Florida Fruits Research Articles

CITPATH: Diagnostic and Hypertext Software for Fungal Diseases of Citrus Foliage and Fruit

CITPATH, a computerized diagnostic key and information system, was developed to identify the major fungal diseases of citrus foliage and fruit in Florida. This software provides hypertext-linked descriptions and graphic displays of symptoms, maps of geographic occurrence, diagrams of disease development, and management strategies, with reference to chemical control methods detailed in the current Florida Citrus Pest Management Guide. Reciprocal lists of citrus cultivars susceptible to specific diseases and diseases affecting specific cultivars are included. Developed for commercial growers, county extension programs, citrus horticulture classes, and master gardeners, this software is available for MS-DOS-based computers and on CD-ROM disks containing other citrus databases.

CITPATH: Diagnostic and Hypertext Software for Fungal Diseases of Citrus Foliage and Fruit

Fungal diseases have their greatest impact on citrus in Florida by reducing tree vigor, fruit yield, and quality. Given the complex etiology of these diseases, this software was developed to facilitate diagnosis of symptoms and to explain the dynamics of Alternaria brown spot of mandarins, greasy spot, melanose, Phytophthora brown rot, post-bloom fruit drop, and sour orange scab. CITPATH includes a diagnostic key to identify symptoms of the major fungal diseases of citrus foliage and fruit in Florida and a hypertext program containing a description and graphic display of symptoms, maps of geographic occurrence, diagrams of disease development, and management strategies. Users can also consult a list of citrus cultivars susceptible to specific diseases and a reciprocal list of diseases affecting specific cultivars. Chemical control methods are discussed briefly with reference to the current Florida Citrus Spray Guide, a hardcopy of which is included with the software purchase. Developed for commercial growers, county extension programs, citrus horticulture classes, and master gardeners, this software is available on CD-ROM disks containing other citrus databases and as a separate disk for MS-DOS-based computers.

Comparing Objective Quality Attributes of Grapefruit Imported Into Europe

Grapefruit (Citrus paradisi Macf.) were sampled biweekly from importers in Rotterdam, the Netherlands, from Oct. 1992 through Sept. 1993. For each sample, fruit size, weight, peel thickness, internal pulp color, juice weight, total soluble solids (TSS), and total acid (TA) were measured. Three grapefruit cultivars—`Marsh' white, `Ruby Red', and `Star Ruby'—were sampled from 12 countries of origin. Florida fruit weighed more, had the thinnest peel, the most juice, the lowest TA, and the highest TSS/TA ratio for all three cultivars compared to all other origins, except for `Ruby Red' grapefruit from California, which had a lower TA and a higher TSS/TA ratio. Turkish `Ruby Red' and Spanish `Star Ruby' fruit weighed the least and had the least amount of juice compared to fruit from other origins. Turkish fruit had the highest TA and the lowest TSS/TA ratio for all three cultivars from all origins. Israeli `Marsh' white and `Star Ruby' had the highest TSS. Overall, the internal quality characteristics of Florida fruit was high compared to fruit from other origins.

370 GRAPEFRUIT QUALITY IMPORTED INTO THE NETHERLANDS

Size 56 grapefruit (Citrus paradisi Macf.) were sampled biweekly from importers Rotterdam, the Netherlands from October 1992 through September 1993. For each sample, fruit size, weight, diameter, peel thickness, internal color, juice volume, total soluble solids (TSS), and total acid (TA) were measured for three cultivars `Marsh White', `Ruby Red' and `Star Ruby' from 12 countries of origin. Florida fruit followed by Cuban fruit weighed more, had the thinnest peel, the most juice, the lowest TA, and the highest TSS/TA ratio for all three cultivars compared to most other origins. Spanish `Ruby Red' and `Star Ruby' fruit weighed the least and had the least amount of juice compared to other origins. Turkish fruit had the highest TA and the lowest TSS/TA ratio for all three cultivars. Israelian `Marsh White' and `Star Ruby' had the highest TSS.

