352 Bulletin 313 



order that the farmer may use early, medium, and late varieties and 

 thereby have different fields maturing at different times. In this way 

 he may extend his harvest over a longer period and still have his entire 

 crop harvested at the proper period of matiirity. In bad harvest seasons, 

 when the acreage grown is extensive this may be very important. 



A feature of the season of maturing, distinct from the ripening of the 

 seed, is found in the difference of time exhibited by some plants in 

 maturing the leaves and stems. Probably in the majority of plants, 

 the leaves and stems are considerably dried up and discolored by the time 

 the seed is ripe, all parts of the plant apparently maturing at the same 

 time. In other and apparently rarer cases, the foliage and stems remain 

 green and fresh, retaining their ability to function in assimilation, until 

 the heads are dry and the seeds are fully mature. Such types, in our 

 experitnents, have come to be known as " green leaf types." This green 

 leaf character would seem to be very valuable in a hay type of plant, 

 as such plants apparently retain their good quality and digestibility much 

 longer than do those plants that dry up early. 



Rust resistance. — One of the very interesting discoveries made in con- 

 nection with the Cornell experiments is that different timothy plants 

 show great variation in their susceptibility to rust {Puccinia graminis). 

 Rust on timothy has not been generally known as a serious malady, but 

 one of the first observations made by the writer in 1907 was the very 

 great abundance of rust on the experimental plats. This led to extended 

 observations and the malady was found to be abundant throughout the 

 State. Correspondence brought out the fact that it was also abundant 

 in Pennsylvania, the District of Columbia, and Indiana. Observations 

 made every year for the last five years in various parts of the State have 

 shown that rust is the most serious disease affecting timothy. The vari- 

 ation of different plants in their susceptibility to rust indicates the proba- 

 bility of securing strains resistant to the disease, and all selections of 

 practical types are made with this in view. Indeed, where rust is so 

 abundant as it has become in New York during the last five years, 

 a hea\^-yielding sort is likely at the same time to be largely resistant to 

 rust (Plate V, Figs, i and 2). 



It seems probable, from our experience, that rust-resistant types of 

 almost all forms of plants can be obtained. 



Variations in rapidity of growth. — Another interesting factor is the 

 rapidity of growth of different individuals. Many plants reach their 

 highest yield in the second year and decline thereafter, while other plants 

 do not reach their greatest yield until the fourth or fifth crop year. Ap- 

 parently those of rapid growth soon die, while those of slower growth 

 are longer-lived. How long timothy plants will live when cultivated as 



