Water uptake through sweet cherry (Prunus avium L.) fruit pedicels in relation to fruit development.

摘要

Potometric studies of water uptake through the pedicel of two cultivars of sweet cherry (Van and Sunburst) were conducted in relation to fruit development. Fruits were positioned immediately after harvest in the potometer and water uptake was measured through their pedicels for 4 and 6 h in 1995 and 1997, respectively. Ten fruits were weighed gravimetrically and examined for colour. Water uptake was highest during the first dates of harvest (early stage III) 52-56, 40-54 and 39-49 days after full bloom (DAFB) for Van in 1995, Van in 1997 and Sunburst in 1997, respectively. The values for water loss were statistically higher at 52 and 56 DAFB compared to the other dates. The measured water uptake decreased significantly in the periods 59-70, 43-68 and 42-67 DAFB, respectively, and continued to decrease with increasing stage of fruit maturity. During stage II (31-37 DAFB), the total conductance was constant, in early stage III (43-64 DAFB) it increased, while it markedly decreased in later developmental stages. After 64 DAFB, the conductance decreased, while the water uptake continued to decrease. The fruit weight constantly increased until 77, 68 and 67 DAFB for Van in 1995, Van in 1997 and Sunburst in 1997, respectively. Similarly, the maximum increase in weight occurred around 59, 54 and 53 DAFB, respectively. In late stage III, the fruit expansion was high, while both the rates of water uptake and the cuticular membrane conductance simultaneously decreased. Decreased conductance allowed more of the absorbed water to be utilized for size expansion.