10 BULLETIN 668, U. S. DEPARTMENT OF AGRICULTURE. 



beans, such as the tepary or soy, were used as the nurse crop. A 9- 

 hole plate was used in planting a mixture of cotton and soy beans, 

 but owing to the low percentage of germination of the latter the 

 stand secured was rather poor. 



In making these plantings the seeds were mixed on the basis ratio 

 of 1 to 1. Some rows were planted with mixtures containing less 

 than half cotton, but none containing more than that amount. Where 

 a 1 to 2 mixture was used the stand of cotton was not as good as 

 desired. However, the cotton used had a relatively low percentage 

 of germination. "With a variety giving a better germination the 

 1 to '2 mixture might prove to be satisfactory. Here, again, the rate 

 of mixing must be determined in each instance on the basis of the 

 percentage germination of the different seeds used and the size of the 

 corn plates used in planting. 



Under specially favorable conditions it may not be necessary to 

 plant a nurse crop in order to conserve select cotton seed. Mr. D. A. 

 Saunders, of, the Bureau of Plant Industry, obtained very satisfac- 

 tory stands in 1917 at Greenville, Tex., by planting delinted Lone 

 Star cotton seed alone with both a 4-hole and a 5-hole corn plate. 

 The seeds were dropped 12 to 18 inches apart, and one or two plants 

 grew in each hill, as the soil conditions were favorable to good germi- 

 nation. As no thinning was necessary, a maximum increase of seed 

 resulted. But under most conditions the chances of obtaining a 

 good stand would be greater were a nurse crop used. 



ADVANTAGES IN NURSE PLANTING. 



The chief advantages to be gained by using a nurse crop in in- 

 creasing select cotton seed are the saving in select seed and the result- 

 ant possibility of more rapidly increasing the supply of such seed. 



The saving involved in planting seed mixtures in hills, as sug- 

 gested herein, might easily amount to 30 or CO per cent where three 

 to six seeds are planted in each hill. In subsequent increase plant- 

 ings the saving might be even greater, as most of the plants removed 

 in thinning would be nurse plants and not select cotton plants. 



The following hypothetical example will serve to illustrate thesa 

 advantages of nurse planting: Assuming that from a select plant 

 there has been gathered a quarter of a pound of seed cotton contain- 

 ing 600 seeds and that all these seeds are to be planted in a progeny 

 row, the number of hills that may be planted will vary between 100 

 and 600, according to whether the seeds planted in each hill number 

 six. five, four, three, two, or one. Assuming further that only one 

 plant in a hill is to be left to mature, and that each will produce, as 

 did the parent plant, 600 seeds, then on the basis of 3,600 seeds to the 

 pound, the increase in seed will vary from 17 to 100 pounds, depend- 

 ing on the rate of seeding used. (Table I.) 



