Sweet j strain skin#

Sweet j strain skin#

The effect of exocarp cell turgor on strain in the ES (evidenced by the difference in the reversible strain between ES with and without turgor) was closely and positively related to the relative area growth rate of the skin ( r 2 = 0.957). Thereafter, significant elastic strain developed, reaching a maximum of 47.6% ± 2.5% at 87 DAFB. In developing ‘Hedelfinger’ sweet cherry fruit, there was essentially no elastic strain in the exocarp at 45 days after full bloom (DAFB). Increasing the temperature from 2 to 35 ☌ increased the rate of strain release and also the total percent strain released at 96 hours. Elastic strain in the ES was always lower than that measured in an isolated cuticular membrane (CM). Across eight cherry cultivars, the biaxial strain in the exocarp at maturity ranged from 18.7% ± 1.9% in ‘Lapins’ to 36.0% ± 1.8% in ‘Katalin’. Relaxation continued, but at a decreasing rate, for up to 48 hours. In ES, monitoring the time course of relaxation after excision revealed a rapid release of biaxial strain, having a half-time of ≈2.7 minutes. Increasing the number of cuts from two to 12 increased the cumulative gape widths to 14.9% ± 0.2%.

By 24 hours the combined widths of two gapes represented 8.8% ± 0.1% of the fruit circumference. When mature sweet cherry fruit were cut (by making two or more deep, longitudinal incisions parallel to the stylar/pedicel axis and on opposing sides of the fruit down to the pit), the incisions rapidly “gaped.” The gaping wounds continued to widen as they progressively released the linear elastic strain in the skin. The release of linear elastic strain was followed in vivo using a gaping assay, whereas the release of biaxial elastic strain was followed in vitro after excision of small exocarp segments (ESs) that were submerged in silicone oil and strain release quantified by image analysis. The objective of our study was to quantify exocarp strain in developing cherries. Rain-cracking of sweet cherry ( Prunus avium L.) fruit involves failure of the exocarp caused by excessive stress and strain.