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A History of Plant Pathology in Virginia: The Foy Era (1974-1980)
John M. Skelly was the dynamic leader of forest pathology during the Foy Era. He was ably assisted by L. W. Kress and a number of other graduate students. Emphasis was on what came to be known as annosus root rot of loblolly and white pine and air pollution damage to several species of forest trees. Skelly also prepared a number of Extension publications on forest tree diseases. During the Foy Era, Skelly was promoted to Professor in 1978 and he was relieved of Extension duties so that he could concentrate on research. Most of the research was a continuation of that initiated in the Couch Era.
E. M. Hayes, a graduate student advisee of Skelly, made a study of ambient oxidant levels at three sites in Virginia mountains. The sites were on Salt Pond Mountain at the Horton Center, Giles County; at Rocky Knob, Floyd County; and at Dayton, Rockingham County. Sites were monitored from May 1, 1975 to March 31, 1976 in Giles and Floyd Counties, and until only October 1975 in Rockingham. The effects of oxidants on white pine were observed. Hayes noted that increases in oxidants occurred when weather patterns brought air masses from the north and northeast. Decreases occurred when air masses came from the northwest, west, southwest, south, and southeast. The highest concentration was observed on July 3, 1975; there followed significant injury to the white pine test plants (E. M. Hayes. 1976. M. S. Thesis, VPI & SU; Proc. Amer. Phytopathol. Soc. 3: 326, 1976; Plant Dis. Reptr. 61: 778-782, 1977). Kress and C. Nicholson constructed and used open-top indoor chambers with charcoal filters for experiments to determine effects of air pollutants upon small plants of loblolly and white pine and sycamore. They observed high and low sensitivity among clones and hybrids of these species and found that high or low sensitivity to oxidants was apparently inherited (Proc. Amer. Phytopathol. Soc. 3: 130, 3: 228; 4: 86, 4: 87, 4: 120). It was also reaffirmed by Skelly and Y. S. Yang that earlier observations correlating radial growth retardant with peak production periods at the Radford Army Ammunition Plant were correct. Indicator plants were sought for detecting broad-scale episodes of high oxidant periods. Common milkweed was found to be promising (Duchelle. S. F. 1981, M. S. Thesis VPI & SU., Duchelle, Skelly, Kress. 1980. Phytopathology 70: 689).
Judy Trimble and Marsha Ward made further studies on sensitive and insensitive clones of pine species. Trimble examined thickness of epicuticular wax and density of stomata on white pine needles but found no correlations with these features and sensitivity to ozone. Alkane content of wax was greater in the tolerant clone (Trimble, 1980. M. S. Thesis.). Ward compared sensitivity to ozone in half-sibs of loblolly pine. Ozone at 0.10 ppm surpressed growth and biomass accumulation in all clones but some clones resisted expressing symptoms. Again growth and biomass accumulation did not correlate well with foliar sensitivity (Ward, 1980. M. S. Thesis). Air pollution research was continued beyond the Foy era.
The following thesis and dissertations addressing air pollution effects on forest trees were completed during the Foy era:
Phillips, S. O. 1975. Growth loss of loblolly pine (Pinus taeda L.), white pine (P. strobus L.), and sycamore (Platanus occidentalis L.) proximal to a periodic source of air pollution. M. S. Thesis.
Hayes, E. M . 1976. The effects of an oxidant air pollution regime in southwestern Virginia on eastern white pine (Pinus strobus L.). M. S. Thesis.
Nicholson, C. R. 1977. The response of 12 clones of eastern white pine (Pinus strobus L.) to ozone and nitrogen dioxide. M. S. Thesis.
Kress, L. W. 1978. Growth impact of O3, SO2, and NO2 singly and in combination on loblolly pine (Pinus taeda L. ) and American sycamore (Platanus occidentalis L.). Ph. D. Dissertation.
Trimble, J. L. 1980. Epicuticular wax and stomata characterization of two Pinus strobus L. clones differing in sensitivity to ozone. M. S. Thesis.
Ward, M. M. 1980. Variation in the response of loblolly pine to ozone. M. S. Thesis.
Skelly led a group of student researchers through the rigors of investigating the etiology and epidemiology of pine root rot caused by Fomes annosus. During the span 1975 to 1980, the fungus was renamed Fomitopsis annosa and finally Heterobasidion annosum. Such instability in names prompted M. C. Shurtleff to say in his book " How to Control Plant Disease in Home and Garden" that he preferred to use common names because they have more stability. The disease became known familiarly as annosus root rot. Students involved were B. Bradford, H. D. Hertert, and R. S. Webb; S. A. Alexander also participated. Their research validated the belief that H. annosus was a primary pathogen of loblolly pine which reduced the growth rate and often predisposed trees to attack by the pine bark beetle (Phytopathology 65: 585-591, 1975; Proc. Amer. Phytopathology Soc. 2: 127, 155, 1975; 3: 324, 326, 1976; 4: 120, 1977; Phytopathology News 12: 166, 1978). Dissertations and thesis concerning this research prepared from 1974 to 1980 were:
Bradford, B. 1977. The incidence of Heterobasidion annosus (Fr.) Bref. in loblolly pine plantations and the effect on radial increment growth. M. S. Thesis. VPI & SU.
