Responses of Cynoglossum officinale L. and Senecio jacobaea L. to various degrees of defoliation.

Effects of various degrees of defoliation on Cynoglossum officinale and Senecio jocobaea were studied under favourable growing conditions. Regrowth was found in both species, but did not overcompensate for defoliation. The physiological mechanisms responsible for regrowth after defoliation were found to relate either to an increase in net assimilation rate or to an increase in relative investment in aboveground parts.

When does grazing benefit plants?

Many recent studies have attempted to support the hypothesis that grazing can have positive effects on plant growth and fitness. However, a recent critical survey has shown that many of these studies suffer from poor experimental design, and consequently that the hypothesis may only be tenable under very particular circumstances.

THE RESPONSES OF CYNOGLOSSUM OFFICINALE L. AND VERBASCUM THAPSUS L. TO DEFOLIATION IN RELATION TO NITROGEN SUPPLY.

The effects of defoliation of Cynoglossum officinale L. and Verbascum thapsus L. on growth, net assimilation rate and dry matter distribution were studied under various nitrogen regimes.