{"id":827,"date":"2018-10-29T17:32:00","date_gmt":"2018-10-29T17:32:00","guid":{"rendered":"https:\/\/greencastadvisory.com\/blog\/disease-population-growth\/"},"modified":"2022-06-20T06:24:21","modified_gmt":"2022-06-20T06:24:21","slug":"disease-population-growth","status":"publish","type":"post","link":"https:\/\/greencastadvisory.com\/it\/blog\/disease-population-growth\/","title":{"rendered":"Disease population growth"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-1078 aligncenter\" src=\"https:\/\/greencastadvisory.com\/wp-content\/uploads\/2018\/10\/44985081_412851935918660_5215788497348067328_n.jpg\" alt=\"44985081_412851935918660_5215788497348067328_n\" width=\"469\" height=\"351\" \/>The last few weeks I&#8217;ve been on the road presenting my &#8220;Fungicide planning presentation&#8221;. The core message has been slightly simpler than &#8220;planning&#8221; though. In an attempt to try to understand the way to get the best out of fungicides I think it&#8217;s imperative we<img loading=\"lazy\" decoding=\"async\" class=\" wp-image-1074 alignleft\" src=\"https:\/\/greencastadvisory.com\/wp-content\/uploads\/2018\/10\/dr-d.png\" alt=\"dr d\" width=\"316\" height=\"180\" \/>understand the way that the disease develops. <a href=\"http:\/\/archive.lib.msu.edu\/tic\/bigga\/gki\/article\/2008dec51.pdf\" target=\"_blank\" rel=\"noopener\">This 2008 article by Dr Danneberger<\/a> got me thinking about this concept. During periods when conditions aren&#8217;t conducive to disease development the disease will sit quietly in the fibrous layer near the surface in Conidia form waiting for the right conditions:<\/p>\n<ul>\n<li>Mild<\/li>\n<li>Damp<\/li>\n<li>Humidity<\/li>\n<li>Lush growth<\/li>\n<\/ul>\n<p>When these conditions arrive the impact isn&#8217;t instant. The process from the Conidia germination to population levels being high enough to make disease visible takes a while. The key message here is whilst the conditions are conducive to Microdochium development it will take a while for the disease to become visible. Everyday waited <span style=\"background-color:#ffffff;color:#3d596d;font-size:16px;\">means a higher population of disease you&#8217;re asking a fungicide to deal with.<\/span><\/p>\n<figure id=\"attachment_1073\" aria-describedby=\"caption-attachment-1073\" style=\"width: 420px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-1073 alignright\" src=\"https:\/\/greencastadvisory.com\/wp-content\/uploads\/2018\/10\/ai-chart.png\" alt=\"AI chart\" width=\"420\" height=\"232\" \/><figcaption id=\"caption-attachment-1073\" class=\"wp-caption-text\">This chart shows the reduction of quantities of Active ingredient per Ha over the last 25 year<\/figcaption><\/figure>\n<p>Modern pesticides have much lower quantities of active ingredient than their predecessors although their mode of actions are far more effective at reducing disease populations when applied earlier.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-1031 alignleft\" src=\"https:\/\/greencastadvisory.com\/wp-content\/uploads\/2018\/08\/20180820_085659-1.jpg\" alt=\"20180820_085659 (1)\" width=\"257\" height=\"343\" \/><\/p>\n<p>I did an experiment earlier in the year and took a plug from a green in Early August and in an attempt to accelerate disease I placed it in a plastic bag with some moisture. This kept the plug in a constant high pressure situation. I was surprised to see that it took 7 days for the plug to develop any signs of disease, however once it started the disease spread rapidly.<\/p>\n<p>This ties in really well with the exponential growth theory, whilst in the Autumn we&#8217;re generally studying our greens looking for disease because we know the conditions are right, however we won&#8217;t see any visible signs until the disease population has got to a point where it can cause damage. The speed this happens will vary dependent on many factors, including:<\/p>\n<ul>\n<li>Moisture on leaf<\/li>\n<li>Temperature<\/li>\n<li>Historical disease pressure<\/li>\n<li>Fibre content<\/li>\n<li>Grass species<\/li>\n<\/ul>\n<p>By using forecasted weather to help us decide when to apply fungicides we can pull applications forward by a few days which will have a dramatic impact on the success rate of the fungicide.<\/p>\n<p>A cold snap in the weather like the one we&#8217;re getting at the moment is fantastic as it will halt that disease population increasing, if it&#8217;s under some kind of fungicide protection then it will also increase its longevity.<\/p>\n<h3><span style=\"color:#ff9900;\"><span style=\"color:#000000;\">Key message:<\/span> <span style=\"color:#008000;\">A planned approach to fungicide applications which is then altered based on a forecast rather than waiting for visible symptoms will have a greater impact. <\/span><\/span><\/h3>\n<p>During my presentations I try to separate out the effects of Integrated Turf Management and Fungicides. I believe that they are doing separate jobs. I&#8217;ll go into that in my next blog<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The last few weeks I&#8217;ve been on the road presenting my &#8220;Fungicide planning presentation&#8221;. The core message has been slightly simpler than &#8220;planning&#8221; though. In an attempt to try to understand the way to get the best out of fungicides I think it&#8217;s imperative weunderstand the way that the disease develops. This 2008 article by&hellip;<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[40],"tags":[],"class_list":["post-827","post","type-post","status-publish","format-standard","hentry","category-disease","entry"],"acf":[],"_links":{"self":[{"href":"https:\/\/greencastadvisory.com\/it\/wp-json\/wp\/v2\/posts\/827","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/greencastadvisory.com\/it\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/greencastadvisory.com\/it\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/greencastadvisory.com\/it\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/greencastadvisory.com\/it\/wp-json\/wp\/v2\/comments?post=827"}],"version-history":[{"count":0,"href":"https:\/\/greencastadvisory.com\/it\/wp-json\/wp\/v2\/posts\/827\/revisions"}],"wp:attachment":[{"href":"https:\/\/greencastadvisory.com\/it\/wp-json\/wp\/v2\/media?parent=827"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/greencastadvisory.com\/it\/wp-json\/wp\/v2\/categories?post=827"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/greencastadvisory.com\/it\/wp-json\/wp\/v2\/tags?post=827"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}