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Extension Plant Pathology: Bringing Our Science to the Public,
A Century of Service

Barry J. Jacobsen
and Mary E. Burrows
Department of Plant Sciences and Plant Pathology,
Montana State University, Bozeman, MT

Kevin L. Ong
Department of Plant Pathology & Microbiology,
Texas AgriLife Extension Service,
Texas A&M University System, College Station, TX

(Corresponding author: Barry Jacobsen
Jacobsen, B.J., Burrows, M.E., Ong, K.L. 2008. Extension Plant Pathology: Bringing Our Service to the Public, A Century of Service. Online. APSnet Feature. doi: 10.1094/APSnetFeature-2008-0508

Extension plant pathologists have been the face of our science to farmers, horticulturalists, homeowners, and agribusiness since the passage of the Smith-Lever Act in 1914. The job of an extension specialist has changed over this time, but the need to be knowledgeable about all facets of our science and to have the ability to apply and effectively teach this knowledge to a diverse clientele has remained constant. Extension’s mission was and is to be the “translator” between the university and their clientele, originally the farmer and now farmers, consultants, agribusiness, urban landscape professionals, nurserymen, homeowners, and many others.

Extension work in plant pathology was first undertaken by state land grant university or college faculty in the context of county fairs, farmer institutes, short courses, field demonstrations, farm trains, and other efforts to deliver information to clientele. The concept of a local, state and federal partnership “to provide for cooperative agricultural extension work between the agricultural colleges in the several states … and the United States Department of Agriculture” was first proposed by Congressman Asbury F. Lever of South Carolina and Senator Hoke Smith of Georgia in 1913. The Smith-Lever Act that created the Cooperative Extension Service was signed into law by President Woodrow Wilson on May 8, 1914. The stated purpose of this act was “to aid in diffusing among the people of the United States useful and practical information on subjects relating to agriculture and home economics and to encourage application of the same.” Further, the act stated that agricultural extension work was to “consist of the giving of instruction and practical demonstrations in agriculture and home economics to persons not attending or resident in said colleges in several communities and imparting to such persons information on said subjects through field demonstrations, publications and otherwise.” The act initially provided that each state receive $10,000 annually with additional amounts to be determined on the basis of rural population. These additional amounts had to be matched by state, county, local authority, or individual contributions from within a given state. An excellent review of extension activities through its first 75 years can be found in Rasmussen 1989.

The first officially appointed extension plant pathologists were R. E. Vaughan at Wisconsin and M. F. Barrus at Cornell in 1915. However, it should be pointed out that Dr. Barrus had already been appointed assistant professor of extension work on September 20, 1911 at the New York State College of Agriculture. Following establishment of the Land Grant Universities, “extension work” was done largely by the teaching/research faculties of these new universities in the various states. Extension plant pathologists of this era took on the role of organizing and teaching at farmer institutes, short courses, and local grower meetings. In addition, extension plant pathologists began conducting demonstration projects and producing extension publications. Later, as the county agent system became better established, extension plant pathologists coordinated their work through county agents, who brought the needs of the local community to the state-based extension specialists. The county agent system created a new education audience for extension specialists who now had to provide the “in-service training” that kept the local extension agents in leadership positions. The early extension plant pathologists generally had 100% extension appointments tied to Smith-Lever funding and were members of plant pathology, agronomy, horticulture, crop science, or extension departments at the state land grant universities.

Today there are extension plant pathology specialists in every state and United States territory, with most being associated with plant pathology departments or departments with plant pathologists as faculty. During the past 20 years, a significant number of extension plant pathologists have been stationed at regional extension or extension research centers. In reviewing the history of the American Phytopathological Society, the first reference to an extension plant pathologist’s meeting was in 1925. However, the first official meeting of the extension committee of APS was in 1931. Extension plant pathologists continue to be a critical part of APS membership and now comprise 9% of United States APS membership.

Extension plant pathologists have contributed to APS in many ways, but perhaps most notable is the APS Compendium series that started with Malcolm Shurtleff editing The Compendium of Corn Diseases in 1973. Today the majority of Compendia have significant contributions from extension specialists. Table 1 provides information on the number of extension plant pathologists in the USA and its territories and their percentage extension appointment for the years 1953, 1965, 1972, 1982, 1989, and 2007.

