The internal browning (IB) disorder of `Pink Lady' apples is the manifestation of some undefined physiological conditions of the fruit at harvest, which predispose them to damage during CA storage. Internal browning problems generally occur intermittently and in unpredictable patterns. This type of disorder has the potential for widespread economic impacts. The optimum storage conditions and underlying physiological factors remain understood. In Fall 2002, `Pink Lady' apples were harvested in Stockton, Calif., at two maturities, then placed into CA storage. After storage, the percentage of fruit with IB increased with greater CO2 and with lower O2 concentrations. The incidence of IB injury was greater in fruit from the second harvest, but there was not a great difference in incidence between 2 and 6 months of storage. In Fall 2003, `Pink Lady' apples were harvested on the same orchard at three maturities and placed into CA storage. In all three experiments, fruit were stored in either air, 2% O2 + 1% CO2, or 2% O2 + 3% CO2 at 0.5 °C. In the first experiment, three harvest maturities were placed into storage immediately after harvest. For the second experiment, apples from harvest 2 were treated prior to fruit storage with 1ppm 1-MCP for 24 hours, 2200 ppm DPA, or were untreated. In the third experiment fruit from harvest 3 were placed into CA storage after 0, 2, or 4 weeks in air at 0.5 °C. No IB was observed for any of the three maturities after 0.5 and 1 month storage. After 2 months IB injury was present in 4.8% of the fruit stored in 1% CO2 and 4.6% stored in 3% CO2 from harvest one. A lower percentage of IB was observed in harvest two. Harvest three presented 0% and 2.6% of IB in 1% and 3%CO2 respectively. The effect of 1-MCP,DPA and delayed CA on IB will be discussed.
Elena De Castro Hernandez*, Bill Biasi, and Elisabeth Mitcham
Xingbin Xie, Todd Einhorn, and Yan Wang
) flesh firmness (FF) determined after exposing fruit to 20 °C for 5 h immediately after removal from cold storage, ( C and D ) internal browning (IB), and ( E and F ) decay of ‘Starkrimson’ pears during a 16-week storage period at −1.1 °C in 2
Our study found that storage temperature, storage atmosphere and growing region interactively affect the probability of internal browning disorder in `McIntosh' apples (Malus domestica Borkh.). Higher incidence of internal browning occurred in apples stored for 6 months at 1 °C (34 °F) in controlled atmosphere (CA) with 2.5% O2 + 1.5% CO2 or in CA with 1.0% O2 + 0.5% CO2 than apples stored at 1 °C in air or stored at 3 °C (37 °F) in air or CA conditions. The magnitude of the incidence of internal browning varied among apples harvested from different growing regions. Apples from London, Ontario, Canada were less tolerant to these two storage conditions and therefore greater number of fruit developed internal browning than apples from other regions. In addition, apples from the London growing region and stored at 1 °C in CA with 1.0% O2 + 0.5% CO2 had greater probability of internal browning than apples stored at 1 °C in CA with 2.5% O2 + 1.5% CO2. However, there was no difference between these two CA storage conditions in causing internal browning among apples harvested from other three growing regions. Few apples showed internal browning when they were stored at 3 °C, no matter of what storage atmosphere was used. Therefore, internal browning disorder can be avoided or significantly reduced by storing apples at 3 instead of 1 °C, in these two CA conditions. Internal browning disorder will not be a risk if apples are stored in air at 1 or 3 °C.
Carlos H. Crisosto, David Garner, Gayle M. Crisosto, Steve Sibbett, and Kevin R. Day
Brown discoloration of the core, carpels, and flesh areas of `Ya Li' and `Seuri' Chinese pears [Pyrus bretschmeideri (Rehd.)] depended on harvest date. Fruit harvested no later than 180 days after full bloom (3000 degree days) did not develop the disorder. Browning of the core and flesh tissues increased when cooling was delayed, but was not influenced by subsequent storage temperatures of 0,10, or 20C. In both cultivars, the onset of internal browning was evident after storage in fruit that had been harvested when skin color had changed from green to light green-yellow. Thus, skin color can be used to determine harvest date to avoid internal browninincidence during storage of `Ya Li' and `Seuri' Chinese pears.
C.R Roberts, Dean E. Knavel, John Snyder, Terry Jones, and Dave Spalding
Internal brown spot (IBS) was found consistently in the `Atlantic' cultivar at Lexington in 1967, 1968 and 1989, and at Owensboro and Quicksand, KY in 1987, Treatments of foliar and soil applied CaSO4 in 1987, soil-applied CaSO4 in 1988, and straw mulching in 1989 did not reduce IBS. Irrigation increased IBS because of larger tubers and increased Ca content of plants as compared with non-irrigated plants. Tubers showing IBS had higher Ca content in affected tissue than in non-affected tissue. Both IBS and Ca content of leaves increased as the plants aged.
