Proper Plant and Tissue Sampling

We recommend starting tissue sampling in the spring, post bloom so there will be ample time to remediate a deficiency prior to harvest. For micro nutrients such as Boron and Zinc, you should submit leaf blades for testing. Petiole testing is a very good method for determining nitrogen and nitrogen movement. If nitrogen is your primary concern, a petiole test is recommended. Some growers will collect both samples, then we will split them and base the report on the micro nutrients of the blade and the nitrate nitrogen of the petioles. This allows the best of both methods for a small increase in fees. Pull tissue opposite the fruit on the vine, trying to pick the average, knowing that your eye will be attracted to the abnormal. A sample size should consist of a large handful, typically 25-35 leaves or 40-50 petioles are optimal.

Pod vs. Random
Many growers are switching to pods for their soil and tissue testing. A pod is where there are a few known locations in a block with known vines that are an average representative of the block; all the tests are from these vines. Each year for example, pod 7-10 equals block 7-10 tenth tractor row from the south west vines 10-11-12 on the left and right side for a total of 6 vines. The benefit of this method is that since one returns to the same vines each time they test, they eliminate the intra-vineyard difference and allow for a closer analysis of cultural factors as well as yearly weather influences.