Limited Resource Farmers and the Marketing System

tifying and finding solutions to the problems they face.' Much of this effort has focused on identifying enterprises that are profitable on a small scale; that is, enterprises which require little land and capital but provide a high return to the producer. These alternative crops include new and improved varieties of traditional cash crops and other nontraditional enterprises, such as fruits and vegetables, herbs and spices, ornamentals and specialty animals (French, Whatley). The success of fruit and vegetable producers in California, Florida, Texas, and Arizona has triggered discussions as to whether other areas in the United States, particularly the southern states, could compete with these major producing states (Capps, Babb and Long). Coupled with this push for diversification is the belief that LRFs may benefit from alternative enterprises because they suffer adversely from price fluctuations and low net returns from production of traditional crops. Colette and Wall allude to the high income potentials of vegetables but argue that these crops tend to be very risky enterprises and that LRFs usually have insufficient cash reserves to carry them over a bad year. Efforts have also been directed toward the marketing problems facing LRFs (Christy, Dagher, McLean-Meyinsse). While much attention has been given to alternative enterprises, a full understanding of the marketing system, including market risks, strategies, and alternative market outlets, requires more attention by producers, policy makers, and our profession. Most farmers allocate more time, energy, and resources to production than to marketing. Limited-resource farmers, in general, have not invested the resources required to identify and use viable marketing plans and strategies that can exploit the full potential gains these markets offer sellers of agricultural products. In some cases, LRFs have identified marketing niches and developed innovative marketing strategies (Wysong and Handwerker). The strategic behavior exhibited by small farmers has profit performance implications, such as (a) providing the consumer with high quality, usually fresh products, and (b) gaining the net margins that accrue from performing specific marketing services or functions.

Tropical Fruit in Florida

Abstract Significant changes are occurring in tropical fruit production in Florida. The greatest production occurs in the Dade County southwest of Miami, but there are plantings in warm areas of several other counties in the southern half of the Florida peninsula.

Consequences of Transportation Regulatory Reform on Agriculture and Rural Areas: Discussion

present an idea in a favorable context he identifies it in purr words. If derogation is intended, snarl words are employed, Gray said. For a title to this session a choice among purr words is available. could address regulatory reform or deregulation. The former was opted for. The term is the more accurate technically, but it has the further quality that it is so accommodating. is malleable, elastic, ambiguous. Unfortunately, though, it is often regarded as synonymous with its alternate, deregulation. Sorenson, in his paper, is careful to dissociate regulatory reform from deregulation. The issue discussed does not fall into a regulation-deregulation dichotomy, he insists. It is not a regulation versus deregulation debate but rather a search for that set of operating rules that most nearly fits collective concepts of equity, economic efficiency, and productivity growth. Yea, verily; but few commentators on transportation policy nowadays are so perceptive. Even the other papers in this set, those by Beilock, Freeman, and Fuller, and by Beilock and Casavant, are written as inquiries into alleged or real blessings of deregulation. The authors find the blessings to be real and considerable. To be sure, in the two papers protective caveats are thrown in at the end, but the authors extrapolate to a generalized endorsement of transport deregulation. My position regarding transportation policy has been favorable to regulatory reform on the terms I would specify but totally opposed to deregulation as a sweeping principle. I am particularly opposed to the revisionism in the Staggers Act as administered by an Interstate Commerce Commission that, in my judgment, displays ineptitude. The three papers are interesting and useful commentaries but it would be unscholarly to expand a couple of years' experiences in Kansas wheat and West Coast or Florida fruit, or even the several rural community trucking studies, into a generalized judgment on a naional transportation policy. I offer this caution on the basis of three reasons. First, the studies are essentially beforeand after-(' 'deregulation). Temporal comparisons always violate the ceteris paribus condition for research. This axiom particularly applies to transportation studies made before and after so-called deregulation. In rail, the Staggers Act came into being almost precisely at the time rail carriage shifted from shortage to surplus. Although rate bureaus contributed to pre-Staggers inflexibility of rail freight r tes, by and large it was easy to keep rates high when freight cars were scarce. In fact, it is likely that rates would have been even higher w re it not for the regulatory restraints. Then when cars became super-surplus, there would have been pressure to ease rates without Staggers Act. The situation in rail freight changed so dramatically after Staggers that it would be irresponsible to attribute all post-Staggers events to the Staggers law. Moreover, we may find irony in the high probability that the lower rates the last couple of years would have represented an even sharper reduction, had the decline begun from a nonregulated starting point. By and large, regulation tends to keep the overall level of rates below what it would otherwise be during shortage of carriage, and higher during Harold F. Breimyer is a professor in the Department of Agricultural Economics, University of Missouri.

Extension Response to a Serious Freeze in Florida1

Abstract The severe freeze of January 12–14, 1981 gave Florida Fruit Crops Extension faculty some serious challenges and unique opportunities in ensuing months. Record-breaking low temperatures throughout peninsular Florida severely damaged much of Florida’s citrus and growers were faced with many problems dealing with rehabilitation and care of frozen fruit and trees. Within 24 hours after the severity of the freeze was apparent, Extension faculty of the University of Florida's Department of Fruit Crops had formulated a massive state-wide effort of intensive Extension to help growers cope with their problems. This paper outlines the procedure used to formulate this educational program.

