You are looking at 1 - 10 of 16 items for
- Author or Editor: J. L. Perry x
In 1987, the NC 140 Regional Rootstock Testing Committee established sweet and sour cherry rootstock trials in 16 locations in North America. This paper will present preliminary results on the performance of Hedelfingen (sweet) and Montmoreney (sour) cherry cultivars at the New York and Michigan sites. The rootstock under test include 3 clones from Gembloux, Belgium, Colt, 4 MxM hybrids, and 9 to 13 interspecific hybrid clones from Giessen, West Germany. Clonal rootstock also under test for Montmorency include St. Lucie 64, 275 and, in New York, Holly Jolivette. Rootstock treatments differ slightly among sites and are replicated 7-8 times in a randomized complete block design. The Giessen rootstock 148/1 and 195/1 have, to date, demonstrated excellent influence on sweet cherry precocity. Sweet and sour cherry on Colt and the MxM hybrids have been most vigorous at both sites. Montmorency is most precocious on Mahaleb seedling followed by Giessen 148/1 at both locations. Data for 1990 on rootstock performance will be included in the oral presentation.
Blackberry pollen germination in vitro decreased linearly with increased duration of storage at 22°C. Time required to reach 50% nonviability varied among cultivars from 2.5 to 10 days. Storage at 6° more than doubled the time required to reach 50% non viability. A 20% sucrose-agar medium was satisfactory for germination assay of pollen from tetraploid blackberries but gave poor results on a diploid clone.
No differences in percentage fruit set resulted from self or cross pollination in 8 tetraploid cultivars of erect blackberry (Rubus subgenus Eubatus), but 2 selections with diploid ancestry showed decreased fruit set from self-pollination. In some cultivars, self-pollination resulted in reduced fruit size and generally resulted in decreased seed number per fruit. Fluorescence microscopy showed no differences in rate or extent of pollen tube growth from self or cross pollen within blackberry styles. Caging experiments indicated that blackberries are not dependent on insects for pollination, but wind dispersal of pollen is important in securing uniform fruit set.
Seeds of Asparagus densiflorus (Kunth) Jessop ‘Sprengen’, Brassaia actinophylla Endl., and Musa balbisiana Colla., were exposed to 5 durations of ultrasonics at a frequency of 60 Hz. Some seeds were then given a 12 hour water soak before sowing. No differences were noted in germination rates for all species. The only significantly improved germination percentage occurred with seeds of Musa balbisiana given a 30 second exposure and no water soak. Seeds of Asparagus densiflorus ‘Sprengeri’, Brassaia actinophylla, Cordyline australis (G. Forst.) Hook, f., and Philodendron lundii Warm., were given 15 minute soaks in 3 concentrations of 3 fungicides before sowing but no significant differences in final germination percentage or germination rate were observed among treatments.
Effects of 5 soilless media and 2 sowing depths, 4 pH levels and 3 medium temperatures on tropical foliage plant seed germination were analyzed using germination rate and final percentage germination. Cordyline australis had highest germination percentages in highly organic media, Philodendron selloum germinated well in all media at a depth of twice the seed diameter, Asparagus densiflorus ‘Sprengeri’ and Brassaia actinophylla germinated equally well in all media and at depths of 2 and 4 times the seed diameter. Most deeper sown seeds took longer to emerge. Best germination occurred in Brassaia actinophylla, C. australis and Philodendron lundii without bottom heat (27°C), and in Nephthytis ‘Emerald Gem’ with bottom heat (30°-33°). Species germinated well between pH 3.7 and pH 6.2 except for Musa balbisiana at pH 3.7.
Three diploid taxons (Vaccinium darrowi Camp, V. elliottii Chapm., and interspecific V. darrowi x V. elliottii) were treated with various colchicine concentrations and treatment durations to determine the best method for inducing autopolyploidy in in vitro blueberry cultures. Shoot-tip cuttings were the best in vitro planting material for induction of shoots with increased diameter, an indicator of polyploidy. Tetraploids were produced at colchicine concentrations from 0% to 0.20%. The best treatment combinations were genotype-dependent.
The influence of two rootstocks on leaf nutrient concentrations of ‘Montmorency’ sour cherry (Prunus cerasus L.) was studied at two locations for 4 years. Trees on Mazzard (Prunus avium L.) rootstocks were generally higher in leaf K, Ca, B, N, and Mn concentrations, but lower in leaf Mg than trees on Mahaleb (Prunus mahaleb L.) rootstocks. Differences due to rootstocks did not appear to be related to crop load or tree vigor.
The root distribution of peach trees [Prunus persica (L.) Batsch cv. Redhaven/Halford] as affected by six orchard floor management treatments was evaluated after 3 years of growth. Two treatments were maintained vegetation-free and four had vegetative covers in the alleyway with a 1.2-m-wide herbicide strip in the tree row. The profile wall method was used to determine root distribution. Trees maintained vegetation-free with herbicide had the most roots. Trees in the vegetation-free plots, maintained with herbicide or cultivation, produced more roots 1.2 m from the tree than trees in the vegetative covers. The number of roots, 1.2 m from the tree, was lowest in the tall fescue treatment. The number of roots were higher in the Kentucky bluegrass (Poa pratensis L.) or alfalfa (Medicago sativa L.) than with tall fescue (Festuca arundinacea, Schreb.).
In organic apple production systems, orchard floor management is of prime importance because it determines weed management and soil fertility. In this experiment, we evaluated the response of the cultivar Pacific Gala on three rootstocks of different vigor: M.9 NAKB 337, M.9 RN 29, and Supporter 4 (in respective order of vigor from dwarfing to semivigorous). The rootstocks were also evaluated for the response to three orchard floor management systems (OFMSs): mulching using alfalfa hay, flame burning, and shallow strip tillage using the Swiss sandwich system (SSS). The experiment was conducted in an experimental orchard planted in 2000.
Understanding the effect of catastrophic disturbances on natural communities is necessary and vital to planning and executing development and to reclamation and restoration projects. Two nearby sites one catastrophically disturbed by flooding and one undisturbed area were compared. Field vegetation analysis three years after the flood in the disturbed area showed changes in the community structure along the stream, no overstory and a majority of obligate emergent wetland vegetation. In the undisturbed site, community structure along the stream is uniform; the overstory is well-developed, and herbaceous plants are predominantly facultative wetland but with few emergents. The field water quality analysis of temperature, pH, dissolved oxygen and specific conductivity are compared in the areas. GIS (Geographic Information System) analysis used the USGS 1:24,000 maps of the area and SCS county soil survey maps to analyze erosion risk, soil types, topography and vegetation potential in the 200 km2 Miller Springs Natural Area and the immediately surrounding 5 10 km2 watershed.