Webb, R. H. 1980. The incidence and severity of Heterobasidion annosum (Fr.) Bref. in loblolly pine (Pinus taeda L.) unthinned plantations and seed orchards. Ph. D. Dissertation. VPI & SU.
Interest in restoring chestnut (Castanea dentata ) to its former place in American forests had gripped pathologists, geneticists and others in the late 1960's and was gaining momentum in the 1970's. In Virginia, the exploratory work was initiated by R. J. Stipes and J. R. Elkins, a chemist of Concord College in Athens, West Virginia. Elkins had spent a sabbatical leave in 1975 with Stipes studying chemical compositions of American and Chinese chestnuts and their hybrids and had been appointed Adjunct Professor of Plant Pathology. Martha Roane, a recent Ph. D. graduate in mycology at VPI & SU, took an interest in the genus Endothia and diseases caused by Endothia spp.; she was also appointed Adjunct Professor. This group and several graduate students made numerous investigations into cultural characteristics of Endothia spp. They were soon joined by G. J. Griffin who became involved in chestnut studies because of his love of woodlands and desire to see the chestnut restored. He was an excellent soil microbiologist and methodologist. With Stipes expertise in uptake and translocation of systemic fungicides, the team produced an impressive array of publications on Endothia and diseases caused by members of its genus.
It is uncertain when interest in chestnut blight arose; apparently, work with pin oak canker caused by Endothia gyrosa led into studies of taxonomic criteria of the genus Endothia (Proc. A. I . B. S., 1975, Paper 1473; Va. J. Sci. 26: 65, 1975; 27: 60, 1976; 28: 70, 75, 77, 1977; 29: 71, 76, 1978). Certainly the contagious enthusiasm of John Elkins while on sabbatical leave in Stipes laboratory had infected Stipes, Martha Roane and Gary Griffin. Some of the early published notes were on chemical comparisons between American and Chinese chestnut trees and their hybrids (Proc. W. Va. Acad. Sci. 49: 9, 1977; 50: 9, 1978) and chemical comparisons among isolates of Endothia parasitica and other Endothia spp. (Proc. A. I . B. S. 1975, Paper 1473; Va. J. Sci. 26: 25, 1975; 27: 60, 1976; 28: 70, 75, 1977). They also extended experimentation of soil-injection of systemic fungicides that had been applied to elm for Dutch elm disease control to chestnut. Translocation, deposition at infection sites and efficacy of chestnut blight control were noted (Sugarloaf Mountain Bul. 6, 1975; Proc. Amer. Phytopath. Soc. 4: 95, 1977). The group sought means of controlling chestnut blight by injecting benomyl and other systemic fungicides into the soil of chestnut root zones (Proc. Amer. Phytopath. Soc. 4: 95, 1977, Proc. Amer. Chestnut Symp., Morgantown, W. Va., Jan. 4-5, 1978). Although benomyl was taken up by trees, it did not come in contact with blight fungus colonies and thus was no value.
Three avenues of blight control seemed open to chestnut workers: application of systemic chemicals, a procedure useful only for individual trees or nursery stock; breeding disease resistant lines; and use of hypovirulent strains of E. parasitica which have a mitigating effect on pathogenicity of naturally occurring virulent strains.
Breeding for blight resistance was begun in 1922 by Clapper and Gravatt, the latter was a V.P.I. graduate, B. S. 1911, M. S. 1912, under H. S. Reed. Many of the F1 hybrids between American and Chinese chestnut produced by them are surviving at sites in Virginia. These and other breeding lines from Connecticut have been planted at Lesesne State Forest in Nelson Co., Virginia. Individuals up through the 5th generation are represented among surviving trees. The Virginia Division of Forestry has been the principle cooperating agency (Dierauff, T. A. 1977. Chestnut research in Virginia. Nut Grow. Assoc. Annu. Rep. 68: 130-134; Roane. M. K., G. J. Griffin, and J. R. Elkins. 1986. Chestnut Blight, Other Endothia Diseases, and the Genus Endothia. Amer. Phytopath. Soc. Monograph). Although the Nut Growers Association is vitally interested in chestnut restoration for nut production, the emphasis at Lesesne S. F. has been on selection of timber-type trees. Tom Dierauff was the principle forest pathologist assigned to the Lesesne S. F. project in the Foy era.
In 1975, efforts to implement hypovirulence as a means of controlling chestnut in the United Sates were underway primarily at the Connecticut Agricultural Experiment Station. In Virginia, under the leadership of G. J. Griffin, a survey for hypovirulence was conducted. Although some hypovirulent isolates were obtained, W20 and PCM, their virulence was greater than that of the European-derived hypovirulent reference culture, Ep43. Griffin et al. concluded that sampled surviving trees were not infected with hypovirulent E. parasitica and, thus, may have some degree of resistance (MacDonald, W. L., F. C. Luchok & C. Smith, eds. 1978. Proc. Amer. Chestnut Symp., W. Va. Univ. Books, Morgantown).
In the forgoing section, excessive discussion has been devoted to chestnut blight. Should chestnut once again be restored to the forest canopy, tribute must be paid to those everywhere who believed and persisted. Virginian's, even "naturalized" ones, will have contributed considerably to the task.
