The effect of 2,4-dichlorophenoxyacetic acid on the formononetin content of Dwalganup subterranean clover

1973 ◽  
Vol 24 (1) ◽  
pp. 59 ◽  
Author(s):  
RC Rossiter ◽  
DW Barrett ◽  
L Klein
Keyword(s):  
Sodium Salt ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Controlled Environment ◽  
Dichlorophenoxyacetic Acid ◽  
Progressive Decrease ◽  
Leaf Production ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Practical Implications ◽  
Pot Culture

Two pot culture experiments were done, the first in an open-sided glasshouse and the second in a controlled environment cabinet. The sodium salt of 2,4-dichlorophenoxyacetic acid (2,4-D) was applied as a spray, at sublethal levels, to young clover plants. Increasing levels of 2,4-D led to a progressive decrease in the formononetin concentration (percentage of dry matter) in the clover leaves. At the highest 2,4-D levels of 112 48 mg/m2 (1 12 mg/m2 = 1 lb/acre), formononetin concentrations fell to one-half to one-third of the untreated control values. In the first experiment plant dry weights and leaf numbers were decreased by almost 50 % at high 2,4-D levels. In the second experiment-of much briefer duration-the rate of leaf production was also strongly decreased. Practical implications of the results are discussed briefly, and it is suggested that 2,4-D influences isoflavone synthesis by some means other than via carbohydrate metabolism.

The influence of seed size and depth of sowing on pre-emergence and early vegetative growth of subterranean clover (Trifolium subterraneum L.)

1956 ◽  
Vol 7 (2) ◽  
pp. 98 ◽  
Author(s):  
JN Black
Keyword(s):  
Leaf Area ◽  
Seed Size ◽  
Vegetative Growth ◽  
Dry Matter ◽  
Relative Rate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Total Leaf Area ◽  
Pot Culture

Changes in the pre-emergence distribution of dry matter in subterranean clover (Trifolium subterraneum L.) variety Bacchus Marsh were followed at 21°C, using three sizes of seed and three depths of sowing, ½, 1¼, and 2 in. Decreasing seed size and increasing depth of sowing both reduce the weight of the cotyledons a t emergence. Seed of the three sizes were sown a t three depths in pot culture a t staggered intervals so that emergence was simultaneous. Dry weight in the early vegetative stage was proportional to seed size, and total leaf area and leaf numbers showed similar trends. Plants of each seed size grew at the same relative rate. No effect of depth of sowing could be detected, and this was shown to be due to the cotyledon area a t emergence being constant for any given seed size, regardless of varying depth of sowing and hence of cotyledon weight. It was concluded that seed size in a plant having epigeal germination and without endosperm is of importance: firstly, in limiting the maximum hypocotyl elongation and hence depth of sowing, and secondly, in determining cotyledon area. Cotyledon area in turn influences seedling growth, which is not affected by cotyledon weight. Once emergence has taken place, cotyledonary reserves are of no further significance in the growth of the plants.

Differential tolerance of annual medics, Nungarin subterranean clover and hedge mustard to broadleaf herbicides

1992 ◽  
Vol 32 (1) ◽  
pp. 49 ◽  
Author(s):  
RR Young ◽  
KJ Morthorpe ◽  
PH Croft ◽  
H Nicol
Keyword(s):  
Sodium Salt ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Effective Control ◽  
Medicago Littoralis ◽  
Annual Medics ◽  
Seed Yields ◽  
Test Plants ◽  
Degree Of Recovery

The tolerance of 5 species of annual medics (Medicago spp.), Trifolium subterraneum cv. Nungarin, and hedge mustard (Sisymbrium orientale) to a range of post-emergence broadleaf herbicides was tested over 2 years. The least damaging to M. truncatula was 2,4-DB, which provided more consistent and effective control of hedge mustard than the other chemicals tested, including the less expensive tank mix of 2,4-DB + diuron. MCPA amine or sodium salt (300 g a.i./ha), bromoxynil (420 g a.i./ha), and tank mixes containing MCPA amine (150-175 g a.i./ha) severely damaged annual medics, particularly M. truncatula, with flowering delayed by up to 21 days, and dry matter and seed yields often significantly (P<0.05) reduced. Seed yields of most test plants indicated a degree of recovery from herbicide damage assessed visually after 10 days. Hedge mustard was not always as severely damaged by MCPA amine as was M. truncatula. Nungarin subterranean clover and M. aculeata SAD 2356 were more tolerant than the M. truncatula cultivars of MCPA amine, MCPA sodium salt, MCPA tank mixes, and bromoxynil, and less tolerant of 2,4-DB. Medicago littoralis, M. polymorpha and M. laciniata were severely damaged by bromoxynil but were more tolerant of MCPA than M. truncatula.

