Regional cooperative efforts such as the Southern Association of Agricultural Experiment Station Director's Advisory Committees, Development Committees, Multi-State Research Fund supported projects, and Southern Extension/Research Activities Information Exchange Groups have been in existence and have been successful for many years. However, there are opportunities and compelling circumstances for more intensive regionalized efforts, including multi-state faculty positions and multi-state cooperatives. The University of Georgia is involved in three multistate horticulture faculty positions—an orchard floor management specialist (shared with Clemson University and North Carolina State University), an apple research position (shared with Clemson University, North Carolina State University, and The University of Tennessee), and an apple extension specialist (shared with The University of Tennessee)—and one multi-state cooperative, the Southern Region Small Fruit Consortium (supported by Clemson University, North Carolina State University, The University of Georgia, and The University of Tennessee). Justification for these regional efforts includes the following: 1) federal legislation now mandates multi-institutional and integrated (research and extension) activities; 2) state boundaries form artificial barriers that are transparent to clientele groups, problems, and solutions; 3) decreasing state budgets have resulted in faculty and staff reductions at many institutions, with a subsequent decline in services to clientele groups; and 4) in times of limited funding, universities must focus on areas of excellence and collaborate with other institutions to fill in the remaining gaps. Benefits we have realized from these efforts include the following: 1) better service for minor commodities; 2) better educational programs due to larger venues and pooled overhead funds; 3) enhanced communication among institutions leading to increased cooperative efforts in other areas; and 4) reduced duplicity among institutions resulting in freed up resources to address other high priority areas. There are challenges unique to regional cooperatives: 1) travel distances for extension faculty may be increased and require a high degree of planning and coordination; 2) depending on the housing location of the shared specialist, response time can be greater than if program were housed in-state; and 3) shared programs require open, effective, and increased communications among cooperators. In our experience, the benefits of regionalization far outweigh the additional challenges encountered. However, to be successful: 1) the whole must be greater than the sum of the parts; 2) each partner must have identify preservation; 3) stakeholders must realize value from the programs and must be kept abreast of program successes to assure their continued support.
The Southern Horticultural Laboratory evolved from the USDA Small Fruit Research Station located at Poplarville, MS. A short history of the research facility and present horticultural research directions will be discussed. Emphases will be on past and present cooperative regional research efforts in horticultural crops.
Autumnberry (Elaeagnus umbellata, “A”) and cornelian cherry (Cornusmas, “CC”) genotypes were examined for mineral composition, anthocyanin, phenolic and tannin contents, antioxidant characteristics and levels of individual phenolic compounds via GC-MS. Values were compared with those of 58 cultivars of blackberries (“B”), black raspberries (“BR”), cranberries (“C”), elderberries (“E”), grapes (“G”), red raspberries (“RR”) and strawberries (“S”). The phenolic content of “CC” (6955 μg·gfw-1) was greater than 2× that of “B”, “BR” and “E”. Phenolic contents of “A” samples (1058-1776 μg·gfw-1) were similar to those of “RR”, red “G” and “S”. Anthocyanin levels in “CC” (270 μg·gfw-1) resembled those in “C”. “A” did not contain anthocyanins. Fruit of “CC” and “A” possessed high tannin levels (9291 μg·gfw-1 and 1410–5403 μg·gfw-1, respectively) and exhibited high antioxidant potential (μmol·gfw-1 trolox equiv.). DPPH and FRAP values of “CC” (72.1 and 94.9, respectively) were greater than 2× those of “BR”. DPPH values of “A” (23.9–56.2) were ≥ values for “BR”, whereas “A” FRAP values (13.3–34.0) were similar to those of “B” and “RR”. However, the lipid-soluble antioxidant potential of lycopene-rich “A” was substantial. Levels of individual compounds varied among cultivars. Ca and Mg contents of “A” were less than those found in “CC” and “BR”. Other mineral levels were comparable.
The Tatura Trellis was developed from principles to overcome problems identified in existing cultural systems (2, 3, 6). For optimum early bearing and yield, we wanted a) a tree design that fills the allotted space quickly, resulting in optimum land use; b) a uniform and controlled distribution of leaves and fruit to improve light interception (16) and photosynthetic efficiency (5); c) an ordered branch and leaf array that diminishes light competition within and between trees, so as to minimize the effects of crowding that usually result from high plant densities, especially with peach trees; d) close planting to create root competition, thereby reducing vegetative vigor while increasing fruitfulness (4); and e) large tree numbers per hectare for high yields early in the life of the planting. In addition, we proposed that within the above constraints, the new system should be simple to mechanize. The requirements we considered important were f) an orchard with planar, though not necessarily horizontal or vertical, surfaces for easy positioning of machines and aids; g) a canopy under which machines can operate to recover fruit simply during harvesting, and over the canopy for summer pruning; h) a shallow canopy to decrease the chance of fruit striking limbs or other obstructions, which could damage the fruit after they were removed mechanically (30); i) a shallow canopy to increase penetration and coverage of protective sprays; and j) single limbs that repeat at regular intervals to simplify the positioning of mechanical devices.
