Effects of Root Temperature on the Growth and Nitrogen Fixation of Trifolium semipilosum and Trifolium repens

1986 ◽  
Vol 22 (2) ◽  
pp. 133-147 ◽  
Author(s):  
R. A. Date ◽  
R. J. Roughley

SUMMARYChanges in plant dry weight and nitrogen content of Trifolium semipilosum cv. Safari and T. repens cv. Grasslands Huia were monitored when the root systems of effectively nodulated 28-day-old plants were exposed to a range of constant and diurnal temperatures for 21 days. Nitrogen fixation was more sensitive to high root temperatures than was dry weight accumulation, and T. semipilosum was relatively more tolerant of high root temperatures than T. repens for both dry weight and nitrogen content. The optimum temperatures for dry weight yield and nitrogen fixation (≡nitrogen content) were similar (21–23°C) for both species.Our data suggest that growth and nitrogen fixation in T. semipilosum are more tolerant of short-term exposure to increase in root temperature than in T. repens. In addition, both species accumulated more dry matter and fixed more nitrogen when night temperatures were reduced from either 30 or 35°C to 25°C. The increase was greater with T. semipilosum and may be a major factor in its adaptation to the humid subtropics and cooler (elevated) tropics.

1989 ◽  
Vol 25 (4) ◽  
pp. 461-472 ◽  
Author(s):  
R. A. Date

SUMMARYNodulated plants of six varieties of Stylosanthes were grown at a constant temperature of 30°C for 21 days in a controlled environment and then for a further 21 days at a range of day/night root temperatures. Dry matter and nitrogen content of S. hamata cv. Verano and CPI40264A were measured after growth at day/night root temperatures of 30/30, 40/30, 50/30, 60/30 and 60/35°C. Similarly, growth and nitrogen content were measured for Verano, CPI40264A, S. gvianensis cv. Oxley and cv. Cook, S. humilis cv. Lawson and S. scabra cv. Seca after growth at root temperatures of 25/20, 25/25, 30/25, 30/30, 35/30 and 40/30°C. There were strong interactions of root temperature with variety and harvest time (31 and 42 days) but all varieties grew well even at the highest temperatures (50–60°C) provided they were supplied with nitrogen. Symbiotically dependent plants of S. hamata cv. Verano were more tolerant of high root temperatures and maintained better growth and nitrogen fixation at 40/30°C than those of CPI40264A, especially after the 31 day harvest. All six varieties responded similarly, but to differing extents, to the lower range of root temperatures. Nitrogen fixation was more severely affected than dry weight by high root temperature.


1989 ◽  
Vol 25 (4) ◽  
pp. 447-460 ◽  
Author(s):  
R. A. Date ◽  
D. Ratcliff

SUMMARYNodulated plants of Stylosanthes hamata, S. guianensis, S. humilis, S. scabra and S. fruticosa were grown in controlled environments with varied root and shoot temperatures. Measurement of dry matter and nitrogen content suggested that shoot temperature may be more important than root temperature in controlling growth and nitrogen fixation. There were strong interactions with variety. A fall in relative growth rate with increase in shoot temperature was least for S. guianensis and greatest for S. hamata and S. scabra. The optimum root temperature for growth and nitrogen fixation was approximately 30°C. Ninety percent maximum yield was achieved between root temperatures of 15–36°C for growth and 23–34°C for nitrogen fixation but varied with variety. Nitrogen fixation was more sensitive than dry weight to root temperature. The pattern of response of percentage nitrogen and nitrogen fixation efficiency reflected those for dry weight and nitrogen yields. Shoot to root ratios decreased toward the optimum root temperature then increased at the highest temperature. The reaction of varieties to root and shoot temperatures may be an important factor in determining their suitability for new regions.


Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 751-757 ◽  
Author(s):  
David T. Patterson ◽  
Maxine T. Highsmith ◽  
Elizabeth P. Flint

Cotton, spurred anoda, and velvetleaf were grown in controlled-environment chambers at day/night temperatures of 32/23 or 26/17 C and CO2concentrations of 350 or 700 ppm. After 5 weeks, CO2enrichment to 700 ppm increased dry matter accumulation by 38, 26, and 29% in cotton, spurred anoda, and velvetleaf, respectively, at 26/17 C and by 61, 41, and 29% at 32/23 C. Increases in leaf weight accounted for over 80% of the increase in total plant weight in cotton and spurred anoda in both temperature regimes. Leaf area was not increased by CO2enrichment. The observed increases in dry matter production with CO2enrichment were caused by increased net assimilation rate. In a second experiment, plants were grown at 350 ppm CO2and 29/23 C day/night for 17 days before exposure to 700 ppm CO2at 26/17 C for 1 week. Short-term exposure to high CO2significantly increased net assimilation rate, dry matter production, total dry weight, leaf dry weight, and specific leaf weight in comparison with plants maintained at 350 ppm CO2at 26/17 C. Increases in leaf weight in response to short-term CO2enrichment accounted for 100, 87, and 68% of the observed increase in total plant dry weight of cotton, spurred anoda, and velvetleaf, respectively. Comparisons among the species showed that CO2enrichment decreased the weed/crop ratio for total dry weight, possibly indicating a potential competitive advantage for cotton under elevated CO2, even at suboptimum temperatures.


