66 PHYSIOLOGICAL PROCESSES IN PLANTS 



3. Suppose there are four good plants,but the fifth is smaller, or cannot 

 be seen at all. Dig down carefully and see if the kernel germinated, but 

 with its tip held in place by the tough skin of the kernel. What is your 

 conclusion ? 



4. Suppose one kernel out of the five has not even sprouted, while Mie 

 other four are an inch or so high. Conclusion ? 



5. Which is more likely to cause a poor early showing in the field, 

 crows, cold weather, or poor seed ? 



6. Show why seed corn should not be purchased already shelled. 



7. Why is it unwise to use the kernels at the tip of the ears ? Give at 

 least two reasons. 



Problems 



1. How many hills of corn in an acre if the hills are 3 ft. 6 in. apart ? 



2. How many kernels needed to plant an acre at three kernels to a 

 hill? 



3. How many kernels in an average-sized ear you are testing ? How 

 many ears of the sort you are testing to plant an acre ? 



Note. Fifteen ears of good size, at three kernels per hill, should 

 suffice for an acre. 



4. How many acres can be planted with the seed corn tested in one 

 tray? 



Note. Pupils may well test the germination of seed corn which their 

 fathers expect to use, wherever conditions permit. If their fathers are 

 not using seed corn, pupils may well offer to do this for neighboring 

 farmers. The ears to be tested should be carefully numbered, five 

 kernels taken from each by those doing the testing and arranged in small 

 envelopes or packets, numbered to correspond with the ears. When the 

 test is finished, send the numbers of the poor ears back to the farmer, 

 that he may know just what ears to reject. 



2. PERCENTAGE OF GERMINATION 



Method. A simple seed tester may be made out of two shallow ves- 

 sels, such as pie tins, and blotting paper or cloth. Cut the blotting paper 

 or cloth so as to fit the bottoms of the vessels. Heat the blotters in an 

 oven or boil the cloths in order to kill any germs that may be present. 

 Place a blotter or cloth in the bottom of one of the shallow vessels, wet it, 

 and place one hundred soaked radish or clover seeds upon it. Cover these 

 with another wet blotter or cloth, and place the second vessel on the other 

 as a cover. A glass plate may perhaps serve better as a cover. See that 

 the rims fit well. Set aside in a good growing temperature. 



Observe the seeds from time to time and remove all that have germi- 



