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ARS Home » Northeast Area » Orono, Maine » New England Plant, Soil and Water Research Laboratory » Research » Publications at this Location » Publication #281072
Title: Rapeseed rotation, compost and biocontrol amendments reduce soilborne diseases and increase tuber yield in conventional and organic potato production systems

Author
item BERNARD, ED - University Of Maine
item Larkin, Robert - Bob
item TAVANTZIS, STELLOS - University Of Maine
item ERICH, M. - University Of Maine
item ALYOKHIN, ANDREI - University Of Maine
item GROSS, SERENA - Purdue University

Submitted to: Plant and Soil
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/6/2013
Publication Date: 9/24/2013
Citation: Bernard, E., Larkin, R.P., Tavantzis, S., Erich, M.S., Alyokhin, A., Gross, S. 2013. Rapeseed rotation, compost and biocontrol amendments reduce soilborne diseases and increase tuber yield in conventional and organic potato production systems. Plant and Soil. 374:611-627.

Interpretive Summary: Potato growers face many challenges from soilborne diseases, including reduced plant growth and vigor, and losses in tuber quality and yield. In this research, three different potential disease-suppressive management practices, including a rapeseed green manure rotation crop, a conifer-based compost amendment, and three different biological control organisms, were evaluated alone and in combination under both conventional and organic management practices over the course of three potato cropping seasons for their effects on soilborne diseases and tuber yield. Presence of a rapeseed rotation prior to planting potatoes resulted in reductions in all observed soilborne diseases in one or more years at both sites. Compost amendment increased tuber yield in multiple years at both sites. However, compost amendment also had inconsistent effects on disease, with decreased disease observed in one year and increased disease in some others. Biocontrol effects were variable, but significant reductions of multiple diseases were observed at each site in some years. Combinations of treatments generally resulted in complementary effects, such as, the combination of rapeseed rotation and compost amendment resulted in both increased yield (due to compost component) and reduced disease (due to rapeseed component). This research demonstrated that each management approach can provide significant but variable results, and that by combining multiple approaches, more consistent and significant disease reduction and yield increases can be achieved. This research is useful for scientists, extension personnel, and growers, providing practical information on the use of management practices for improved crop production in both conventional and organic potato production systems.

Technical Abstract: Three different potential disease-suppressive management practices, including a Brassica napus (rapeseed) green manure rotation crop, a conifer-based compost amendment, and three biological control organisms (Trichoderma virens, Bacillus subtilis, and Rhizoctonia solani hypovirulent isolate Rhs1A1), were evaluated alone and in combination at two agricultural sites with different management histories (organic vs. conventional production) over the course of three potato cropping seasons for their effects on soilborne diseases and tuber yield. Rapeseed rotation reduced all observed soilborne diseases (stem canker, black scurf, common scab, and silver scurf) by 10 to 52% in at least one year at both sites. Compost amendment resulted in decreased black scurf severity and incidence in 2007 (12 to 27% reduction) at the conventional site, but increased some diseases in subsequent years. Biocontrol effects on disease were variable, though Rhs1A1 decreased black scurf by 17 to 31% at the conventional site in 2007 and 2008, and T.virens reduced multiple diseases at the organic site by 10 to 42% in at least one year. Compost amendment significantly increased total yield in all years at the conventional site (by 13 to 15%) and in two of three years at the organic site (by 9 to 10%), while rapeseed and biocontrol amendments had only transient effects. Treatment combinations generally displayed the combined effects of individual treatments, such as, the combination of rapeseed rotation and compost amendment resulted in both increased yield (due to compost component) and reduced disease (due to rapeseed component). These complementary effects demonstrate the need for studies to address the interplay between multiple disease management techniques.