Dry matter yield response of pasture grass to application of Nemafos (thionazin).

Results of several field trials on the response of permanent grass swards and of sown swards with and without clover to application of thionazin (as Nemafos) at about 8 ml/m2 before each cut are described. Where N was the main factor limiting growth, plots with Nemafos grew better than the controls because of an increase in available soil N. At high levels of N, growth was improved because of direct stimulation of regrowth after cutting. Nemafos had a favourable effect, which lasted longer with successive cuts, on the development and vigour of tillers. The yield responses were unrelated to control of nematodes. [See also HbA 39, 422]. (Abstract retrieved from CAB Abstracts by CABI’s permission

Variation in the root mass of ryegrass types and its ecological consequences.

The shoot:root ratio of Italian ryegrass and perennial ryegrass cv. in the vegetative phase was constant under constant conditions. With intermittent N supply, root mass and shoot:root ratio of ryegrass in monoculture varied widely. Both relatively and absolutely, root mass was larger than with constant N supply. Short periods of low N were sufficient for a marked increase in root growth. Under constant environmental conditions root mass was closely related to defoliation frequency. Considerable genetic variation in root mass existed between perennial ryegrass clones. Differences were largest under conditions of max. root growth. Root mass was positively related to competitive ability. (Abstract retrieved from CAB Abstracts by CABI’s permission

Investigation into plant characters affecting the competitive ability of perennial ryegrass (Lolium perenne L.).

In a number of pot and tray experiments in soil and in sol. culture the same clone of 6 perennial ryegrass clones tested was always the most competitive both in the vegetative phase and the reproductive phase, while another clone always showed the least competitive ability. The most competitive clone had the relatively greatest root system, the least competitive clone the relatively smallest root system. The soluble carbohydrate content in tillers and stubbles of the clones did not yield any evidence on competitive ability. (Abstract retrieved from CAB Abstracts by CABI’s permission

Grasgroei en beworteling

Bij hoge N-bemesting is de wortelmassa van gras klein vergeleken met die bij een minder hoge N-bemesting. Door het regelmatig oogsten wordt de wortelmassa nog eens extra gedrukt ten opzichte van die bij ongestoorde groei. Er bestaan belangrijke erfelijke verschillen in wortelmassa tussen klonen van Engels raaigras. Een grotere wortelmassa gaat samen met een grotere concurrentiekrach

Ontwikkeling en groei van produktiegras onder Nederlandse omstandigheden

Bedoeld voor onderzoek en onderwijs zijn verschillende onderzoeksresultaten bijeengebracht om een indruk te geven van de stand van zaken en de kennis m.b.t. groei en ontwikkeling van gra

Over concurrentie

The statistical aspects of experiments on plant competition are described for plants which do, and those which do not, derive benefit from the presence of another sp. It is shown that it is much simpler to carry out one-year experiments, using varying proportions of each species in the experimental population, than to follow the change in composition of a mixture over several years, as the former are not complicated by changes in growing conditions from year to year. Experiments to determine the effect on yield of the distance between rows of crops can be treated as experiments on competition between rows with plants and rows without plants. A linear relationship can be demonstrated between the row spacing and the reciprocal of the yield