Recommendations for Degreening Florida Fresh Citrus Fruits

Early varieties of citrus fruit in Florida usually meet legal maturity standards before the peel attains the characteristic varietal color and therefore require degreening. Occasionally, later maturing varieties may similarly require degreening. The degreening process, which involves the use of ethylene gas in specially constructed degreening rooms, destroys the chlorophyll and allows the yellow or orange peel to predominate. This document is Cir 1170, Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: August 2003. 
 Cir 1170/HS195: Recommendations for Degreening Florida Fresh Citrus Fruits (ufl.edu)

Studies on the Climatically Favorable Place for Fruit Culture

This paper presents data on the degree of subcooling and critical air temperature for natural and artificial freezing of the fruit on the tree, in Citrus natsudaidai together with the effects of freezing on the weight and volume of fruits.The results obtained are summarized as follows;(1) The freezing points of the pulp, indicated by the maximum temperature after ice formation, ranged from -1.0°C to -2.7°C with the average of -1.7°C as shown in Table 1. The pulp was subcooled as much as 2.2°C before freezing occurred.(2) When freezing occurred naturally, the pulp temperature increased suddenly to its freezing point (-1.5°C-1.6°C) and remained within 0.1°C at this temperature till morning (Figure 1.) This increase in temperature on freezing and the maintenance of the higher temperature than air are explained by the release of heat of fusion.(3) In general, there was a tendency that the peel freezing occurred before the pulp freezing (Table 3.)(4) Figure 2 represents that the lower the minimum air temperature at night, the longer the frozen fruit required to thaw.(5) The injured fruits which had been exposed to -11°C before ten days of the second treatment were subcooled by no more than 1.2°C (Figure 3). while non-damaged fruits were subcooled as much as 2.2°C described before.(6) No freezing of the fruits occurred when the fruits were exposed to -4.9°C or higher temperature (Table 1). However, air temperature of -5°C or lower resulted in 100per cent freezing of the fruits. This showed that air temperature near -5°C was found to be critical for freezing of the fruit. From the comparison of this result with the report by HENDERSHOTT (1962), it may be said that the freezing of the fruit of Citrus natsudaidai in our country is harder than the orange fruits in Florida.(7) In early period of Fecruary, fruits on the tree were set and tested in a portable freezing chamber (see Fig. 4) in order to make clear the dependence of the degree of cold damage on the length of freezing.In Table 4 and Figure 5, it was recognized that the frozen fruits, harvested in late March, diminished in size and decreased considerably in specific weight, especially in treatment of longer freezing.(8) The climatological data at Hagi, Uwajima and Sumoto, the major districts of production of Citrus natsudaidai in our country were analysed. The minimum temperature of -4.5°C occurred every 20 years at Hagi. The minimum of -5°C occurred every 15 years at Uwajima and 15-20 years at Sumoto (Figure 6).(9) It would be desirable to culture Citrus natsudaidai at meteorologically favorable places where the occurrence of the minimum air temperature of -5°C or lower is every 15-20 years.

Tropical and subtropical fruits in florida (other than citrus)

Avocado and mango are the leading commercial fruits of South Florida. Lychee, guava, pineapple, bananas, papayas, and persimmon, are of minor economic value, while sapodilla, macadamia nut, Barbados cherry and the Mysore black raspberry show promise of commercial development. All of these fruits and many more are grown as dooryard plants. The fact that such a large number of tropical and subtropical fruits can be grown in South Florida has made the subject of tropical pomology a very important one for this area.

Investigation of the Vitamin C Content of Florida Fruits and Vegetables: I. Effects of Maturation and of Cold Storage on the Vitamin C Potency of Oranges and Grapefruit, Five Figures

Differences in vitamin C content both among samples of one variety and among different varieties of citrus fruit may be very large. Individual trees tend to produce fruit the vitamin C content of which varies only within narrow limits, but these small variations are sufficient to mask any changes occurring during maturation of the fruit. Changes in vitamin C content of oranges during maturation are not large. Variations in vitamin C content among oranges did not correlate with the different geographical locations in which they were grown. The vitamin C concentration of oranges and grapefruit may increase during the first few weeks of cold storage; after this, the concentration of vitamin C drops off slowly.