Fraser fir [Abies fraseri (Pursh) Poir.] Christmas trees up to 3.2 m in height were sampled from 18 well-managed plantations in western North Carolina to determine the yield of decoration greenery (wreaths, roping). Trees were not sidesheared in the year of harvest. The proportion of branch material suitable for decoration greenery decreased with increasing height and crown taper, but crown density had no effect. Mean annual yield of decoration greenery (establishment in the field, until reaching an average height of 3.2 m 10 years later) was 1.9 to 2.3 kg/tree per year, respectively, for trees with medium or heavy crown density.
sativa L. ‘Early Impulse’, ‘King Crown’, and ‘Cos Lettuce’) were produced in the commercial CSAL for 35 d at a planting density of 133 plants/m 2 for the first 25 d and 33 plants/m 2 for the next 10 d. Photosynthetic photon flux ( PPF ) on the
. sclerotiorum ( Bolton et al., 2006 ; Grau and Radke, 1984 ). Although white mold causes significant levels of stem rot, crown rot, wilt, and death of many common herbaceous ornamental plants ( Bolton et al., 2006 ), relatively little research has been done on
related to differences in particle film coverage between leaf surfaces would be of practical consideration in informing the method of product application. The current study is comprised of a ‘Ginger Gold’ apple field trial and a ‘Triple Crown’ ( Rubus L
Although the effect of cold winters on the severity of bermudagrass (Cynodon dactylon Pers.) spring dead spot (SDS) has been studied, information is needed concerning the effect of infection by fungi associated with SDS on the host's freezing resistance. A-22 bermudagrass was inoculated with Leptosphaeria korrae J. Walker & A.M. Smith and Ophiospharella herpotricha (Fr.) J. Walker & A.M Smith. Differential thermal analysis was used to monitor exotherm temperatures of healthy and O. herpotricha- and L. korrae-infected A-22 bermudagrass at 10-day intervals during 90 days of acclimation in cold chambers. Healthy bermudagrass crowns supercooled to an average of -6.7C and fungi-infected crowns supercooled to an average of -4.8 and -4.4C, respectively. Healthy crown exotherm temperatures were significantly lower than those of fungi-infected bermudagrass crowns on all nine sampling dates. This result indicates that fungi-infected plants are more susceptible to cold damage.
Electrolyte leakage and regrowth were measured from September through January to determine cold hardiness of Sedum spectabile × telephium L. `Autumn Joy' and Sedum spectabile Boreau. `Brilliant' plants grown outdoors in central Iowa. Crowns were subjected to 0, –3, –6, –9, –12, –15, –18, –21, –24, or –27C. Regrowth tests were performed on whole crowns and electrolyte leakage was determined on excised tuberous root and crown tissue. Both cultivars were killed at –3C in September, but they acclimated gradually through January. Maximum hardiness was achieved in January, with killing temperatures of –27C for `Autumn Joy' and –21C for `Brilliant'. Regrowth quality ratings were significantly correlated with crown and tuberous root electrolyte leakage measurements, although the relationship was stronger for `Autumn Joy'.
Fraser fir [Abies fraseri (Pursh) Poir.] Christmas trees were sheared once annually over a 4-year period using fixed schedules ranging from July to March. Shearng in July reduced potential growth of the upper crown by 38%; when done in October or March, the reduction was about 50%. Length, dry weight, and one-sided area of individual needles were smallest on nonsheared trees, and increased to maximum values on trees sheared in March. In the upper crown (top three internodes), trees sheared in July were 16% to 33% heavier than those sheared in August or later. Dry matter in the upper crown was 30% foliage and 70% woody material. Sixty-one percent of the biomass in the upper crown was branches for trees sheared in July, compared to 55% for October. In the upper crown, foliage comprised about 50% of the branch dry weight (all treatments); in 3-year-old branches, it was 54% to 58%. Among treatments, shearing in July caused the smallest reduction of potential growth and yielded the largest and heaviest branches with significantly more foliage and lateral shoots, all of which would be expected to improve crown density and commercial value. October was the least favorable time to shear.
., 1992 ). Mother plants affected by anthracnose may collapse entirely due to crown rot. Root necrosis incited by C. acutatum may also stunt plants ( Freeman and Katan, 1997 ). Infected transplants can spread the disease from the nursery to the field
, and the United States ( Hawley, 1971 ). Z. sinica is one of the most popular landscape plants in China because of its adaptability to varied environmental conditions, strong disease resistance, outstanding crown, and beautiful fall color ( Jin and He
inflorescence is formed at the shoot apical meristem, the AXB can break dormancy. The AXM can then develop into either a branch crown (new compressed shoot section with similar behavior as primary crown, possessing the ability of producing flowers and stolons