H. John Elgar, Douglas M. Burmeister, and Christopher B. Watkins
`Braeburn' apple (Malus ×domestica Borkh.) fruit can be susceptible to the development of an internal disorder called “`Braeburn' browning disorder” (BBD). Factors associated with development of this disorder were investigated. Susceptibility to injury was greater in fruit exposed to 2 or 5 kPa CO2 than to 0 kPa CO2 during storage. Susceptibility also increased with decreasing O2 partial pressure in the range of 5 to 1 kPa in the storage atmosphere. However, fruit stored in 1 kPa O2 remained firmer than those stored at higher partial pressures, regardless of CO2 level. BBD appeared to develop during the first 2 weeks of storage, and delays in air at 0 °C prior to controlled-atmosphere (CA) storage decreased incidence and severity of the disorder. The incidence of BBD was also reduced when the time to establish CA conditions was prolonged. We recommend that `Braeburn' apples be stored under CA conditions of ≤1.0 kPa CO2 and 3.0 kPa O2. Delayed application of CA for 2 weeks after fruit enter the coldstorage may also reduce development of BBD.
Larry E. Schrader, Jianguang Zhang, Jianshe Sun, Jizhong Xu, Don C. Elfving, and Cindy Kahn
. Under these conditions, FST of sun-exposed apples can reach 45 to 50 °C. Exposure of apples to these high FST required for sunburn browning raises questions about what effects these high temperatures have on internal fruit quality. Yet very little has
Matthew D. Kleinhenz, Christopher C. Gunter, and Jiwan P. Palta
A direct comparison was made of several commercially available calcium sources applied on two different schedules for their effectiveness in increasing tuber medullary and periderm tissue calcium concentrations in 170–284-g tubers of the cultivar Atlantic grown on a Plainfield sandy loam. Plots (6 x 3 m) were arranged in a CR design in 1993 and a RCBD in 1994 (eight replications). Paired measurements of tuber Ca concentration and internal quality (±hollow heart, ±internal brown spot) were made on individual tubers produced in plots with no additional or additional Ca (168 kg Ca/ha) supplied from either gypsum, liquid calcium nitrate, or NHIB. Two Ca and N application schedules were compared: 1) application at emergence and hilling (non-split), 2) application at emergence, hilling, and 4 and 8 weeks after hilling (split). All plots received 224 kg H/ha balanced with ammonium nitrate. In general, tuber yield and grade were unaffected by treatments in 1993 and 1994, but overall percent A-grade was lowest and percent B-grade highest in 1993 compared with 1994 data. In 1993, all treatments receiving Ca had greater mean tuber medullary and periderm tissue Ca concentration values and a greater percentage of tubers with an elevated Ca concentration compared with non-Ca-supplemented controls. The overall incidence of tuber internal defects was 5% in 1993. All split schedule treatments receiving Ca showed 0% internal defects. In contrast, nearly 8% of the tubers from control plots showed some defect. The medullary tissue Ca concentration of 65% of the tubers having either defect was below the median value of Ca concentration for the entire experiment in 1993. Similar evaluations are underway for the 1994 crop. These data suggest that tuber calcium concentration may be related to the incidence of these internal defects.
Ahmed A. Tawfik and Jiwan P. Palta
We have shown that tuber calcium can be enhanced by supplying soluble forms of calcium near the tuber stolon region during bulking. In the present study we applied calcium nitrate or N-HIB during bulking (hilling, 3 and 6 wks after hilling) by injecting these Ca sources into sprinkler irrigation line. Field plots were established with cv `Russet Burbank' in sandy loam soil containing about 1200 Kg Ca ha-1. All plots received equal amounts of nitrogen. Plots receiving only nitrogen (as NH4NO3) at the same time served as split N controls and the plots receiving complete nitrogen by the time of hilling (non-split N) served as the grower control.
In 1990 compared to non-split-N control a consistently higher tuber yield was obtained with split-N, N-HIB (113 Kg.Ca ha-1) calcium nitrate (113 Kg Ca ha-1). However, these differences were not significant. Tuber calcium contents were increased with N-HIB and calcium nitrate. After 5 months of storage the incidence of soft rot and of internal brown spot was significantly reduced. In 1991 N-HIB (113 Kg ha-1) gave significantly higher tuber yield than other treatments. Tuber calcium contents were increased with both calcium nitrate and N-HIB treatments. After four months of storage incidence of internal brown spot was reduced by calcium nitrate and N-HIB although calcium nitrate was most effective. These results demonstrate that it is possible to improve tuber calcium contents by application of 113-226 Kg Ca ha-1 during bulking even in a soil containing sufficient calcium for plant growth.
Peter J. Dittmar, Jonathan R. Schultheis, Katherine M. Jennings, David W. Monks, Sushila Chaudhari, Stephen Meyers, and Chen Jiang
growers in North Carolina for production in smaller commercial acreages for its attractive dark ruby skin, orange flesh, and outstanding taste (S. Scott, personal communication). Internal necrosis occurs in the sweetpotato flesh near the proximal end as