Three indicator species [rye (Secale cereale L.), radish (Raphanus sativus L.), and alfalfa (Medicago sativa L.)] and nonrooted cuttings of `Stevens' cranberry (Vaccinium macrocarpon Ait.) vines were grown in pots to establish the dose response levels for a sand-applied phytotoxin(s) from a crude extract of Pseudomonas syringae (strain 3366) culture. At 114 ppm [milligrams phytotoxin(s)/kilograms sand], the material was noninhibitory, whereas 1140 ppm reduced root and shoot growth significantly in all four species. In subsequent experiments, a 10-ppm dose controlled corn spurry (Spergula arvensis L.) and fireweed (Epilobium angustifolium L.) seedlings, while 103 ppm reduced root or shoot growth of cuttings of the perennial weeds birdsfoot trefoil (Lotus corniculatus L.) and silverleaf (Potentilla pacifica Howell). Root and shoot growth of partially rooted `McFarlin' cranberry vines was reduced at 103 and 563 ppm, respectively. The phytotoxin(s) could potentially control germinating annual weeds in newly established `Stevens' cranberry bogs.
Michael A. Norman, Kim D. Patten, and Sarangamat Gurusiddaiah
Kim Patten, John Wang, Fred Katz, Don Riemer, Chuck Kusek, and Herb Hopen
Tolerance of cranberry (Vaccinium macrocarpon Ait.) at different phenological stages to the postemergent broadleaf herbicide clopyralid (0.21 or 0.42 kg a.i./ha) was evaluated in Washington, New Jersey, Massachusetts, and Wisconsin. Tolerance varied among states, rates, and application times. Applications made during early shoot growth, especially at the high rate, usually resulted in the most crop injury (leaf cupping and epinasty and reduced yield); while applications at the low rate made after vegetative development occurred usually resulted in less or no injury. No phytotoxicity occurred when applications were made before shoot growth (Washington and New Jersey). Chemical name used: 3,6-dichloro-2-pyridinecarboxylic acid (clopyralid).
Kim Patten, Elizabeth Neuendorff, Gary Nimr, John R. Clark, and Gina Fernandez
The relative tolerance of flower buds and flowers of southern highbush blueberry (Vaccinium spp.) to cold damage was compared to rabbiteye (Vaccinium ashei Reade) and highbush blueberry (Vaccinium corymbosum L.). For similar stages of floral bud development, southern highbush and highbush cultivars had less winter freeze and spring frost damage than rabbiteye cultivars. Cold damage increased linearly with stage of flower bud development. Small fruit were more sensitive to frost damage than open flowers. Rabbiteye blueberry flower buds formed during the fall growth flush were more hardy than buds formed during the spring growth flush, regardless of cultivar or stage of development.
Edward L. Proebsting, David Ophardt, William E. Howell, Gaylord I. Mink, and Kim D. Patten
Thirty-five `Bing' sweet cherry (Prunus avium L.) clones were collected, primarily from old commercial orchards in central Washington; propagated on P. mahaleb L. rootstock; and their horticultural performance was evaluated. Nine of the 35 clones were not infected with the common pollen-borne ilarviruses prunus necrotic ringspot virus and prune dwarf virus—four of the clones after decades of exposure in commercial orchards. As a group, the nine virus-free clones produced larger trees with earlier fruit maturity and less rain cracking, but softer fruit, than did the 26 infected clones. These data challenge the general assumption that the presence of one or both of these ilarviruses is always detrimental. This assumption has driven development of many valuable virus certification programs and the adoption of virus-free trees as the standard for commercial fruit growing in most states.
Eric Hanson, Carolyn DeMoranville, Benjamin Little, David McArthur, Jacques Painchaud, Kim Patten, Teryl Roper, Nicholi Vorsa, and David Yarborough
Since up to 2.4 m (8 ft) of water may be applied annually to cranberry beds for various production purposes, water quality can alter soil chemical properties and potentially affect plant health. Many cranberry plantings have recently been developed in nontraditional production regions and on atypical sites, wherechemical properties of the available water may differ from those in cranberry sites in the traditional production regions. Water currently being used for cranberry production was sampled from farms in most major production regions to characterize its chemical characteristics. High alkalinity in many samples was a concern, since alkalinity can increase soil pH above the desired level for cranberries. Total soluble salt concentrations and sodium adsorption ratios were seldom high enough to be of concern. Water samples from long-established plantings were lower in alkalinity, pH, and soluble salt concentrations than samples from newer plantings without production histories.
Carolyn J. DeMoranville, Joan R. Davenport, Kim Patten, Teryl R. Roper, Bernadine C. Strik, Nicholi Vorsa, and Arthur P. Poole
Fruit mass development in `Crowley', `Pilgrim', and `Stevens' cranberry (Vaccinium macrocarpon Ait.) was compared in five states for two seasons. Comparing all locations, `Stevens' and `Pilgrim' cranberries had similar growth curves with a faster growth rate than that of `Crowley'. Regional differences in fruit development were observed. Shorter growing seasons, especially in Wisconsin, were compensated for by more rapid growth rates. Conversely, low initial mass and slower growth rates were compensated for by the longer growing season in the Pacific Northwest. Solar radiation intensity accounted for little of the variability in fruit growth. Neither growing degree days nor numbers of days were good predictors of cranberry fruit fresh mass accumulation. Instead, numbers of moderate temperature days (between 16 and 30 °C) appeared to be key, accounting for greater than 80% of the variability in cranberry fresh biomass accumulation. The most rapid growth rates occurred when temperatures were in this range. High temperatures were limiting in New Jersey while low temperatures were limiting in Oregon and Washington. In one of two seasons, low temperatures were limiting in Wisconsin: accumulation of 0.5 g fresh mass took 11 d longer. Massachusetts had the fewest periods of temperature extremes in both seasons, resulting in the shortest number of days required to accumulate 0.5 g fresh mass.
John R. Clark, David Creech, Max E. Austin, M.E. “Butch” Ferree, Paul Lyrene, Mike Mainland, Don Makus, Liz Neuendorff, Kim Patten, and James M. Spiers
Highbush (Vaccinium corymbosum L.), rabbiteye (V. ashei Reade), and southern highbush (Vaccinium spp.) blueberries grown at seven locations in six southern states were sampled in 1988 and 1989 to determine foliar elemental levels among blueberry cultivars and types. Across locations, elemental levels of N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, and Al were similar for highbush and southern highbush types. Rabbiteye elemental levels were different from highbush and southern highbush for N, P, K, Ca, S, Mn, Cu, and Al. Rabbiteye blueberries appear to have different foliar levels, and may require species-specific standards for nutritional monitoring of plantings.