scholarly journals The Productivity of Cassava (Manihot esculenta Crantz) in Kagoshima, Japan, Which Belongs to the Temperate Zone

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2021
Author(s):  
Shin Yabuta ◽  
Tamami Fukuta ◽  
Shotaro Tamaru ◽  
Keita Goto ◽  
Yoshihiro Nakao ◽  
...  
Keyword(s):  
Exchange Rate ◽  
Gas Exchange ◽  
Dry Matter ◽  
Ground Surface ◽  
Temperate Zone ◽  
Light Transmittance ◽  
Matter Distribution ◽  
Manihot Esculenta Crantz ◽  
Dry Matter Distribution ◽  
Gas Exchange Rate

The cultivation period of cassava in Kagoshima, Japan, which belongs to the temperate zone, is limited by the low temperature in winter. To maximize productivity under this limited period, investigations were conducted on the gas exchange rate and production structure relating to light utilization in a plant community of cassava grown under different nitrogen fertilization conditions. Fertilization either at planting or three months after planting significantly increased stomatal conductance in the upper canopy and root dry weight compared to the control. In addition, the dry matter distribution to stem and root dry matter rate of initial fertilization treatment were significantly higher, and the dry matter distribution to root of the latter fertilization treatment tended to be higher than that of the control. However, light transmittance at 80 cm below the top of the canopy was almost the same as that at the ground surface, which was a common tendency among the treatments. In conclusion, it was revealed that the effects of fertilization on yield were mainly the increase in the gas exchange rate of individual leaves and the change of dry matter distribution rather than an improvement in light transmittance.

scholarly journals A model of dry matter distribution in cassava (Manihot esculenta Crantz).

1978 ◽  
Vol 26 (3) ◽  
pp. 267-277 ◽  
Author(s):  
B.W.J. Boerboom
Keyword(s):  
Environmental Conditions ◽  
Manihot Esculenta ◽  
Harvest Index ◽  
Dry Matter ◽  
Growth Cycle ◽  
Matter Distribution ◽  
Manihot Esculenta Crantz ◽  
Dry Matter Distribution ◽  
Cassava Plant ◽  
Tuber Production

Results of an experiment in Trinidad were analysed and data obtained from literature were recalculated to determine which factors control the DM distribution in the cassava plant. Under given conditions for long periods, possibly for the storage life of cassava, the distribution of DM over tubers and shoot proved to be constant. Based on this finding, a model was developed and 2 parameters were introduced: ESRP, efficiency of the plant at producing tubers; ISS, initial plant wt. at which tuber production starts. The model was used to visualize genetic differences and the effect of environmental conditions on DM distribution. The relation between harvest index and ESRP was discussed. It is recommended that ESRP is used instead of harvest index as a selection trait. Selection material on ESRP can be screened rather early in the growth cycle as tuber wt. is linearly related to plant wt. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Measurement of gas-exchange rate in streams by the oxygen–carbon method

2018 ◽  
Vol 37 (2) ◽  
pp. 222-237 ◽  
Author(s):  
Robert Pennington ◽  
Alba Argerich ◽  
Roy Haggerty
Keyword(s):  
Exchange Rate ◽  
Gas Exchange ◽  
Gas Exchange Rate

Gas-Exchange Rates in a Small Lake as Determined by the Radon Method

1973 ◽  
Vol 30 (10) ◽  
pp. 1475-1484 ◽  
Author(s):  
Steve Emerson ◽  
Wallace Broecker ◽  
D. W. Schindler
Keyword(s):  
Exchange Rate ◽  
Gas Exchange ◽  
Exchange Rates ◽  
Partial Pressure ◽  
Lake Water ◽  
Radon Concentration ◽  
Natural Waters ◽  
Carbon Dioxide Partial Pressure ◽  
Nitrogen And Phosphorus ◽  
Gas Exchange Rate

The radon method, used previously in ocean-atmosphere systems, is used here to determine the gas-exchange rate between the atmosphere and lake 227 of the Experimental Lakes Area. Fertilization of the lake with nitrogen and phosphorus caused the carbon dioxide partial pressure in the lake water to drop well below atmospheric levels; hence, in order to better understand the carbon budget of the lake, an estimate of the CO2 gas-exchange rate was necessary.To determine gas-exchange rates by measuring radon evasion to the atmosphere the source of radon in the lake water must be dissolved radium. Since the radon concentration in lakes derives not only from the decay of dissolved radium but also from the inflow of radon-rich groundwaters, radium was added to the lake to increase the radon concentration well above this fluctuating background level. Although this procedure was complicated by algal uptake of the radium in the lake (Emerson and Hesslein 1973), we were able to place limits on the gas-exchange rate.Our results indicate that the "stagnant boundary layer" thickness is approximately 300 μ. This value is among the largest observed in natural waters. Using this value and the partial pressure of CO2 in the lake water we have calculated an invasion rate of 17 ± 8 mmoles CO2/m2 day.

