334 EXPERIMENT STATION RECORD. 



wlik-b is followed by cowpeas. This may be made a 5 or 6 year rotation by 

 leaving the land in grass either 1 or 2 years. 



As described in the previous abstract the tobacco grown received different 

 quantities of fertilizers. In 1906, wheat after a highly fertilized crop of tobacco 

 yielded 21 bu. to the acre, while after the tobacco fertilized with 400 lbs. of 

 3-8-3 fertilizer it yielded 8 bu. In 1907 the yield of wheat after a heavy fer- 

 tilized crop of tobacco was 29 bu. per acre, and after a poorly fertilized crop 

 only 12 bu. No fertilizer was apiilied to the wheat except that the fields were 

 limed for the benefit of the succeeding grass crop. 



In 1900 the wheat stubble was disked during the simimer and a heavy seeding 

 of grass sown September 3. One part of the field received a mixture of timothy, 

 redtop, and clover, and another clover alone. April .5 a top-dressing of 300 lbs. 

 of nitrate of soda per acre was applied just before a i-ain. Where the nitrate 

 was used on the clover the yield of field-cured hay was 2.8 tons, and where it 

 was not used 2.09 tons per acre. The increase in yield failed to pay for the 

 nitrate ai)plied per acre by $1.61. The mixed grasses receiving nitrate gave a 

 yield of 5.06 tons per acre of first-class hay, while where the nitrate was not 

 used the yield was only 3.3 tons. The hay was sold for $13 yier ton, so that the 

 gain from the use of the nitrate was $22.88 per acre, the cost of the nitrate 

 being $8. 



The successful points with grass in the dark tobacco district, as indicated by 

 this work, are a fine mellow seed bed 2 or 3 in. deep, a heavy seeding of mixed 

 grasses, and a liberal top-dressing with nitrate of soda in the spring. The corn 

 and the cowpeas have not yet been grown, but from 40 to 60 bu^ per acre of coi-n 

 and 1 ton or more of cowpea hay are expected. 



Notes are given on the home growing of tobacco seed, and the improvement 

 of tobacco by seed selection and breeding. 



Results of seed investigations for 1907, Ij. II. Pammel and Charlotte M. 

 King (loica Sta. Bah 99, pp. 71-91, figs. 22 ).^The results of analyses of seed 

 samples sent in by farmers and others, and also of some purchased in the open 

 market in 1907, are reported. 



Of 134 samples of red clover examined the average purity was 96.6 per cent 

 and the average vitality, grown in sand, 86 per cent. Medium I'ed clover 

 showed an average germination of 86.6 per cent in 41 samjiles examined, and 

 28 samples showed a purity of 99 per cent or more. In 14 samples of mam- 

 moth clover tested the average germination was 88.5 per cent. Ten samples 

 had a purity of 99 per cent or more and 14 of 97 per cent or more. Five 

 samples of white clover were all above 98 per cent in purity, with an average 

 germination of 76.6 per cent. Alsike clover in 40 samples received contained 

 impurities of 1.14 per cent on the average. The average vitality of all sam- 

 ples was 81.6 per cent. One sample had a vitality of 95 per cent, 5 of about 75 

 per cent, while some ran as low as 22 per cent. 



The average vitality of 44 samples of alfalfa seed was 69.2 per cent and the 

 average purity 91.1 per cent. The different samples ranged from 90 to 38 per 

 cent in vitality. The impurities found in 44 samples of timothy were not very 

 pronounced except in a few cases. The purity in 34 samples was 99 per cent 

 or more and the average of all samples was 98.9 per cent: The purity of 21 

 out of 24 samples of flax ranged from 96 to 100 per cent. The average vitality 

 in sand was only 66 per cent, but in the incubator the avei'age rose to 98 per 

 cent. The pei'centage of purity in 28 samples of millet was 95 per cent or more. 

 In 3 samples it ranged from 85 to about 95 per cent, and in 2 samples it was 

 under 85 per cent. 



The purity of 7 samples of blue grass was 99.7 per cent, with an average 

 germination of only 17 per cent. The percentage of germination in the best 



