). In ‘Honeycrisp’ grown in Nova Scotia, apples have reduced the risk of bitter pit and soft scald when I AD is in the range of 0.36 to 0.59 ( DeLong et al., 2014 ). However, these studies were based on harvest means of I AD , and they do not consider
Renae Moran, Jennifer DeEll, and Cindy B.S. Tong
In a 3-year study, the effectiveness of 0.7% and 1.5% O2 to attenuate scald was evaluated on three strains of `Delicious' apples (Malus ×domestica Borkh.)—`Harrold Red', `Starking', and `Starkrimson'—harvested five times at weekly intervals from a wide range of orchards. Scald susceptibility of fruit held in air, 1.5% O2 + 1.0% CO2, and 0.7% O2 + 1.0% CO2 at 0 °C decreased sharply as the fruit matured on the tree (starch index 1.0 to 2.5 on a 0 to 9 scale). Later harvests (starch index >2.8) further reduced scald but the fruit had more watercore-induced breakdown and were 3 N softer than fruit picked at a less advanced maturity. Early picked `Starkrimson' (starch index <2.0) scalded more than `Starking' and `Harrold Red' in air, 1.5% O2, and 0.7% O2 storage at 0 °C, and 0.7% O2 was less effective than 1.5% O2 in scald control. While 0.7% O2 storage effectively reduced scald (less than 10%) for 8 months in `Starking' and `Harrold Red' picked over a wide range of maturity (starch index 0.7 to 4.3), it did not adequately control scald (up to 45%) in early picked `Starkrimson' (starch index <2.0). Storage in 0.7% also reduced watercore-induced breakdown in `Starkrimson' (starch index >3.0) and did not result in skin purpling or alcoholic taste in `Harrold Red', `Starking', and `Starkrimson'.
F. Ghahramani, K.J. Scott, and R. Holmes
`Delicious' (Malus ×domestica Borkh.) apples were kept in sealed polyethylene bags (thickness 0.05 mm) and exposed to ethanol, propan-1-ol, butan-1-ol, and pentan-1-ol during storage at 0 °C. Rates of application varied from 1.85 to 120 mmol·kg-1. Complete control of superficial scald was achieved using 30 mmol·kg-1 of fruit with butan-1-ol or propan-1-ol; ethanol required 120 mmol·kg-1 to control the disorder, but at this concentration, purpling of the red skin occurred. Butan-1-ol and propan-1-ol did not affect the color. Pentan-1-ol caused severe skin injury resembling soft or deep scald of `Jonathan' apples. Apples were also kept in high purity N at 20 °C for up to 8 days before storage at 0 °C. Complete control of scald occurred with a 6- or 8-day exposure to N. Control of scald appears to be due to the accumulation of ethanol during exposure to N. Nitrogen treatments did not affect skin color.
Christopher B. Watkins, Mustafa Erkan, Jacqueline F. Nock, Kevin A. Iungerman, Randolph M. Beaudry, and Renae E. Moran
`Honeycrisp' is a new apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] cultivar that has been planted extensively in North America, but the storage disorders soggy breakdown and soft scald have resulted in major fruit losses. The effects of harvest date and storage temperature on fruit quality and susceptibility of fruit to these disorders have been investigated in Michigan, New York, and Maine. Internal ethylene concentrations were variable over a wide range of harvest dates, and a rapid increase in autocatalytic ethylene production was not always apparent. The starch pattern index, soluble solids content, titratable acidity and firmness also appear to have limited use as harvest indices. Development of soggy breakdown and soft scald is associated with later harvest dates and storage of fruit at temperatures of 0 to 0.5 °C compared with higher storage temperatures. It is recommended that `Honeycrisp' be stored at 3 °C, although storage disorders still can occur at this temperature if fruit are harvested late. In addition, greasiness development may be worse at higher storage temperatures.
W.R. Miller and R.E. McDonald
Carambolas (Averrhoa carambola L.) must be treated with an approved insect quarantine procedure such as cold treatment before shipment to certain markets. Condition and quality of mature-green (MG) and slightly yellow (SY) fruit were determined after they were: 1) treated with ethylene at 0.1 ml·L-1 for 48 hours (C2H4), 2) subjected to cold treatment (CT) at 1 °C for 15 days, and 3) held in storage at 5 °C for 7 days plus 3 days at 15 °C. Ethylene-treated fruit were softer and yellowness was enhanced compared with non-C2H4-treated fruit. MG fruit were firmer and lost more mass following CT and storage than SY fruit. C2H4 treatment increased the severity of peel scald, stem-end breakdown (SEB), and fin browning but had no effect on pitting. CT increased the severity of scald and pitting, and the severity of SEB, but did not affect fin browning. Peel scald, pitting, SEB, and fin browning were more severe in MG than in SY fruit at the final evaluation. C2H4-treated fruit had lower total soluble solids concentration, higher titratable acidity and pH, and a less preferred flavor and texture than control fruit. We conclude that carambola fruit should be selected at harvest at the slight-yellow stage (3% to 25% of surface area) instead of at the mature-green stage. Fruit to be cold-stored should not be C2H4 treated due to enhanced mold development and severity of SEB.
