Effect of droughting and chilling on maturation and chemical composition of Townsville Stylo (Stylosanthes humilis)

1971 ◽  
Vol 22 (3) ◽  
pp. 369 ◽  
Author(s):  
CT Gates ◽  
WT Williams ◽  
RD Court

The effects of droughting and chilling on maturing Townsville stylo plants was assessed in terms of growth, seed and leaf shed, nitrogen, phosphorus, and amino acid composition. The major effect was due to droughting. Temperature participated as a small temperature-droughting interaction, in that cold reduced growth and increased proline under moist, but not under dry conditions. With droughting under warm conditions seed and leaf shed were increased and the nutrient content of seed was raised, which resulted in more of the plant's nitrogen and phosphorus being lost in these fractions. Droughting increased soluble nitrogen at the expense of protein nitrogen, but the amino acids fell as a proportion of the soluble nitrogen. The interrelations of nine amino acids were examined by multivariate techniques and it was shown that proline and aspartic acid behaved atypically, and that while other amino acids fell, proline increased some 10-fold under drought or cold stress. These effects indicate that soluble nitrogenous components may both increase and change in composition in the maturing plant as a result of stress, so rendering the plant more susceptible under field conditions to leaching or breakdown caused by dew or by slight showers of rain.

1973 ◽  
Vol 13 (64) ◽  
pp. 544 ◽  
Author(s):  
MJT Norman ◽  
LJ Phillips

A Townsville stylo (Stylosanthes humilis)-annual grass pasture at Katherine, N.T., was subjected to a series of treatments in 1969-70 and 1970-71 under which plots were grazed heavily from the beginning of the wet season for a period and then allowed to recover undefoliated for the remainder of the season. The dates at which heavy grazing ceased were spaced at 2-week intervals from November 24 to March 16. At the end of the wet season, total dry matter yield was linearly related to length of recovery period. Townsville stylo yield declined as recovery period was reduced from 18 to 8 weeks, but showed little response to a further reduction to 4 weeks. In contrast, annual grass yield showed little change as recovery period was reduced from 18 to 8 weeks, but fell with a further reduction to 4 weeks. As a result, the proportion of Townsville stylo in the pasture at the end of the season was high with long and short recovery periods but reached a minimum with an 8 - 10 week recovery period. Dry conditions prevailed in the first half of both seasons. The evidence suggests that young Townsville stylo is sensitive to heavy grazing when under water stress, and that early grazing for grass control should be imposed only during periods of active growth.


1996 ◽  
Vol 2 (5) ◽  
pp. 335-339 ◽  
Author(s):  
F.C. Ibáñez ◽  
A.I. Ordóñez ◽  
M.S. Vicente ◽  
M.I. Torres ◽  
Y. Barcina

Idiazábal cheeses were made employing brining times of 12 h (batch A) and 36 h (batch B). Proteolytic changes in both batches were examined over 270 d of ripening; proteolysis was low in both batches, but lower in batch B than in batch A. Electrophoretic analysis revealed incom plete breakdown of αs and β-caseins at the end of the ripening period, particularly in batch B. The proportion of soluble nitrogen as a percentage of total nitrogen was 17.55% in batch B and 19.48% in batch A, while the proportion of non-protein nitrogen was 11.78% in batch B and 15.16% in batch A. The proportion of non-protein nitrogen as a percentage of soluble nitrogen was 67.17% in batch B and 77.88% in batch A. The free amino acids, the smallest non-protein nitrogen frac tion, attained values of 1203 mg/100 g of dry matter in batch B and 1902 mg/100 g of dry matter in batch A. After 60 d of ripening, the main free amino acids were glutamic acid, valine, leucine, lysine, and phenylalanine in both batches, although levels were higher in the batch with the shorter brining time. There was no clear trend in the non-protein-forming amino acids with either ripening time or brining time.


2015 ◽  
Vol 27 (1) ◽  
pp. 105-114 ◽  
Author(s):  
R. Kubiczek ◽  
M. Rakowska

Total and soluble nitrogen, protein and non-protein -nitrogen was determined as well as the amino acid composition of the caryopses of ten rye varieties including three bred in Poland and cultivated on a commercial scale: 'Dańkowskie Złote', 'Dańkowskie Selekcyjne' and 'Borkowskie Tetra'. and seven foreign varieties characterized by a high total protein content (11.9-16.4% in dry weight). In the varieties examined the amount of protein nitrogen increased in the same degree as did the content of total nitrogen. The amino acids limiting the nutritive value of the protein in rye caryopses were mostly lysine and methionine, and in the varieties with high protein content tryptophan. The low-protein varieties had a relatively higher content of lysine, sulphur amino acids, tryptophan and other amino acids (as % of protein) than the high protein ones, but their absolute amino acid content (as % of dry weight) was lower.


