water relations of the tomato plant under partial rootzone drying (prd)

the world is facing a dwindling supply of water, therefore deficit irrigation is becoming more of a necessity than a choice. partial rootzone drying (prd) is a new water saving irrigation technique where at each irrigation time only one part of the rootzone is watered. the un-irrigated part is watered during the next irrigation. we explored the potential of prd for `petopride´ processing tomato. there were two treatments: control (c, normal irrigation) and prd. we collected data on water relations of vegetative and reproductive organs. prd saved water by 50% and increased water use efficiency of the plant compared to c. leaf water potential was more negative under prd compared to c. irrigated and non-irrigated roots of prd had similar water potential and this could have happened by water movement between the two sides of root system. water potential of fruit was lower in prd than in c. but pressure potential (turgor potential) was similar between prd and c fruit. this was indicative of osmotic adjustment (osmoregulation) in prd fruit. to our best knowledge, this is the first report of osmotic adjustment of fruit under prd treatment.