A canker disease of pin oak, caused by E. gyrosa was found for the first time in the United States at Hampton, Virginia 1970 (Roane, M. K., R. J. Stipes, P. M. Phipps, and O. K. Miller. 1974. Mycologia 66: 1042-1047.) Since this disease has been observed mostly in landscape trees, it will be discussed under "Pathology of Ornamental and Landscape Plants."
Thesis and dissertations relative to Endothia spp., chestnut and oak blights and cankers, 1975-1980:
Headland, Jane K. 1975. Severity of natural Endothia parasitica infection of Chinese chestnut, Castanea mollissima. M. S. Proj. & Rept.
Dawson, G. B. 1977. Uptake, translocation and persistence of fungitoxicants and other pesticides in trees including pin oak (Quercus palustris Muenchh.). M. S. Proj. & Rept.
Hunter, P. P. 1977. The blight and canker of pin oak (Quercus palustris Muenchh.) incited by Endothia gyrosa (Schw.) Fr. : Some factors affecting disease development. Ph. D. Dissertation.
Jones, C. 1978. Resistance of Chinese chestnut, Castanea mollissima Blume, to Endothia parasitica (Murr.) And. & And. in different cold-hardiness zones in the eastern United States. M. S. Proj. & Rept.
Appel, D. N. 1980. The influence of selected urban site factors, host nutrition and water stress on the decline and blight of pin oak (Quercus palustris Muenchh.) incited by Endothia gyrosa Fr. Ph. D. Dissertation.
Vegetable disease research was conducted mostly at the Eastern Shore substation of the Virginia Truck and Ornamentals Research Station. R. E. Baldwin was the pathologist there and he cooperated with R. C. Lambe and T. J. Nugent most of his efforts were of an individual nature. This work was primarily evaluation of new cultivars, pesticides, and procedures; it did not culminate in many peer reviewed journal articles but rather in brief articles in Fungicide and Nematicide Tests. There were 19 such articles in the 1975-1980 period; six described tests with materials to control cucumber anthracnose and downy and powdery mildews; four addressed potato seed-piece treatment; two pertained to tomato early blight and fruit rot control; two stressed sweet potato sprout treatment for control of scruf; and two were on control of root-rot of potato and carrot. There were also items on control of potato early blight, and strawberry gray mold, and leaf search. These items were addressed to the scientific community and the results were used as springboards for release to farmers of current disease measures. The growers received needed information from articles in the Vegetable Growers News (VGN), a monthly publication from the Truck Station.
In the period 1975-1980, Baldwin authored 24 articles in VGN on vegetable diseases based on information from publications mentioned in the preceding paragraph. Schedules for pesticide applications were frequently included. The final article of the period addressed control of soybean cyst nematode which by then had become a widespread problem on the Eastern Shore. Despite its recognition as a truck-crop producing county, Accomack had become one of the state's leading soybean producer and growers were demanding attention. Baldwin answered their call.
A long-standing problem for cabbage growers in Southwest Virginia is club root. M. D. Hutter reviewed the status of the disease in his M. S. project and report and graduate student L. W. Datnoff was assigned to study the disease and seek new control measures. Fox advised Hutter; Lacy advised Datnoff. T. K. Kroll began studies on the disease in the late '70's' with Moore and Lacy as co-advisors.
Hutter thoroughly reviewed the literature through early 1978. Sanitation, application of lime, use of disease-free seedlings, and crop rotation were the principle means of club root control. The newest measure was use of pentachloronitrobenzene (Terrachlor) in the transplant water (Hutter, M. S. Proj. & Rept., 1978). Datnoff discovered that ponds in the problem area had high numbers of resting spores of Plasmodiophora brassicae in the sediment (up to 2X107/g). In laboratory experiments, he found that NaOCl in irrigation water was effective in reducing the incidence of clubroot. This was not tested in the field (Datnoff, M. S. Thesis, 1981). Kroll initiated his studies on resistance to and chemical control of P. brassicae in 1979, but the results were not available in the Foy era.
Most vegetable pathology was handled through Extension Service releases. The publications were "Plant Pathology: Vegetable and Field Crop Research Summary", Va. Truck and Ornam. Res. Sta.; and, "Commercial Vegetable Production Recommendations for Virginia", VPI & SU Pub 456-420, both published annually. Sections in these publications provided up-to-date information for disease control of vegetables grown throughout Virginia. Extension Specialists and Agents could use them as sourcebooks for preparing leaflets and hand-out literature.
Four other projects and reports were prepared on vegetable diseases during the Foy era, but no original research was involved:
Okie, W. R., III. 1976. Control of Fusarium wilt of tomato with systemic fungitoxicants. M. S. Proj. & Rept. Hutter, M. D. 1978. Integrated control of clubroot of cabbage incited by Plasmodiophora brassicae. M. S. Proj. & Rept.
Spoor, Cynthia A. 1978. Control of Fusarium wilt of tomato with Cycocel and/or Lignasan BLP. M. S. Proj. & Rept.
Terry, W. R. 1980. Rhizoctonia solani as a pathogen of cabbage and possible management procedures for its control. M. S. Proj. & Rept.
