The response of replanted peach trees to weedicide, daily irrigation, nitrogen and phosphorus

Abstract

One-year-old replant peach trees in an old peach orchard were used in a trial to compare performance under daily or longer interval watering, with or without a weedicide treatment to eliminate weed competition, two levels of nitrogen, and three levels of phosphorus in a replicated factorial design. Both irrigation treatments were based on nett evaporation, and were designed to supply about the same total amount of water over the season. Statistically significant responses were obtained on top weight, weight of new wood, and root weight in favour of weedicide, daily watering and high nitrogen. There was no response to phosphorus. Shoot thickening was the dominant factor in the response to irrigation, and shoot length the dominant factor in the response to nitrogen. Both factors played a part in the response to weedicide. Under daily watering the root spread was greater, the main roots more uniformly tapered, and the fibre root longer and less contorted than under longer interval watering.