Table 1. Number of extension plant pathology appointments in the USA and territories and the percent time appointments for 1953, 1965, 1972, 1982, 1989, and 2007.*

  1953 1965 1972 1982 1989 2007
Number of extension appointments 48   102   150   228   214   281  
Number of 100% appointments 23   54   75   106   74   83  
Number of 50-99% appointments 77   20   47   74   83   116  
Number of < 50% appointments 8   28   28   46   57   82  
Percent split appointments 52   47   50   53   65   70  
Number of full time equivalents 35   —   —   167   145   183  

* Portions of this table are adapted from Sherf 1973.

Since 1953, the number of plant pathologists with extension appointments and the number of full time equivalents (FTE) increased dramatically, while the percentage of 100% appointments decreased from approximately 50% to 30%. Currently, 71% of extension specialists have split appointments with most having research responsibilities as part of their appointment, although three way appointments including research and teaching are more common. The inclusion of teaching appointments has occurred because often only extension plant pathologists have the broad training and experience needed to teach courses on disease control, diagnosis, or diseases of field crops, turf, ornamentals, vegetables, fruits, or other plant groups. Although precise data are not available, we suspect that most of the recent increase in extension FTE is a result of funding from the National Plant Diagnostic Network (NPDN) which started in 2002. In 1989, 36 states reported personnel with plant diagnostic responsibilities. Today, every state and United States territory has faculty with specific diagnostic responsibilities. Before the establishment of the NPDN, diagnostic responsibilities were commonly the responsibility of extension specialists, who also had many other responsibilities.

The increase in split appointments reflects the increasing specialization of extension specialist assignments. Initially extension plant pathologists were generalists. Today, very few extension specialists have to handle all crop and ornamental disease problems. Most specialists now have assignments limited only to agronomic or horticultural crops and many specialists with < 50% appointments have responsibilities for only a small subset of agronomic or horticultural crops. This specialization reflects the increased size and specialization of modern farm enterprises, growth of responsibilities to urban and suburban clientele, increased environmental awareness of Americans, the sophistication of clientele and scientific advances in our profession, and other additional factors. Table 2 presents data for extension appointments for the five APS divisions for the years 1989 and 2007. These data reveal that the number of split appointments has markedly increased for states in the Pacific and the Southern divisions, while decreasing 50% for states in the Potomac Division. The increased number of split appointments in the Pacific and Southern divisions follows the trend that started earlier in the Northeast and North Central divisions. The average FTE per state has increased in all divisions except the Pacific and Potomac.

Table 2. Number of extension full time equivalents and percent split appointments in the USA by region in 1989 and 2007.

Region* 1989 2007
% split
% split

26.73 2.43 40 30.07 2.31
Northeast 17.76 2.22 72 27.09 3.01
Potomac 10.30 2.58 61 12.87 2.57
North Central 30.53 2.54 74 40.31 3.36
Southern 59.90 4.6 32 71.60 5.97

* Pacific includes: Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming;
Northeast includes: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, and Rhode Island;
Potomac includes: Delaware, Maryland, Virginia, and West Virginia;

North Central includes: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin;
Southern includes: Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, and Texas.

Changing Clientele

Until the late 1950s, the majority of extension plant pathologists focused on disease problems influencing food production. The educational level of their clientele varied from very few college graduates to many with little formal exposure to science and science–based farming practices. Suspicion of “book farming” was a major problem for early extension specialists and made skill in educational psychology second only to the need for sound knowledge of the biology of plant pathogens and their control. Today the clientele often includes PhD-holding farmers and consultants in addition to clientele with little formal education in plant production or plant protection. County agents and regional extension personnel remain key for both extension programming and as a focus for educational programs.

In 2007, only 9% of extension plant pathologists listed their responsibilities as general or all plants and 17% have a non-food crop (e.g. turf, ornamentals, shade trees, floriculture, or others) as their primary area of responsibility. These appointments reflect the increasing urbanization of our clientele and the corresponding increase in importance of the turf, ornamental and nursery industries that supply products and services to homeowners in urban and suburban landscapes. The remaining ~75% of extension specialists have listed their one or more responsibilities as agronomic crops, cereal crops, forage crops, tree fruit, small fruit, vegetable crops, potato, citrus, mycotoxins, mushrooms, nematology, or others, reflecting the importance and specialization of these industries or specific problems of local importance. Other areas of specialization indicated by extension plant pathology specialists include: IPM, pesticide applicator training, diagnostics, urban gardening, water quality, and others. This specialization is reflective of specific governmental funding initiatives for integrative programs.

