Cotton-seed treatment with sulphuric acid

1936 ◽  
Vol 26 (4) ◽  
pp. 648-663 ◽  
Author(s):  
Basil G. Christidis
Keyword(s):  
Sulphuric Acid ◽  
Cotton Seed ◽  
Acid Treatment ◽  
Seed Treatment ◽  
Field Trials ◽  
Seed Cotton ◽  
Time Intervals ◽  
Series Of Experiments ◽  
Small Decline ◽  
The One

1. Several authors have previously reported that the sulphuric acid treatment of the cotton seed resulted in: (a) earlier germination, (b) higher percentage of seeds germinating, (c) higher yield of seed cotton per acre, and (d) better and more uniform planting (this paper is not concerned with the disinfecting effect of this process).2. A series of experiments, both in the laboratory and under field conditions have been carried out to determine whether the above statements are in agreement with actual experimental data.3. In so far as the rate of germination is concerned, it was found that: (a) untreated seeds often show a smaller percentage of germination than seeds treated with sulphuric acid for various time-intervals, particularly when tested in the laboratory; (b) cotton seed treated with the reagent for from 5 min. to 2 hr. or even 5 hr. in some cases, does not show any decrease in its germinative value as determined by laboratory tests. In field trials seeds treated for 5 or 12 hr. practically do not germinate at all, whereas the 2 hr. treatment often shows a small decline in germination; (c) an enormous difference in the rate of germination has been revealed between the laboratory determinations on the one hand and the field determinations on the other.

Experiments on the gas voltaic battery, with a view of ascertaining the rationale of its action and on its application to eudiometry

1843 ◽  
Vol 4 ◽  
pp. 463-465
Keyword(s):  
Oxalic Acid ◽  
Sulphuric Acid ◽  
Carbonic Acid ◽  
The Other ◽  
Philosophical Magazine ◽  
Faraday’S Law ◽  
New Apparatus ◽  
Series Of Experiments ◽  
The One ◽  
Decomposition Of Water

The author, referring to a paper published in the Philosophical Magazine for December 1842, giving an account of a voltaic battery of which the active ingredients are gases, and by which the decomposition of water is effected by means of its composition, describes several variations in the form of the apparatus recorded in that paper. The experiments he has made with this new apparatus, and the details of which occupy the greater part of the present memoir, he conceives establish the conclusion that the phenomena exhibited in the gaseous battery are in strict conformity with Faraday’s law of definite electrolysis. They also confirm him in the opinion which he had expressed in his original paper, and which had been controverted by Dr. Schœnbein, in a communication to the Philosophical Magazine for March 1843, as well as by other philosophers, namely, that the oxygen, in that battery, immediately contributes to the production of the voltaic current. Besides employing as the active agents oxygen and hydrogen gases, he extends his experiments to the following combinations: namely, Oxygen and peroxide of nitrogen; Oxygen and protoxide of nitrogen; Oxygen and olefiant gas; Oxygen and carbonic oxide; Oxygen and chlorine; Chlorine and dilute sulphuric acid; Chlorine and solutions of bromine and iodine in alternate tubes; Chlorine and hydrogen; Hydrogen and carbonic oxide; Chlorine and olefiant gas; Oxygen and binoxide of nitrogen; Oxygen and nitrogen, with solution of sulphate of ammonia; Carbonic acid and carbonic oxide, with oxalic acid as an electrolyte; Hydrogen, nitrogen, and sulphate of ammonia. The author concludes, on reviewing the whole of this series of experiments, that, with the exception, perhaps, of olefiant gas, which appears to give rise to an extremely feeble current, chlorine and oxygen, on the one hand, and hydrogen and carbonic oxide, on the other, are the only gases which are decidedly capable of electro-synthetically combining so as to produce a voltaic current. He thinks that the vapours of bromine and of iodine, were they less soluble, would probably also be found efficient as electro-negative gases.

scholarly journals Benefits of Cotton Seed Treatments for the Control of Seedling Diseases in Relation to Inoculum Densities of Pythium Species and Rhizoctonia solani

