A Self‐recording Porometer and Potometer.

Jones, W. Neilson

doi:10.1111/j.1469-8137.1914.tb07158.x

Cited by 8 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In conjunction with Mr. Laidlaw this apparatus was modified to render it selfrecording (16), thus obviating the necessity of continuous attention when a continuous record is required. Self-recording porometers had already been described by Balls (4) and by Neilson Jones (25), but these were comparatively elaborate, whilst that devised by Laidlaw and Knight is simple in construction. ' With the help of these forms of apparatus the porometer method was tested with a view to determining its efficiency.…”

Section: R Esearches On Transpiration In Recent Years Have Resultedmentioning

confidence: 99%

Recent Work on Transpiration

Knight

1917

New Phytologist

View full text Add to dashboard Cite

Section: R Esearches On Transpiration In Recent Years Have Resultedmentioning

confidence: 99%

Recent Work on Transpiration

Knight

1917

New Phytologist

View full text Add to dashboard Cite

“…Improvements were made on this type of porometer by KNIGHT (7), and by LAIDLAW and KNIGHT (9) who devised a constant flow aspirator and made the process self-recording. Other porometers were devised by BALLs (2), and by JoNEs (6). A porometer which measures changes in the rate of flow of air through the leaves in terms of pressure was devised by GREGORY and PEARSE (4).…”

mentioning

confidence: 99%

The Porometer Method for the Continuous Estimation of Dimensions of Stomates

Wilson

1947

Plant Physiol.

View full text Add to dashboard Cite

In studies concerning the movement of gases and vapors into and out of the leaf, it is frequently necessary that the dimensions of the stomates be determined. Such information may be more useful if it consists of a continuous record of the stomatal aperture rather than a series of periodic measurements. Two methods are generally used for the procurement of such continuous data; direct microscopic measurement and the porometer.Direct microscopic measurement of the dimensions of the stomates has been considered the most accurate method by many workers. There are, however, several difficulties which make accurate measurements by the microscope difficult. For certain leaves, under some conditions, accurate measurements can be made only with extreme difficulty. For other leaves, the microscope cannot be used at all. The method is not well adapted for continuous observation, because of the strain imposed upon the worker and because of undesired changes induced through mechanical manipulation and the use of light. Also, since only a few stomates can be measured at one time, the question arises as to whether they constitute a representative sample or reflect correctly the average stomatal aperture. However, when employed for the determination of the dimensions of the stomates at a particular instant, a high degree of accuracy may be achieved.The porometer is a device used to measure changes in the rate of flow of air through the leaf. A cup or tube is attached to the leaf and the pressure of the air within the cup is either raised or lowered with respect to normal air pressure. It is assumed that the changes in the rate of air flow are directly proportional to the changes in the dimensions of the stomates.The porometer was first proposed by Dutrochet in 1832, according to DARWIN and PERTZ (3). In 1876, Muller constructed an apparatus employing this principle which proved too complicated and cumbersome for general use and acceptance. The modern design for the porometer was developed by DARWIN and PERTZ (3). Improvements were made on this type of porometer by KNIGHT (7), and by LAIDLAW and KNIGHT (9) who devised a constant flow aspirator and made the process self-recording. Other porometers were devised by BALLs (2), and by JoNEs (6). A porometer which measures changes in the rate of flow of air through the leaves in terms of pressure was devised by GREGORY and PEARSE (4). This method uses small rates of air flow and low pressures. It will be described in detail in another section.

show abstract

Die pflanzliche Transpiration

Seybold

1929

Ergebnisse Der Biologie

View full text Add to dashboard Cite

A Self‐recording Porometer and Potometer.

Cited by 8 publications

References 0 publications

Recent Work on Transpiration

Recent Work on Transpiration

The Porometer Method for the Continuous Estimation of Dimensions of Stomates

Die pflanzliche Transpiration

Contact Info

Product

Resources

About