Water uptake through sweet cherry (Prunus avium L.) fruit pedicels: Influence of fruit surface water status and intact fruit skin

Figures & data

Fig. 1 Schematically shown potometric apparatus modified to measure water uptake in cherry fruit pedicels. A fruit is mounted in the end of a waterfilled capillary glass tube through a rubber tubing. The glass tube is mounted parallell to a metric scale on a rectangular piece of cardboard. The apparatus is placed horizontally onto a grate and readings are made every 15 min.

Table 1. Two years of experiments with potometric water uptake by sweet cherry fruit by experiment, cultivar, date of experiment, number of fruits and order of applied treatments. Air is normal air of approximately 50±5% RH and immersed in water means that the fruits were covered with continously wet tissue paper. When the fruit skin was ruptured it was cut with 4 razor blades 1–2 mm into the fruit flesh

Experiment	Cultivar	Date	No. fruits	Order of applied treatment
Introductory	Merton Glory	July 19 1994	3	6h in air
studies	Merton Glory	July 20 1994	3	Pedicels without fruit, 5h in air
		July 20 1994	3	Pedicels with fruit, 5h in air
Fruit immersed in water	Merton Glory	July 25, 26, 27 1994	10	2h in air – 2h immersed in water – 2h in air
	Merton Glory	July 25, 26, 27 1994	10	6h in air (control)
	Ulster	July 28, 29 1994	5	2h in air – 2h immersed in water – 2h in air
	Ulster	July 28, 29 1994	5	6h in air (control)
	Rainier	August 15, 18 1997	9	1h in air – 4h immersed in water – 1h in air
	Rainier	August 15, 18 1997	5	6h in air (control)
	Sunburst	August 14 1997	9	1h in air – 4h immersed in water – 1h in air
Fruit with ruptured fruit skin	Van	August 9 1994	4	Intact for 1h – fruit skin ruptured for 5h
	Van	August 9 1994	4	Fruits in air (control), 5h
	Sunburst	August 25 1994	4	Intact for 1h – fruit skin ruptured for 5h
	Sunburst	August 25 1994	4	Fruits in air (control), 5h

Fig. 2 Potometrically measured accumulated water uptake through sweet cherry fruit pedicels with and without fruits of ‘Merton Glory’ (1994) for 5 h.

Fig. 3 Accumulated water uptake through the pedicels of fruit of sweet cherry ‘Merton Glory’ (1994) kept in air and interrupted by fruit immersion in water for 3 h. The first break in line is when the fruits were immersed in water, while the second break is when the fruits were dried. Vertical bars represent standard error of the means (SE) and each point represents 10 fruits. Regressions describing the data are: (▴) y=–0.69+9.90x, r ²=0.865; (-) y=–0.14+8.21x, r ²=0.840; y=0.98+5.06x, r ²=0.523 and y=3.91+1.54x, r ²=0.090 before, during and after immersion, respectively.

Fig. 4 Accumulated water uptake through the pedicel of fruits of sweet cherry ‘Ulster’ (1994) kept in air and interrupted by fruit immersion in water for 3 h. The first break in line is when the fruits were immersed in water, while the second break is when the fruits were dried. Vertical bars represent standard error of the means (SE) and each point represents 5 fruits. Regression describing the data are: (▴) y=−1.10+8.32x, r ²=0.984; (-) y=0.18+8.15x, r ²=0.911; y=0.64+4.69x, r ²=0.954 and y=−0.52+5.75x, r ²=0.971 before, during and after immersion, respectively.

Fig. 5 Accumulated water uptake through the pedicel of fruits of sweet cherry ‘Rainier’ (1997) kept in air and interrupted by fruit immersion in water for 3 h. The first break in line is when the fruits were immersed in water, while the second break is when the fruits were dried. Vertical bars represents standard error of the means (SE) and 9 fruits were immersed in water in addition to 5 control fruits. Regression describing the data are: (▴) y=0.79+6.17x, r ²=0.923; (-) y=0.11+8.08x, r ²=0.536; y=0.98+3.38x, r ²=0.648 and y=0.13+4.30x, r ²=0.334 before, during and after immersion, respectively.

Fig. 6 Accumulated water uptake through the pedicel of fruits of sweet cherry ‘Sunburst’ (1997) in air and interrupted by fruit immersion in water for 4 h. The first break in line is when the fruits were immersed in water, while the second break is when the fruits were dried. Vertical bars represents standard error of the means (SE) and each point represents 9 fruits. Regression describing the data are: y=−0.53+6.55x, r ²=0.780; y=0.82+1.43x, r ²=0.553 and y=0.11+9.64x, r ²=0.792 before, during and after immersion, respectively.

Table 2. Potometrically measured water uptake through the pedicel (μl fruit⁻¹ h⁻¹) and regression equations for the relationship between water uptake through the pedicel (y) and time (x) in two cultivars of sweet cherries with ruptured fruit skin (4 cuts with razor blades) and control fruits with intact fruit skin, 1997. Linear regression model y=a+bx

Cultivar	Treatment	Measured water uptake, μl fruit^−1 h^−1	Regression equation	Regression coefficient^a (r ^2)
Van	Control	6.83	0.24+6.98x	0.986***
	Ruptured fruit skin	9.26	−0.93+9.24x	0.973***
Sunburst	Control	2.95	0.14+3.92x	0.974***
	Ruptured fruit skin	4.33	0.03+4.21x	0.860***
^aSignificance of regression coefficient at the 5, 1 and 0.1% levels is indicated by *, ** and ***, respectively.