EFFECT OF STORAGE ON VIABILITY OF FUSARIUM HEAD BLIGHT-AFFECTED SPRING WHEAT SEED

The effects of storage temperature and duration on germination, emerge nce, and vigor of Fusarium head blight-affected seed were studied in t he spring wheat cvs. Glenlea and Roblin. Seed was stored at -10, 2.5, 10, or 20 degrees C. Germination was assessed at cold (5 degrees C) an d moderate 20/15 degrees C for 16/8 h daily) temperatures following 0, 8, 16, and 24 weeks of storage. Emergence from a soilless mix was cou nted 10 days after planting. Vigor was assessed following germination by measuring root and shoot lengths and in emerged plants by determini ng dry shoot weights. Germination after storage at the three colder te mperatures decreased with length of storage, but storage at 20 degrees C did not affect germination. Overall, germination of Fusarium affect ed seed at moderate temperatures was significantly lower than for heal thy seed. Germination of infected seed at 5 degrees C was better than at moderate temperatures, probably due to lack of fungal activity at l ow temperatures. Seed treatment with Vitaflo 280 improved germination, but not emergence, of infected seed. However, roots from treated infe cted seed were shorter than from untreated seed. Emergence of infected seeds was better after storage at 10 and 20 degrees C than at -10 and 2.5 degrees C. Storage temperature did not significantly affect vigor . Dry shoot weight at 14 days was lower after storage at -10 than at 2 0 degrees C.