EFFECTS OF CULTIVATION PRACTICES ON LEAF AREA, PHOTOSYNTHETIC RATE AND GRAPE YIELD OF CV. ‘DIMIAT’ VINES

1996 ◽  
pp. 209-216 ◽  
Author(s):  
T. Slavtcheva
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yinli Bi ◽  
Huili Zhou

AbstractA well-developed canopy structure can increase the biomass accumulation and yield of crops. Peanut seeds were sown in a soil inoculated with an arbuscular mycorrhizal fungus (AMF) and uninoculated controls were also sown. Canopy structure was monitored using a 3-D laser scanner and photosynthetic characteristics with an LI-6400 XT photosynthesis system after 30, 45 and 70 days of growth to explore the effects of the AMF on growth, canopy structure and photosynthetic characteristics and yield. The AMF colonized the roots and AMF inoculation significantly increased the height, canopy width and total leaf area of the host plants and improved canopy structure. AMF reduced the tiller angle of the upper and middle canopy layers, increased that of the lower layer, reduced the leaf inclination of the upper, middle and lower layers, and increased the average leaf area and leaf area index after 45 days of growth, producing a well-developed and hierarchical canopy. Moreover, AMF inoculation increased the net photosynthetic rate in the upper, middle and lower layers. Plant height, canopy width, and total leaf area were positively correlated with net photosynthetic rate, and the inclination angle and tiller angle of the upper leaves were negatively correlated with net photosynthetic rate. Overall, the results demonstrate the effects of AMF inoculation on plant canopy structure and net photosynthetic rate.


2002 ◽  
Vol 127 (2) ◽  
pp. 290-296 ◽  
Author(s):  
Keith A. Funnell ◽  
Errol W. Hewett ◽  
Julie A. Plummer ◽  
Ian J. Warrington

Photosynthetic activity of individual leaves of Zantedeschia Spreng. `Best Gold' aff. Z. pentlandii (Wats.) Wittm. [syn. Richardia pentlandii Wats.] (`Best Gold'), were quantified with leaf expansion and diurnally, under a range of temperature and photosynthetic photon flux (PPF) regimes. Predictive models incorporating PPF, day temperature, and percentage leaf area expansion accounted for 78% and 81% of variation in net photosynthetic rate (Pn) before, and postattainment of, 75% maximum leaf area, respectively. Minimal changes in Pn occurred during the photoperiod when environmental conditions were stable. Maximum Pn (10.9μmol·m-2·s-1 or 13.3 μmol·g-1·s-1) occurred for plants grown under high PPF (694 μmol·m-2·s-1) and day temperature (28 °C). Acclimation of Pn was less than complete, with any gain through a greater light-saturated photosynthetic rate (Pmax) at high PPF also resulting in a reduction in quantum yield. Similarly, any gain in acclimation through increased quantum yield under low PPF occurred concurrently with reduced Pmax. It was concluded that Zantedeschia `Best Gold' is a shade tolerant selection, adapted to optimize photosynthetic rate under the climate of its natural habitat, by not having obligate adaptation to sun or shade habitats.


1997 ◽  
Vol 24 (5) ◽  
pp. 693 ◽  
Author(s):  
Zhenmin Lu ◽  
Jiwei Chen ◽  
Richard G. Percy ◽  
Eduardo Zeiger

Gossypium barbadense L. (Pima) and Gossypium hirsutum L. (upland) cottons are the two major fibre producing species grown in the south-western United States, where lint yields are adversely affected by high temperatures. In these environments, heat-adapted upland cultivars show higher yields and heat resistance than advanced Pima cultivars. Recent studies with an historical series of commercial Pima cultivars have shown that increases in lint yield and heat resistance are tightly coupled to increases in stomatal conductance and photosynthetic rate, and to decreases in leaf area. In the present study, Pima S-6 and Pima S-7 (advanced Pima cultivars) and Deltapine 90 (advanced upland cultivar) were compared under field and laboratory conditions to determine whether the physiological and morphological gradients found in the Pima historical series extrapolate to upland cotton. In the field, Deltapine 90 showed 25–35% higher stomatal conductance, 35–50% higher photosynthetic rate and 45% smaller leaf area than Pima S-6. The higher photosynthetic rate and stomatal conductance of Deltapine 90 leaves were partially related to their sun-tracking ability. In gas exchange experiments that prevented sun-tracking, the two cultivars had comparable photosynthetic rate as a function of incident radiation, while stomatal conductance was higher in upland cotton. In the 25–35°C range, photosynthetic rate as a function of temperature remained nearly constant in both cultivars, and was higher in upland cotton at all temperatures. Stomatal conductance showed a strong temperature-dependence, and conductance value and the slope of the stomatal response to temperature were higher in Deltapine 90. In progeny from a cross between Deltapine 90 and Pima S-7, the segregation of stomatal conductance in F1 and F2 populations showed a clear genetic component. These results indicate that the differences in photosynthetic rate, stomatal conductance and leaf area associated with increases in lint yield and heat resistance in the Pima historical series are also evident in a comparison between advanced cultivars of upland and Pima cotton. Upland cotton could be used as a source of genetic variation for high stomatal conductance in Pima breeding programs.


