Published online by Cambridge University Press: 12 June 2017
Clopyralid at 0.3 or 0.6 kg ae ha–1 applied once or twice during the asparagus harvest season for two consecutive years did not significantly reduce the number of spears or total weight of asparagus harvested. In a second study, clopyralid applied at 0.3 kg ha–1 twice during the harvest season and once at layby for two consecutive years did not reduce asparagus yield in the first year of treatment. In the second year, the number and weight of asparagus spears was reduced. Clopyralid applied during the harvest season caused some epinastic growth of asparagus after layby. Clopyralid applied to emerged asparagus spears slightly increased the number of cull spears harvested, but was less damaging than 2,4-D or dicamba.