Four tissue-cultured mints, Mentha arvensis L., M. spicata L., M. suaveolens Ehrh. hybrid, and M. suaveolens cv. Variegata, were evaluated for survival during storage in media containing three concentrations of N and in four light and temperature regimes. Shoots were placed in plastic, five-chamber, tissue-culture bags on Murashige and Skoog medium (1962) containing 25%, 50%, and 100% of the normal N concentration (MS-N) and stored at 4 °C and –1 °C in darkness, at 4 °C with a 12-hour photoperiod, and at 25 °C with a 16-hour photoperiod. Shoots of all four genotypes stored at 25 °C were in excellent condition after 6 months but required subculture after 18 months. Condition ratings of stored shoots varied with genotype and N concentration. Cultures survived longest at 4 °C with a 12-hour photoperiod on 50% MS-N. Under this regime, all four genotypes were rated in good condition at 30 months but declined to poor condition by 36 months. Based on these data, I recommend that mint cultures be stored on MS medium with 50% MS-N at 4 °C with a 12-hour photoperiod. This regime should provide a minimum of 24 to 36 months of storage before subculture is required. Cold-sensitive genotypes could be stored for 18 months at 25 °C on 50% MS-N medium.
Barbara M. Reed
Keith A. Funnell
shoots per plant. The remaining 30 plants, and those once removed from cold storage, were randomly allocated to each of the three forcing treatment environments identified as: cool (shade house with no temperature control), warm (greenhouse heated at 15
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
Martha Edith López-López, José Ángel López-Valenzuela, Francisco Delgado-Vargas, Gabriela López-Angulo, Armando Carrillo-López, Lidia Elena Ayón-Reyna, and Misael Odín Vega-García
reactive oxygen species (ROS) production ( Chidtragool et al., 2011 ). It has been demonstrated that visual CI symptoms appear after the fruit is removed from the cold storage and transferred to ripening conditions ( Ding et al., 2007 ). The susceptibility
Engin Ertan, Esra Erdal, Gülsüm Alkan, and Burak E. Algül
certain level to ensure good storage. Cold storage (CS) is the best method to ensure appropriate storage conditions for fruit ( Soylu, 2004 ). Chestnuts can withstand CS because they are not susceptible to damage caused by low temperatures. The best
Suzanne S. Sanxter, Kate A. Nishijima, and Harvey T. Chan Jr.
Chilling injury symptoms were reduced when `Sharwil' avocados (Persea americana Mill.) were held at 37 to 38C for 17 to 18 hours and then air-cooled at 20C for 4 hours before storage at 1.1C for ≥14 days. In contrast, nonheated fruit developed severe surface discoloration and pitting. Chilling injury symptoms were reduced further when the heated fruit were stored in perforated polyethylene bags during 1.1C storage. No treatment equaled or surpassed the quality of fruit in nontreated controls.
Anne M. Hanchek and Arthur C. Cameron
The effect of harvest dates between September and December on regrowth after storage of field-grown Coreopsis grandiflora Hogg × Sweet `Sunburst' and `Sunray', Geum quellyon Sweet `Mrs. Bradshaw', Gypsophila paniculata L. `Snowflake', Iberis sempervirens L. `Snowflake', and Dicentra spectabilis (L.) Lem. crowns was determined. After 0 to 7 months of storage at 0C, stored crowns were repotted and grown in a greenhouse. Plants from later harvests were of higher quality than those from earlier harvests, showing higher rates of survival after longer storage periods, less mold development in storage, and stronger regrowth after storage. Late field harvest is recommended for optimum storage quality.
Guy D'hallewin, Mario Schirra, Enzo Manueddu, Antonio Piga, and Shimshon Ben-Yehoshua
`Washington Navel', `Biondo Comune', `Tarocco', and `Valencia Late' orange [Citrus sinensis (L.) Obsek] fruit, harvested at various periods of time, were subjected to ultraviolet-C (UV-C) irradiation at 0.5, 1.5, or 3.0 kJ·m-2 doses and then stored at 7 °C and 90% to 95% relative humidity (RH) for 4 weeks plus one additional week at 20 °C and 80% RH. Following UV-C treatment, there was varying amounts of rind browning and necrotic peel damage, depending on cultivar, treatment dose, and harvest date. `Tarocco' fruit were damaged more easily by UV-C treatment than the other cultivars. `Valencia L.' were the most resistant to UV-C irradiation, showing no adverse effects at the lowest dosage and having the lowest percentages of damaged fruit at higher dosages. `Washington Navel' and `Biondo Comune' oranges showed an intermediate susceptibility to UV-C treatment, with negligible differences between these cultivars. The percentage of damaged fruit after irradiation at the higher UV-C dosages decreased in most fruit samples as the season progressed. UV-C irradiation at 0.5 kJ·m-2 effectively reduced decay development compared with nontreated fruit. Irradiation with 1.5 kJ·m-2 was more effective compared with 0.5 kJ·m-2 only in early harvested fruit. In `Washington Navel' and `Biondo Comune' oranges in the later harvests, treatment with 3.0 kJ·m-2 improved decay control further, compared with 0.5 kJ·m-2. Following UV-C treatments the phytoalexins, scoparone and scopoletin, accumulated in flavedo tissue depending on the cultivar, fruit age, and UV-C treatment. Both phytoalexins displayed a similar accumulation pattern, however, the levels of scopoletin were very low compared with scoparone. Concentrations of phytoalexins rose as the irradiation dose increased. No scoparone and scopoletin could be detected in nontreated fruit. The highest concentration of phytoalexins among cultivars was recorded in `Valencia Late' oranges, the lowest in `Tarocco', with similar intermediate accumulations in `Washington Navel' and `Biondo Comune'. In `Washington Navel', `Biondo Comune', and `Tarocco' oranges, the rate of scoparone accumulation was significantly higher in fruit harvested earlier in the season while `Valencia late' oranges exhibited an opposite trend.
Kate A. Nishijima, Harvey T. Chan Jr., Suzanne S. Sanxter, and Edward S. Linse
A reduced heat shock period for `Sharwil' avocado (Persea americana Mill.) before quarantine cold treatment is described. The shortened heat pretreatment period of 8 to 12 hours, rather than the originally recommended 18 hours at 38C, is effective in reducing chilling injury symptoms when the pulp is at ≤2.2C during 16 days of storage. The reduced durations and the range of pretreatment hours affords packinghouses greater efficiency and more flexibility and will reduce handling costs relative to the longer exposure.
Renae E. Moran, Jennifer R. DeEll, and Dennis P. Murr
‘Honeycrisp’ apples develop the disorders soft scald and soggy breakdown in cold storage, particularly at temperatures below 3 °C ( Watkins et al., 2003 ). Soft scald is a low-temperature disorder that is characterized by sharply defined