Short-term effects of nitrogen on the growth and nitrogen nutrition of small swards of white clover and perennial ryegrass in spring

1990 ◽  
Vol 45 (4) ◽  
pp. 413-421 ◽  
Author(s):  
I. A. DAVIDSON ◽  
M. J. ROBSON AFRC
HortScience ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 238-241 ◽  
Author(s):  
Pat Bowen ◽  
Stan Freyman

Raspberries (Rubus idaeus L.) were grown for 5 years with three floor management treatments: clean cultivation (CC) and ground covers of white clover (Trifolium repens L.) (WC) and perennial ryegrass (Lolium perenne L.) (PR). Primocane growth was strongest with WC and weakest with PR. Fruit production did not differ between WC and CC treatments and was higher than with PR. On 22 Aug. and 10 Sept. in the last year, primocanes grown with WC were taller, had more nodes and a higher dry weight, contained more N, and had retained more leaves than those grown with PR. Net CO2 assimilation per unit leaf area was higher with WC than with PR, and the difference was greater at the more proximal position. The estimated net CO2 assimilation rate per primocane was more than twice as high with WC than with PR.


2011 ◽  
Vol 90 (3) ◽  
pp. 299-308 ◽  
Author(s):  
Gustavo Brunetto ◽  
Maurizio Ventura ◽  
Francesca Scandellari ◽  
Carlos Alberto Ceretta ◽  
João Kaminski ◽  
...  

2004 ◽  
Vol 55 (6) ◽  
pp. 625 ◽  
Author(s):  
Z. N. Nie ◽  
D. F. Chapman ◽  
J. Tharmaraj ◽  
R. Clements

An experiment was conducted on 2 contrasting soil types for 4 years (1998–2001) to determine the effects of plant species mixture, management inputs, and environment on sown species herbage accumulation (SSHA) and seasonal growth pattern of pastures for dairy production. Five pasture types, combined with 3 management treatments, were established in south-west Victoria. Three of the pasture types were based on perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.). One pasture type included short-term, winter- or summer-active species in the perennial ryegrass–white clover mixture. The final pasture type was based on the perennial grasses cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.), and phalaris (Phalaris aquatica L.). The 3 management treatments involved different levels of fertiliser input and weed/pest control. Pasture type had a significant impact on SSHA in 3 of 4 years. In the first year, the mixture based on cocksfoot, tall fescue, and phalaris had the lowest SSHA, but this pasture matched other types from 1999 onwards and yielded the highest in 2000, the year with the driest summer during the experiment. Ryegrass–white clover mixture based on old cultivars had generally lower SSHA than the other types except in the first year. Higher fertiliser inputs increased SSHA by 16–28% in 1998, 1999, and 2001. There was a significant site × pasture type interaction on SSHA in 2000. The mixture based on cocksfoot, tall fescue, and phalaris produced up to 1–2 t DM/ha.year more than the other types in summer and autumn in dry–normal years. The inclusion of short-term species, or more stoloniferous white clover cultivars, in the ryegrass–white clover mixture, had little effect on SSHA, or on the seasonal distribution of pasture growth. Pastures based on perennial grasses other than perennial ryegrass appear to have potential for altering the seasonality of pasture growth in south-west Victoria, although the benefits resulting from changing pasture type will depend on environment. Overall, increasing management inputs usually had a greater effect on SSHA than changing pasture type, but management responses were also affected by environment, particularly through the effects of a dry season on a sandy soil type.


Agronomie ◽  
2003 ◽  
Vol 23 (5-6) ◽  
pp. 503-510 ◽  
Author(s):  
Florence Paynel ◽  
Jean Bernard Cliquet

Author(s):  
D.W.R. White

Cell culture and genetic engineering techniques can be used to develop improved pasture plants. To utilise these methods we have developed procedures for regenerating plants from tissue cultures of perennial ryegrass and white clover. In both, the plant genotype influences regeneration capacity. There was significant genetic variation among regenerated perennial ryegrass plants in a wide range of characteristics. Most of the regenerants were resIstant to crown rust and this trait was highly heritable. This rust resistance is being used to breed a new ryegrass cultivar. A system for introducing cloned genes into white clover is described. This capability is bemg used to incorporate genes with the potential to improve nutritional quality and pest resistance. Other possibilities for engineering genetic improvements in white clover, genes conferring herbicide tolerance and resistance to white clover mosaic virus, are briefly outlined. Keywords: Lolium perenne, Trifolium repens, cell culture, somaclonal variation, crown rust resistance, transformation, cloned genes, nutritional quality, proteinase inhibitors, Bt toxins, pest resistance, WCMV viral cross-protection, herbicide tolerance, Agrobacterium, Bacillus thuringenisis.


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