Potato Grower

January 2018

Issue link: http://read.uberflip.com/i/918682

Contents of this Issue


Page 102 of 111

WWW.POTATOGROWER.COM 103 WWW.POTATOGROWER.COM 103 163631Noffsi13s.indd 1 6/15/17 3:46 PM 168308GowGro13s.indd 1 8/22/17 4:58 PM overall, they appear to be of acceptable quality. The highlight of the visit to NAK was learning about their pathogen-testing programs and touring their diagnostic labs. The Netherlands has completely replaced all post-harvest grow-outs with laboratory testing. A post-harvest test sample comes from 200 tubers, from which tests for six pathogens are conducted. Peels from the heel end of the tuber are analyzed for PVY, PVX , PVA and Pectobacterium using real-time PCR. Cores are also extracted from the heel end and are tested for Clavibacter and Ralstonia through immunofluorescence. Real-time assays have been developed for Clavibacter and Ralstonia but are not yet recognized in the EU directive. A unique twist on their virus-testing program is that they combine their subsamples into 50 tubers for just four tests per 200 tubers. Their results indicate a "most probable infection" in each sample of 200. If a seed lot tests at zero out of four, it can be classified as "PreBasic." If one out of four tests is positive, the most probable infection is 0.6 percent with a 0.01 to 3.2 percent confidence interval, and the lot can be classified as "Basic." If two out of four are positive, the most probable infection is 1.4 percent with a 0.1 to 5.3 percent confidence interval and will also be classified as "Basic." Three out of four indicates a probable infection of 2.7 percent with a 0.4 to 9.6 percent confidence interval, and the lot will be classified as "Certified." A result of four out of four results in a rejection of that lot. The highlight of the meeting portion of the trip was being able to report to the committee that the Spanish translation of the "UNECE Guide to Seed Potato Diseases, Pests and Defects" is near completion by Potatoes USA, and that it will be submitted to UN staff for approval of the translation. The group was excited at the prospect of having the translation available by the time of the World Potato Congress, which will be held in Cusco, Peru in May 2018. The delegate from Australia reported that his country is supporting the development of an app that can be used to access contents from the same publication, which they also hope to have available by the World Potato Congress.

Articles in this issue

Links on this page

Archives of this issue

view archives of Potato Grower - January 2018