Friday, July 17, 2020

Collecting leaf samples for analysis

    This week I collected leaf samples from my pecan grove so I could submit them for nutrient analysis. Leaf analysis is the best way to discover if pecan trees are getting all the nutrients from the soil needed to ensure optimum tree grow and nut production.
 

    Before I show you how to collect a sample of pecan leaf tissue for leaf analysis, I thought it best to review the parts of a pecan leaf. The photo above shows a single pecan leaf attached to a small section of stem. Pecan trees produce a pinnately compound leaves with 13 to 17 leaflets. The leaflets are attached to the rachis (pronounced ray-kiss) which ultimately attached to the stem. New buds are located within the axis of rachis and stem.
  
     In sampling pecan leaves for analysis, I collected leaf tissue that represents the entire tree's nutritional status. Pictured at right is the current season's new growth. I located a mid-shoot leaf and harvested two leaflets from that leaf. I repeated that process on a total of ten shoots moving around the tree at random. For each sample, I collected leaflets from ten trees selected at random across the orchard. My first sample was entirely Kanza leaves while my second sample was drawn from my breeding plot.
   
     The photo at left shows how I collected the middle pair of leaflets from a mid shoot leaf. In theory, selecting the middle pair of leaflets from a mid-shoot leaf, best represents the average nutritional status of an orchard.
     I collected the leaflets in paper bags and brought them in to dry. I used a food dehydrator set at 105 degree F to hasten the drying process. In 24 hours the leaflets were fully dry, crispy, and ready to be sent off to the lab.
     Both State Agricultural Colleges and Commercial Laboratories process and analyze pecan leaf samples. Check with your local County Ag Agent to discover your best options.