2014 ◽  
Vol 41 (No. 3) ◽  
pp. 138-146 ◽  
Author(s):  
C. Xu ◽  
D.I. Leskovar

Field experiments were conducted in two seasons to investigate growth, physiology and yield responses of cabbage (Brassica oleracea L. cvs Pennant and Rio Grande) to deficit irrigation. In 2012 season, 50% of crop evapotranspiration (ETc) irrigation temporarily decreased plant size, reduced leaf area, fresh weight, relative water content, specific leaf area and gas exchange during late development, and decreased head fresh weight, size, marketable and total yield. Deficit irrigation at 75% ETc had little influence on plant growth and physiology, but it still reduced both marketable and total yield. In 2013 season, 75% ETc irrigation had little influence on plant growth, leaf characteristics, photosynthetic rate, head fresh weight and size, but it temporarily increased chlorophyll and carotenoid content, and decreased stomata conductance, transpiration, and marketable yield. Pennant, the green-head cultivar, had higher photosynthetic rate, head fresh weight, marketable and total yield than the red-head cultivar Rio Grande. In both seasons, deficit irrigations did not influence cabbage head dry weight, indicating that most yield reduction under deficit irrigations is related to water content.  


1982 ◽  
Vol 99 (3) ◽  
pp. 661-663 ◽  
Author(s):  
P. S. Kettlewell ◽  
W. P. Davies ◽  
T. J. Hocking

Fungicide applications to wheat have been reported to maintain the green area of the leaves (Dickinson & Walpole, 1975; Stevens & Palmer, 1980). It is not known, however, whether the photosynthetic rate of the leaves is also maintained. It was therefore decided to investigate disease development, green leaf area and photosynthesis of the flag leaf of winter wheat in response to the fungicide propiconazole, which has not previously been reported to influence senescence in the field.


2017 ◽  
Vol 6 (2) ◽  
pp. 1531 ◽  
Author(s):  
Prajjwal Dubey ◽  
Raghubanshi A. S. ◽  
Anil K. Dwivedi*

A range of leaf attributes was measured for 17 herbaceous species in four contrasting habitats fortnightly from July to September during 2996-2007. All herbaceous vegetation in 5 randomly located plots within each of four sites were clipped at ground level and analyzed fortnightly. Leaf area was recorded by the leaf area meter (Systronics; Leaf area meter- 211). Fresh leaves were dried at 80o C for 48 hr to estimate their dry weight. Specific Leaf Area (SLA) was determined as ratio of leaf area to leaf dry weight. Leaf nitrogen was measured by Kjeldahl method and phosphorus by phosphomolybdic blue colorimetric method. The obtained values were subjected to Two- tailed Pearson correlation coefficients using SPSS (2004 ver. 13) package. SLA, leaf nitrogen, leaf phosphorus and photosynthetic rate show positive relationship with each other.


1994 ◽  
Vol 63 (3) ◽  
pp. 502-509 ◽  
Author(s):  
M.T. ISLAM ◽  
Waichi AGATA ◽  
Fumitake KUBOTA ◽  
Abdul HAMID

2018 ◽  
Vol 44 (2) ◽  
pp. 339-350 ◽  
Author(s):  
Ian J. Wright ◽  
Julia Cooke ◽  
Lucas A. Cernusak ◽  
Lindsay B. Hutley ◽  
Marina C. Scalon ◽  
...  

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