The best material for tissue sampling comes from mature leaves. One should be careful to pick sample material only from the right plant and at the right stage in it’s growth cycle. The sample should never be taken right after application of pesticides or fertlizers and should be large enough for the lab to analyse. The sample should be put in a paper bag, NOT a polythene bag or a metal container.
The paper bag should be properly labelled with your name, field name or number, date, crop and growth stage. The sample should never be refrigarated or frozem but should be taken to the lab immediately. Note that taking samples the right way the first time saves you money in the long run.
Different crops call for different sampling times and parts. Fact sheets with crop-specific information for field, vegetable and root crops are available from MEA labaratory services office. These fact sheets explain optimum sampling time, techniques and expected nutrient results.