A Simple and Efficient Inoculation Method for Fusarium Dry Rot Evaluations in Potatoes

Plain language summary: Fusarium dry rot (FDR), caused by fungal pathogens (germs), Fusarium species, is an important potato disease world-wide, causing post-harvest rotting and seed-piece decay after planting. The estimated annual loss to FDR ranged from 6 to 20%. Breeding potato varieties resistant to the disease is currently not very efficient because the traditional inoculation methods are low efficiency and time consuming. The most commonly used method is the cork borer wounding method. But it consists of multiple steps and is time consuming and easy to get cross-contamination. We developed a new inoculation method, the plastic crew wounding method, to replace the traditional cork borer inoculation method. In six trials with eight potato genotypes conducted in the winters of 2018 and 2019, tuber dry rot, in the same sets of the tubers, produced by using the plastic screw was comparable to that produced by using the cork borer method. The plastic screw inoculation method has advantages over the other reported inoculation methods including the cork borer wounding method. It condenses the wounding, introduction of germs and wound sealing into a single step, as compared to multiple steps needed in other reported inoculation methods. As a result, it significantly shortens the inoculation time and eliminate the germ cross-contamination among tubers by the wounding tools. The new method can be efficiently used to study the capacity of the germs causing potato tuber rot, to screen resistance of the potato breeding lines against the germs for variety development.