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.     

The Effect of Afforestation on Water Runoff in the Woodburn Catchment Area

Weekly runoff and rainfall records for 1960–71 are analysedin this paper for two catchments: a forest area, planted between1958 and 1960, of 111.5 ha and a grass area kept permanentlyfor grazing of 26.5 ha. Analysis of the data failed to detectany significant changes in the water yield from the forestedcatchment. The experiment has demonstrated the difficultiesof making precise measurements and comparisons from data collectedin areas of rolling topography where soils among other factorsdiffer.     

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.     

Problems in Monocultures

In the author's opinion, modern farm management techniques compel a critical evaluation of established concepts of the use of rotations in arable farming as rapid changes have put many formerly accepted reasons for their use in doubt. From literature, examples are cited which show clearly that monocultures of cereals, or cereals grown in narrow rotations, can attain economically acceptable yield levels. From his own personal work in this field the author cites results which demonstrate that with adequate husbandry techniques, even monocultures of wheat can reach normal yields. In the conclusion, the need for close co-operation between specialists in order to obtain results, which can be applied to a wider scale of farming conditions, is stressed.