SEED INSPECTION 31 



FIELD TESTS OF VEGETABLE SEEDS 

 TYPE AND VARIETY STUDIES— SECTION 261 II 



Conducted by the Seed Laboratory* 



Again, lor the 23r(l year, field trials were conducted by the State Seed Laboratorv 

 to determine the trueness-to-type of certain kinds of vegetable seed offered for sale 

 in the Commonwealth. Tests were run on sweet corn and radishes from a collection 

 made by the State Seed Inspectors. These samples were taken by the Inspectors 

 from 35 retail establishments, and represent the offerings of 26 wholesale seedsmen 

 selling in the Commonwealth. 



Forty-nine samples of sweet corn were field-tested. These forty-nine samples 

 represented seventeen varieties. All corn varieties were hybrids, i.e., none were 

 open pollinated. All samples of both corn and radish were subjected to laboratory 

 germination tests prior to field testing. 



The corn was planted May 27. Each sample was planted in duplicated 60-foot 

 rows, with the seeds spread one foot apart in the rows and the rows three feet apart. 

 Wherever possible an authentic cheek sample was included as a basis of comparison. 

 Observations were made several times during the growing period and complete 

 records were taken. All samples were found to be properly labeled. 



Observations were also made to determine the number of "inbred" plants pro- 

 duced by the 120 kernels planted from each lot of hybrid seed. The term inbred 

 for the purposes of this discussion is defined as "a plant uniform in gross character- 

 istics owing to self or sib pollination for several generations." In these hybrid 

 varieties the inbred plants stood out because of their smaller size and atypical or 

 unmarketable ears. 



The remarks found in the Field Performance column in Table 4 indicate the 

 numbers of inbreds found. This column was figured on the total of the duplicate 

 rows, i.e., the plants produced from 120 seeds. 



The economic importance of inbred plants in a sample of hybrid sweet corn should 

 be mentioned. An average acre of corn should yield 12,000 marketable ears, and if 

 5% of the plants are off-type to the extent that the cars are not marketable, the re- 

 sultant loss would be 600 ears per acre. This is an example of how seed that is true- 

 to-type, as well as of good quality otherwise, can pay off in dollars and cents. 



On May 28th forty-eight lots of radish were planted in 12-foot rows Avith the rows 

 3 feet apart. All samples were duplicated at random in the field, and authentic 

 check samples were included for all the varieties grown. All 48 lots were found to be 

 labeled correctly, i.e., there were no violations to be reported. 



*\^'a!do C. Lincoln, Research Instructor 

 Kenneth Pelton, Laboratory .Assistant 



