The minimum seasonal water potential a plant experiences, cmin, provides an important measure of plant water status, as it reflects the maximum water deficit that leaves and xylem must tolerate to maintain physiological activity.

A suggestion: measure as frequently as possible at or shortly after periods of maximum transpiration and , ideally also after periods of minimum transpiration, over the whole season, including when leaves have dropped. That way you would have a good description of the water potential experienced by the plants. It would be a lot of work but might be scientifically very valuable, if related to growth and other data.

I agree Dr. Lawlor's suggestion would provided a good indication of Pmins at the threshold of leaf drop. But sampling maybe resource intensive. Not sure if there is any real way to measure leaf Pmin at the peak of summer when there are no leaves....

Have you considered stem psychrometers? They should be work even when there are no leaves, although interpreting stem water potential before and after leaf drop may mean different things.

May some hardcore plant physiologist have better ideas....

thanks for the document I.V.Srinivasa Reddy

Thanks David W. Lawlor , Unfortunately frequent measurement is very difficult+expensive as our field sites are far away from where we are based.

Siddarth Machado I am seriously considering a psychrometer, but am also vary about how comparable it would be. Just trying to see if there is a way to work with pressure chambers since we already have that equipment.