foliar analysis of natural deciduous tree species of basswood (tilia americana l.) (ba), american beech (acer grandifolia enrh) (be), and white ash (fraxinus americana l.) (wa) was carried out in 1994 in southern quebec. the diagnosis and recommendation integrated system (dris) was developed from the traditional method to find the preliminary norm and indices of n, p, k, ca, and mg for the ...

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...

A better knowledge of the nitrogen nutrition of Medicago truncatula at the whole plant level and its modulation by environmental factors is a crucial step to reach a complete understanding of legume nitrogen nutrition. This study was based on the symbiotic system that is the most commonly used by the research community (M. truncatula cv. Jemalong A17 x Rhizobium meliloti strain 2011). Plant nit...

Modelling the spatial and temporal distribution of leaf nitrogen (N) is central to specify photosynthetic parameters and simulate canopy photosynthesis. Leaf photosynthetic parameters depend on both local light availability and whole-plant N status. The interaction between these two levels of integration has generally been modelled by assuming optimal canopy functioning, which is not supported ...

Remobilization of mineral nutrients from leaves to reproductive structures is a possible regulatory factor in leaf senescence. The relationship between P remobilization from leaves of soybean (Glycine max [L.] Merr. cv McCall) during reproductive development and leaf senescence was determined by utilizing soil P treatments that supplied deficient, optimum, and supraoptimum soil P levels. The so...

The use of non-conventional feed resources (NCFR) either as replacement or as a supplement in the nutrition of livestock is discussed in this paper. The shortage of feed resources for livestock and poultry feeding diverted majority of research in the field of animal nutrition to look into possibilities to overcome this nutritional crisis. A possible and perhaps the most viable proposition could...

Several lines of evidence indicate that the partitioning of photosynthate between starch and sucrose is influenced by the relative concentrations of inorganic phosphate (Pi) in the cytosol and chloroplast. Two greenhouse experiments were conducted to determine the influence of long-term differences in soil P levels, ranging from deficient to supraoptimum, on leaf starch and sucrose concentratio...

Soybean (Glycine max [L.] Merr. cv Hobbit) plants were grown in a growth chamber for 56 days in a phosphorus- and nitrogen-deficient soil and were colonized by the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus mosseae (Nicol. & Gerd) Gerd. and Trappe and Rhizobium japonicum strain USDA 136, or by either organism alone, or by neither. Non-VAM plants received supplemental phosphorus and no...

Iron (Fe) and copper (Cu) homeostasis are tightly linked across biology. Understanding crosstalk between Fe and Cu nutrition could lead to strategies for improved growth on soils with low or excess metals, with implications for agriculture and phytoremediation. Here, we show that Cu and Fe nutrition interact to increase or decrease Fe and/or Cu accumulation in leaves and Fe uptake processes. Le...

BACKGROUND AND AIMS Epiphytism imposes physiological constraints resulting from the lack of access to the nutrient sources available to ground-rooted plants. A conspicuous adaptation in response to that lack is the phytotelm (plant-held waters) of tank-bromeliad species that are often nutrient-rich. Associations with terrestrial invertebrates also result in higher plant nutrient acquisition. As...