1973 ◽  
Vol 13 (63) ◽  
pp. 389 ◽  
Author(s):  
MJ Fisher

A one-year experiment was done in the field at Katherine, Northern Territory, to determine the influence of defoliation at different times (January, February, and March) and heights (5, 13 and 20 cm) on the growth and development of Townsville stylo (Stylosanthes humilis) in ungrazed swards grown with complete fertilizer and irrigation. Townsville stylo withstood repeated defoliation at 5 cm provided that cutting started in January, but, when the first defoliation was delayed, single cuts at 5 cm in either February or March killed 82 and 53 per cent of the swards. Defoliation to 5 cm early in the season reduced total cumulative yield by less than 450 kg ha-1, and did not affect pod yield or nitrogen and phosphorus concentrations at the end of the growing season. Immediately after defoliation nitrogen and phosphorus concentrations were reduced, but there was rapid recovery to higher levels with 5-cm and the same levels with 13-cm defoliation. Successive defoliation at 4 3 cm in February and March increased yield of pods. Defoliation at both 5 and 13 cm increased relative growth rate compared with the control and less frequently defoliated treatments. Defoliation to 5 cm each four weeks altered the stand morphology to a dense mat of foliage at cutting height. The ability of Townsville stylo to withstand continued defoliation suggests that sustained grazing during the growing season may be successful in controlling grass weeds vulnerable to grazing without greatly reducing pod yield or total dry matter production of Townsville stylo.


1968 ◽  
Vol 46 (7) ◽  
pp. 929-937 ◽  
Author(s):  
D. J. Durzan

In spring, buds of spruce shoots under moisture stress contracted during the day and expanded at night. Increased water supply to roots removed the shrinkage of buds and stimulated rapid expansion. In leaves of buds about to break and under moisture stress, the alcohol-soluble nitrogen, high in arginine content, was maximal at midday, after midnight, and again at noon the next day. As a percentage of the soluble nitrogen, all compounds, except arginine, contributed most at sunset and again at sunrise. Other prominent amino acids included proline, alanine, γ-aminobutyric acid, and the amides glutamine and asparagine. Except for the amides, these and other compounds, present at lower levels, gave diurnal patterns similar on a fresh weight basis to arginine. Values for protein nitrogen were greatest at 2 p.m. followed by an increase of asparagine nitrogen, and again at 4 a.m., followed by an increase of glutamine nitrogen. At night the composition of newly synthesized protein increased significantly in aspartic acid, serine, glycine, alanine, leucine, and isoleucine. Chlorophyll a increased from 2 p.m. to 10 p.m., whereas chlorophyll b was present at lower levels and showed little diurnal variation.


HortScience ◽  
2004 ◽  
Vol 39 (5) ◽  
pp. 1015-1019 ◽  
Author(s):  
Sandra B. Wilson ◽  
P. Chris Wilson ◽  
Joseph A. Albano

Invasive species have disrupted thousands of acres of natural areas in Florida and appear to have a physiological competitive advantage over native species. The influence of light and temperature on germination was determined for the invasive Mexican petunia (Ruellia tweediana Griseb.) and native wild petunia (Ruellia caroliniensis Steud.). Seeds were collected and germinated in incubators with light or darkness at 15, 24, 33, and 30/20 °C. Light increased germination for each species, except at 15 °C (R. caroliniensis). For R. caroliniensis, highest germination (86% to 94%) occurred at 33 °C and 30/20 °C. Highest germination of R. tweediana (98% to 100%) occurred at 30/20 °C. Studies also were initiated to determine if R. tweediana has a competitive advantage over the native species when grown under wet and dry substrate conditions. Growth and development measurements after 8 weeks under controlled conditions revealed that R. tweediana grown in wet conditions had the greatest dry weight increase as compared to other treatments. Ruellia caroliniensis had higher specific leaf area when grown in wet or dry conditions, as compared to R. tweediana. Throughout the experiment, net CO2 assimilation of R. caroliniensis grown under dry or wet conditions was consistently lower than that of R. tweediana. Shoot nitrogen and phosphorus use efficiencies were generally greatest for R. tweediana plants grown in wet conditions. For shoot nutrient content, significant species × moisture interactions occurred for measured phosphorus (P) and calcium (Ca). When grown in wet conditions, R. tweediana had less shoot P and Ca as compared to dry conditions. For root nutrient content, species × moisture interactions were insignificant for each measured nutrient, with the exception of potassium (K). Potassium use efficiency of R. tweediana roots grown in wet conditions was higher than that of R. tweediana grown in dry conditions and R. caroliniensis grown in wet conditions.