Pathology of Ornamental and Landscape Plants
Two landscape tree diseases that had received attention from pathologists for a number of years were mimosa (Albizzia julibrissan) wilt (caused by Fusarium oxysporum f. sp. perniciosum) and Dutch elm disease (caused by Ceratocystis ulmi). Indeed, the latter entered North America in 1930 through the port cities of Hampton Roads. Mimosa wilt in Virginia was first discovered by T. J. Nugent to be killing trees in 1941. A third disease, pin oak canker (caused by Endothia gyrosa) was recognized by Stipes and P. M. Phipps in 1970. This disease was the topic of dissertations by P. P. Hunter and D. N. Appel during the Foy era.
Dutch elm disease eradication in the thirties had failed. The number of surviving American elm trees was gradually diminished. Destruction of trees in cities where elms were the predominant shade providers has been devastating. Stipes and his student D. B. Janutolo concentrated on the use of systemic fungicides to control Dutch elm disease. A number of factors enter into successful chemotherapy of infected trees. As a consequence, the disease may be arrested but the inciting fungus is rarely eliminated. Thus, continued application of fungicides is necessary. The procedures are clumsy and not adaptable to large populations. Thus, many trees have died; only a few have survived. Summaries of the situation appear in Janutolo's Ph. D. dissertation (Janutolo, D. B., 1977. Fungitoxicants in the Ceratocystis ulmi-Ulmus americana-soil continuum. Ph. D. Diss. V. P. I. & S. U.) and the elm compendium (Stipes, R. J., and R. J. Compana, eds. 1981. Compendium of Elm Diseases. Amer. Phytopathol. Soc. ).
Stipes and his associates studied several aspects of mimosa wilt. Stipes and G. J. Griffin reported on numbers of macroconidia produced in lenticils and the high concentration of spores in soil beneath wilted trees (Pl. Dis. Reptr. 59: 787-790, 1975) and P. M. Phipps published with Stipes papers resulting from his M. S. thesis project. He emphasized the histology of developing wilt noting that infection occurred through roots and the fungus (Fusarium oxysporum f. sp. perniciosum) microconidia spread through the xylem elements leading to and colonization of distal parts of the tree. He also reported on control experiments with benomyl and thiabendazole. Used as soil drenches these materials were efficacious only if applied before roots were exposed to Fusarium spores. Thus, the most important control measure remained the removal of diseased trees and destruction of them by burning (Phytopathology 65: 188-190, 504-506, 1975; 66: 839-843, 1976).
Pin oak canker and blight caused by Endothia gyrosa, was first discovered in Hampton, Virginia in 1970. The disease was the subject of dissertations by P. P. Hunter in 1970 and D. N. Appel in 1980. Hunter found from monthly inoculations that May was most favorable for disease development and that lower osmotic water potentials in the host following pruning favored diseases development. Appel examined host nutrition, site factors, and water stress for their effects on the disease. Surprisingly, infection percentages were not correlated with root-confining factors, pH, major and minor elements in soil; even so, trees of least vigor were most susceptible to blight. Appel recommended regular watering to reduce drought stress, sanitary pruning practices, and removal of trees that did not recover normally from pruning stress. He provided evidence to support Hunter's hypothesis that water stress was a very important predisposing factor in pin oak blight (Proc. Amer. Phytopathol. Soc. 4: 84, 1977; Phytopathol. News 12: 206, 1978; Pl. Dis. Reptr. 62: 940-944, 1978).
In addition to the studies reported above, there were two first reports of fungi occurring on trees. Glomerella cingulata was found on Acer platanoides and Scoleconectria cucurbitula was found on Cedrus deodara (Va. J. Sci. 29: 47, 76, 1978).
In the mid-seventies, nurserymen who propagated Japanese holly (Ilex crenata) noted many plants grew poorly after transplanting to containers. The problem was investigated by Wills and Lambe; they found that Thielaviopsis basicola was causing a root rot (first report) and impairing growth (Pl. Dis. Reptr. 62: 859-863, 1102-1106, 1978). Excellent photographs of diseased plants were included. They made numerous isolations and inoculations and concluded T. basicola colonized a broad spectrum of related hollies. Isolates from I. crenata colonized several species of woody and agronomic plants, indicating the fungus was not very host specific.
A disease of boxwood (Buxus sempervirens) called "decline" began to cause concern to growers in northern Virginia in 1968. Paecilomyces buxi seemed to be the primary organism associated with many root diseases Phytophthora, Fusarium, Pythium, and Rhizoctonia spp. were frequently present. The disease was the subject of considerable research by Wills, Lambe, and graduate student G. B. Montgomery (Pl. Dis. Rept. 59: 1105-108, 1975; 61: 404-408, 1976; Montgomery, Ph. D. Dissertation, V. P. I. & S. U., 1975).
The organism P. buxi has history of confusion in the literature having been named Verticillium buxi and Volutella buxi (Pl. Dis. Reptr. 59: 105-108) and since those writings, Sesquicillium buxi (Farr et al. Fungi on Plants and Plant Products in the United States, Amer. Phytopathol. Soc. Press, 1989). Mary C. McBryde (Miller) first isolated it during preparation of her M. S. thesis (V.P.I., 1933.) and J. G. Harrar also found it in his survey of ornamental plant diseases in Virginia (Pl. Dis. Reptr. 21: 217, 1937). Not until Wills and Lambe started their investigations of boxwood decline, was the organism isolated again from Virginia boxwood. During the Foy era, no control measures were suggested. Wills and Lambe had no success in controlling the disease by soil fumigation with methyl bromide.
