Leaf sampling procedures<\/a><\/p>\nBut, what should you be looking for in your leaf samples? You may get a range of\u00a0recommendations based on your results depending on the laboratory you use. There have been some recent changes to a few key nutrient threshold levels that you need to be aware of as you look at your tissue results. Mike Smith from Oklahoma State was the lead author on a paper a couple of years ago that re-addressed leaf nutrient concentrations for pecans. His results led to the following recommendations and these ranges are the levels you should go by when making fertilization decisions:<\/p>\n
Nitrogen (% ):\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2.5 \u2013 3.0<\/p>\n
Phosphorus (% )\u00a0 0.14 \u2013 0.30<\/p>\n
Potassium (% )\u00a0\u00a0\u00a0\u00a0 1.00 \u2013 2.50<\/p>\n
Sulfur (%)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.20 \u2013 0.35<\/p>\n
Calcium (% )\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.70 \u2013 1.75<\/p>\n
Magnesium (% )\u00a0\u00a0 0.30 \u2013 0.60<\/p>\n
Boron (ppm)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a015 \u2013 50<\/p>\n
Copper (ppm)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 6 \u2013 30<\/p>\n
Iron (ppm)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 50 \u2013 300<\/p>\n
Manganese (ppm)\u00a0\u00a0\u00a0 100 \u2013 2000<\/p>\n
Zinc (ppm)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 50 \u2013 150<\/p>\n
Nickel (ppm)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Greater than 2.5<\/p>\n
If trees have a pretty heavy crop load and leaf N is below 2.75, I would recommend the\u00a0application of another 30-50 lbs N depending on the total amount applied to date. Also, with a heavy crop, K should be around 1.20 because the fruit will begin to pull a lot of K from the leaves as they develop. Its difficult to reach 0.14% on leaf P in many cases. Most of the time soil P is adequate but uptake is a problem. If soil P is sufficient but leaf P is low,\u00a0applying P as a banded application rather than a broadcast application is more effective in increasing P absorption. Zn levels are often artificially high in commercial orchards due to the application of foliar Zn. There may be nutrient residues present on the leaf\u00a0 that are not actually present inside the leaf itself. To get a true reading, samples should be washed\u00a0off with a 0.1% phosphate-free detergent and rinsed in de-ionized water prior to analysis. Since this is not practical for most producers, just know that if you have been spraying foliar Zn or other micronutrients \u00a0and get very high results in your samples, it is likely due to residue.<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
The time for pecan\u00a0leaf tissue sampling has arrived. The recommended \u00a0period for this is from July 7-August 7. The reason for this window of time is that the nutrients are at their most stable point here at mid-season. This gives you the best idea of the nutritional status of your trees. Prior to this some […]<\/p>\n","protected":false},"author":55,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-407","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/site.extension.uga.edu\/pecan\/wp-json\/wp\/v2\/posts\/407","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/site.extension.uga.edu\/pecan\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/site.extension.uga.edu\/pecan\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/site.extension.uga.edu\/pecan\/wp-json\/wp\/v2\/users\/55"}],"replies":[{"embeddable":true,"href":"https:\/\/site.extension.uga.edu\/pecan\/wp-json\/wp\/v2\/comments?post=407"}],"version-history":[{"count":3,"href":"https:\/\/site.extension.uga.edu\/pecan\/wp-json\/wp\/v2\/posts\/407\/revisions"}],"predecessor-version":[{"id":410,"href":"https:\/\/site.extension.uga.edu\/pecan\/wp-json\/wp\/v2\/posts\/407\/revisions\/410"}],"wp:attachment":[{"href":"https:\/\/site.extension.uga.edu\/pecan\/wp-json\/wp\/v2\/media?parent=407"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/site.extension.uga.edu\/pecan\/wp-json\/wp\/v2\/categories?post=407"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/site.extension.uga.edu\/pecan\/wp-json\/wp\/v2\/tags?post=407"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}