The means by which extension clientele receive their information has dramatically changed. Reliance on field demonstrations, local meetings, short courses and farmer institutes, local county extension agents, and printed fact sheets and bulletins has given way to 7-day a week internet access to information. More sophisticated clientele are becoming reliant on the computer for information that is increasingly dynamic in nature. Examples include weather based disease prediction programs and interactive diagnostic keys. The challenge to extension specialists to meet demands of increasingly diverse clientele is intimidating, and mechanisms used by specialists to meet these demands must also constantly evolve. Educational psychology remains a useful skill, but today is more commonly known as “adult learning styles.”

Changing Delivery Techniques

As extension methodology and clientele have evolved, so have the means by which we deliver information to our clientele. One major change is the internet, which has made extension bulletins, newsletters, and diagnostic keys available to the general public and other interested parties on a “24/7” basis. This technology now allows fact sheets and bulletins to be updated in “real time,” as well as the use of color illustrations at low cost. Often, the only hard copy is printed by the user at home or in the county extension office. In an effort to provide credible, research-based information on the web, eXtension was launched by the Extension Committee on Organization and Policy in 2006. Currently there are more than 70 university partners for eXtension, plus many industry and private sponsors. However, adoption of eXtension has been slow and many universities still rely on state-focused fact sheets and information sources. There is a movement​ towards centralization of information to reduce redundancy of effort outside of the eXtension format. An example includes accessible and easy-to-use image databases such as IPM Images ( IPM Images is one of several accessible and easy-to-use image databases available on the web. These databases also facilitate wiki-based fact sheets and other media that can be updated by users. Other examples include a diagnostic image database for the NPDN and fact sheets for a number of different websites such as, and vegetablemdonlin​ (Vegetable MD Online). All of these websites are updated on a regular basis. These are just a few examples of websites that are replacing books and CDs, and are often used by authors seeking to regularly update information such as resistant variety or pesticide recommendations. Websites that incorporate current weather data and dynamic disease prediction models are now widely available to growers and ag industry. The internet has also facilitated diagnostic efforts via digital photography, allowing county agents, growers, consultants, homeowners, and other clientele to rapidly communicate with extension specialists regarding plant diagnosis and problem solving.

The distribution of newsletters has changed significantly – from periodic mailings via the postal service to electronic newsletters, blogs, wikis, and podcasts. An integral feature of the NPDN’s Plant Diagnostic Information System (PDIS) is the AgAlert system, which uses e-mail to quickly alert stakeholders about pest threats. This information often reaches additional producers when news media, county extension agents, and others extend the AgAlert via more traditional venues such as radio spots, newsletters, and newspaper articles.

The internet also encourages direct communication between clientele and the extension specialist thorough email, IM (instant messaging), and video messaging. More sophisticated clients now seek particular specialists and contact them personally. Of personal note, it is interesting that on a weekly basis we will have growers and others ask us about research articles published in professional scientific journals that are now available on the web. The extension plant pathologists may now find themselves helping people from beyond the state of their assignment. These technologies also encourage communication among fellow co-workers that facilitate the collaboration that expands and maximizes educational efforts.

Other technology coming into broader use includes podcasts and informational videos which are available on the web. Included among this class of technology are online meeting venues such as that offered by the Adobe Connect software. Participants have the opportunity to log onto a website with features such as a chat box, PowerPoint presentation space, and quiz modules to facilitate participant interaction. Members can either call into a conference number on their telephone line or have the audio interaction solely via the web interface. Adobe Connect sessions are replacing conference calls because the software allows experts to share their knowledge with an audience, and because the sessions can be recorded and preserved indefinitely. Therefore, the Adobe Connect session, or portions of that session, can be replayed for training of additional audiences. There are several other software packages that offer similar technologies for computer-based education delivery, such as Centra Symposium.

