12 BULLETIN 188, U. S. DEPARTMENT OF AGRICULTURE. 



A special point in connection with the maturing period of the 

 differently spaced plants is that the plants in the six spacings fall 

 into three distinct classes, based on time of maturity. In order to 

 show this clearly, the lower part of Table V was compiled from the 

 data in the upper part of the same table. The unthinned plants 

 and those spaced to 2 inches are considered together as one class, 

 those spaced to 5 inches and those spaced to 8 inches are considered 

 as a second class, and the plants spaced to 12 and 18 inches are con- 

 sidered as a third class. The figures given are the averages of two 

 spacings in each instance. 



As already pointed out, the heads on the close-spaced plants 

 ripened earlier than those on the plants spaced to 5 or more inches, but 

 the table shows that the earliness was not proportionate to the 

 closeness of spacing throughout the six plats. The unthinned plants 

 and those spaced to 2 inches matured their seed at practically the 

 same time; the widest spaced plants, 12 and 18 inches, came next in 

 time of maturity; and the plants in the intermediate spacings, 5 

 and 8 inches, ripened last. This was probably due to the relative 

 favorableness to tillering and to head production by the tillers result- 

 ing from the different spacings. The close-sj^aced plants produced 

 very few tillers and the heads on the main stalks grew up and ripened 

 promptly and uniformly; the widest spaced plants had the best 

 conditions for tillering and the heads on the tillers had a fairly good 

 opportunity to develop; but the plants spaced to intermediate dis- 

 tances, while producing a relatively large number of tillers, were 

 sufficiently crowded to make it difficult for the heads on the tillers to 

 reach maturity. 



While the widest spaced plants matured earher than those spaced 

 to intermediate distances, and in this respect produced more favor- 

 able results, it is likely that the stumps left after harvest would be 

 larger on the widest spaced plants, and this would be a serious 

 objection, as is pointed out later. Considering the entire series, the 

 results obtained mth the closest spacing show that thicker seeding is 

 much to be preferred. 



In the results obtained in the 1914 test, as is indicated in Table 

 III, giving the yields, none of the tillers or branches produced seed. 

 There was a rather severe infestation of the field with midges at the 

 time the fijst heads (main stalks) were m flower, so that when the 

 later heads (branches and tillers) flowered, the field was so badly 

 infested that the heads were practically sterile. 



As is shown in Table III, close spacing resulted in only a slight 

 increase in the number of stalks per row over the number produced 

 by wide spacing, up to 12 inches. Table VI, a comparison of the 

 1913 results of the 12-inch spacing and of the rows in which the 

 plants were not thinned, shows this condition. 