1978 ◽  
Vol 50 (2) ◽  
pp. 137-146
Author(s):  
Terttu Ettala ◽  
Matti Kreula ◽  
Hilkka Tähtinen

The effect of sulphur deficiency and sulphur fertilisation on the nitrogen compounds of plants was studied, using timothy as the test species. The samples were obtained from 4 field trials performed in northern Finland. The nitrogen and sulphur treatments in each of these trials were as follows: a) N O, S O, b) N 48, S O, c) N 48, S 34, d) N 96, S O and e) N 96, S 68 kg/ha. Nitrogen was applied as NPK compound fertiliser and sulphur in the form of gypsum. In trials 1and 2 sulphur given in addition to nitrogen increased the yield considerably. The contents of soluble-, protein-, a-amino-, ammonium- and nitrate-nitrogen, as well as the free and peptide- and protein-bound amino acids were determined in the harvested timothy. Nitrogen fertilisation did not have any noticeable effect on the protein-nitrogen content of sulphur-deficient plants, but sulphur fertilisation increased it by an average of 26 % (trial 2). The proportion of soluble nitrogen of the total nitrogen in trials 1 and 2 averaged 50 % with N-fertilisation and 37 % with N+S fertilisation. Sulphur fertilisation decreased the contents of a-amino-, ammonium- and nitrate-nitrogen, and also their proportions of the total nitrogen. In those trials (3 and 4) in which sulphur fertilisation did not increase the yield, the proportion of soluble nitrogen of the total nitrogen was an average of 33 % with all treatments. In sulphur-deficient timothy the content of asparagine and aspartic acid totalled 60 % of the content of free amino acids, and their nitrogen formed about 17% of the total plant nitrogen. The corresponding figures with sulphur fertilisation were 39 % and 3.5 %, and in those trials where there was no sulphur deficiency (trials 3 and 4) on average 27 % and 2.5 %, irrespective of fertilisation. The proportion of soluble nitrogen of the total nitrogen of timothy was closely correlated (r = 0.79***) to the N/S ratio, as was the proportion of asparagine plus aspartic acid of the total free amino acids (r = 0.91***).


1970 ◽  
Vol 10 (47) ◽  
pp. 716 ◽  
Author(s):  
MJ Fisher

The effects of four levels of superphosphate (0, 112, 224, and 448 lb an acre) on the growth and development of ungrazed Townsville stylo (Stylosanthes humilis) in pure swards were examined on virgin Tippera clay loam at Katherine, N.T. Yields and distribution of dry matter, nitrogen, and phosphorus, leaf area, and growth rate, were measured every two weeks. Leaf relative water content and soil water extraction were measured at the end of the wet season. Yield responses to superphosphate were curvilinear and fitted regressions of the form y = a nx + bx + c at all harvests. Superphosphate encouraged root exploitation of the soil volume, but phosphorus deficient swards were more resistant to drought. The maximum recovery of phosphorus was 20, 14, and 14 per cent respectively when 112, 224, and 448 lb an acre superphosphate was applied. Loss of 31 per cent dry matter, 34 per cent nitrogen, and 44 per cent phosphorus in the eight weeks following maximum yield was concluded to be due to translocation to the root system. Even with 448 lb an acre superphosphate the phosphorus content of standing material was below the the critical percentage quoted in the literature as indicating phosphorus sufficiency.


1974 ◽  
Vol 14 (69) ◽  
pp. 495 ◽  
Author(s):  
JR Ive ◽  
MJ Fisher

Townsville stylo (Stylosanthes humilis) selections collected from twelve naturalized populations, in Queensland and the Northern Territory, and certified seed of the Katherine ecotype ('lines'), were grown for three years in a field experiment at Katherine, N.T. (latitude 14.3�S). In the third year, the experiment was oversown with Digitaria ciliaris. Flowering of all lines was delayed by late sowing, but was hastened by drought. However, the order in which the lines flowered was basically the same for all three years, and similar to that at Lansdown, Queensland (latitude 19.7�S). Although seasonally dependent, highest dry matter production was associated with erect mid- or late mid-season maturity lines which were often lowest in nitrogen and phosphorus concentration. There were no differences between lines in their ability to compete with Digitaria. Grazing reduced the proportion of grass in the swards compared with the forage harvested and non-defoliated treatments largely because Townsville stylo appeared to withstand grazing and trampling better than Digitaria.


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