The relationship between environment and abundance of rhizobia was described by determining the populations of root nodule bacteria at 14 diverse sites on the island of Maui. Mean annual rainfall at the sites ranged from 320 to 1,875 mm, elevation from 37 to 1,650 m, and soil pH from 4.6 to 7.9. Four different soil orders were represented in this study: inceptisols, mollisols, ultisols, and an ...

Breeding for improved resistance and tolerance to the clover root-knot nematode, Meloidogyne trifoliophila, and the clover cyst nematode, Heterodera trifolii , has been successful in white c lover, Trifolium repens. White clover lines developed from three independent breeding programmes were established in field trials at Lincoln, Palmerston North, Cambridge and Kerikeri. Plants were establishe...

Cost reduction in plant breeding and conservation programs depends largely on correctly defining the minimal sample size required for the trustworthy assessment of intra- and inter-cultivar genetic variation. White clover, an important pasture legume, was chosen for studying this aspect. In clonal plants, such as the aforementioned, an appropriate sampling scheme eliminates the redundant analys...

Plant species richness and productivity often show a positive relationship, but the underlying mechanisms are not fully understood, especially at the plant species level. We examined how growing plants in species mixture influences intraspecific rates of short-term carbon (C-) translocation, and determined whether such short-term responses are reflected in biomass yields. We grew monocultures a...

BACKGROUND AND AIMS One of the special properties of clonal plants is the capacity for physiological integration, which can increase plant performance through mechanisms such as resource sharing and co-ordinated phenotypic plasticity when plants grow in microsites with contrasting resource availabilities. However, many clonal plants are colonized by arbuscular mycorrhizal fungi (AMF). Since AMF...

To determine if host plant abundance determined the size of clover root weevil (CRW) Sitona obsoletus larval populations, a study was conducted over 4 years in plots sown in ryegrass (Lolium perenne) (cv. Nui) sown at either 6 or 30 kg/ha and white clover (Trifolium repens) sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establish...

BACKGROUND AND AIMS White clover (Trifolium repens) is, due to nitrogen (N) fixation, important to the N dynamics of several northern temperate agroecosystems. This study aimed at monitoring growth and death of major white clover plant organs to assess their potential contribution to within-season N input and risk of off-season N losses. METHODS White clover ('Snowy') was studied in a plot an...

The responses of selected clones of white clover (Trifolium repens) to simultaneous infection by the southern root-knot nematode (Meloidogyne incognita) and peanut stunt virus (PSV) were determined. Two white clover clones, which were resistant (NC-R) or sensitive (NC-S) to ozone injury, were evaluated. Plant growth and M. incognita reproduction were measured. Root, stolon, and top growth were ...

Green manure (GM) is widely adopted for agricultural productivity and sustainability. The present study supplemented the GM effect with that of water retaining agent (WRA) to enhance sustainability tobacco planting purple soils in Sichuan Province, China. employed three legumes varieties (Trifolium repens, Vicia villosa Medicago sativa), while WRA used was polyacrylamide at different applicatio...

Alternative stable states have long been thought to exist in natural communities, but direct evidence for their presence and for the environmental switches that cause them has been scarce. Using a combination of greenhouse and field experiments, we investigated the environmental drivers associated with two distinctive herbaceous communities in coastal ecosystems in New Zealand. In a mosaic unre...