EFFECT OF TIME OF DIGGING ON INCIDENCE OF FUSARIUM ROT IN TULIP BULBS

Apparently healthy "Paul Richter" tulip bulbs, selected from a heavily diseased stock, were planted near Puyallup, Washington, on August 23, 1971, harvested in 1972 on 20 April, 4 May, 18 May, 1 June or 15 June, replanted 29 August 1972 and harvested 14 June 1973. The best production of flowers and healthy bulbs in 1973 was from bulbs dug on 4 May 1972. Assuming the 4 May yield to be 100 percent, the percentage by weight of healthy bulbs for the dates in sequence were 73%, 100%, 87%, 73% and 59%. Presumably, the lower yield on 20 April was caused primarily by immaturity while reduced yields on the three later dates were caused by increasing spread of Fusarium which is favoured by warm soil temperatures.
At a nearby weather station, the maximum soil temperatures during the two weeks preceding each digging date in 1972 averaged 11, 13, 16, 17 and 18°C.

II International Symposium on Flower Bulbs

C.J. Gould, V.L. Miller

https://doi.org/10.17660/ActaHortic.1975.47.18