scholarly journals Viability of Cyperus rotundus L. tubers after application of herbicide in pre- and postemergence

2020 ◽  
Vol 87 ◽  
Author(s):  
Ana Ligia Giraldeli ◽  
André Felipe Moreira Silva ◽  
Felipe Carrara de Brito ◽  
Robson Josadaque Nogueira de Lima ◽  
Beatriz Sizilio dos Santos ◽  
...  
Keyword(s):  
Active Ingredient ◽  
Dry Matter ◽  
Visual Control ◽  
Cyperus Rotundus ◽  
Dichlorophenoxyacetic Acid ◽  
Purple Nutsedge ◽  
Chemical Management ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
2,4 Dichlorophenoxyacetic Acid

ABSTRACT Chemical management is the most widely adopted technique to control weeds in sugarcane crops. Purple nutsedge (Cyperus rotundus L.) is among the most difficult species to control. Herbicides need to be absorbed and translocated in a sufficient amount for the tuber chain to be effective. Thus, this study aimed to evaluate the effectiveness of the herbicides sulfentrazone, diclosulam, imazapic, imazapyr, halosulfuron, ethoxysulfuron, monosodium methyl arsenate (MSMA), and 2,4-dichlorophenoxyacetic acid (2,4-D) in controlling C. rotundus and reducing the viability of its tubers. The experiment was carried out in a greenhouse in a completely randomized design, with nine treatments and four replications. The herbicides sulfentrazone (800 g active ingredient – ai·ha?1), diclosulam (193.17 g ai·ha?1), imazapic (133 g ai·ha?1), and imazapyr (500 g acid equivalent – ae·ha?1) were applied in preemergence at five days after planting the tubers, while halosulfuron (112.5 g ai·ha?1), ethoxysulfuron (135 g ai·ha?1), MSMA (1,975 g ai·ha?1), and 2,4-D (1,340 g ae·ha?1) were applied in postemergence (4 to 5 leaves). The parameters visual control, shoot dry matter, number of tubers and bulbs, weight of tubers + bulbs, number of epigeal manifestations, and tuber viability were analyzed. The herbicides diclosulam, halosulfuron, and ethoxysulfuron provided 100% control of the shoot at 90 days after application (DAA). All herbicides reduced the number of bulbs, weight of tubers + bulbs, and shoot dry matter. The herbicides sulfentrazone, imazapic, halosulfuron, ethoxysulfuron, and MSMA provided the highest reduction in tuber viability.

Woody Plant Shoot Management and Response to Herbicidal Treatment

Weed Science ◽  
1969 ◽  
Vol 17 (2) ◽  
pp. 175-180
Author(s):  
R. P. Upchurch ◽  
J. A. Keaton ◽  
H. D. Coble
Keyword(s):  
North Carolina ◽  
Woody Plants ◽  
Woody Plant ◽  
Acer Rubrum ◽  
Dichlorophenoxyacetic Acid ◽  
Red Maple ◽  
Shoot Height ◽  
Management Procedures ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Practical Implications

Shoots of naturally established, foliated red maple (Acer rubrumL.) and persimmon (Diospyros virginianaL.) growing in North Carolina were treated with 2,4-dichlorophenoxyacetic acid (2,4-D) or 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) formulations following various shoot management procedures. Shoot management prior to treatment consisted of decapitating or not decapitating shoots at 2 inches above the ground line in May when the plants were 3 to 6 ft high. Herbicidal applications were made to uncut shoots and to resprouts of previously cut shoots at 30 and 60 days after decapitation. Responses measured 10, 14, and 22 months after treatment were percent control or original shoots, percent control of new shoots, shoot height, number of live stems/plant. The original shoot and new shoot values were averaged to provide a total shoot control index. Spraying of previously cut shoots at 30 or 60 days after cutting was more effective than spraying of uncut shoots except for 2,4,5-T applied to persimmon. The average total shoot control index for 2,4-D treated red maple, considering all rates, application dates, and evaluation dates was 82% for previously cut shoots and 56% for uncut shoots while the corresponding heights were 0.9 and 4.2 ft, respectively. For 2,4,5-T-treated red maple, the total shoot control indices were 92% and 78% for previously cut and uncut shoots, respectively, while the corresponding heights were 0.4 and 1.4 ft. For persimmon, there was a net advantage for treating previously cut shoots with 2,4-D, but the reverse was true for 2,4,5-T. The results are consistent with the theoretical behavior of 2,4-D and 2,4,5-T in woody plants outlined as a basis for conducting the study. Alternate explanations of results are proposed and practical implications described.

