An NC-140 apple cultivar/rootstock trial was conducted near Blacksburg, VA from 1990 through 1999. In addition to the four cultivars common to all sites ('Golden Delicious', 'Jonagold', 'Empire', and 'Rome'), we also had 'Stayman', and 'York'. Rootstocks were Mark, Ottawa 3 (O.3), Budagovsky 9 (B.9), Mailing 9 EMLA (M.9EMLA), and Mailing 26 EMLA (M.26EMLA). Our objective in this supplemental study was to evaluate cultivar and rootstock effects on yield, distribution of fruit sizes, and color in order to estimate value of the crop. After eight years of cropping, there were very few significant cultivar x rootstock interactions; therefore, mostly main effects are presented. Fruit size was largest for 'Rome' and 'Jonagold', intermediate for 'Stayman' and 'York', and smallest for 'Golden Delicious' and 'Empire'. Trees on M.26EMLA and M.9EMLA produced somewhat larger fruit than did trees on Mark and O.3. Fruit from trees on B.9 were intermediate in size. Red color was variable, so in spite of significant differences, general conclusions were impossible. Projected value/tree for fresh fruit ('Empire', 'Rome', and 'Stayman') based on yield, fruit size, and red color was greatest for trees on M.26EMLA and M.9EMLA, intermediate for trees on O.3, and lowest for trees on Mark and B.9. In estimated value for processing; 'York' was higher than 'Golden Delicious', and fruit from trees on M26EMLA, O.3, and M.9EMLA were higher in value than those from trees on Mark and B.9.As apple rootstocks have been evaluated in NC-140 trials, prime attention has been paid to survival, tree size, precocity, yield, and mean fruit size (1, 10, 11). In some cases, there have been data published on fruit quality attributes such as soluble solids levels, starch indices, and maturity ratings (2, 3, 4). However, because of limited time and resources, most of the fruit size data have been based on mean fruit weight determined from a 50-fruit sub-sample per tree (10, 11). Unfortunately, mean fruit weight provides no information on either the range or distribution of fruit sizes. Therefore, economic projections of the relative value of the crop from the test trees is impossible.As a supplement to the 1990 NC-140 Apple Cultivar/Rootstock Trial, we sized all fruit, for six of the eight years in which fruit were harvested. In addition, a sub-sample of fruits was evaluated for red color. From a combination of yield data within these two data sets, we estimated crop values.
In 1990, trees of 'Gala' apple (Malus x domestica Borkh.) on 8 dwarfing rootstocks were planted at 8 locations in North America according to the guidelines established for cooperative testing by the North Central regional cooperative project (NC-140). Rootstocks in this trial included MAC.39, P.1, O.3, M.27, B.9, Mark, M.9 EMLA, and M.26 EMLA. Tree survival was not affected by rootstock. P.1 produced trees with the largest trunk cross-sectional areas, lowest yield and yield efficiency, and smallest fruit. O.3 and M.26 EMLA produced trees with similar TCSA, but M.26 EMLA was the least productive. Mark, MAC.39, B.9 and M.9 EMLA produced trees with similar TCSA, yields and yield efficiencies. M.27 produced trees with the smallest TCSA and relatively low yields.
In 1984, trees of 'Redhaven' peach [Prunus persica (L.) Batsch] on 9 rootstocks were planted at 16 sites in North America according to guidelines established for cooperative testing by the North Central Regional Cooperative Project (NC-140). After 7 years, tree loss was greatest on 'Citation' (52%) and 'Damas 1869' (32%). Survival was greatest for trees on 'Bailey,' 'Halford' and own-rooted 'Redhaven.' Tree loss was greatest at the Ohio and Kentucky sites, due primarily to winter damage and heavy soil conditions, respectively. Trees on 'GF 677' were the most vigorous and those on 'Citation,' 'GF 655-2' and 'Damas 1869' were the least vigorous. Greatest cumulative yield was experienced on 'GF 677: 'Halford,' 'Bailey,' 'Siberian C' and own-rooted 'Redhaven.'