Mechanical harvesting has, of course, long been standard for many annual crops, the “combine harvester” for wheat being an early, and successful, example. In some instances (e.g., tomato, plant breeders have “tailor made” cultivars to adapt them to mechanical harvesting. Typically, such annuals are destroyed in harvesting. The plant must be preserved with perennial crops, although sometimes considerable injury to the plant can be acceptable when (as for grapes or raspberries) the plant is severely pruned annually. Substantial damage to the plant (tree) is not acceptable, in mechanical harvesting of tree crops, but leaf damage is of minor consequence for deciduous tree crops, and the fruit is biologically destined to abscise; if it is not harvested. Damage to the product is not a problem, it will soon fall naturally for some deciduous tree crops (particularly nuts of various kinds). In contrast, mechanical harvesting of citrus fruits involves quite extraordinary problems. The tree is evergreen and substantial leaf damage is not acceptable. The fruit has no clearly defined abscission period. The same grapefruit that might be picked in October can hang on the tree until May. Citrus fruits are extremely subject to decay. ‘Valencia’ (an important cannery orange cultivar) takes 12 to 18 months from bloom to acceptable maturity to complicate matters further. Thus, there are 2 crops on the tree at harvest time; mature fruit that are to be harvested and immature fruit that must not be damaged or removed. It is apparent after 20 years and millions of dollars spent in Florida that the problem (particularly for ‘Valencia’) is as much biological as it is mechanical. The fruit, but not the leaves, must be made to abscise and, for ‘Valencia’, the tree must retain the immature crop while releasing the mature fruit.
Banana (Musa sp.), mango (Mangifera indica), and avocado (Persea americana) plants were grown in controlled-environment glasshouses in ambient (350 μmol CO2/mol) and enriched (700–1000 (mol CO2/mol) atmospheric CO2 concentrations. At each CO2 concentration, plants were either exposed to sink-limiting (root restriction) or non-sink-limiting conditions (no root restriction). Total carbon assimilation and dry matter accumulation were generally greater for plants in the enriched CO2 environment than for plants grown in ambient CO2. However, plants grown in the enriched CO2 environment were less efficient at assimilating carbon than plants grown in ambient CO2. There was a downward regulation of net CO2 assimilation due to root restriction that resulted in less dry matter accumulation than in non-root-restricted plants. This may explain the lower net CO2 assimilation rates often observed for tropical fruit trees grown in containers compared to those of field-grown trees. Atmospheric CO2 enrichment generally did not compensate for reductions in net CO2 assimilation and dry matter accumulation that resulted from root restriction.
The TFRUIT·Xpert and CIT·Xpert computerbased diagnostic programs can quickly assist commercial producers, extension agents, and homeowners in the diagnosis of diseases, insect pest problems and physiological disorders. The CIT·Xpert system focuses on citrus (Citrus spp.), whereas the TFRUIT·Xpert system focuses on avocado (Persea americana Mill.), carambola (Averrhoa carambola L.), lychee (Litchi chinensis Sonn.), mango (Mangifera indica L.), papaya (Carica papaya L.), and `Tahiti' lime (Citrus latifolia Tan.). The systems were developed in cooperation with research and extension specialists with expertise in the area of diagnosing diseases, disorders, and pest problems of citrus and tropical fruit. The systems' methodology reproduces the diagnostic reasoning process of these experts. Reviews of extension and research literature and 35-mm color slide images were completed to obtain representative information and slide images illustrative of diseases, disorders, and pest problems specific to Florida. The diagnostic programs operate under Microsoft-Windows. Full-screen color images are linked to symptoms (87 for CIT·Xpert and 167 for TFRUIT·Xpert) of diseases, disorders, and insect pest problems of citrus and tropical fruit, respectively. Users can also refer to summary documents and retrieve management information from the Univ. of Florida's Institute of Food and Agricultural Sciences extension publications through hypertext links. The programs are available separately on CD-ROM and each contains over 150 digital color images of symptoms.