Some aspects of the absorption of picloram by gorse (Ulex europaeus L.)

Plants of Ulex europaeus were grown from cuttings and studies made of the absorption of 14C-picloram applied with unlabelled 2,4,5-T. In vivo experiments in a growth chamber showed that absorption ceased after 10 h, but was resumed on wetting. In in vitro experiments the Q10 and the activation energy for uptake decreased with increasing temperature. Absorption was increased by addition of non-ionic surfactants, by lowering the pH and by removal of cuticular wax. Gorse shoots were shown to have a high wax content but scanning electron microscopy revealed no obvious wax structures and the contact angle of spray droplets was less than 900, indicating that the surfaces were not difficult to wet.     

Photosynthetic inhibition in Phaseolus vulgaris II. The influence of light on herbicidal action

The influence of pre-treatment and post-treatment illumination upon the herbicidal effect produced in Phaseolus vulgaris L. cv. Berna by simeton, diuron, diquat and ioxynil was examined. The increased effect noted at lower pre-treatment and higher post-treatment levels of illumination was correlated with increased inhibition of net photosynthesis. This increased effect was ascribed to enhanced photo-oxidation.     

CONTROL OF WEEDS IN MARROWSTEM KALE BY EPTC AND SOME OTHER HERBICIDES

Summary. Two experiments on chemical weed control in marrowstem kale are reported. In the first of these three herbicides applied before sowing were compared; in the second experiment four herbicides were studied, one applied before sowing and the others applied after emergence. Of all the herbicides examined, EPTC, applied before sowing and incorporated into the seedbed, was the most satisfactory in terms of both weed control and yield of kale. Neither endothal + propham nor dinoseb + TCA proved satisfactory as pre-sowing treatments. The three herbicides applied post-emergence (all methylmercapto triazines) were ineffective for the control of Polygonum spp. and Poa annua , although fairly effective against Stellaria media and Chenopodium album . They caused considerable damage to the crop and reduced yields by at least 25%.
Le désherbage du chou moellier par l'EPTC et quelques autres herbicides