on the proper sampling location.
CROP | TIME TO SAMPLE | NUMBER OF SAMPLES/PLANT PART | LOCATION ON PLANT |
---|---|---|---|
Blueberries | 1st week of harvest | 40 leaves (detach petioles) | Current season’s growth |
Brambles | August 1st – August 20th | 60 leaves (detach petioles) | Select the most recent fully expanded leaf blade of each non-fruiting cane |
Grapes | Full bloom; or 70-100 days post-bloom | Small = about 75 petioles Large = about 50 petioles |
Bloom: Petiole of leaf opposite 1st blossom cluster or 75-100 days after bloom: Petiole from last fully expanded leaf |
Fruit Trees | July 15th – Sept. 1st | 50 leaves and petioles | Select shoots at eye level from around outside of the tree. Select shoots that make a vertical angle of 45-60 degrees to the ground. Remove 1 or 2 leaves from the mid-portion of the current season’s growth (figure 1.) |
Strawberries | Late July or early August; after renovation | At least 50 leaves (not petioles) | Newly expanded leaves after renovation |