Differences in the Ripening of Two Clover Species and the Effect of Pre-harvest Desiccation

Experiments were focused on differences in the ripening of crimson clover (Trifolium incarnatum L.) and red clover (Trifolium pratense L.) and on the influence of the pre-har vest treatment with desiccants. The drying of leaves, stems and heads during ripening, regrowing, breakdown of heads and yield parameters including seed were compared. The crimson clover exhibited the natural drying of leaves, stems and heads faster than the red clover. In crimson clover, the drying of leaves, stems and heads before the har vest was 80 - 100%, 50– 95%, and 100 %, respectively. In red clover, the drying of leaves, stems and heads was 25 - 84 %, 20–72% and 45–99%, respectively. There were also dif ferences in the regrowing and in the breakdown of heads. In the pre-harvest treatments of crimson clover and red clover, the effect of diquat was compared with the efficiency of other herbicide substances (pyraflufen-ethyl, carfentrazone-ethyl and pelargonic acid) and with the efficiency of a high dose of DAM fertilizer (liquid fertilizer, urea-ammonium nitrate). Compared with diquat, the drying was slower with the other active substances. Significant effects of tested active substances on yield, WTS (weight of thousand seeds) and germination were not recorded.