Jinhe Bai, Xinhua Yin, Bruce D. Whitaker, Kristi Deschuytter, and Paul M. Chen
Superficial scald is a major physiological disorder of ‘Anjou’ pears that occurs after ≥3 or 5 months of cold storage in air or controlled atmosphere (CA), respectively ( Hansen and Mellenthin, 1979 ). The commercial air storage target for ‘Anjou
James M. Wargo and Chris B. Watkins
`Honeycrisp' apples (Malus × domestica) were harvested over 3-week periods in 2001 and 2002. Maturity and quality indices were determined at harvest. Fruit quality was evaluated after air storage [0.0 to 2.2 °C (32 to 36 °F), 95% relative humidity] for 10-13 weeks and 15-18 weeks for the 2001 and 2002 harvests, respectively. Internal ethylene concentrations (IEC), starch indices (1-8 scale), firmness and soluble solids content (SSC) did not show consistent patterns of change over time. Starch hydrolysis was advanced on all harvest dates, but it is suggested that a starch index of 7 is a useful guide for timing harvest of fruit in western New York. After storage, firmness closely followed that observed immediately after harvest, and softening during storage was slow. No change in SSC was observed during storage in either year. Incidence of bitter pit and soft scald was generally low and was not affected consistently by harvest date. The incidence of stem punctures averaged 18.5% over both years, but was not affected by harvest date. Development of stem end cracking in both years, and rot development in one year, increased with later harvest dates. A panel of storage operators, packers, growers, and fruit extension specialists evaluated the samples for appearance and eating quality after storage, and results suggested that a 2-week harvest window is optimal for `Honeycrisp' apples that are spot picked to select the most mature fruit at each harvest.
Keryl Jacobi, Janet Giles, Elspeth MacRae, and Teresa Wegrzyn
In an effort to develop an inexpensive alternative to vapor-heat insect disinfestation of `Kensington' mango (Mangifera indica Linn.), the effect of postharvest hot water treatments (HWT) on fruit quality was determined. Fruit were given 46C HWT for 30 minutes at a fruit core temperature of 45C either 24 hours after harvest or after various conditioning treatments of 4 to 24 hours at 39 ± 1C in air. Fruit were compared to nontreated fruit after a subsequent 7 days at 22C. The HWT increased fruit softening and reduced chlorophyll fluorescence and disease incidence. The longer conditioning times produced softer fruit. Conditioning reduced damage to the fruit caused by HWT. Preconditioning for ≥8 hours resulted in <1% of fruit being damaged as shown by cavities, skin scald, and starch layer formation. The quantitatively measured higher mesocarp starch content paralleled the visible starch layer injury. Skin yellowing increased in response to HWTs that were not damaging to the fruit. Fruit ripening changes were unequally affected by HWT and by conditioning before HWT; thus, the sequence and extent of these changes must be determined to establish a reliable and useful hot water disinfestation treatment.
Laura Lehman-Salada and George M. Greene II
In both experiments. 20-apple samples from 6 commercial orchards were harvested and stored in 208 liter containers at 0C for 4, 6, and 8 months. Additional samples were removed from CA and held at 0C for 14 days before evaluation. Gas composition was measured and controlled 6 times per day using automatic control equipment.
In the first experiment, samples were stored at constant 0.0% CO2 and one of three O2 regimes (constant 2.0%. 0.5 rising to 3.5%. or 3.5% falling to 0.5% O2). Apples stored at 3.5% falling to 0.5% O2 during the storage period were softer than apples held at constant 2.0% or those held at 0.5% rising to 3.5% O2 during the storage period. Variable O2 concentrations did not influence weight loss during storage and insignificant scald, flesh browning, core browning, rot, and low 02 injury were observed.
In the second experiment, samples were stored at constant 2.0% O2 and one of three CO2 regimes (constant 0%, constant 5%. or 0% rising to 6% CO2). Constant 5% or rising CO2 conditions did not significantly influence flesh softening or weight loss during storage. Negligible CO2 injury was observed.
Juan Pablo Zoffoli, Valentina Sanguedolce, Paulina Naranjo, and Carolina Contreras
times of conditioning, are effective in reducing superficial and soft scald in apples ( Moggia et al., 2009 ; Watkins et al., 2004 ). Conditioning has also been shown to be effective in reducing mealiness in peaches and nectarines ( Crisosto et al