Plant Disease ◽  
1997 ◽  
Vol 81 (7) ◽  
pp. 766-768 ◽  
Author(s):  
R. M. Davis ◽  
J. J. Nunez ◽  
K. V. Subbarao
Keyword(s):  
Rhizoctonia Solani ◽  
Cotton Seed ◽  
Seed Treatment ◽  
Field Trials ◽  
Particle Analysis ◽  
Soil Parameters ◽  
Pythium Species ◽  
Damping Off ◽  
Air Temperatures ◽  
Pathogen Populations

Twenty-five field trials conducted over a 3-year period in five San Joaquin Valley counties included the following treatments: nontreated cotton seed; seed treated with myclobutanil for the control of Rhizoctonia solani-induced damping-off; seed treated with metalaxyl for the control of Pythium-induced damping-off; and seed treated with a combination of the two fungicides. The following parameters were measured: soil populations of Pythium spp. and R. solani at planting, soil temperature at planting, air temperatures for 5 days after planting, soil particle analysis, EC, calcium, pH, organic matter, and plant stands from each treatment. In 1993 and 1994, myclobutanil and the combination of the two fungicides resulted in improved stands in 15 of 18 fields. Metalaxyl did not increase stands in any field in 1993 to 1994. In 1995, the combination of fungicides increased stands relative to the nontreated seeds and was more effective in increasing stands than myclobutanil or metalaxyl alone. Pythium populations were much greater in 1995 than in 1993 to 1994 and may explain the increase in plant stands with the combination of fungicides and metalaxyl alone. Covariate analysis of the data indicated no relationship between stand increases from fungicide seed treatment and any of the soil parameters measured. Heat units following planting were not limiting and had no effect on stands. Populations of pathogens were not related to benefits of fungicides, with the exception of a negative correlation between stand increases from seed treatment with myclobutanil and Pythium populations. Apparently, seed protected with a fungicide active against R. solani were more susceptible to infection by Pythium spp. In general, the fungicide seed treatment active against R. solani increased stands of the cultivar Maxxa regardless of soil type and pathogen populations. Increased stands from the metalaxyl treatment occurred in 1 of the 3 years of the study.

Experimental methods with cotton. III. Sulphuric acid treatment of cotton seed, and its effects on germination, development and yield

1947 ◽  
Vol 37 (4) ◽  
pp. 291-296 ◽  
Author(s):  
D. Macdonald ◽  
W. L. Fielding ◽  
D. F. Ruston
Keyword(s):  
Sulphuric Acid ◽  
Cotton Seed ◽  
Acid Treatment ◽  
Experimental Methods ◽  
Meteorological Conditions ◽  
Seed Rate ◽  
Treated Seed

1. For experimental purposes the treatment of cotton seed with sulphuric acid, prior to planting, has always been the custom at Barberton. In view of the doubts about the benefits of this treatment which were expressed by Christidis (1936), experiments were carried out at Barberton in the 1938–9 and 1939–40 seasons, to provide concrete proof, if possible, of the advantages which it was believed resulted from it.2. A series of stand counts made soon after germination revealed definite benefits with acid treatment, in all experiments in both seasons. The seedlings emerged considerably earlier than those from untreated seeds, and the stands recorded at the final counts revealed a significant advantage for acid-treated seed, throughout the experiments. The second season's experiments gave a greater advantage for acid treating when meteorological conditions were bad than when they were good, but the advantage even with ideal weather was still significant. The benefit of acid treatment was shown to be greater, too, with poor samples of seed than with good, and with the smaller seed rate than with the greater.

scholarly journals On the relative attractions of sulphuric acid for water, under particular circumstances: with suggestion of means of improving the ordinary process of manufacturing sulphuric acid

1843 ◽  
Vol 4 ◽  
pp. 81-82
Keyword(s):  
High Temperature ◽  
Specific Gravity ◽  
Sulphuric Acid ◽  
Conclusive Evidence ◽  
Dew Point ◽  
Chemical Affinity ◽  
Dilute Acid ◽  
Atmospheric Air ◽  
Open Atmosphere ◽  
Series Of Experiments

