b'CANADIAN POTATO COUNCILdahliae. It kills potato vines early in the season reducing latethe barley-potato two-year rotation. Chen notes the three-year season tuber bulking making for smaller potatoes, Tenutarotations resulted in a higher yield than the two-year rotation. It explains. was also found PED severity was reduced by 10 to 35 per cent. Verticillium dahliae can produce PED on its own or inAnother project has focused on increasing soil carbon input by conjunction with a pest. One of the major pests it partners withplanting summer cover crops with and without manure in P.E.I. is the root lesion nematode Pratylenchus penetrans. There areCow manure was used as a fertilizer on cover crop rotations other diseases that it can work with also. including alfalfa and orchardgrass; sorghum sudan grass; PED will cause vascular wilt disease in potatoes. Tenuta saysryegrass, common vetch and crimson clover; forage pearl millet; it gums up the vascular tissue turning it brown, plugging it upsorghum sudan grass and verticillium resistant alfalfa; and winter and stopping it from being able to transfer water anymore puttingrye and hairy vetch.it under heat stress. The plant overheats by being unable toThrough the studies it was discovered manure increased total transpire enough water, causing it to die or wilt. To try and fightyield by 28 per cent and marketable yield by 26 per cent. It was PED, the plant will produce more new vines to circumvent thealso found manure increased soil nitrogen levels by an average plugged-up areas. But when it cant circumvent the plugged-upof 44 per cent and manure also significantly reduced Verticillium areas, thats when tuber size is reduced, robbing the plant ofdahliae densitybut the effect didnt last long in fields. large potatoes. Theres still more work to be done on reducing PED severity As part of CanPEDNet, PED samples from across Canada havebut based on the first few tests it has been found three-year crop been collected and studied to identify the species and populationrotations reduce disease severity and improve potato yield more levels of the major causal agents. Through tests at the ACS Lab,than a two-year rotation. Its also been discovered the choice of it was discovered the main Verticillium species present acrossrotation crops affects PED severity, potato yield and soil fertility. Canada is Verticillium dahliae, along with some Verticillium albo-atrum. There have also been other soil-borne pathogens associated with PED found. Pathogens discovered during tests have included Colletotrichum coccodes, Spongospora subterranea, Fusarium spp., Pythium ultimum, Streptomyces scabies,CANPEDNET PROJECT BREAKDOWNHelminthosporium solani, Phytophthora erythroseptica, andResearch teamRhizoctonia solani. oMario Tenuta, in Manitoba (co-lead)Tenuta says theyre working on putting in place a protocol for Vikram Bishtgrowers from across Canada to be able to send their samples inoDahu Chen in New Brunswick (co-lead)for PCR testing to identify PED pathogens and quantity in soil.Oscar Molina, Tanya Arseneault, Benjamin Stopping PED in its Tracks Mimee, Judith Nyrianeza, Cameron Wagg, To try and find ways to reduce PED severity, eight fields in 2020Louis-Pierre Comeau, Khalil I. Al-Mughrabi, and 2021 in New Brunswick and P.E.I. were studied. Up to 30Mathuresh Singh and Claudia Goyerfields were originally tested for PED pathogen population densityoDmytro Yevtushenko in Albertain a fall survey with eight of them then being selected for a caseoKaterina Jordan in Ontariostudyfour having high pathogen levels and four having lowoRyan Barrett in Prince Edward Islandpathogen levels. Provinces involvedThe tests found that by reducing Verticillium dahliae inoculumoAlbertadensity, they could reduce PED severity and potato yieldoManitobaloss. Another test compared PED levels after a two-year cropoOntariorotation starting 2017, and a three-year crop rotation startingoQuebecin 2019. Rotation crops planted in fields included mustard as aoNew Brunswickbiofumigant, forage pearl millet, marigold, sorghum sudan grass,oPrince Edward Islandpea, buckwheat, soybean, Verticillium-resistant alfalfa, barley and a multi-species mix from McCain Foods. In the first cycle of the two-year crop rotation study, they found significant root lesion nematode differences among treatments but no effect on Verticillium dahliae levels, ChenFor more stories on research work being done by the Canadian Potato Council visit explains during the Congress presentation. In the second cyclespudsmart.com/category/viewpoints/canadian-potato-council/ of two-year crop rotation, there werent significant differencesBanding Together to Stop Potato Early Dying in Canada detected among rotation crops on root lesion nematodes,spudsmart.com/banding-together-to-stop-potato-early-dying-in-canada/Verticillium dahliae density, and no yield differences either. For the three-year rotation there was an 18.9 per cent yieldResearch Roundup: Potato Early Dying Complex increase of the pearl millet-brown mustard-potato rotation overspudsmart.com/research-roundup-potato-early-dying-complex/ 20SPUDSMART.COM Spring 2022'