Potato Review

18 POTATO REVIEW MARCH/APRIL 2023 FLN/SPRAING TRIALS FLN target cuts spraing tuber damage New independent research provides an insight for tackling free-living nematodes and spraing damage to tubers when they transmit tobacco rattle virus. T RIALS by agronomy and root crop research specialists, Produce Solutions, have shown over 150% increase in the proportion of tubers that conform to stringent processing protocol standards with Nemathorin nematicide treatment, Syngenta Technical Manager Andy Cunningham revealed to Potato Review. In the eld trial, in a commercial crop of Pentland Dell on a high-risk site in Shropshire, less than 24% of harvested tubers from untreated areas hit the grading acceptability for a processor, compared to more than 60%meeting the speci cation with Nemathorin treatment. Tuber assessments ranked 56% of untreated area tubers in the more severely damaged categories with over 12.5% of surface area a ected by spraing symptoms. at compared to just 8% of Nemathorin treated tubers exceeding 12.5% of damage and zero in the highest damage category of 50% surface area a ected. Speaking at the Syngenta Potato Science Live events this season, Andy pointed out that changing climatic conditions have been conducive to FLN activity in recent seasons. FLN move more easily in a lm of soil moisture between soil particles, with lighter sandy soils - favoured for potato cropping - the most susceptible in a wet early spring season after planting. Furthermore, stubby root nematodes can proliferate on some plants in green cover crops. New generations of nematodes can pick up TRV from speci c host weed species and perpetuate the potential to infect through any rotational break. Investigations have also shown that some potato varieties can carry symptomless TRV, whereby undetected infected seed could result in the introduction of the virus into previously clean elds. “As FLN move freely through the soil they can infect multiple plants from initial foci points,” warned Andy. “Tubers are most susceptible to more damaging e ects of spraing from early TRV infection. FLN activity can also result in reduced root formation and make plants more susceptible to other stresses through the season. “Nemathorin can e ectively protect the crop by paralysing nematodes for long enough to reduce initial TRV infection and for crops to develop past the danger period,” he added. Spraing e ects in cut tuber 1. Spraing e ects in cut tuber 2. Andy Cunningham, Technical Manager, Syngenta.