The object of the inquiry detailed in the present paper is to determine at what degree of concentration the affinity of sulphuric acid for aqueous vapour is equal to that of anhydrous space for the same vapour at given temperatures. It has long been known that concentrated sulphuric acid abstracts moisture from the atmosphere, but the amount and the rate of this absorption have never been ascertained with accuracy; and consequently, in applying this acid to purposes of exsiccation, the experimenter has often been at a loss to know whether the acid was sufficiently strong to render the space in which it was confined perfectly anhydrous. By placing portions of the acid, previously weighed, and diluted with known quantities of water, under the receiver of an air-pump, with equal portions of concentrated acid, of the specific gravity 1·8428, in similar dishes, the author ascertained that the dilute acid could be concentrated to the specific gravity 1·814, at a temperature varying from 65° to 57°: whence he concludes that acid of such strength is capable of drying a vacuum when the temperature does not exceed 57°. By making similar experiments in air, the author compared together the weights lost by ten grains of dilute sulphuric acid of the specific gravity 1·135, at three different periods of the day for six days, taking note of the dew-point and the temperature; and infers that when the affinity of space for vapour, or the evaporating force, is equal to 0·15 of an inch of mercury, it is just able to balance the affinity for water of sulphuric acid of the specific gravity 1·249. The author next instituted a series of experiments to ascertain whether the evaporation of water from dilute sulphuric acid is capable of being carried on to the same extent in air as in vacuo, and found that the evaporating force of air exerted upon such acid is less than that of a vacuum at the same temperature. He observes that his experiments offer conclusive evidence that the evaporation of water is not owing to the existence of a chemical affinity between the vapour of the liquid and atmospheric air; but thinks that they favour the notion that the obstruction to this process in the open atmosphere is rather owing to the pressure than to the inertiæ of the particles of air. He is also of opinion that improvements will hereafter arise from this inquiry with regard to the economical management of the process of manufacturing sulphuric acid, which process would be greatly expedited by the regulated admission of steam into the condensing chambers kept at a constant high temperature.

Hot water seed treatment for Leucaena glauca (L.) Benth

1962 ◽  
Vol 2 (6) ◽  
pp. 178 ◽  
Author(s):  
SG Gray
Keyword(s):  
Water Treatment ◽  
Effective Treatment ◽  
Sulphuric Acid ◽  
Seed Treatment ◽  
Hot Water ◽  
Sowing Seed

Seed of Leucaena glauca (L.) Benth. germinates slowly, and irregularly unless treated before sowing to render the testa permeable to water. Treatment with sulphuric acid is effective but inconvenient to use. Experiments with hot water over a range of temperature and time are described. An effective treatment was to immerse the seed in water at 80�Cfor two minutes. After this treatment seed can be dried rapidly and stored before sowing. Seed treated in this way has retained full viability for 15 months.

A stochastic process whose successive intervals between events form a first order Markov chain — I

1968 ◽  
Vol 5 (03) ◽  
pp. 648-668
Author(s):  
D. G. Lampard
Keyword(s):  
Markov Chain ◽  
Point Processes ◽  
Electronic Device ◽  
Statistical Properties ◽  
Time Intervals ◽  
First Order ◽  
Stochastic Point Process ◽  
Order Markov Chain ◽  
The One ◽  
Stochastic Point Processes

In this paper we discuss a counter system whose output is a stochastic point process such that the time intervals between pairs of successive events form a first order Markov chain. Such processes may be regarded as next, in order of complexity, in a hierarchy of stochastic point processes, to “renewal” processes, which latter have been studied extensively. The main virtue of the particular system which is studied here is that virtually all its important statistical properties can be obtained in closed form and that it is physically realizable as an electronic device. As such it forms the basis for a laboratory generator whose output may be used for experimental work involving processes of this kind. Such statistical properties as the one and two-dimensional probability densities for the time intervals are considered in both the stationary and nonstationary state and also discussed are corresponding properties of the successive numbers arising in the stores of the counter system. In particular it is shown that the degree of coupling between successive time intervals may be adjusted in practice without altering the one dimensional probability density for the interval lengths. It is pointed out that operation of the counter system may also be regarded as a problem in queueing theory involving one server alternately serving two queues. A generalization of the counter system, whose inputs are normally a pair of statistically independent Poisson processes, to the case where one of the inputs is a renewal process is considered and leads to some interesting functional equations.