1991 ◽  
Vol 116 (6) ◽  
pp. 981-986 ◽  
Author(s):  
F.J.A. Niederholzer ◽  
R.M. Carlson ◽  
K. Uriu ◽  
N.H. Willits ◽  
J.P. Pearson

A study was undertaken to determine the seasonal dynamics of leaf and fruit K content and the influence of tree K status and fruit growth on leaf and fruit K accumulation rates in French prune (Prunus domestics L. cv. d'Agen). Mature trees in a commercial orchard were treated with various rates of K2 SO4. (O to ≈20 kg/tree) in the fall. Fruit dry weight yield per tree at harvest and fruit K content were higher for high-K trees, but fruit percent K (by dry weight) was ≈1.0% for all trees. Leaf scorch and subsequent abscission severely reduced the canopy of K-deficient trees. Significant positive linear relationships between leaf and fruit K accumulation rates existed for the periods of 28 Apr.-28 May (May) and 28 May-7 July (June). A significant negative linear relationship existed between these two criteria from 7 July-3 Aug. (July). May (0.237 mg K per fruit-day) and July (0.267 mg K per fruit-day) mean fruit K accumulation rates were similar, but both were significantly higher (P = 0.001) than those for June (0.140 mg K per fruit-day). Mean leaf K accumulation rates for May (- 0.007 mg K per leaf-day) and July (-0.010 mg K per leaf-day) were similar, but both were significantly (P = 0.001) less than for June (0.005 mg K per leaf-day). Potassium per fruit accumulation was highest in trees with highest K status. Periods of net leaf K efflux and influx did not precisely correlate with fruit growth stages measured by fruit dry weight. The period of lowest fruit K accumulation (28 May-7 July) coincided with the period of maximum dry matter accumulation by the kernel. After 7 July, all increases in fruit dry weight and K content were due to mesocarp growth.


2011 ◽  
Vol 48 (No. 8) ◽  
pp. 356-360
Author(s):  
V. Milić ◽  
N. Mrkovački ◽  
M. Popović ◽  
Đ. Malenčić

The objective of the study was to investigate how the inoculation of soybean seed (variety Afrodita, and lines NS-L-2016 and NS-L-300168) with strains of Bradyrhizobium japonicum (1, 1a, 2b), Azotobacter chroococcum (3, 13, 14), and GA3 (gibberellic acid) affected plant dry weight, nitrogen content of nodules and whole plant, the enzymes of nitrogen assimilation (NR, GS) and soluble protein content. The highest dry matter mass and nitrogen content were found in the variety Afrodita, followed by line NS-L-300168. The GS and NR activity was increased significantly by all three inoculation treatments relative to the control. In all three genotypes, the highest values for the enzymatic activity were achieved with treatment mixture of B. japonicum and A. chroococcum strains. Each measurement was performed with three replications. The results were processed using variance analysis and the values were tested with the LSD at 5%.


1976 ◽  
Vol 16 (80) ◽  
pp. 387 ◽  
Author(s):  
P Farrington

Reproductive development, and the distribution of dry matter and nitrogen were followed in field plantings of Lupinus angustifolius cv. Uniharvest and L. cosentinii selection CB12 from the start of flowering until maturity. L. cosentinii (CBI 2) commenced flowering one week earlier, but developed one less order of inflorescences and fewer flowers than L. angustfiolius (Uniharvest) ; yet it set more pods and produced more seed. In both species seeds did not commence to fill until the leaves began to fall shortly after flowering ended. Seeds in pods on all orders of inflorescence filled concurrently. The increase in seed weight coincided with a rapid fall in the nitrogen content of other fractions of the tops.


2006 ◽  
Vol 38 (3) ◽  
pp. 267-275 ◽  
Author(s):  
Barbara PAWLIK-SKOWROŃSKA ◽  
O. William PURVIS ◽  
Jacek PIRSZEL ◽  
Tadeusz SKOWROŃSKI