Ventilation and gas exchange in lizards during treadmill exercise.

1997 ◽  
Vol 200 (20) ◽  
pp. 2629-2639
Author(s):  
T Wang ◽  
D R Carrier ◽  
J W Hicks
Keyword(s):  
Exchange Rate ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Minute Ventilation ◽  
Oxygen Demand ◽  
Lung Ventilation ◽  
Iguana Iguana ◽  
Maximal Aerobic Speed ◽  
Gas Exchange Rate ◽  
Treadmill Locomotion

The extent to which lizards ventilate their lungs during locomotion is controversial. Direct measurements of airflow across the nostrils suggest a progressive reduction in tidal volume and minute ventilation with increased running speed, while other studies have demonstrated that arterial PO2 remains constant during exercise. To resolve these conflicting findings, we measured minute ventilation and gas exchange rate in five specimens of Varanus exanthematicus and five specimens of Iguana iguana during treadmill locomotion at speeds between 0.14 and 1.11ms-1 at 35 degrees C. These speeds are much lower than maximal running speeds, but are greater than the maximal aerobic speed. In both species, the ventilatory pattern during locomotion was highly irregular, indicating an interference between locomotion and lung ventilation. In Varanus exanthematicus, treadmill locomotion elicited a six- to eightfold increase in minute ventilation from a pre-exercise level of 102mlkg-1min-1, whereas the rate of oxygen uptake increased approximately threefold (from 3.9 to 12.6mlkg-1min-1). After exercise, both minute ventilation and gas exchange rate decreased immediately. Because minute ventilation increased more than did oxygen consumption, an increase in lung PO2 during exercise is predicted and, thus, Varanus exanthematicus appears effectively to ventilate its lungs to match the increased metabolic rate during locomotion at moderate speed. In Iguana iguana, both minute ventilation and gas exchange rate increased above resting values during locomotion at 0.28ms-1, but both decreased with further increases in locomotor speed. Furthermore, following exercise, both minute ventilation and oxygen uptake rate increased significantly. Iguana iguana, therefore, appears to be unable to match the increased oxygen demand with adequate ventilation at moderate and higher speeds.

Plasticity in growth and patterns of dry matter distribution of two genotypes of Trifolium repens grown in different environments of neighbours

1983 ◽  
Vol 61 (8) ◽  
pp. 2186-2194 ◽  
Author(s):  
Roy Turkington
Keyword(s):  
Trifolium Repens ◽  
Dry Matter ◽  
Poa Pratensis ◽  
Dactylis Glomerata ◽  
Hostile Environment ◽  
Matter Distribution ◽  
Dry Matter Distribution ◽  
Trade Off ◽  
Mobile Plant ◽  
Trifolium Repens L

Replicates of two genotypes of Trifolium repens L., collected from a Poa pratensis dominated sward and a Dactylis glomerata dominated sward, respectively, were grown in swards composed of various proportions of P. pratensis and D. glomerata. These swards represented a range of environments of neighbours; an increasing proportion of P. pratensis was considered as an increasingly alien environment for individuals of T. repens collected from the D. glomerata dominated site, and vice-versa for the individuals from the P. pratensis dominated site. The individuals of T. repens were harvested on five occasions over a period of 27 months. Both genotypes responded to increasingly alien environments by producing more inflorescences and by distributing proportionately more dry matter to inflorescence production. Some evidence is also presented which suggests that allocation to stolons and inflorescences are alternatives and the balance of the trade off is dependent on the advantages of possibly producing new, better adapted offspring from seed, against the chances of a wandering stolon encountering a less hostile environment. Results are discussed in the context of environmental alienness, a major source of which is the different relative proportions of neighbours. The various genotypes of organisms which a relatively mobile plant species encounters are a major source of this environmental, or biotic, alienness.

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