Response of Strawberry Fruiting to Hydrogen Fluoride Fumigation

Abstract

Strawberry plants in growth chambers were continuously exposed to HF gas at concentrations averaging 0.55, 2.0, 5.0, and 10.4μg F/m3, throughout flowering and fruiting. At 0.55 μg F/m3, there was a small but significant increase in fruit deformation, predominantly at the apical end of the fruit, which was associated with lack of development of some seeds and the adjacent receptacle tissue. In the higher HF treatments, deformities were proportionately more prevalent and severe. At 2.0 μg F/m3 and higher, the average fruit weights also were significantly lower than in the control atmosphere; and at 5.0 and 10.4 μg F/m3, the proportion of the flowers that developed into fruit was smaller. None of the HF treatments significantly influenced the number of flowers produced. There were no fluoride injury symptoms on the foliage at 0.5 μg F/m3 and only very mild, uncertain symptoms at 2.0 μg F/m3. Therefore, the effects of HF on strawberry fruiting seemed to be independent of visible injury to the foliage and to result from inhibition of seed development.