Cellular responses to copper stress were investigated for the first time in a saxicolous lichen species, Lecanora polytropa (Hoffm.) Rabenh. Bright blue-green apothecia accumulated up to 1·3% Cu on a dry weight basis (205 μ mol Cu g−1), c. 50% in an exchangeable form. A bright turquoise-blue layer extended beneath the hymenium into the medulla, above and between a dentate photobiont layer. Oxalic (1·88 μ mol g−1), citric (0·83 μ mol g−1) and lower concentrations of malic (0·45 μ mol g−1) acids were determined by GC/MS analysis. Short-term exposure to high Cu2+ concentrations (40 and 400 μ mol g−1) under non-complexing conditions caused a dose-dependent decrease in chlorophyll a content; chlorophyll b and total carotenoid contents remained constant. The phaeophytinization quotient remained unchanged during Cu2+ exposure. Analysis of thiol peptides confirmed glutathione was reduced (GSH) in native L. polytropa (0·538 μ mol g−1), and phytochelatins (PC2 and PC3) oxidised. Short-term exposure to 40 μ mol g−1 Cu2+ oxidised c. 28% of the glutathione pool; oxidised phytochelatin concentrations remained unchanged. This is the first report of phytochelatin production and thiol peptide status in a crustose lichen. These represent two possible detoxification mechanisms in this Cu-tolerant species. Copper complexation by low molecular mass organic acids and non-protein thiols do not entirely account for its tolerance.


1969 ◽  
Vol 22 (4) ◽  
pp. 829 ◽  
Author(s):  
AH Gibson

The effect of bacterial strain and root temperature on the retention of nitrogen in the root system of Trifolium Bubterraneum plants was re-examined. The root systems of plants nodulated by the moderately effective Rhizobium trifolii strain NA30 possessed a higher percentage nitrogen than those nodulated by the fully effective strain TAl, although the number of nodules formed by each strain was similar. The difference was due to a greater weight of nodule tissue on the NA30-nodulated plants, and also to a higher percentage nitrogen in the NA30 nodules; this latter effect was due to a higher concentration of non-protein nitrogen. The overall effect of these differences was to reduce the amount of nitrogen translocated to the shoots of the NA30 plants, in both absolute terms and as a proportion of the total amount of nitrogen fixed. Another difference between the two strains was the rate of nitrogen fixation per unit (dry weight or leghaemoglobin content) of nodule tissue.


1966 ◽  
Vol 6 (21) ◽  
pp. 150 ◽  
Author(s):  
NH Shaw ◽  
CT Gates ◽  
JR Wilson

In a field experiment on a solodic soil, applications of superphosphate, in the presence of molybdenum, increased the dry matter yield of S. humilis H.B.K. from 2,450 to 5,800 lb an acre, and increased the relative nitrogen content from 2.36 to 3.28 per cent. When this result was examined under more closely controlled conditions in a pot experiment, using the constituent elements of molybdenized superphosphate, it was found that the combination of phosphorus and sulphur produced the greatest dry weight and nitrogen responses. Nevertheless, substantial increases in dry weight of plant tops were obtained with added phosphorus in the absence of sulphur, although the relative nitrogen content of this dry matter was low unless sulphur was also present. There was a small response to molybdenum in this experiment, but calcium played only a minor role. In the pot experiment three replicates were placed in a glasshouse, and one under a light bank in a growth room. Plants grew faster and gave higher dry matter and nitrogen yields under the light bank than in the glasshouse. Attention is drawn to the adaptability that S. humilis displays to a wide range of nutritional conditions, and it is suggested that both the yield and nitrogen content of this legume are probably being limited by nutrient deficiency in most areas of northern Australia where it is being grown.


1985 ◽  
Vol 65 (2) ◽  
pp. 423-433 ◽  
Author(s):  
G. BELANGER ◽  
J. E. WINCH ◽  
J. L. TOWNSHEND

Field experiments were conducted to determine the effects of carbofuran on the establishment and subsequent yields of sod-seeded legumes. The effects of carbofuran on plant growth, nodulation and nitrogen fixation of birdsfoot trefoil (Lotus corniculatus L.) in non-sterilized and sterilized soil were evaluated in growth cabinet experiments. In the field experiments carbofuran, applied immediately after seeding, had a positive effect on plant stand and seedling dry matter production of birdsfoot trefoil and alfalfa (Medicago sativa L. ssp. falcata L.) in the weeks following seeding. In the first production years of these field trials, there was a trend for the total and legume yields to be higher in the carbofuran plots than where carbofuran was not used. In either growth cabinet experiment, however, shoot growth was not affected by carbofuran but a reduction in the number of plants in the non-sterilized and carbofuran pots occurred. A toxic effect of carbofuran on seedlings may have been involved. No correlation between soil nematode numbers and plant stand or dry matter production was found in either field or growth cabinet experiments. In the growth cabinet experiments, carbofuran did not affect the number of nodules but improved nitrogen fixation in sterilized pots of exp. B. Carbofuran increased the dry weight of individual nodules in the sterilized pots of exp. A but a decrease was observed in exp. B. These effects of carbofuran on the dry weight of individual nodules and specific nodule activity were also observed in the nematode-free environment created by sterilization. In view of these responses in sterile soil, it was suggested that the effect of carbofuran was not as a nematicide but rather a positive physiological effect on the plant component of the plant-rhizobium system.Key words: Carbofuran, establishment, legumes, nitrogen fixation, nematodes


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