Corn Tissue Sampling Instructions
Corn Tissue Sampling Instruction (download pdf)
For those sampling independently of Project personnel.
If concerned, see Will Tissue Sampling Decrease My Yield?
Please sample a single area of about 1 acre that is under Yield-Contest Management within or as near as possible to where you expect to harvest your Contest acre. Download and use the prepopulated NCDA&CS PLANT SAMPLE INFORMATION form specific to each sampling time (FYI: Corn Growth Stages Corn Growth and Development pdf).
SAMPLE ID: please use your (the grower’s) initials and the number corresponding to the tissue sampling times listed below. . Project will reimburse costs and/or supply materials and has prepaid the analyses.
When and what to sample (links to pre-populated INFORMATION FORMs, which are specific to sampling growth stages)
1. Seeding (less than 4 inches) OR Early (4 to 12 inches): 20 whole plants cut 1” above the soil surface
2. Early (greater than 12 inches; about V10: 10-leaf stage): most recent mature leaf: uppermost leaf with a collar, 20 plants
3. Tasseling (VT) through silking (R1): ear leaf: adjacent/immediately under the uppermost ear, 20 plants
4. Maturity (black layer-R6): ear leaves from 20 plants
Avoid material with visible dust, soil, or chemicals. Rinse if need be, ideally with distilled water. Place in clean PAPER bag.
If you can get it to NCDA&CS within 12 hours, nothing more need be done. If within 24 hrs, refrigerate. Otherwise dry ASAP using ONE of the methods below:
Drying:
For whole plants, we suggest splitting the stalk & teasing apart the leaves and collars. Tissue can be torn or cut to facilitate drying by ONE of these methods:
1) Microwave: The goal is to heat the sample just long enough to dry it without burning. The necessary power and time depend on the sample and oven. Keep an eye on things; DO NOT leave unattended. These are conservative guidelines: you may need to experiment! Place a microwave-safe cup of water in the corner of oven. Place sample in a glass baking dish or on a glass microwave platter, microwave on Medium for 1 to 5 min at a time until brittle. Redistribute sample at the end of each interval. As brittleness approaches, reduce the time to avoid charring. If charring occurs, discard charred portions.
2) Conventional oven: set to 175°, distribute material evenly in paper bag or glass baking dish, dry overnight or until brittle. Use convection or leave oven door ajar.
3) “Natural”: place paper bag in a hot, dry place (such as an attic or loft), or in the sun and dry until brittle.
Place dry sample (which can be crushed to fit) and the PLANT SAMPLE INFORMATION form into a clean paper envelope and send to NCDA&CS.