Net photosynthesis was measured under field conditions in 23-year-old slash pine (Pinus elliottii Engelm. var. elliottii) trees to determine how it was affected by fertilization and climate. There was only a small decrease in rates of net photosynthesis from late summer through winter demonstrating that appreciable carbon gain occurs throughout the year in slash pine. Although fertilization sub...

Effect of Seed Biofertilizers Inoculation on Photosynthesis Rate, Yield, and Competitiveness Ability Quinoa (Chenopodium quinoa Willd.) with Weeds

Photosynthesis is a process that indicates the productivity of crops. The estimation this variable can be achieved through methods based on mathematical models. Mathematical models are usually classified as empirical, mechanistic, and hybrid. To mathematically model photosynthesis, it essential to know: input/output variables their units; modeling used its classification (empirical, or hybrid);...

Rates of ecosystem recovery following disturbance affect many ecological processes, including carbon cycling in the biosphere. Here, we present a model that predicts the temperature dependence of the biomass accumulation rate following disturbances in forests. Model predictions are derived based on allometric and biochemical principles that govern plant energetics and are tested using a global ...

BACKGROUND: Suitable and useful usage of different kind of fertilizers is the main way for reformation and potential of soil fertility and increasing of crops yield. Microelements are the critical elements for plants; also play the important role in crop productivity where it is used in low rate. Optimum plant nutrition and maximum yield is achieved when nutrient elements are a...

The effect of 3,3-dichloro-2-(dihydroxyphosphinoylmethyl)propenoate (DCDP), an analog of phosphoenolpyruvate (PEP), on PEP carboxylase activity in crude leaf extracts and on photosynthesis of excised leaves was examined. DCDP is an effective inhibitor of PEP carboxylase from Zea mays or Pancum miliaceum; 50% inhibition was obtained at 70 or 350 micromolar, respectively, in the presence of I mil...

Arabidopsis thaliana shows hybrid vigor (heterosis) in progeny of crosses between Columbia-0 and C24 accessions. Hybrid vigor was evident as early as mature seeds and in seedlings 3 d after sowing (DAS). At 3 DAS, genes encoding chloroplast-located proteins were significantly overrepresented (187) among the 724 genes that have greater than midparent values of expression in the hybrid. Many of t...

The possible alleviating effects of salicylic acid on protection of cowpea (Vigna unguiculata) cv. Parastu under water stress conditions were investigated in the University of Zanjan Agriculture Research Station during 2008. Water stress was imposed by withholding irrigation at 50% flowering (flowering water stress, FWS) and when 50% of the pods grew 2-3cm (pod-formation water stress, PFWS). Sa...