The relationship between trunk cross-sectional area (TCSA) and total tree dry weight (DW), and between harvest index (HI) and yield efficiency (YE) of 'Starkspur Supreme Delicious' (Malus domestica Borkh.) apple trees on nine different rootstocks was examined. In general, as tree size increased, the reliability of TCSA as a predictor of total tree DW decreased. A log transformation increased the accuracy of the estimate. The relationship between YE and HI was improved when a log transformation of TCSA is used to compute the YE. A comparison of tree evaluations based on TCSA and total tree DMI revealed that trees on M.27 EMLA had a greater partitioning of dry matter to flowers and fruit when actual DW was used in calculations. The larger trees on MAC.23 and M.7 EMLA rootstocks, ranked higher in YE and flower density when TCSA was used instead of DW as a basis for accounting for tree size. The rootstocks with the highest HI's, ranging from 0.46 to 0.48, were M.9, M.27 EMLA, M.9 EMLA, MAC.9, and 0.3. OAR1, M.26 EMLA, M.7 EMLA, and MAC.24 were contained in a second grouping with HI's ranging from 0.33 to 0.39. M.27 EMLA had one of the lowest YE's but had a high HI. M.7 EMLA had a relatively high YE but a low HI. OAR1 had the lowest YE but not the lowest HI.
The dry matter partitioning to vegetative and reproductive components of 'Starkspur Supreme Delicious' apple (Malus domestica Borkh.) on nine rootstocks in the 1980-81 NC140 Apple Rootstock Trial was determined in March. and again in Oct.-Nov. 1990. Trees on MAC.24 and M.7 EMLA had the heaviest total tree dry weight (DW), while M.26 EMLA was intermediate. Trees on OAR 1, O.3, M.9 EMLA, MAC.9, and M.9 did not differ, and M.27 EMLA had the least total DW. Total tree DW was correlated negatively with percent of fruit, spur, and spur leaf DW and was correlated positively with the percentage of frame, 2-yr and 1-yr wood, current season's growth, and shoot leaf DW.
The construction costs (CCcomp) of vegetative and reproductive components, and total tree (total CC) and net (CCnet) construction costs were calculated using the gross heat of combustion, percentage ash content, and total nitrogen for 'Starkspur Supreme Delicious' apple trees (Malus domestica Borkh) grafted onto MAC.24, M.7 EMLA, M.26 EMLA, M.9 EMLA, MAC.9, and M.27 EMLA. The CCcomp in Oct./Nov. of 1-yr wood, 2-yr wood, and roots was Lower in trees grafted onto more: dwarfing rootstocks than in those on more vigorous rootstocks. Leaves had the highest CCcomp. Frame, 2-yr, 1-yr, shoot, and root had similar CCcomp. Fruit and spurs had the lowest CCcomp. As tree size decreased, total CC and CCnet decreased.
Four- and 5-year-old pecan trees (Carya illinoinensis (Wangenh.) K. Koch) were damaged by cold temperatures during the winter of 1998-1999, although winter temperatures were normal or above normal and not commonly considered harmful. Injury symptoms were small longitudinal splits in the bark. Wounds were exclusively on the sun-exposed side of the trees. One year-old branches had more damage than 2-year-old branches, but the white-painted trunks were not injured. 'Giles' and 642 generally had less damage than 'Pawnee,' 'Shawnee' and 'Kanza.' Mulched 'Giles' trees had less cold injury than those that were not mulched. Drought stress during 1998 apparently predisposed trees to cold injury at temperatures that are not normally injurious.
'Chardonnay #4,' 'Gruner Veltliner #1,' 'Malvasia bianca #3,' 'Muscat Ottonel #1,' 'Petit Manseng,' 'Viognier,' 'Vidal' and Chardonel' were evaluated at Winchester, Virginia for components of crop yield, fruit chemistry, and dormant bud cold hardiness over eight crop seasons. 'Chardonnay' and 'Vidal' represented "standards" for comparison in mat they were grown commercially and successfully in Virginia; we lacked experience with the others. All cultivars were trained to bi-lateral cordons and spur-pruned. The novel cultivars all possessed mid-winter, dormant bud cold hardiness superior to that of 'Chardonnay: Highest crop yields were attained with 'Vidal' (11.0 kg/vine) and 'Gruner Veltliner' (10.4 kg/vine); lowest with 'Muscat Ottonel' (5.1 kg/vine) and 'Viognier' (5.1 kg/vine). High sugar accumulating cultivars were 'Chardonel' (23.4 degrees Brix), 'Petit Manseng' (27.6 degrees Brix), and 'Viognier' (23.2 degrees Brix), whereas 'Malvasia bianca' and 'Muscat Ottonel' were harvested at relatively low soluble solids concentration but pronounced fruit aromas. Ungrafted 'Chardonel' suffered vine loss due to phylloxera. With the exception of 'Gruner Veltliner: all cultivars warranted general recommendation in the established grape production regions of Virginia. 'Gruner Veltliner' was susceptible to increased fruit rot severity, but was otherwise viticulturally acceptable.
