Search Results
Abstract
Foliar sprays of undecanol increased branching in some cultivars of Euphorbia pulcherrima Willd. compared to unpinched controls, but did not increase branching compared to manually pinched plants. However, phytotoxicity at concentrations necessary to achieve these results made the plants marketably unacceptable.
Abstract
Kalanchoe × sp. cvs. Mace, Thor, and Telstar were subjected to 2, 3, 4, or 5 weeks of long nights (LN) at 10, 16, or 21°C. The cultivars varied in the number of LN for 100% flowering, and this was influenced by temperature. No temperature was more inductive than 16°C; yet, ‘Thor’ required twice as many LN as ‘Mace’. After 2 weeks of LN the relative growth-rate patterns among ‘Mace’ plants under non-inductive conditions continued, but the patterns of ‘Thor’ and ‘Telstar’ changed. Flowering after 2 weeks of LN averaged 91.7% for ‘Mace’, nil for ‘Thor’, and 25.3% for ‘Telstar’.
Abstract
‘Liberty’ is a new red-fruited grape cultivar with resistance to Pierce’s disease, an essential character for successful grape production in Florida. The name ‘Liberty’ commemorates our nation’s bicentennial.
Abstract
‘Blanc Du Bois’ grape was released by the Univ. of Florida as a hybrid bunch grape for use in making premium white wine. It is early ripening, resistant to Pierce's disease (PD), and grows and fruits well on its own roots (Fig. 1). The name is in honor of Emile DuBois, an accomplished grape grower and winemaker in the Tallahassee, Fla. area, who emigrated from France in 1882. DuBois spearheaded viticultural and enological efforts in Florida for 20 years.
Abstract
The use of genetic material from other countries to improve domestic cultivars through breeding and selection has contributed to the progress made in the development of the fruit and nut industry in different areas of the world. Future progress by using foreign selections, desirable mutants, or wild species will surely have an important economic, aesthetic, and even social impact. As the enthusiasm for such a promising future develops into more interest in international exchange of plant germplasm, it is important to emphasize the possibility that foreign pests can be introduced into the domestic agriculture along with the desired genetic material (52). In fact, a foreign pest may minimize or completely eliminate the benefits of the contaminated imported germplasm as well as damage nearby susceptible cultivars laboriously created by plant breeding programs. Such pests may cause negative economic, aesthetic, and social consequences. Therefore, the effort to import desirable foreign germplasm must be complemented by a concentrated effort to exclude hazardous pests from the imported plant material.
The behavior of turfgrass grown on paper-sludge-amended soils was evaluated over 2 years. Two experiments were performed, one with deinked sludge and another with primary sludge. Four paper sludge, sand, and organic soil substrate mixtures with proportions ranging from 0% to 50% paper sludge were incorporated into existing soils. Two fertilization levels were applied in strip plots across sludge treatments and three turfgrasses of seeded Kentucky bluegrass (Poa pratensis L. `Georgetown'), Kentucky bluegrass sod, and an 80 Kentucky bluegrass: 20 perennial ryegrass (Lolium perenne L. `Prelude') seed mix were arranged within split plots. Effects of deinked and primary sludge experiments were similar. Supplemental N and, to a lesser degree, P and K fertilization with N at ≈4.5 to 5.5 t·ha–1, P at 1.18 to 1.26 t·ha–1, and K at 1.34 to 1.46 t·ha–1 improved ground cover, turf color, and stand quality. Despite differences in visual evaluations, leaf mineral nutrition was only slightly affected by fertilization treatments. Soil in nonfertilized plots was several times lower in N-NO3 when compared to fertilized plots, regardless of sludge rate. Soil in fertilized plots had higher concentrations of inorganic N regardless of sludge amendment. The soil C: N ratio was ≈13:1 in nonamended plots and more than 15:1 under the highest sludge rate. Deinked and primary paper sludges can be used effectively as soil amendments if turfgrass receives adequate supplemental N, P, and K.
Skin russet in apple fruit, which causes a considerable decrease in marketing and exporting potentials, is one of the major problems in the word fruit markets. In this project, the effect of GA4+7, GA3, and dimethoate on russeting of `Golden Delicious' apple was examined. A complete randomized-block design with 13 treatments and four replications was used. In all treatments, the trees had the same size and medium growth and were homogeneous. The distances between trees were 6 x 6 m and the age was 18 years. The total number of trees, including controls, was 52. The 12 treatments were GA4+7 and GA3 with 10 ppm and 20 ppm concentrations in one and two times of spray in petal fall (PF) and PF + 10 days. Dimethoate at a concentration of 0.03% and 0.05% in one and two times of spray in PF and PF + 10 days. Fruit russeting was reduced in all treatments except with GA3. The largest decrease of russeting was caused by GA4+7, especially with 20 ppm and also dimethoate with a significant decrease in russeting. Seed number also decreased significantly with GA4+7 and GA3, but dimethoate had no significant effect on TSS, while ACD ratio was decreased significantly by GA4+7 and dimethoate, but GA3 had no significant effect. Compared with the control, the treatment did not show differences with the other characteristics.
Thirteen sweetpotato (Ipomoea batatas) genotypes were characterized for resistance to Meloidogyne incognita, M. javanica, M. hapla, and M. arenaria races 1 and 2 in greenhouse tests. The following sweetpotato genotypes representing a range of reactions to M. incognita were evaluated: U.S. Plant Introduction (PI) 399163 (highly resistant = HR), Sumor (HR), Nemagold (HR), Excel (HR), Tinian (HR), Hernandez (resistant = R), Jewel (R), Regal (R), Porto Rico (intermediate = I), Centennial (susceptible = S), Georgia Jet (S), Sulfur (S), and Beauregard (S). Meloidogyne incognita was most pathogenic to sweetpotato of the four Meloidogyne spp. evaluated in these studies. The U.S. Plant Introduction (PI) 399163 and Sumor were resistant to M. incognita in all tests. Only two genotypes, Beauregard and Porto Rico, were susceptible to M. javanica. All genotypes evaluated were resistant to M. hapla, M. arenaria race 1, and M. arenaria race 2. Sumor, U.S. PI 399163, and Nemagold appear to provide the highest levels of resistance against the four Meloidogyne spp. used in these studies. Since M. incognita is the most commonly occurring root-knot nematode species in sweetpotato growing areas of the southern U.S. and is pathogenic to most of the commonly grown sweetpotato cultivars, efforts to develop resistant cultivars that have desirable horticultural characteristics for the U.S. market should be directed toward this root-knot nematode species.