Impact of flumioxazin herbicide on growth and carbohydrate physiology in Vitis vinifera L.

The impact of flumioxazin herbicide on in vitro-grown grapevine ( Vitis vinifera L. cv. Chardonnay) was investigated. The herbicide treatments (1, 10 or 100 micro M flumioxazin in MM medium) had a negative impact on photosynthesis, as revealed by a reduction in foliar chlorophyll and carotenoid contents, gas exchanges and alteration in plastid structure and, consequently, resulted in a strong inhibition of plantlet growth. Surprisingly, soluble sugars and starch accumulated in all organs, suggesting a stimulation of sugar uptake from the medium. Moreover, photosynthetic activity and starch content partially recovered within 3 weeks of treatment at the weakest herbicide concentration. These results provide new insights into the physiological responses of non-target crops to flumioxazin, showing that flumioxazin is active in photosynthetic tissues of the non-target grapevine via root uptake, which is contrary to what is mentioned in the literature, and that the in vitro-grown plantlet is a good model for investigating the physiological effects of pesticides on crop species.