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- Author or Editor: A.A Powell x
A journal of the type proposed as HortTechnology is long overdue. Extension and other applied horticulturists thought Hortscience, when introduced several years ago, would become their primary repository for reporting professional accomplishments, etc. However, this 2nd Journal quickly became the house organ for short term research. The format for HortTechnology looks good if implemented as proposed. An overview committee consisting of a majority of Extension Horticulturists should be established to monitor progress and development of this publication (in addition to present development committee). Extension specialists and others involved in applied horticulture must avail themselves of the opportunity to publish in one or more of the peer reviewed as well as other sections of the publication. To make this journal a success Extension workers must support this effort through submitting papers on a regular basis. This referred journal could and probably will become the most popular and widely used of ASHS publications.
A very successful project at N. C. State University began in 1983, with the first N. C. Landscape and Turfgrass Field Day. The Field Day is co-sponsored with the N. C. Landscape Contractors Association and the Turfgrass Council of North Carolina. The Field Day is an excellent opportunity for industry to visit with faculty and observe research projects and extension demonstrations. Over the years the attendance has grown to over 1200 paid attendees. The Field Day is actually divided into four separate functions: 1) Educational Field Day, 2) Product and Equipment Field Day, 3) Turf Workshops, and 4) Construction Workshops. The Extension and Research projects benefit financially from this endeavor. Any projects from the Field Day are given back to the University. This typically is about $4000.00. The Field Day is held the third Wednesday in May, rain or shine.
Self-pollination, emasculation and gibberellic acid (GA) were used to study translocation patterns of l4C-metabolites during flowering and fruiting in calamondin (Citrus madurensis Lour.). Radioautographs showed similar translocation patterns with self-pollination and GA. GA and self-pollination resulted in a considerably stronger mobilization of 14C-metabolites to young ovaries and developing fruits than when flowers were emasculated and no further stimulus provided. The movement of l4C-metabolites to fruits, especially in the 3-week period after anthesis, appeared essential for fruit set and development.
As with other crops, the establishment of a stand in the field is the essential first step in the growing of vegetables. There are, however, several production and economic factors that make field performance of vegetable seeds particularly crucial. The worst possibility, emergence failure that necessitates resowing, could mean a delay in harvest that leads to a drastic fall in market price. Uneven emergence reduces overall yield in wide-spaced crops such as lettuce (5, 13) and leads to variability in harvest date and size (5, 13), both of which are critical in satisfying the demands of the market in terms of availability and grading quality. Lack of uniformity in the rate of emergence can also adversely affect the ability to harvest at one time and still achieve uniform standards of size and quality.
Sixty-eight percent of the `Pineapple', 52% of the `Navel', 46% of the `Valencia', 38% of the `Hamlin', and 0% of the `Ambersweet' orange [Citrus sinensis (L.) Osh.] trees in five Florida citrus nurseries were infected with severe strains of citrus tristeza virus (CTV), as demonstrated by reaction with a monoclinal antibody specific for severe strains of the virus. Severe strains of CTV infected 4%, 46%, 76%, 30%, and 48% of the trees at each of the five nurseries, respectively, indicating a considerable difference in severe strain prevalence among the nurseries. Thirty-five percent of the trees in the scion blocks (budwood source) of the nurseries also contained severe strains of CTV.
Lack of winter chilling (480 hrs. at or below 7.2°C by 02/28/89) occurred along Alabama's Gulf Coast in the winter of 1988-89. Varieties requiring 650 hours of chilling or more were under stress. To evaluate hydrogen cyanamide (HC), a product used world wide to replace part of some fruit plants chilling req., a study was conducted along the Gulf Coast using Bicentennial (700 hr.), Sentinel (850 hr.) and Loring (900 hr.) peach varieties. Full tree sprays (applied to drip with handgun) using 0, .5 and 1% a.i. plus .25% × 77 were applied 03/01/89. Fruit buds were dormant to slight swell when sprayed. HC greatly enhanced rate and % of leaf bud break at the 1% conc., for all varieties. Rate and % of flowering were significantly increased at 1% conc. in Loring and Sentinel but nearly all fruit dropped. Flowering, yield and fruit size of Bicentennial-were significantly improved at .5 and 1% conc. HC was effective in replacing lack of chilling in this variety.
