Some Effects of Water Stress on the Growth and Development of Apple Trees

Abstract

SummaryApart from slight differences in patterns of shoot growth, the performance of eight-year-old Cox’s Orange Pippin apple trees in a hedgerow-type orchard was little affected by drought or irrigation treatments applied from mid-June to harvest. However, similar treatments applied in the previous three months were found, at harvest, to have had significant effects on fruit development and, in the following spring (1974), on bud morphogenesis. These effects are discussed in terms of the adaptation of plants to changed conditions.The paper discusses evaporative demand (calculated from m icro-meteorological measurements) and its effects on the water status of plants and soil. Soil water status was monitored by gypsum resistance blocks. A modification in pressure-bomb technique made it possible to determine the total water potentials of two leaves at the same time.