1930s, anthracnose crown rot caused by C. fragariae and C. gloeosporioides has been a destructive disease in strawberry nurseries and fruit-production fields in the southeastern United States ( Brooks, 1931 ). In 1986, the presence of the
field on 1 Sept. These unexpected results were attributed to a high plant density (320 transplants/m 2 ) that provided a continuous and heavy leaf cover, which eliminated red light (less than 700 nm) from reaching the crowns ( Takeda, 2008 ). In contrast
Marsteller Street, West Lafayette, IN 47907-2033. We thank the following: S. Bassein for statistical advice; G. McGranahan for initiating and coordinating the Paradox Diversity Study; M. Schroth and B. Teviotdale for advice on crown gall; M
the crown. Heißner et al. (2006) examined the effect of soil temperature on white asparagus yield, and high temperature treatments surrounding the crowns have been shown to control white asparagus sprouting ( Paroussi et al., 2002 ; Watanabe et al
More than 10 species of Phytophthora de Bary are reported to affect cultivated Prunus L. worldwide, causing root rot, crown rot, trunk and scaffold cankers, and even fruit rots ( Browne and Doster, 2002 ; Browne and Mircetich, 1995 ; Félix
The carrot rust fly (Psila rosae) lays eggs in the crowns of carrots, celery, and parsnips. Its larvae are dark brown maggots which burrow into the crown and roots of the plants making them unsalable. This is a pest of economic significance in coastal plantings. This project evaluated several non-chemical strategies available to organic farmers over three growing seasons. These included the use of traps to monitor populations and determine fields where infcstations are likely to occur, parasitic nematodes, the use of trap crops, and row covers as an exclusion technique. Floating row covers were the only successful treatment in reducing maggot damage in these fresh market carrots.
sieve. Plants were then divided into roots, crowns, leaves (including petioles), and fruiting structures (flowers and fruit). The number of crowns was counted, and dry weight of leaves, roots, crowns, and fruiting structures was measured. Feeder root
Crowns of ostrich fern (Matteuccia struthiopteris L. Todaro) were field-planted in June 1993 on a Hadley silt loam in South Deerfield, Mass. Shade cloth was used to alter light intensity to determine if light intensity effects growth and development of fronds and crowns. Light levels were 22% (low), 45% (intermediate), 72% (high), and 100% (full) of ambient conditions. Survival of crowns decreased with increasing light intensity with only 22% survival under full light. Low, intermediate, and high light levels resulted in 89%, 75%, and 56%, respectively, of crowns producing shoots. Light intensity did not effect the number or length of fronds produced. Frond length reached a maximum after 2 months growth. Development of secondary crowns was enhanced at intermediate and high light intensities. Final crown weight was significantly correlated with initial crown weight regardless of light intensity. Crowns will be vernalized and forced hydroponically to determine effects of light intensity and crown size on growth of croziers.
the destructive oomycete Phytophthora cactorum (Lebert & Cohn) J. Schröt., which causes crown rot. P. cactorum causes disease in more than 200 plant species, including 150 genera representing 60 plant families, several of them within the rose
Persian (english) walnut ( Juglans regia L.) orchards can incur serious economic loss from attack by several soilborne pathogens, including Agrobacterium tumefaciens Smith and Townsend (causal agent of crown gall disease), Armillaria mellea