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  • Author or Editor: C. Richard Unrath x
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Abstract

Apple (Malus domestica Borkh.) (‘MM 111’ rooted layers) and peach (Prunus persica L. Batsch) (‘Lovell’ seedlings) trees were subjected to two root temperatures (5° and 16°C) in a cold room during dormancy with the shoot maintained at 5°. Trees were removed after specific cold treatments (5°), ranging from 0 to 1870 hr. Respiration and carbohydrate fractions were determined on shoots and roots immediately upon removal from the temperature treatments. A second set of trees treated identically were placed in a greenhouse for 30 days, and respiration, budbreak, new root number, and new root and shoot dry weights were determined. Warm (16°) root temperature reduced total soluble carbohydrates and respiration in roots of apple and peach after removal from the cold room, and this response did not change with additional chilling. Root starch levels of both species decreased with increased chilling time, but were not affected by root temperature. After 30 days in the greenhouse, budbreak, new shoot dry weight, and new root number and weight were significantly higher in apple trees that had their roots chilled as compared to those with unchilled roots. These parameters were independent of root temperature in peach. Respiration rates showed greater increases during the greenhouse phase, with increased shoot chilling in peach and root and shoot chilling in apple after the chilling requirements were surpassed. Shoot and root respiration rates did not rise in apple when the roots were not chilled.

Open Access

Abstract

A simple measure of fruit asymmetry was used to evaluate fruit shape in ‘Delicious’ apple (Malus domestica Borkh.). The maximum/minimum length ratio, the ratio of the maximum distance between an individual calyx lobe and the stem end shoulder of the fruit to the minimum distance between calyx lobe and stem end shoulder, gave consistent results for evaluating normal and abnormal fruit shape.

Open Access

With the current situation facing land grant universities of declining resources and a portion of federal funding being dependent upon multistate activities, the search for means to successfully address clientele needs may be handled through multistate activity. In the Southeast, the tree fruit programs, both research and extension, have been evaluating areas that could be addressed with multistate programming. To date, most of the tree fruit multistate activities have been informal in nature. The apple program was the first to look at multistate activity because of the heavy concentration of the industry in the mountains of NC, SC, GA, and TN. The formation of the Southeastern Apple Growers Meeting, which combined the annual educational meeting for apple growers in NC, GA, SC, and TN, was the first initiative. It proved to be very successful with the completion of the eighth joint meeting. In addition, the pest management guides for both apple and peach have been combined for many of the southeastern (five states) and southern states (11 states), respectively. Numerous working groups, workshops, tours, and field days are held on a regional scale as well. However, in order for multistate programming to succeed, our experience suggest the need for several key components. The technical competence in the program to be addressed, a supportive university administration, backing of the industry groups, and personnel that are neither territorial nor resistant to change must be present. From our experience multistate programming can be very successful!

Free access

`Fuji' apples (Malus domestica Borkh.) were harvested at three maturities for three consecutive seasons. Fruit firmness, soluble solids concentration, starch—iodine index (SI), and internal ethylene concentration were measured at harvest. Fruit were stored in 0 °C air storage for 8 months. Fruit firmness and other maturity indices were measured monthly during storage. Using a stepwise regression procedure, harvest maturity indices were used to predict firmness after air storage. When all maturity indices measured were represented in the model, R 2 = 0.29, 0.34, and 0.26 at 4, 6, and 8 months, respectively. Use of only SI and fruit firmness in the model gave R 2 values of 0.25, 0.29, and 0.24 for 4, 6, and 8 months, respectively. Although R 2 values were low, they were highly significant. The model using fruit firmness and SI resulted in the best fit. Thus, an equation was developed using months of air storage, firmness, and SI at harvest. Actual firmness values correlated fairly well with predicted firmness values, usually within ≈5 N. On Washington apples, predicted values were 4.3 and 3.7 N too low compared to actual firmness values after 3 or 5 months' storage. In 1993, when predicted and actual firmness values were compared for Pennsylvania apples, predicted values ranged from 2.6 to 8.3 N too high after 3 months' storage, depending on harvest date. In 1994, Pennsylvania fruit stored 4 months had predicted values 0.5 N too high to 6.3 N too low, depending on harvest date. It may be possible to develop and refine models for an apple variety that would be applicable to several regions.

Free access