INTRODUCTORY NOTES 



These notes are written to suggest some of the methods of teaching 

 farm crops and also to suggest to the instructor how he may use the exer- 

 cises in this manual most effectively. The plan is to discuss some of the more 

 important types of laboratory exercises used in teaching farm crops. 



1. Identification of Plants and Seeds. Several methods may be used in 

 order to fix the identity of plants and seeds in the student's mind. 



(a) Drawing. Drawing seeds and plants necessitates the observation of 

 certain characters which might otherwise escape attention. In the case of 

 seeds a minimum size or standard should be set because the natural tendency 

 of the student is to make the drawings too small. Correct labeling is essential. 



(b) The Use of a Key. Keys are in printed form for the identification of 

 such crops as oats, barley, grasses and clovers. Many of these keys should 

 be simplified for use in secondary schools. 



(c) Descriptive Outlines. Describing specimens according to a set outline 

 is a useful method but has serious limitations. The student should have a 

 set of definite descriptive terms of which he knows the meaning. This method 

 should always be supplemented by one of the other methods in order to bring 

 out the differences in the specimens described. When literature on variety 

 or type description is available it may be used to supplement the study of the 

 specimens at first hand. 



(d) The Identification of Numbered Specimens Unlabeled. This method 

 is valuable because of the interest it arouses. Its purpose, however, is not 

 to teach but to test and drill. The student should know what mistakes he 

 has made and should correct them. 



(e) Class Discussion. Contrasts between specimens may be brought out 

 by class discussion. 



2. Judging. The most common error in judging exercises consists of 

 scoring and judging by the student before he has a real acquaintance with 

 the score card. To avoid this error and for the sake of thoroughness judging 

 work may well consist of three steps. 



Step. 1. Let the instructor explain the score card. Then have the stu- 

 dent examine specimens which illustrate the score card points as in Exercise 9. 



Step 2. In the case of potatoes, for example, have the student take 

 several samples which are later to be judged and place them in the order of 



7 