The growth of swards of subterranean clover with particular reference to leaf area

1958 ◽  
Vol 9 (1) ◽  
pp. 53 ◽  
Author(s):  
JL Davidson ◽  
CM Donald
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Substantial Reduction ◽  
Ground Surface ◽  
Subterranean Clover ◽  
Climatic Conditions ◽  
Dry Matter Production ◽  
Leaf Production ◽  
Area Index ◽  
Matter Production

An experiment was conducted to study the growth of subterranean clover (Trifolium subterraneum L.) sown at different densities; the control swards were not defoliated while others were subjected to a single defoliation at various dates. During the final month the rate of dry matter production (tops only) increased to a maximum when the leaf area index (the ratio of the area of the leaves to the area of the ground surface — L.A.I.) was about 4-5, falling by about 30 per cent. as the L.A.I. increased to 8.7. The rate of leaf production was greatest at about L.A.I. 4-5, falling to zero at L.A.I. 8.7. Climatic conditions during the growing season influenced the relationship of L.A.I. to growth; as conditions became more favorable the values of the optimum LA.1. for growth and of the ceiling L.,4.1. progressively rose. Irrespective of the density, all swards tended towards a common ceiling L.A.I. and yield by the end of the season. The effect of defoliation depended on the L.A.I. at which defoliation occurred, on the value to which the L.A.I. was reduced, and on current climatic conditions. If swards near the ceiling L.A.I. were defoliated, total dry matter production was slightly increased and there was a great increase in leaf production. On the other hand, defoliation of swards from about the optimum L.A.I. to very low L.A.I. values led to a substantial reduction in both dry matter and leaf production. It is suggested that all these effects depend on the light relationships within the sward and their influence on the balance of photosynthesis and respiration. Pasture at the optimum L.A.I. will give greater production than swards of lower or higher L.A.I.; defoliation can give greatly increased leaf production, unless L.A.I. is reduced to very low values.

2,4-D residues in stored lemons from post-harvest treatments

1977 ◽  
Vol 17 (84) ◽  
pp. 167 ◽  
Author(s):  
G Singh ◽  
LE Rippon ◽  
WS Gilbert
Keyword(s):  
Ethyl Ester ◽  
Sodium Salt ◽  
Storage Conditions ◽  
Dichlorophenoxyacetic Acid ◽  
Line Treatment ◽  
Single Treatment ◽  
Post Harvest ◽  
Permissible Limits ◽  
Residue Levels ◽  
2,4 Dichlorophenoxyacetic Acid

Lemons were treated under simulated commercial conditions with various forms of 2,4- dichlorophenoxyacetic acid (2,4-D) to reduce losses in storage from stem end rot caused by the fungus Diaporthe citri. The 2,4-D was applied either as a single packing line treatment in wax, or as a double treatment in a benomyl fungicide bulk dip followed by the packing line treatment. The fruit were held under commercially used storage conditions and analysed at intervals for 2,4-D residues. In one trial, the sodium salt at 100 to 500 mg 2,4-Dl-1 in wax was used, and the wax applied by the foaming and dipping methods, Initial residue levels on the fruit varied with rate of application of the salt, but foaming and dipping modes of application gave similar levels. At eight weeks, residues were only detectable in double treated fruit. In a second trial, the sodium and dimethylamine salts and the ethyl ester forms were used, as a single treatment at 500 mg 2,4-D l-1 in wax foam or a double treatment at 500 mg 2,4-D l-1 in a benomyl dip followed by 500 mg 2,4-D l-1 in wax foam. The residue levels were in the order: sodium salt < dimethylamine salt < ethyl ester. Residues declined in storage, but were still detectable after 12 weeks, except for the single treatment with the sodium salt. Residues from both single and double 2,4-D treatments were always within Australian and U.S permissible limits. Provided that the recommended rate of 500 mg 2.4-D l-1 is not exceeded, none of the 2,4-D formulations tested should give excessive residues in fruit.