I. On the volumetric relations of ozone and the action of the electrical discharge on oxygen and other gases

1860 ◽  
Vol 10 ◽  
pp. 427-428 ◽  
Keyword(s):  
Electrical Discharge ◽  
The Other ◽  
Pure Oxygen ◽  
Silent Discharge ◽  
Gaseous Substance ◽  
Series Of Experiments ◽  
The One

This paper contains the full details of the authors’ experiments on the volumetric changes which occur in the formation of ozone. From three distinct series of experiments, performed by different methods, they show that when ozone is formed from pure oxygen by the action of the electrical discharge, a condensation takes place, as had already been announced in a former Note published in the 'Proceedings.’ But the condensation is much greater than the earlier experiments of the authors on the expansion by heat of electrolytic ozone had indicated. It is, in fact, so great, that if the allotropic view of the constitution of ozone be correct, the density of that body, as compared with oxygen, would be represented by a number corresponding to the density of a solid or liquid rather than that of a gaseous substance. This conclusion follows necessarily from the authors’ experiments, unless it be assumed that when ozone comes into contact with such substances as iodine, or a solution of iodide of potassium, one portion of it is changed back into common oxygen, while the remainder enters into combination, and that these portions are so related to one another, that the expansion due to the one is exactly equal to the contraction arising from the other. For the details of the experiments and of the methods of investigation employed, reference must be made to the original paper. The second part of the communication is devoted to the action of the silent discharge and of the electrical spark on other gases. Hydrogen and nitrogen undergo no change of volume when exposed to the action of either form of discharge. Cyanogen is readily decomposed by the spark, but presents so great a resistance to the passage of electricity, that the action of the silent discharge can scarcely be observed. Protoxide of nitrogen is readily attacked by both forms of discharge, with increase of volume and formation of nitrogen and hyponitric acid. Deutoxide of nitrogen exhibits the remarkable example of a gas which, under the action either of the silent discharge or of the spark, undergoes, like oxygen, a diminution of volume. It also is resolved into nitrogen and hyponitric acid. Carbonic oxide has given results of great interest; but the nature of the reaction has been only partially investigated. The silent discharge decomposes this gas with production of a substance of a bronze colour on the positive wire. The spark acts differently, destroying, as in the case of oxygen, the greater part of the contraction produced by the silent discharge. The authors are engaged in the further prosecution of this inquiry.

scholarly journals Retinomotor movements in the Antarctic fish Trematomus newnesi Boulenger submitted to different environmental light conditions

2007 ◽  
Vol 24 (2) ◽  
pp. 457-462 ◽  
Author(s):  
Lucélia Donatti ◽  
Edith Fanta
Keyword(s):  
Pigment Epithelium ◽  
Antarctic Fish ◽  
Constant Darkness ◽  
Time Intervals ◽  
Mean Values ◽  
Environmental Light ◽  
The Mean ◽  
The Difference ◽  
The One ◽  
The Antarctic

The Antarctic fish Trematomus newnesi (Boulenger, 1902) occurs from benthic to pelagic habitats, in seasonally and daily varied photic conditions that induce retinomotor movements. Fish were experimentally kept under constant darkness or light, and 12Light/12Dark for seven days. The retinomotor movement of the pigment epithelium was established through the pigment index, while that of the cones was calculated as the length of the myoid. The retinomotor movement of the pigment epithelium in T.newnesi,revealed that the adaptation to constant light occurred in the one hour of exposure, remaining constant for the next seven days. However, the adaptation to constant darkness, was slower. The difference between the mean values of the pigment indices in the time intervals of sampling was significant in the first hours of the experiment, and only after six hours they were not significant any more. The myoid of cones became elongated in darkness and contracted in light. In the experiments where T.newnesiwas exposed initially to 12 hours light followed by 12 hours darkness 12 was evidenced that the speed and intensity of the retinomotor movements was higher when darkness changed into light, than when light changed into darkness.

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