Vol. 51—1997 - NorthEastern Weed Science Society

192
AGRICULTURE NEEDS MORE WEED SCIENTISTS
Larry J. Kuhns and Tracey L. Harpster!
INTRODUCTION
Weeds ust be controlled to produce marketable crop yields, for human safety, and for aesthetic
reasons. Ph sical methods of weed control are highly labor and/or energy intensive, and in many
cases are m re dangerous to crops and people than herbicides. They are not practical solutions to
most weed roblems in developed countries. Non-chemical control methods used to control insects
and disease, such as selecting and breeding crops for resistance, or developing biological controls,
have limi applications in weed control.
MEfHODS AND MATERIALS
In 199 , current and historical data on pesticide production and use were collected from
governmen and industry sources. It was organized and summarized to show the significance of
herbicides t late twentieth century agriculture.
At the ame time a survey of 15 of the leading universities in the country in entomology
(Alabama, rizona, California, Florida, Georgia, Indiana, Michigan, Nebraska, North Carolina,
Oregon, Pe nsylvania, South Carolina, Tennessee, Virginia, and Washington); plant pathology
(Arizona, alifornia, Colorado, Iowa, Kansas, Kentucky, Minnesota, New York, New Jersey,
North Car ina, Ohio, Oregon, Pennsylvania, Virginia, and Wisconsin); and weed science
(Alabama, rkansas, California, Colorado, Florida, Indiana, Iowa, Kentucky, Michigan,
Mississippj, Nebraska, North Carolina, North Dakota, Oklahoma, and Wisconsin) was conducted.
The num r of Masters and PhD degrees conferred to U.S. citizens and foreign students, graduate
students cu ently enrolled, courses offered, and teaching facuIty were determined. All data
represent a erages of the 15 programs surveyed.
RESULTS AND DISCUSSION
Chem cals are needed to efficiently and effectively control weeds. Only 4.2% of farm
expenditur s were used for all pesticides in 1993 (Table 1). Based on the data in Table 2 (56% of
pesticides sed are herbicides), only about 23% of farm expenditures were used on herbicides.
Herbi ide use steadily increased until 1984 (Table 3). The decrease in use since 1984 is
probably d e to the introduction of new products that are applied at extremely low rates of ai/ha
compared 0 older materials.
Herbi ide use, in terms of product used or expenditures, is greater by a wide margin than that of
insecticid and fungicides combined (Tables 2,3,4).
The .S. produced about 1.3 billion pounds of pesticide with a sales value of $8.25 billion in
1993 (Tab e 5). About two thirds of all pesticides produced in, and exported from, the U.S. are
herbicides (Table 6).
Abou 40% of all of the herbicides used in the world are used in the U.S. (Table 7). Only 32%
of the ins ticides and 14% of the fungicides are used in the U.S.
1Prof. of 0 ental Horticulture and Research Associate.Dept. of Horticulture. The Pennsylvania State
University. niversity Park, PA 16802