Search

The seed yield response of cocksfoot (Dactylis glomerataL.) to stem-shortening plant growth regulators (PGRs) chlormequat chloride (CCC) and trinexapac-ethyl (TE) applied during stem elongation were evaluated in eight field trials in Canterbury; five irrigated and three non-irrigated. Across all trials and treatments the average seed yield increase was 53% resulting in an extra 290 kg/ha. In irrigated trials, the average response to PGRs was 68%, resulting in an extra 380 kg/ha of seed, compared with an average 27% response in non-irrigated trials. A mixture of CCC + TE (either 750 + 100 or 1500 + 200 g active ingredient [ai]/ha), applied at Zadoks growth stage (GS) 32 or split between GS 32 and GS 37–39, provided the largest and most consistent seed yield response of 86%, an extra 450 kg/ha. Reduced lodging was a factor in one trial only. In all trials, reduced stem length was associated with increased seed yield even in the absence of lodging. Seed yields increased at 12.5 kg/ha for every cm reduction in stem length from 130 cm (untreated) to 76 cm. This research provides evidence that the use of PGRs will improve seed yields of cocksfoot and the response is economic with a three- and sevenfold return on the cost of PGR and its application for dryland and irrigated crops, respectively. [ABSTRACT FROM AUTHOR]

He travelled extensively, carrying out veterinary work in many countries around the world., (© 2023 British Veterinary Association.)

The biological control of insulin is vital as it is administered daily to a large proportion of the population during the major part of their lives. The development of the biological assay of insulin will be described with the progressive evolution of methods eventually to dispense with the need for animals. From the quantal Mouse Convulsion Method using around 600 mice per sample to the quantitative Mouse Blood Glucose method using an average of 120 mice per sample in which the fall in the blood glucose levels is used to estimate the potency of insulin by its hypoglycaemic effect. This was followed by the development of the in vitro Radioreceptor Method which is a procedure based on competition between the binding of insulin and [125I]-insulin to cells of the cultured human IM-9 cell line. The production of highly purified insulin by the Pharmaceutical Industry has made possible the recent introduction of new High Performance Liquid Chromatography technology.