The distribution pattern of citrus tristeza virus (CTV) T-36 isolate in leaves of infected mexican lime [Citrus aurantifolia (Christm.) Swingle] plants was visualized using a whole-leaf-blot immunoassay (WLBIA) procedure in combination with a computer scanning imaging technique and CTV-specific monoclonal antibody 17G11 (CTV MAb 17G11). The distribution pattern of CTV T-36 in leaves varied with the age of the leaves and shoots of infected plants. In the young leaves, especially the about 5-day-old leaves and the completed expanded leaves, CTV T-36 was easily detected in most of the leaf veins, the main veins and the large and small primary veins. In the old leaves, CTV T-36 only was detected in the main veins, sometimes in a few of the large primary veins with weak signals, and seldom in the small primary veins. The distribution density and immunoassay reaction signals of CTV T-36 reacted to CTV MAb 17G11 in leaves from new shoots were much higher than that in leaves from old shoots. ELISA test results using leaves with different ages from different shoots of the same mexican lime plants infected with CTV T-36 supported the visualized-test results obtained by the WLBIA in combination with computer scanning imaging technique. This is the first reported visual analysis of the distribution pattern of CTV in leaves of infected citrus plants. The results indicate that the WLBIA in combination with computer scanning imaging technique is a useful tool for studying the distribution of plant viruses in leaves of virus-infected plants.
One hundred single brown citrus aphid (BCA) (Toxoptera citricida Kirkaldy) transmission attempts were made from each of 16 different citrus trees [8 grapefruit (Citrus paradisi Macf.) and 8 sweet orange (C. sinensis (L.) Osbeck)] previously inoculated with decline-inducing (T36-CTV), non-decline-inducing (T30-CTV), a mixture of the two Citrus tristeza virus isolate types, or no CTV. Successful CTV transmission occurred in 1.5% of attempts from grapefruit trees that had been bark-chip-inoculated with T36-CTV, 3% of attempts from orange trees inoculated with T36-CTV, 3% of attempts from grapefruit trees inoculated with both T36- and T30-CTV, 4% of attempts from orange trees inoculated with both T36- and T30-CTV, 1.5% of attempts from grapefruit trees inoculated with T30-CTV, and 3.5% of attempts from orange trees inoculated with T30-CTV. Single BCA were able to recover T30-like-CTV from trees believed to be inoculated only with T36-CTV, and T36-like-CTV from trees believed to be inoculated only with T30-CTV, suggesting that these inoculum sources were also mixtures of T36-CTV and T30-CTV. The T36-CTV was not immunologically detectable in some of the trees from which it was transmitted indicating that single BrCA can recover T36-CTV from a T36-CTV/T30-CTV mixture in which the T36-CTV is an undetectable, minority component.
It has been shown that the `Hayward' kiwifruit requires ≈1000 chilling hours for satisfactory production of female flowers, leading to full cropping in the southeastern United States. Part of the area along the Gulf Coast frequently suffers from inadequate winter chilling, resulting in poor cropping of `Hayward'. Studies were conducted over a 4-year period in a mature `Hayward' planting near the Gulf Coast to evaluate the efficacy of hydrogen cyanamide sprays in replacing lack of chilling and improving cropping. Rates of 2%, 3%, and 4% (v/v) of 50% Dormex significantly increased yield, with the highest rate providing the maximum yield. Fruit size and overall fruit quality from Dormex treatments were good. Dormex sprays performed quite well when only 600 to 700 chilling hours were received in the test area.