net assimilation rate

net assimilation rate

a measurement of plant growth (weight increase per unit time) by assessing change in a particular part of the plant (usually leaf area) rather than in the overall plant.
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We measured the net assimilation rate of C[O.sub.2] (A - [micro]mol C[O.sub.2] [m.sup.-2] [s.sup.-1]), the stomatal conductance of water vapors (Gs - mol [H.sub.2]O [m.sup.-2] [s.sup.-1]), the transpiration rate (E - mol [H.sub.2]O [m.sup.-2] [s.sup.-1]), the intercellular C[O.sub.2] concentration (Ci - [micro]mol [m.sup.-2] [s.sup.-1]).
Stomatal conductance (gs, mol [H.sub.2]O [m.sup.-2] [s.sup.-1]), leaf transpiration rate (E, mmol [H.sub.2]O [m.sup.-2] [s.sup.-1]), C[O.sub.2] net assimilation rate (A, [micro]mol C[O.sub.2] [m.sup.-2] [s.sup.-1]), and intercellular C[O.sub.2] concentration (Ci, [micro]mol C[O.sub.2] mol [air.sup.-1]) were evaluated at 130 DAE.
Regardless of the concentration of the nutrient solution, the relative growth rate of the aerial part and its net assimilation rate displayed the highest values at the beginning of the cycle, decreasing over time.
The plants that were subjected to treatments with 25% I decreased net assimilation rate ([A.sub.net]) and apparent carboxylation efficiency (A/[C.sub.i]) compared those grown with 75% I, which exhibited the highest values of [A.sub.net] (Figure 01a).
I: Variation in net assimilation rate and leaf area between species and varieties, and within and between years.
Results revealed the average maximum leaf area index (7.73), crop growth rate (11.19) and net assimilation rate (2.47) recorded from combined application of compost (1124 kg ha-1) with fertilizer (42:28:28 kg NPK ha-1).
Caption: FIGURE 1: Curves of regression of net assimilation rate of C[O.sub.2] (A), the transpiration rate (E), and stomatal conductance (gs) and water use efficiency (WUE) according to the temperature variation of the sheet young plants of the Sclerolobium paniculatum, from three water regimes (kept irrigated to the field capacity - ICC (*), irrigation suspended for eight days- IS8 (**) and irrigation suspended for 14 days- IS 14 (***)).
The net assimilation rate (NAR) was influenced in rice as crop advances in growth, particularly during flowering to harvest stage in both the years of study (Table 1).
Direct measures of growth such as dry weight, leaf area, and time are used for the quantitative analysis of plant growth, and the following rates are calculated, among others: relative growth rate, crop growth rate, net assimilation rate, leaf area index, and leaf area duration.
Observations recording: Data on leaf area index, total dry matter accumulation (TDM), leaf area duration (days), crop growth rate (g m-2 d-1), net assimilation rate (g m-2 d-1), radiation use efficiency and grain yield (t ha-1) were collected by using standard procedures.
Net assimilation rate curves exhibited a similar trend for all different irrigation treatments and cultivars.