As our clientele evolves in their comfort with technology they have also evolved in their savvy and how they perceive effective information delivery. Extension specialists can no longer travel to a location, deliver a standard seminar-style presentation, and expect the audience to retain and implement that information. The amount of information a grower must process and implement to make their operation profitable is much greater today compared to 1914 when the extension system was first formed. Today’s extension specialist must be creative with hands-on activities, the use of videos for information delivery, and other interactive activities. Considerable research on adult learning styles has been done that we must take into account when designing an effective extension program. In addition, to meet the demands of the administration and granting agencies, the impact of our presentations and implementation of the information must be evaluated by pre- and post-tests or other mechanisms that document audience comprehension. Therefore, in addition to being experts in our field, we also must make others aware that we are making progress in educating clientele and positively impacting the community both economically and environmentally. Marketing, strategy, and advertising have become central to our responsibilities and are necessary for future funding. While there are many new tools for extension specialists to use in educational programs, it is still critical that our clientele have face-to-face access on a regular basis, if they are to have confidence in our ability to understand their problems and make sound recommendations.

Looking to the Future

Extension specialists in plant pathology will certainly become more specialized in the future and most will likely have research appointments. It also is likely that as plant pathology faculty become more basic research oriented that extension personnel will be increasingly asked to teach courses such as plant disease control, plant-problem diagnosis and crop disease-related courses in our graduate curricula. Risks associated with this trend are that a fixed teaching schedule will reduce the ability to travel and may cause a teachable moment to be missed in extension programs. Also, fewer students will be trained as generalists because extension specialists capable of providing this training are becoming more rare. Perhaps of equal importance is who will train future extension plant pathologists? Although broad training will be available from institutions that offer Doctor of Plant Medicine degrees, the trend towards split extension and research positions with increasingly specific assignments suggests that the PhD degree will still be needed for future extension plant pathologists.

Extension programming will become more specialized and more integrated with research and other disciplines in the future. Examples of such programming include IPM, organic farming, sustainable agriculture, water quality, and other areas brought into focus by government programs. Organic agriculture has become mainstream with 6 to 8% of produce being marketed as organic, and there is increasing demand from urban populations for organic or locally raised produce. Growers responding to that demand are increasingly relying on extension specialists for science-based and organically acceptable solutions to pest problems. We must balance the needs of the organic community with the conventional farming community, and promote integrated pest management to both as cost-effective and sustainable pest management.

The government has recognized the value of marketing the results of federal funding to the general public. For example, the most recent Farm Bill requires integrative programs where funded projects must include both research and extension objectives, and money allocated to support both objectives. Federal funding is increasingly dependent on evidence of multi-state outcomes. An area where extension specialists excel is bringing people with specialized skills together to complete a task and communicate it to the public, as well as bringing public feedback back to the University researchers. Extension specialists are the key to effective communication about how taxpayer’s dollars are being spent to support the community and, therefore, are the key to continued federal funding. Recognition of extension’s role in the community is often still underappreciated, particularly by our urban clientele. As extension’s role in the community continues to evolve, those communication skills at which we excel will be tested. Although we will find more novel and effective ways for communicating with our audience, nothing can replace the personal interactions that led to the founding of the extension service in 1914.

Suggested Readings

APS. 1999. Directory of Extens​ion Specialists. Online. APSnet, The American Phytopathological Society, St. Paul, MN

Biggs, A. R., and Grove, G. G. 1998. Role of the world wide web in extension plant pathology: Case studies in tree fruits and grapes. Plant Dis. 82:452-464.

Franz, N. 2007. Adult education theories: informing cooperative extension's transformation. Vol. 45, No. 1, Article 1FEA1, Journal of Extension

Hardwick, N. V. 1998. Whither or wither extension plant pathology? Plant Path. 47:379-393.

Horne, C. W. 1981. Extension: The face of plant pathology. Annu. Rev. Phytopathol. 19:51-67.

Jacobsen, B. J., and Paulus, A. O. 1990. The changing role of extension plant pathologists. Annu. Rev. Phytopathol. 28:271-294.

Rasmussen, W. D. 1989. Taking the university to the people. Seventy-five years of cooperative extension. Iowa State University Press, Ames, IA.

Sherf, A. F. 1973. The development and future of extension plant pathology in the United States. Annu. Rev. Phytopathol. 11:487-512