Evaluation of elite white clover germplasm under rotational cattle and sheep grazing

Four white clover (Trifolium repens L.) cultivars, 4 pre-release cultivars and 24 breeding lines were evaluated in small plots in mixed species swards under rotational cattle and sheep grazing for 2 years. There was no significant stock class x line interaction for proportion of clover in the sward. There was no evidence that medium- and smallleaved types yielded better under sheep grazing while larger-leaved types yielded better under cattle grazing. Lines with the highest clover content tended to be large leaved and upright irrespective of stock class. They also had moderate to high stolon growing point densities. Breeding programmes have developed lines with high stolon growing point densities, ensuring vegetative persistence, while still maintaining a high proportion of clover in the sward. These pre-release cultivars and breeding lines gave significantly better clover contents than existing cultivars. Keywords cultivars, selections, plant habit, cyanogenesis, stolon growing point density, clover content, cattle grazing, sheep grazing</jats:p

Variation in spring growth within white clover

In a spaced plant trial, plants of 27 cultivars in their second year of growth were undefoliated from late winter through spring and their growth rate determined relative to that of 'Grasslands Huia'. Variation between cultivars was large. Cultivars which had higher relative growth rates than Huia during this period included some small-leaved frost tolerant germplasm, although all of these had lower absolute growth scores than Huia. The second study measured proportion of clover, leaf size and stolon growing point densities of 27 white clover cultivars and breeding lines grown in mixed species grazed swards during late winter and spring in two successive years. Once again, variation between cultivars in spring performance relative to Huia was large. It was concluded that there is sufficient variation available within white clover for improvements in spring growth relative to Huia to be achieved by breeding. Nematode Resistant Pitau consistently had high growth rates relative to Huia in late winter and early spring,but this did not carry through into late spring. Cultivars and lines with better late winter growth than Huia had higher stolon growing point densities for their respective leaf sizes than poorer, later winter growers. Keywords evaluation, mixed swards, spaced plants, later winter growth, stolon density</jats:p

PRESIDENTIAL ADDRESS AN OPPORTUNITY LOST AND SORTING FACT FROM FICTION

At the conference in Taupo last year, I identified 12 critical issues confronting agriculture that needed to be managed so that we continue to earn a first world living as a nation from the produce off the land. This year I want to discuss two issues related to improving the effectiveness of grassland technologies that will assist in addressing several of the issues listed above: 1. The feed barrier challenge and options to address it, and 2. Marketing of grassland technologies for improved production and productivity.</jats:p

75 years of scientific and technological advances in pastoral agriculture - what will it take to continue to deliver?

Scientific and technological advances are important for any industry to ensure continued improvement in productivity - achieving more output of value per unit of input. Since the majority of New Zealand's pastoral produce is traded internationally we need to ensure that we are the most efficient at growing and producing this produce, whether it is traded as a commodity or as a value added product. The requirement for continued R &amp; D investment in our agricultural knowledge economy is a prerequisite for continued improvements in pastoral agricultural productivity. In reflection, the major scientific and technological advances that have improved on-farm productivity over the last 75 years are described and the challenge is given to determine how this might continue into the future. Keywords: pastoral agriculture, research and development, technologies</jats:p