MANUAL OF GENERAL AGRICULTURE. 



40 



49. PLUMP AND SHRUNKEN SEEDS. 

 Materials : A box about 4 inches high, a foot wide 

 and 2 feet long. Half pint sample of wheat seed and 

 scales. 



(a) Calculation of Plant Food in Seeds. Weigh 100 

 plump, well-formed wheat seeds. From this weight and 

 the following data compute the grams of nitrogen, phos- 

 phoric acid, and potash per 1000 wheat seeds. Wheat 

 contains about 2 per cent nitrogen and 90 per cent dry 

 matter. The dry matter contains about 2 per cent ash, 

 about 50 per cent of this ash being phosphoric acid and 

 33 per cent potash. Repeat the experiment, using 100 

 shrunken seeds. 



(b) Growth of Plump and Shrunken Seeds. Select 

 12 plump seeds and also 12 that are shrunken. Fill the 

 box with good rich, moist, loamy soil. Plant the plump 

 seeds in one end and the shrunken seeds in the other. 

 Keep the soil moist and warm. Examine the young plants 

 from time to time as they germinate and grow. Note the 

 number of plants secured from the plump seeds and from 

 the shrunken seeds. Let the plants continue to grow for 

 several weeks. 



Questions: Can you detect any difference in the 

 hardiness of the plants and the amount of plant material 

 produced by the two grades of seed? State your conclu- 

 sions. 



50. DEPTH OF GERMINATION. 



Materials: Three half-gallon fruit jars, three pint 

 fruit jars. 



(a) Large Seeds. Place about 1% inches of good 

 moist soil in the bottom of each jar. Plant one with peas, 