Wills and Lambe investigated biological control of boxwood decline. They observed Mortiella sp. isolates from boxwood were antagonistic to Phytophthora and Pythium spp. in culture. They found by inoculating azalea and boxwood roots with Mortiella sp. one week before inoculating them with Pythium and Phytophthora spp. that symptoms caused by these fungi were ameliorated but boxwood decline was not. Mortiella was found non-antagonistic to fungi other than Oomycetes (Phytopathology 70: 694, 1980.). Other aspects of biological control were investigated in the 1980's.
Thesis and Dissertations on Landscape Trees, 1975-1980:
Dawson, G. B. 1977 - See Endothia studies.
Hunter, P. P. 1977. - See Endothia studies.
Janutolo, D. B. 1977. - Fungitoxicants in the Ceratocystis ulmi-Ulmus americana-soil continuum. Ph. D. Dissertation.
Truax, Patricia A. 1978. Comparative distribution of Arbotech 20-5, CG 64251, Lignasan BLP, Nuariniol in Ulmus americana following administration with a Sterrett-Creager miniature pressure injector. M. S. Proj. & Rept.
Appel, D. N. 1980. See Endothia studies.
Thesis and Dissertations on Ornamental Shrubs, 1975-1980:
Montgomery, G. B., 1975. Etiology of root rot and decline of English boxwood (Buxus sempervirens cv. suffructicosa L.). Ph. D. Dissertation.
Bower, Leslie A. 1980. Biotic and abiotic stress factors influencing colonization of Buxus sempervirens var. suffructicosa L. by Paecilomyces buxi (Link Ex. Fr.) Bezerra. M. S. Thesis.
Research on nematodes during the Foy Era in Virginia was dominated by Lawrence Miller. He studied and reported on the morphometric, parasitic, and pathogenic variation of cyst forming nematodes of the genera Heterodera and Globodera. He repeatedly demonstrated their interspecific and intergeneric compatibility, and proposed that species within each genus may have had a common ancestor but by geographic isolation they have become relatively host specific and morphologically distinct. Species of cyst nematodes with which he worked are Heterodera schachtii on sugarbeet, H. glycines on soybean, H. carotae on carrot, H. avenae on cereals, H. humuli on hops, Globodera rostochiensis and G. pallida on potato, G. solanacearum on tobacco, G. virginiae on horse nettle, and G. tobacum on tobacco. (The last three have been consigned to G. tobacum; their original specific epithets are given subspecies rank.)
Miller was ably assisted by Lorraine Ormrod (later L. O. Graney) who was both a graduate student and laboratory technician. Although Miller retired on January 1, 1980, he continued his research on cyst nematodes until his death in March 1996. He was not one who relished manuscript preparation; his research in the Foy Era is found in abstracts published in the following journals:
Journal of Nematology 8: 296-297, 1976; 11: 299, 1979; 12: 223, 1980. Nematologica 27: 35, 1976. Phytopathology 70: 688, 1980. Proceedings of the America Phytopathological Society 2: 125, 1975; 3: 125, 329-220, 1976; 4: 217, 1977. Phytopathology News 12: 67, 1978. Virginia Journal of Science 26: 44, 1975; 27: 35, 1976; 28: 54, 1977; 29: 39, 43, 1978; 30: 32, 1979, 31: 29, 78, 84, 1980.
In 1971, Miller's attention was drawn to some malformed plants of Carduus nutans (musk thistle) and C. acanthoides (plumeless thistle) growing in Rockingham Co. He found the malformations to be associated with the presence of Ditylenchus dipsaci, the stem and bulb nematode. Through 1975, he was able to induce symptoms in thistle plants but not in 16 other species known to be hosts of D. dipsaci, including teasel, Dispsacus spp., from which D. dipsaci was originally described (Proc. Amer. Phytopath. Soc. 3: 329-330, 1976.). In Virginia, D. dipsaci may be found in alfalfa and narcissus.
There are several other items of interest regarding nematology in the Foy Era. J. A. Fox joined forces with D. A. Orcutt, Plant Physiologist in the Department, to examine the various effects sterols might exert on nematodes and host plants parasitized by them. Graduate students Carolyn Jake and D. M. Evans participated in these studies. Evans and Fox found that Metopirone, an inhibitor of steroid synthesis, exerted a female-inducing effect on sex (Proc. Amer. Phytopathol. Soc. 2: 122, 1975; J. Nematol 8: 283-284, 1976; 9: 207-210, 1977; 10: 211-216, 1978).
Fox and L. Spasoff who had retired from the Department in 1974 reported in 1976 on a procedure for selecting vigorous tobacco plants in the presence of large populations of H. solanacearum (now G. tobacum subs. solanacearum). They observed that some vigorous plants inhibited the development of nematodes (designed resistant), but some allowed nematode development (tolerant). Based on plant weight and nematode development, four plant classes were recognized: resistant-tolerant, resistant-intolerant, susceptible-tolerant, and susceptible-intolerant. They concluded that resistance and tolerance were inherited independent by and they inferred that breeding programs should combine these factors (J. Nematol. 8: 284-285, 1976).
