Jun 22, 2017Maine Potato Board highlights industry research
The Maine Potato Board has introduced a new research section in its monthly Maine Potato News e-newsletter. The Potato Research Corner will briefly highlight recent research from the potato industry that growers may find applicable and helpful to their farms. Written by Andrew Plant, plant pathologist, Maine Potato Board, the first feature focuses on recent publications or conference presentations on potato virus management.
Read The Potato Research Corner’s first installment below.
In large part, much of the current research is focusing on pvy management. It has become one of more difficult viruses to manage within certification schemes worldwide. With the shift to more necrotic strains, pvy has become not only a quantity concern (about a 0.5 percent yield decrease per 1 percent virus) (nolte et. al., 2004), it has become a quality concern, causing unsightly spraing and poor frying quality for fresh and processing markets.
1. dupuis, b., cadby, j., goy, g., tallant, m., derron, j., schwaerzel, r., and steinger, t. 2017.Control of potato virus y (pvy) in seed potatoes by oil spraying, straw mulching and intercropping. Plant Pathology.doi: 10.1111/ppa.12698.
In this four-year study out of Switzerland, results showed that the implementation of straw mulching of potato rows right after planting, weekly oil sprays initiated at emergence, or intercropping of oats (similar to our current nurse crop program locally) significantly decreased pvy infection rates in harvested tubers. Oil alone decreased pvy levels by 43 percent, straw mulch by27 percent, and additively decreased pvy infection by 59 percent. Of particular interest was the effect that intercropping had on pvy levels. Their intercropping methodology in this study is essentially equivalent to our local use of nurse cropping, whereby a small grain is broadcast at time of potato planting and allowed to grow for three weeks until chemical desiccation. They found that this practice decreased pvy levels by 34 percent.
2. mackenzie, t.d.b., lavoie, j., nie, x., and singh, m. 2017. Effectiveness of combined use of mineral oil and insecticide spray in reducing potato virus y (pvy) spread under field conditions in New Brunswick, Canada. American Journal of Potato Research 94, 70-80.
This study, conducted just across the border, showed significant reductions in pvy spread when weekly applications of oil combined with knockdown insecticides (pyrethroids or flonicamids) were used. Oil sprayed alone significantly reduced pvy spread, while insecticide alone did not.Together, however, the effects were additive and provided an increased level control. The study also illustrated the importance of initial inoculum levels and their significance to pvy spread.
3. mackenzie, t.d.b., gallagher, a., arju, i., fageria, m., and singh, m. 2017. Mechanical transmission of pvy: evidence of virus spread through field management activities.Northeast Potato Technology Forum, March 15-16, 2017, Fredericton, NB.
Preliminary results of this research were presented at this conference. Trials were conducted in the 2015 and 2016 growing seasons to assess the effects that tractor/implement traffic have on the spread of pvy. Researchers found that in traffic rows, pvy spread was 2.3x to ~ 5x higher than in non-traffic rows. From this research, growers might consider implementing practices that reduce the amount of traffic in fields during the growing season, especially when potato plants are nearing the row closure stage and after.
4. boquel, s., zhang, j., and nie, x. 2017. How long can rogue potato plants left in the field be a source of potato virus y for aphids? American Journal of Potato Research 94, 81-87.
In this research, it was found that rogue pvy infected plants could serve as a source of virus for aphids for a period of 7+ days after roguing. Even after seven days of being pulled, stylets from aphids assayed on leaflets from the pulled plants tested positive for pvy. This survival may or may not be typical as it is likely to change with temperature and moisture conditions.
Determining the rate of desiccation, post-roguing – the take-away: Rogued plants left in the field or nearby could serve as inoculum sources for aphids for an extended period. Plants should be bagged, removed from production areas, and buried or burned.
If you have any research articles or have read something interesting lately that you think the potato industry could benefit from, email Andrew Plant at [email protected].
Learn more about the Maine Potato News at www.mainepotatoes.com.