Differential effects of certain phenoxyacetic acid compounds and phenylcarbamates on plant species. II. Effects of foliage applications with special reference to yields of wheat

1950 ◽  
Vol 1 (4) ◽  
pp. 401 ◽  
Author(s):  
RM Moore
Keyword(s):  
Sodium Salt ◽  
Butyl Ester ◽  
Seedling Stage ◽  
Dichlorophenoxyacetic Acid ◽  
Growth Stages ◽  
Phenoxyacetic Acid ◽  
Grain Yields ◽  
Triticum Vulgare ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Different Growth Stages

The effects of foliage sprays of various phenoxyacetic acid derivatives and of isopropyl n-phenylcarbamate on a dicotyledon, Phaseolus vulgaris, were compared. The carbamate was without effect and although all phenoxyacetic acid compounds were markedly toxic, they differed in the rapidity of their action. Wheat (Triticum vulgare) exhibited differential responses to phenoxyacetic acid compounds and to isopropyl phenylcarbaniate at different growth stages. Applications of four phenoxyacetic acid compounds to wheat at different stages of development, from late seedling to flowering, showed that grain yields were reduced most markedly by applications in the seedling stage; the butyl ester and amine salt of 2,4-dichlorophenoxyacetic acid were more toxic than the sodium salt. 0.1 per cent. foliage sprays of isopropyl phenylcarbamate had no effect on wheat in the late seedling or tillering stages, but severely depressed the yield of grain when applied at flowering. Barley (Hordeum vulgare) responded similarly. Higher concentrations applied to wheat at pre-shooting also reduced grain yields. Flax (Linum sitatissimum), although susceptible to pre-emergence treatment, was not affected by foliage sprays of isopropyl phenylcarbamate at any growth-stage. 0.1 per cent. applications of 2,4-dichlorophenoxyacetic acid as the sodium salt reduced flax yields only when applied at the seedling stage.

Strain reaction to potassium deficiency in subterranean clover (Trifolium subterraneum L.).

1955 ◽  
Vol 6 (1) ◽  
pp. 9 ◽  
Author(s):  
RC Rossiter
Keyword(s):  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Differential Response ◽  
Potassium Deficiency ◽  
Potassium Content ◽  
Dry Matter Yield ◽  
Pot Culture

The results of three experiments — two in pot culture and one in the field — are described in which five commercial strains of subterranean clover (Trifolium subterraneum L.) were grown on Crawley sand at Perth. The strains were Dwalganup, Yarloop, Bacchus Marsh, Mt. Barker, and Tallarook. All strains were affected similarly by potassium deficiency and no evidence of differential response to applied potassium was obtained, either in dry matter yield or potassium content. As an aid in the diagnosis of potassium deficiency, the value 0.8 per cent. potassium in the leaf plus petiole of clover tops (irrespective of strain) sampled 10 weeks or more after germination may be taken to indicate incipient deficiency.

In Vitro Shoot Regeneration from Callus Derived from Marubakaido Apple Rootstock under Different Aluminium Concentrations

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 460e-460 ◽  
Author(s):  
Marisa F. de Oliveira ◽  
Gerson R. de L. Fortes ◽  
João B. da Silva
Keyword(s):  
Shoot Regeneration ◽  
Dichlorophenoxyacetic Acid ◽  
Apple Rootstock ◽  
Under Five ◽  
Significant Difference ◽  
Previously Treated ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
In Vitro Shoot Regeneration

The aim of this work was to evaluate the organogenesis of Marubakaido apple rootstock under different aluminium concentratons. The explants were calli derived from apple internodes treated with either 2,4-dichlorophenoxyacetic acid or pichloram at 0.5 and 1.0 μM and under five different aluminium concentrations (0, 5, 10, 15, 20 mg/L). These calli were then treated with aluminium at 0, 5, 10, 15, and 20 mg/L. It was observed shoot regeneration only for those calli previously treated with pichloram. There were no significant difference among the aluminium concentrations.

Characterization of the Reproductive Mode in Guayule In Vitro

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 483a-483
Author(s):  
Roy N. Keys ◽  
Dennis T. Ray ◽  
David A. Dierig
Keyword(s):  
Field Experiments ◽  
Reproductive Mode ◽  
Dichlorophenoxyacetic Acid ◽  
Initial Field ◽  
Breeding Lines ◽  
Reproductive Modes ◽  
Desert Southwest ◽  
2,4 Dichlorophenoxyacetic Acid

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.

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