For the treatment of foliar diseases of cereals, fungicides may be applied as foliar sprays or systemic seed treatments which are translocated to leaves. Little research has been done to assess the resistance risks associated with foliar-acting systemic seed treatments when used alone or in combination with foliar sprays, even though both types of treatment may share the same mode of action. It...

Fusarium virguliforme causes sudden death syndrome (SDS) in soybean. The pathogen has never been isolated from diseased foliar tissues; therefore, one or more toxins have been considered to cause foliar SDS development. Cell-free F. virguliforme culture filtrates containing a toxin causes foliar SDS in soybean. A low-molecular-weight protein of approximately 13.5 kDa (FvTox1), purified from F. ...

Mineral nutrition of Norway spruce (Picea abies (L.) Karst.) and beech (Fagus sylvatica L.) was investigated along a transect extending from northern Sweden to central Italy. Nitrogen (N) concentrations of needles and leaves in stands growing on acid soils did not differ significantly between central Italy and southern Sweden (1.0 +/- 0.1 mmol N g(-1) for needles and 1.9 +/- 0.14 mmol N g(-1) f...

Recent studies have demonstrated that natural abundance N can be a useful tool for assessing nitrogen saturation, because as nitrification and nitrate loss increase, dN of foliage and soil also increases. We measured foliar dN at 11 high-elevation spruce-fir stands along an N deposition gradient in 1987e1988 and at seven paired northern hardwood and spruce-fir stands in 1999. In 1999, foliar dN...

Arabidopsis thaliana grown in soil from field plots amended with composted forms of paper mill residuals (PMR) exhibited reduced symptoms of bacterial speck caused by Pseudomonas syringae pv. tomato (Pst) compared with plants grown in soil from field plots amended with a non-composted PMR or non-amended soils. Similar results were obtained with tomato (Lycopersicon esculentum Mill.). No relatio...

We measured the level of xylem-derived cytokinins (CKs) entering a cotton leaf, and the CK levels in the same leaf, thus enabling xylem sap and foliar CKs to be compared concurrently. Although zeatin was the dominant CK in xylem sap, zeatin, dihydrozeatin, and N(6)-(2-isopentenyl) adenine were present in approximately equimolar levels in leaves. Elevated [CO(2)] (EC) has an effect on the levels...

Ratios of nitrogen (N) isotopes in leaves could elucidate underlying patterns of N cycling across ecological gradients. To better understand global-scale patterns of N cycling, we compiled data on foliar N isotope ratios (delta(15)N), foliar N concentrations, mycorrhizal type and climate for over 11,000 plants worldwide. Arbuscular mycorrhizal, ectomycorrhizal, and ericoid mycorrhizal plants we...

Foliar respiration is a major component of ecosystem respiration, yet extrapolations are often uncertain in tropical forests because of indirect estimates of leaf area index (LAI). A portable tower was used to directly measure LAI and night-time foliar respiration from 52 vertical transects throughout an old-growth tropical rain forest in Costa Rica. In this study, we (1) explored the effects o...

The 6-year effects of urea (46--) and ammonium nitrate (AN; 34--) fertilizers, applied alone and in combination with other nutrients, on tree growth and foliar nutrition were evaluated in a -year-old, thinned lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) stand in central British Columbia. Results indicate that lodgepole pine has no clear preference for a particular nitroge...

nce County, Wisconsin was the first to receive systematic study (Giese et al., 1964; Westing, 1966; Millers et al., Sugar maple (Acer saccharum Marsh.) decline has been a problem 1989). Since then, well-documented sugar maple deon the Allegheny Plateau for the last two decades. Previous work found that sugar maple is predisposed to decline by poor nutrition clines have occurred in Massachusetts...