In 1999 and 2000 field trials with simulated hail damage in sugar beets were carried out at three sites in Northern and Eastern Germany. Treatments included date and intensity of hail in combination with two levels of nitrogen supply. The course of leaf area index clearly showed a limited regeneration ability of sugar beet canopies damaged by hail, especially if foliage losses occurred after canopy closure in the middle of June. At all sites sugar yield was between 2 and 33 % lower than yield of the undamaged treatments. Higher hail intensity led to higher yield losses, late hail damage until canopy closure increased the losses in comparison to earlier hail. Damages after canopy closure at the end of July (BBCH 45) resulted in yield losses in between those of the first and the second date of hail damage, especially if drought stress limited plant growth. A higher nitrogen dose did not modify the effect of hail. Regression coefficients between measured losses of sugar yield and those estimated from earlier field trials were calculated for the six environments (years x sites). They mostly varied between b = 0,8 and b = 1,2.