, optimum CA conditions must be investigated for cultivars used in organic apple production ( Delate et al., 2003 ). The purpose of this work was to investigate the feasibility of improving yield, quality, and storage life of some organically grown apple
Ibrahim I. Tahir and Hilde Nybom
E. L. Proebsting, S. R. Drake, and R. G. Evans
‘Delicious’ and ‘Golden Delicious’ apples (Malus domestica Borkh.) on seedling rootstock were grown with trickle and sprinkler irrigation, both operated at high frequency of irrigation (daily). Trees with trickle irrigation developed lower leaf water potentials and produced less vegetative growth than trees with sprinkler irrigation, but fruit and productivity were similar. Apples from the trickle-irrigated trees had less water content and higher soluble solids than those from sprinkler-irrigated trees. Titratable acidity tended to be lower and both red color in ‘Delicious’ and yellow color in ‘Golden Delicious’ tended to be higher in fruit from trickle-irrigated trees than from sprinkled trees; firmness at harvest was similar regardless of irrigation procedure. Storage life was not influenced consistently by irrigation. Where differences did occur, the fruit from trickle-irrigated trees was softer after storage. Changes in fruit quality similar to those observed in trickle-irrigated trees were produced by imposing, through high frequency deficit irrigation with sprinklers, similar moisture deficits on apple trees, as measured by leaf water potential.
P. Perkins-Veazie, J.K. Collins, and J.R. Clark
The storage life of blackberry fruit is generally `2 to 3 days when stored at 1C. This study was done to determine the maximum storage life among erect blackberry cultivars, and to determine storage temperature effects on storage life. Shiny black fruit from `Navaho', `Arapaho', and `Shawnee' cultivars were stored at 2C, 5C, or 10C for 20, 14, and 7 days, respectively. At any temperature. only 10-20% of `Navaho' fruit had decay, while 30-50% of `Arapaho' and 40-70% of `Shawnee' fruit had decay. Weight loss was 3-5% depending on temperature and was not different among cultivars. Soluble solids concentration did not change during storage but titratable acidity decreased in all cultivars for fruit held at all temperatures. Anthocyanin content increased during storage in `Shawnee' and `Navaho' but not in `Arapaho' fruit. Results indicate that `Navaho' fruit have a longer shelflife than other blackberry cultivars.
F. W. Liu
Good correlation was found between length of storage life of banana (Musa cavendishii Lambert cv. Dwarf Cavendish) and minimum treatment time required for ethylene ripening response at harvest. All test bananas responded to 24 hours or less of 10 ppm ethylene treatment. Based on 29 sample groups of greenhousegrown ‘Dwarf Cavendish’ bananas, a linear regression equation relating banana storage life in days in air at 21°C (as output Y) and minimum time in hours required for ripening response to 10 ppm ethylene (as input X) was obtained as Y = 4.59 + 1.25X. The 2 variables had a correlation coefficient of 0.92.
Glenn Fuller, Judith A. Kuhnle, Joseph W. Corse, and Bruce E. Mackey
Two natural cytokinins, zeatin and dihydrozeatin, were effective in preserving broccoli appearance and chlorophyll content. Single treatments with 100 ppm aqueous solutions of the 2 compounds, followed by storage at 13°C, permitted storage life of 5 days for zeatin- and 4 days for dihydrozeatin-treated samples of broccoli. Repeated treatments with these compounds increased broccoli storage life to 6 days at 13°C, approaching the apparently limiting value of 7 days conferred by the synthetic cytokinin, 6-benzylamino purine (25 ppm). Broccoli without cytokinin treatment remained salable for only 2 days at 13°C. Visual scores for color were linearly related to chlorophyll concentration.
Albert F. Eboudwarej and Robert C. Herner
The grape variety `Himrod' under conventional storage practices has a short storage life while it has an excellent quality character.
To modify berry size and cluster compactness, different treatments are being used. Application of these cultural practices has pronounced effect on storage life of grapes. The cultural practices consist of different combinations of gibberellin application (two different concentrations), girdling and cluster thjnning.
Biophysical and biochemical evaluation of the grapes under two different modified storage conditions showed that treated grapes react differently during storage. Our results suggest that grapes that were only treated with gibberellin (20 ppm at shatter and 50 ppm postshatter) were better than control slid any other combined treatments and the worst was the case of only girdling application. Combination of these two treatments were intermediate in terms of biophysical evaluation.
Ruth Ben-Arie and Yohanan Zutkhi
The commercial storage life of the nonastringent Japanese `Fuyu' persimmon (Diospyros kaki L.), grown in Israel, was extended from 6 to 18 weeks at 0C by modified-atmosphere packaging (MAP) in a low-density polyethylene (LDPE) film. MAP retarded fruit softening and inhibited development of peel and flesh disorders, which limited the storage life of the naked fruit. The fruit maintained its external and internal quality within the MAP during a subsequent week at 20C in the 0.08-mm LDPE film. Fruit quality deteriorated more rapidly in a 0.06-mm package. The difference between fruit quality in the two packs is attributed to specific physiological effects of the different atmospheric equilibria established due to film thickness.
C.A. Marmo, William J. Bramlage, and Sarah A. Weis
Fruit of equal size but varying Ca concentrations were harvested 4 times at weekly intervals for measurements of firmness, titratable acidity, soluble solids and starch, and of Ca, N, P, K, Mg, B, Fe, Mn, Zn, and A1 concentrations. In another experiment, fruit of 3 different sizes were measured generally as above. These measurements were compared with incidences of senescent breakdown, scald and rot after air storage at 0°C, and stepwise multiple linear regression was used to develop equations for predicting apple storage life. Among minerals and maturity indices, Ca, and starch concentrations, respectively, accounted for the most variations in senescent breakdown. Fruit diameter and fruit firmness also accounted for significant amounts of variation in breakdown after storage when fruit size varied. These results show that predictions of storage life based solely on mineral concentrations can be improved by incorporating maturity and size measurements at harvest when these factors are variable.
Ahmed El Ghaouth, Rathy Ponnampalam, and Joseph Arul
The effect of chitosan coating on the respiration rate, ethylene production and quality attributes of tomatoes stored at 20°C under high humidity-regular atmosphere was investigated. Chitosan coating reduced significantly the respiration rate and ethylene production of tomatoes, with a greater effect at higher concentration. In addition coating modified the internal microatmoaphere of fruits. Furthermore, coated fruits were firmer, higher in titratable acidity, less decayed and their change in color proceeded at a slower rate than the control.
In conclusion chitosan coating delayed senescence and prolonged storage life of tomatoes, without affecting their market quality by acting as diffusion barrier for gases.
Hugo Ramirez, Judith Zambrano, and Eusebio Bracho
They were done studies on the influence of temperature (10, 15 and 24 C) and permeable coatings (Prolong and Primafresh) on the storage life of tomatoes cv `Large River' and `Caribbean'. Fruits were obtained from a commercial source in the Clear River area of the Lara State, at the breaker state. Quality measurements included weight loss, color, titrable acidity, pH, total soluble solids and dry matter. Weight loss was highest in the `Caribbean' cultivar being notorious in the first five days of storage, but it was not observed a meaningful response with respect to permeable coatings. `Large River' developed color early, though it was affected very little by the temperature of 10 C and Prolong. `Caribbean- resulted firmer during all the period of storage and the low temperature. Both cultivars showed equal trend with respect to increase total soluble solids. Dry matter showed a similar trend for both cultivars, temperature and permeable coatings.