EXERCISE 40. A FIELD STUDY OF WEEDS 



Equipment: Spade and magnifying glass. 



Method: During the early fall season make a trip 

 across the neighboring corn fields and secure a sample of 

 each different weed that is encountered. Dig or pull the 

 weeds and see that each specimen includes roots, stems, 

 leaves, and seed or blossom. 



The small plants may be pressed between the leaves 

 of a book and mounted entire on pieces of cardboard. 

 Strips of gunamed paper or court plaster may be used to 

 attach the specimens to the cardboard. Specimens of 

 some of the larger plants may be confined to a section of 

 the stem, a leaf, and the flower or seed. In the lower 

 right-hand corner of the cardboard give the common name, 

 the scientific name, and the date when the weed was 

 collected. Doubtful specimens should be sent to the State 

 agricultural college or experiment station for identification. 

 These mounted specimens will furnish material for a second 

 exercise, at which time a detailed study should be made 

 of the root systems and flowering parts with reference to 

 the method by which the plants are propagated. 



Discussion: Weeds are one of the most persistent and 

 costly annoyances on the farm. They injure the farmer 

 by reducing his crop yields and greatly increasing the labor 

 necessary to produce a crop. Some of the injurious eff'ects 

 of weeds are the following: 



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