ROOT DYNAMICS OF PEACH AS A FUNCTION OF WINTER WATER-TABLE LEVEL AND ROOTSTOCK

The effect of shallow water tables on plant establishment and growth o f peach (Prunus persica) cultivar 'Maycrest' grafted on peach seedling s (P. persica silvestris), rootstocks Prunus domestica (GF 43) and Pru nus domestica x Prunus spinosa (GF 1869) was investigated in a field e xperiment with water table levels ranging from about 0.1 to 1.5 m in t he winter months. At water tables shallower than 0.5 m, plants grafted on the seedling started showing signs of stress in the year of transp lantation. By the end of the fourth year, 50% and 87.5% of seedling pl ants at water tables of 0.57 m and 0.10 m, respectively, were dead, an d above-ground growth was severely reduced at shallow water tables in the seedling, and less severely in plants grafted on the GF rootstocks . No stress or mortality was recorded in the P. persica rootstocks. Ro ot densities of establishing plants were quite low at shallow water ta bles; root distribution in subsequent years was quite superficial for the seedling, while for the GF rootstocks it was concentrated near the surface in spring, but deeper after the growing season, in the absenc e of a shallow water table.The ratio of trunk diameter to root length density suggests that a key to survival in P. persica subjected to flo oding is a growth pattern biased towards below-ground parts to compens ate for reduced root functionality.