Potato petiole sampling and analysis
The reliability of analytical results and recommendations depends, ultimately on the sampling accuracy. The 3 stages in sampling are key, taking a representative sample, correct packing and immediate despatch to lab and supplying all the necessary background information.
A representative sampling path is required across the field. The W-pattern is adaptable to most shaped fields.
Choose the youngest fully expanded leaf (usually 4th) at a stage no earlier than 10% flowering. For each complete leaf, separate the leaflets from the petiole, and discard the leaflets as soon as possible after sampling. Keep samples in a cool dark place, and send to the lab immediately. Draw from at least 20 different locations in the field. At each location take one leaf branch from each of 3-4 plants (minimum of 60-80 branches in total). Do not sample fields within 3-5 days after being sprayed with pesticides or foliar nutrients.
We have collected a massive potato petiole database over the last 10 years. Using biometric analysis of the data a pro-active interpretation system has been developed for use in the crop's bulking phase.
This is now accessible globally with Megalab.net
over the Internet.