Prior to 1980, predictive assays had not been utilized for nematode management. Phipps and Fox introduced the procedure for peanut production in 1980. Their predictions for use of nematicides based on assaying about 350 farms in 1979 for nematode population levels. At that time, 95% of the Virginia peanut acreage was treated with nematicides. Based on the assays, only about 45% should require treatment. They also indicated that after peanuts, 89% of the fields would require treatment to grow peanuts again; after soybeans, 71% required treatment; and after corn, 51%. (Fields that brought the average down to 45% were not mentioned. Most fields in the peanut production area would be planted to one of these three crops.) Thus, for 1980, they could predict which fields needed treatment thereby resulting in big savings for peanut growers. The assay/prediction procedure was developed further in the 1980's (Proc. Am. Peanut Res. & Ed. Assn. 12:35, 1980.).
Stem pitting of peach had been found to be a problem for some Virginia orchardists. The disease was known to be caused by a nematode-transmitted virus (now tomato ringsport virus, TomRSV). T. K. Kroll, a graduate student, was hired to make a 10-county survey of peach orchards to determine its prevalence and determine the presence of associated nematode vectors. Stem pitting was found to be widespread and although absence of vectoring nematodes was not a limiting factor, Xiphinema americanum and Helicotylenchus sp. populations were higher near pitted than healthy trees (Va. J. Sci. 31: 82. 1980).
In 1975, S. B. Hanounik published with his advisor, W. W. Osborne, results obtained during his Ph. D. project completed in 1974. Hanounik and Osborne reported that as nematode (Meloidogyne hapla) density increased, the nicotine content in roots of 'NC 95' (Res.) and 'McNair30' (Susc.) increased. However, leaf nicotine increased in NC95 but decreased in McN30 probably because root damage provided less nicotine to translocate. In another study, where M. incognita predominated, populations were studied after methyl bromide treatment under McN30 plants, after fumigation, a low initial population increased slowly at first then rapidly past mid-summer because more roots than in untreated areas provided more food. In untreated plots, high initial populations increased rapidly at first, then leveled off and finally decreased because of a depleted quantity of roots (Proc. Amer. Phytopath. Soc. 2: 213, 1975).
Osborne retired in early 1977 and Extension Nematology at Virginia Tech lay dormant for awhile. In 1979 and 1980, Fox filled some of the gap by turning to nematicidal control of nematodes in various crops. Phipps and Fox were the two primary cooperators. With support from Research Supervisor Charlie Harris and Laboratory Technician Sue Meredith, tests were also conducted on tobacco cyst nematodes and on peanut, corn, and soybean. These tests usually led to nematode control recommendations in miscellaneous Extension publications. (Amer. Phytopathol. Soc. Fungicide and Nematicide Test Results 35: 226, 228, 229, 231, 233, 1979; 36 ; 184-185, 1980).
Fox resigned at the end of the Foy Era and Alama P. Elliott was hired to exploit developed knowledge in nematology.
Much of the work in virology is reviewed in sections on tobacco, cereals, and soybean. Reviewed here will be research not otherwise mentioned in commodity sections. Sue A. Tolin is the departmental virologist; some accomplishments by Tolin and her cooperators will be discussed.
Tolin maintained cooperation with various virologists and programs through "regional, national and international programs in order to maximize exchange of information as well as materials and techniques for virus identification so as to develop solutions to problems in the States with a minimum of research input on the problem." (Tolin in 1979 Comprehensive Review, Res. Proj. 612065). Research in Tolin's laboratory was centered on developing techniques for virus identification by serology and host symptomatology; on purifying, characterizing, and determining biochemical relationships among naturally occurring isolates of viruses; and on cooperating with other pathologists and breeders to develop virus-resistant crop cultivars, to determine genetic and other mechanisms of resistance, and to appraise virus-induced crop loses. The work on breeding and genetics was reviewed in the section on soybean pathology.
Graduate student Rosemary Ford conducted a study on five strains of tobacco mosaic virus (TMV) from various sources. One strain had been isolated in 1927; others of different ages and origins were compared to it. A strain collected in 1975 in flue-cured tobacco was nearly identical to it; a third yellow mosaic strain was isolated from a legume host and was distantly related to other strains and a mutant strain was consider intermediate. Ford's thesis appeared to be a very comprehensive study of TMV strains.
Dayle Zanziger for her M. S. project reviewed the literature on nepoviruses (nematode transmitted, isometric viruses) and demonstrated that a number of symptomless weeds common to orchards in Virginia were inoculum sources. Samples of red clover, marrow leaf plantain, and dandelion collected in peach orchards, yielded either tobacco or tomato ringspot viruses (TRSV or TmRSV).
Both Ford and Zanziger continued their education and earned Ph. D's; Ford at V. P. I. & S. U., Zanziger at University of Maine. An amusing sidelight to Zanziger's thesis is found in the acknowledgements. She wrote, "Genuine appreciation is expressed to Dr. L. I. Miller whose mumbling enthusiasm, infectious energy, and intellectual curiosity provided considerable inspiration." That was Miller in a nutshell.
Satellites were relatively newly discovered components of viruses at the time of the Foy Era. Tolin collaborated with J. R. Diaz-Ruiz and J. R. Kaper of the U. S. D. A. at Beltsville in studying the role of satellites in certain viruses, especially peanut stunt virus (PSV). By virtue of this collaboration, Diaz-Ruiz was named Research Associate in the Department. PSV is a tripartite virus of the cucumovirus group. The satellite was determined to have an innocuous effect in the pathogenicity of PSV (Virology 88: 166-170, 1978). This paper represents pioneering research on the role of satellites in viruses.
