in order to study the effects of different nutrition systems (organic, chemical and integrated) and biofertilizer (pgpr) on phenology period, grain yield and its component in sunflower (helianthus annuus l.) an experiment was conducted using alestar cultivar at the research farm of college of agriculture, tarbiat modares university in 2007. five levels of nutrition systems including f1 (100% or...

It is well known that nutrient availability controls plant development. Moreover, plant development is finely tuned by a myriad of hormonal signals. Thus, it is not surprising to see increasing evidence of coordination between nutritional and hormonal signaling. In this opinion article, we discuss how nitrogen signals control the hormonal status of plants and how hormonal signals interplay with...

Phosphites (H2PO ÿ 3 ; Phi) are alkali metal salts of phosphorous acid [HPO(OH)2] that are being widely marketed either as an agricultural fungicide or as a superior source of plant phosphorus (P) nutrition. Published research conclusively indicates that Phi functions as an effective control agent for a number of crop diseases caused by various species of pathogenic pseudo fungi belonging to th...

Nanoparticles and nanotechnology have been applied in agriculture, including for plant nutrition improvement, and pest control. Little research has been conducted on nano-calcium carbonate in plant protection and nutrition. In this study, we compared the effects of nano-calcium carbonate and colloidal calcium carbonate and found that nano-calcium carbonate treatments were better at increasing c...

Humic substances, such as those listed in the above title, play a vital role in soil fertility and plant nutrition. Plants grown on soils which contain adequate humin, humic adds (HAs), and fulvic adds (FAs) are less subject to stress, are healthier, produce higher yields; and the nutritional quality of harvested foods and feeds are superior. The value of humic substances in soil fertility and ...

Selenium is an essential mineral element to humans and animals because it is an important component of selenoproteins that are important for functioning of the metabolism. Because of poor soil conditions in various regions of the world, the enrichment of edible plants with selenium via the biofortification strategy has been implemented. However, selenium in the context of plant mineral nutritio...