Two Vaccinium corymbosum cultivars, 'Northland' and 'Patriot: were evaluated at Angstrom s (60 degree N) over the 11 years from 1988-98 after planting bushes spring 1983. All plants survived a minimum temperature of -30 C during winter per year 1984/85. On average, earliest fruit was harvested August 20 and the number of harvests averaged 3.0. Starting in 1993, biennial bearing was more pronounced for 'Northland' than for 'Patriot'. This trend for alternate bearing was broken in 1998 after an unusually warm July-September 1997. Based on one plant per square m, the total yield per year averaged about 0.9 kg fruit per square m during the first 10 years of the trial for both cultivars. However, in the eleventh year 'Northland' produced 3.4 kg per square m, exceeding 'Patriot' by almost 50% in total fruit yield. Fruit size varied from year to year in a similar manner for both cultivars with 'Patriot' having an average of 2.38 g per fruit, while 'Northland fruit averaged 1.19 g. Both cultivars were judged to produce fresh fruit of acceptable quality. These results are the first records of successful highbush blueberry culture in Norway.
The postharvest fruit quality of three strains ('Royal Gala: 'Imperial Gala' and 'Crimson Gala') of apples was evaluated over two or three storage seasons. To determine the influence of carbon dioxide treatment on storage quality, apples were stored in normal controlled atmosphere (1% O-2 & 1% CO2), or treated with 12% CO2 for 7 or 14 days prior to normal CA and evaluated after 90 or 150 days of storage. The use of 12% CO2 prior to storage helped to maintain firmness of 'Royal Gala' apples in 1 of 3 seasons. Firmness of 'Imperial Gala' and 'Crimson Gala' apples was not influenced by high CO2 treatment, regardless of storage season. Other quality factors (color, soluble solids, acidity and carbohydrates) were not influenced to the extent that high CO(2)would be a viable option for the quality enhancement of 'Gala' apples during storage, regardless of strain. Use of normal CA maintained 'Gala' apple quality for 150 days of storage. Harvest date had a major influence on 'Gala' apple quality. A delay of one week reduced firmness and acidity, but enhanced color and content of sucrose, glucose and fructose in 'Royal Gala: 'Imperial Gala' and 'Crimson Gala' apples.
Quarantine testing of imported plant germplasm is essential to protect U.S. agriculture against the inadvertent introduction of foreign pests and pathogens and is required by law. The testing of pome and stone fruits, brambles, potatoes, sweet potatoes, sugarcane, rice, grasses and some other crops is carried out jointly by two agencies within the United States Department of Agriculture at Beltsville, MD. Policy, budget, horticultural and technological questions as well as the perceptions of the user community have a direct impact on the operation of the testing program. A policy question that is of paramount concern to the operation of the testing program is whether or not to release foreign accessions if they are known to be infected with strains of a pathogen that is already found in the U.S. Low funding levels have hampered the program in the past, but additional funds have recently been made available for the program. The implementation of advanced technology has improved the testing program and will continue to do so in the future. A customer panel composed of people with technical knowledge in horticulture, plant pathology and advanced diagnostic methods is essential. Because the composition of this group will necessarily reflect the diverse crop responsibilities of the PGQO, communications among the 'customer' communities will be facilitated which should lead to a better understanding among the user groups of the complexities of the PGQO operations.
Native fruits abound in Vietnam and many of them offer opportunities for agricultural development. There are over 130 species of fruit crops cultivated in Vietnam, representing 39 families. In a previous paper, we described the most important introduced fruit crops in Vietnam. Herein, we discuss the different native fruits, both wild and cultivated.
