@article{phipps_beute_1979, title={Population dynamics of Cylindrocladium crotalariae microsclerotia in naturally-infested soil}, volume={69}, DOI={10.1094/Phyto-69-240}, abstractNote={PHIPPS, P. M., and M. K. BEUTE. 1979. Population dynamics of Cylindrocladium crotalariae microsclerotia in naturally-infested soil. Phytopathology 69:240-243. Microplots of soil in 70-cm diameter fiberglass cylinders were used April. Florigiant, a susceptible peanut cultivar, developed severe symptoms during a 2-yr period to study the dynamics of populations of of Cylindrocladium black rot (CBR) in the second growing season. Cylindrocladium crotalariae microsclerotia (MS) in a naturally-infested Soybean and the CBR-resistant peanut cultivars, Argentine and NC3033, field. The effect of fallow, four rotational crops (corn, cotton, tobacco, and showed few or no symptoms. Populations of MS at harvest were 9.6, 5.2, soybean), and three peanut cultivars on MS densities in soil was studied and 1.6 times preplant densities in soils planted to the peanut cultivars, over two growing seasons. All three peanut cultivars and soybean were Florigiant, Argentine and NC3033, respectively. MS densities increased 3.7 susceptible to infection by C. crotalariae, but corn, cotton, and tobacco times in soils planted to soybean. As in the previous growing season, MS were immune. Low rainfall in the first growing season limited disease densities at harvest were slightly less than preplant densities in fallow soil development, and MS populations did not change significantly in soil and soil planted to nonhost crops. After harvest and incorporation of crop planted to host crops. Slight but significant (P = 0.05) reductions in MS residues in soil, MS densities declined sharply between January and April, densities were detected in fallow soil and soil planted to nonhost crops. when soil water in the plow layer froze during several weeks of subnormal After harvest and incorporation of crop residues in soil,MS densities did temperatures. Field and laboratory tests supported the conclusion that low not change significantly (P = 0.05), according to soil assays in January and soil temperatures (<5 C) caused this sharp decline in MS populations. Additional key words: Arachis hypogaea L., Calonectria crotalariae. Cylindrocladium crotalariae (Loos) Bell and Sobers (1) causes a leaving 25 cm above ground as a splash barrier. Microplots were peg, pod, and root necrosis in peanuts (Arachis hypogaea L.) that is installed without disrupting the soil profile by making a 0.5-1 cm commonly referred to as Cylindrocladium black rot (CBR). Since wide cut in soil with a circular cutter driven by a posthole digger on the first report of CBR in North Carolina and Virginia (2), the a tractor. disease has spread at an alarming rate in both states (11,17). C. Soil sampling and assay. Vertical core samples (2 X 15 cm) were crotalariae also causes disease in soybeans in North Carolina and collected from each microplot with a soil sampling tube. Soil from Virginia (5,16). Greenhouse tests have indicated that tobacco and each microplot was placed in polyethylene bags, closed with wire cotton are susceptible to root infection by C. crotalariae and that tags to prevent moisture loss, and stored at room temperature corn, wheat, and rye are resistant (15). C. crotalariae has not been (23-27 C). Within 2 wk after collection, each soil sample was mixed reported to parasitize or cause disease in cotton or tobacco grown thoroughly by hand, analyzed gravimetrically for moisture in naturally-infested soil in the field. content, and assayed for C. crotalariae MS by the elutriation Microsclerotia (MS) of C. crotalariae form in the cortex of method (10). infected peanut roots and are the primary survival structure of this Selection and culture of crops. One susceptible (Florigiant) and fungus in naturally-infested soil (4,10,18). Development of rapid, two resistant (Argentine, NC3033) peanut cultivars were selected efficient procedures for quantitative estimation of MS populations (8). Tobacco (Speight G28), cotton (Coker 310), corn (Pioneer in soil have provided technology for detailed studies on the 3369A), and soybean (Ransom) were selected on the basis of epidemiology of CBR in peanuts (6,10). current agronomic practices in North Carolina. On 19 May 1975, The primary objectives of our study were to determine: i) the four replicate microplots were selected at random for planting to effects of peanut cultivars, rotational crops (ie, corn, cotton, each crop and four more were selected for fallow. Granular 3-9-9 soybean, and tobacco), and fallow on populations of C. crotalariae fertilizer (22.4 kg of N/ha, 67.2 kg of P 20 5/ ha, 67.2 kg of K20/ ha) MS in naturally-infested soil in the field; and ii) the role of these and aldicarb (19 kg of 15G formulation/ha) were incorporated in crops in the epidemiology of CBR in peanuts. all microplots. No herbicides were applied for weed control. Tobacco was obtained from a transplant bed, but all other crops MATERIALS AND METHODS were established with seed. Plant densities were standardized at two plants per microplot for tobacco and three plants per microplot for Field site and installation of microplots. Experiments were all other crops. Foliar sprays of benomyl (0.56 kg of 50WP conducted in a naturally-infested peanut field (Norfolk sandy formulation/ha) were applied at 2-wk intervals after 1 July to loam) near Roanoke Rapids in northeast North Carolina. peanuts for control of Cercospora leafspot. Carbaryl (1.12 kg of Microplots (70-cm diameter) were constructed from fiberglass 80WP formulation/ha) was applied to all crops as needed to sheets (0.3 cm thick, 60 cm wide, 245 cm long) and inserted in soil, control certain insect pests. Landplaster (1,120 kg of CaSO 4/ha) was applied to the soil surface on 7 July in microplots planted to 00031-949X/79/000041 $03.00/0 peanuts. ©1979 The American Phytopathological Society On 4 May 1976, each crop was planted in the same microplots as}, number={3}, journal={Phytopathology}, author={Phipps, P. M. and Beute, M. K.}, year={1979}, pages={240} }
 @article{phipps_beute_1977, title={Influence of soil temperature and moisture on the severity of Cylindrocladium black rot in peanut}, volume={67}, number={9}, journal={Phytopathology}, author={Phipps, P. M. and Beute, M. K.}, year={1977}, pages={1104} }
 @article{phipps_beute_barker_1976, title={ELUTRIATION METHOD FOR QUANTITATIVE ISOLATION OF CYLINDROCLADIUM CROTALARIAE MICROSCLEROTIA FROM PEANUT FIELD SOIL}, volume={66}, ISSN={["0031-949X"]}, DOI={10.1094/Phyto-66-1255}, number={10}, journal={PHYTOPATHOLOGY}, author={PHIPPS, PM and BEUTE, MK and BARKER, KR}, year={1976}, pages={1255–1259} }