Nitrogen nutrition and wheat growth in relation to absorbed solar radiation

摘要: During two growing seasons (1980–1982), the influence of nitrogen fertilizer on growth winter and spring wheat was assessed. An analysis devised which related grain yield to harvest index, mean daily incident irradiance, duration season, fraction radiation absorbed by foliage (f), efficiency conversion into biomass (e) during vegetative (em), reproductive/senescent phase e. Levels application did not proportion photons total solar transmitted (τq, τt) a general relation τq = τt1.35 closely described all observations. Nitrogen also failed light extinction factor differences in f, increased with increasing availability, were caused variations canopy size. Fertilizer accelerated rate expansion, giving greater maximum size hence improved f. slightly period. Rates senescence area achieved, thus expansion had dominant senescence. Conversion efficiencies for moles quanta anhydrous hexose monomer calculated their values followed trends e energy flux biomass. For both wheat, successive increments applied consistently em level. During reproductive growth, complex interaction between photosynthetic stimulation response actively developing grains intracellular disassembly via senescence, will dictate e. Consequently, post-anthesis are difficult interpret. Rates crop from stem elongation near maturity constant, while quantity irradiance increased. ontogenetic decline inferred this accumulation may be curvilinear. However, linear approximation proved useful producing seasonal constant.