For the most part during the Foy Era, virologists, graduate students, and other researchers devoted attention to the taxonomy of viruses from legumes, tobacco, and various weeds.
Thesis and Dissertations in Virology, 1975-1908:
Ford, Rosemary H. 1976. Comparison of five naturally occurring strains of tobacco mosaic virus. M. S. Thesis.
Polston, Jane E. 1978. Preparation of six Extension publications on plant virus diseases in Virginia. M. S. Proj. & Rept.
Trevathan, L. E. 1978. Symptom expression and lipid composition in flue-cured tobacco in response to ozone and purified tobacco mosaic virus. Ph. D. Diss. Moore and Tolin, co-advisors.
Zanziger, Dayle, H. 1980. The role of week host and nematode vector in the ecology of nepoviruses in Eastern North America. M. S. Proj. & Rept.
Since Couch arrived on campus in 1965, turfgrass pathology had been his province. Having given up department headship, he had to re-establish himself as a full-time researcher, teacher, and author. He moved to a ground floor office near his laboratory and growth room and as was typical of his character, remodeled, redecorated, and refurbished a plain plaster-walled room into an elegant office. Thus, he became a first class member of our beloved Price Hall's "engine room" crew.
Most of Couch's publications centered around summarizing the status of turfgrass pathology in review and encyclopedia articles and in conference proceedings. Since he was an entertaining and informative speaker, he was frequently invited to talk to golf course and turfgrass management groups. He also began a total revamping of his book, Disease of Turfgrass. Although most of his research efforts were in testing and comparing the efficacy of new fungicides on various turfgrass species, he did not avail himself to the annual A. P. S. publication Fungicide and Nematicide Tests. Only one technical article was published in a peer reviewed journal. Thus, it appears that Couch contributed more to Extension pathology than to research pathology in the Foy Era. He contributed to the instruction program by lecturing in course PPWS 5180, Diseases of Landscape Trees, Ornamentals, and Turfgrass, jointly offered with Stipes, Wills, and Couch.
One student completed an M. S. under Couch's guidance in the Foy era:
Bird, R. G. 1976. Effects of chemical adjuvants of turfgrasses and turfgrass soil. M. S. Proj. & Rept.
New Plant Diseases, Pathogens, and Hosts Reported 1975-1980
Wheat spindle streak mosaic virus, in Richmond County, previously thought to be only wheat soil-borne mosaic virus. Roane and Tolin, unpublished.
Peanut stunt virus in crown vetch, a reclassification of a virus described as cucumber mosaic virus in 1967 (Tolin and J. D. Miller Phytopathology 65: 321-324).
Wheat stem rust in eastern Virginia. While not new in Virginia, Puccinia graminis created havoc on 'McNair 701' and 'Blueboy' wheats in 1975, a rare event for the Coastal Plain 1975. (C. W. Roane and T. M. Starling, 1975 Wheat Newsl 22: 122, 1976)
Wheat stripe, Cephalosporium gramineum, occurred in a small area of wheat nurseries at Blacksburg (C. W. Roane and T. M. Startling, Pl. Dis. Reptr. 60: 345, 1975). White clover rust, Uromyces nerviphilus occurred on hybrids of Trifolium repens at Blacksburg in 1974 and 1975. First report for Virginia (M. K. Roane and J. D. Miller, Pl. Dis. Reptr. 60: 432-433, 1976).
Scots pine western gall rust, first report, from Bedford County (J. M .Skelly, Pl. Dis. Reptr. 60: 222, 1976).
Cesphalosporium stripe of rye, Cehpalosporium gramineum (now Hymenula cerealis) was found near Blacksburg on volunteer rye (Jones, J. B. , et al, Pl. Dis. 64: 325, 1980).
Norway maple anthracnose, Glomerella cingulata, on Acer platanoides (Roane, M. K., and Stipes, Va. J. Sci 29: 47: Stipes and G. L. Clement, Ibid., p. 76, 1978).
Deodor canker, Scoleconectria cucurbitula on Cedrus deodara (Ibid., p. 47).
Soybean stem blight, Sclerotinia minor, was first observed in 1978 (Phipps and Porter, Pl. Dis. 66: 163-165, 1982).
Service to Professional Societies
Service to professional societies is voluntary and sometimes very time-consuming. During the Foy Era, the faculty participated in the committee and administrative functions of several professional societies, i.e., the American Phytopathological Society, American Peanut Research and Education Association, Society of Nematology, Mycological Society of America, Virginia Academy of Science. Foy himself was not a member of any pathology related society. Participation in the American Phytopathological Society (A. P. S.) was most evident; P. D. indicates a Potomac Division function:
S. A. Alexander - Forest Pathology Comm., 1978-80. P. D. - Local Arrangements Comm., 1979, Program Comm., 1979; Auditing Comm., 1980.
R. E. Baldwin (Painter, VA) - P. D. - Awards Comm., 1979; Resolutions Comm., 1980.
H. B. Couch - A. P. S. Councilor for P. D., 1973-1977; Nominating Comm, 1975; Diseases of Ornamental Plants and Turf Grasses Comm., 1977-79; Phytopathology Classics Comm., 1978-80; Special Publications Comm., 1974; P. D. - Awards Comm., 1975; Nominating Comm., 1980
C. R. Drake - P. D. - Resolutions Comm., 1977.
G. J. Griffin - Associate Editor of Phytopathology, 1977-79.
K. D. Hickey - Apple and Pear Disease Comm., 1972-74; Business Manager, Fungicide & Nematicide Tests, 1971-74; P. D. - Awards Comm., 1975.
L. W. Kress - Pollutions Effects on Plants Comm., 1980; Special Illustrations of Plant Pathogens, 1980; P. D. - Resolutions Comm., 1979.
R. C. Lambe - Ornamental Plants & Turfgrass Diseases Comm., 1979-80; Associate Editor, Fungicide & Nematicide Tests, 1979-80.
L. I. Miller - A. P. S. Meeting Site Comm., 1974.
L. D. Moore - Pollution Effects on Plants Comm., 1974; Membership Comm., 1974-77; Chm. 1976; Phytopathology News Comm., 1978-80; Necrology Comm., 1978-80; Environmental Quality Comm., 1974-75; P. D. - Secretary-Treasurer, 1978-80; Program Comm., 1976, Chm. 1978; Awards Comm. 1977-80.
P. M. Phipps - New Fungicide and Nematicide Data Comm., 1979-80.
C. W. Roane - Environmental Quality Comm., 1974-75; Compendium Comm. (Subcomm. Of Publications Comm.), 1974-75; Phytopathology Monographs & Reviews, 1975-80; Compendium Comm., 1980. P. D. - Resolutions Comm. Chm. 1975; Vice-Pres. 1977-78, Pres. 1978-79; Awards Comm. Chm., 1978; Associate Editor; Plant Disease Reptr/Plant Disease 1978-80.
J. M. Skelly - Publications Comm., 1974-78; Phytopathology Classics Comm., 1974-77, Chm. 1975; Pollution Effects on Plants, 1977-79, Chm. 1979; Special Illustrations of Plant Pathogens, 1975-78, Chm. 1977-78; Teaching Comm., 1974-75; Slide Salon Comm., 1974; P. D. Program Comm. 1977-78.
R. J. Stipes - Teaching Comm., 1974; Forest Pathology Comm. 1974-77; Chm. 1976; Subcomm. of Teaching Comm. on International Plant Pathology Glossary, 1974-75, Chm. 1975; Monographs & Reviews Comm. 1978-1980; P. D. - Program Comm. 1978, 1980; Nominating Comm., 1975.
R. W. Tillman -Teaching Comm. 1977-79, Chm. 1979; P. D. - Program Comm., 1978.
S. A. Tolin - Plant Virology Comm. 1977-80, Chm. 1980; Member Comm., 1977-79, Chm. 1979; Associate Editor, Plant Disease Reporter 1975-1977; P. D. - Program Comm. 1975; Auditing Comm., 1979; Nominating Comm., 1978; Awards Comm., 1980.
W. H. Wills - P. D. - Nominating Comm., 1977; Auditing Comm. Chm., 1980.
K. S. Yoder -Chemical Control Comm., 1979-1980; Editorial Board, A. P. S. Fungicide and Nematicide Tests, 1980-; P. D. - Program Comm., 1976.
American Peanut Research and Education Association
K. H. Garren - Pres. 1974-1975.
D. M. Porter - Chm., Bailey Awards Comm. 1978-80. Chm. Finance Comm. 1976.
Southern Soybean Disease Workers Council
W. W. Osborne - Member Program Planning Comm. 1925; Award for being first Pres. of SSDW.
Extension-Industry Peanut Workers - Award from, for meritorious service, July 1980.
1980-81 Chm., Publicity and Publications Comm. - Osborne
1980-81 Chm., Soil-borne disease Comm. - Phipps
Tobacco Workers Conference
1975-79 S. A. Tolin - Editorial Board, Tobacco Science.
Virginia State Horticultural Society
K. S. Yoder - Program Comm., 1978.
Virginia Pesticide Association
C. R. Drake - Member of Advisory Board.
K. S. Yoder - Member of Advisory Board and Publicity Comm. 1978-80.
Cumberland - Shenandoah Fruit Workers Conference
C. R. Drake - General Secretary.
Society of Nematology
J. A. Fox - Chm., Host-Plant Resistance Comm., 1976-79.
L. D. Miller - Executive Comm. 1974-78. Editor, Journal of Nematology 1974-75; President, 1976-77.
Virginia Academy of Science
M. K. Roane - Botany Section, Secretary 1975-76, Chm. 1976-77; Member Local Arragnements Comm. 1978, Chm.; Public Relations Subcomm. 1980; Chm., Flora Comm. 1979-81. Editor, Jeffersonia 1979-81; Member Council 1979-81.
R. J. Stipes - Chm., Botany Section, Section of Agriculture. Va. Jour. Sci. Editor 1980.
I am grateful to Drs. Kriton Hatzios and Craig Nessler, Department Heads, for their continuing interest in this history project and for assuring the availability of Departmental facilities, and to Mrs. Arleta Boyd for being the expediter, and to Tawnya Jarrard for pleasant cooperation and word processor expertise. It was a joy to work with all.
C. W. Roane
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