CEREALS AXD PULSE CROPS I43Q 



!?) (ireen leaves. . . . 



b) Grey-green leaves 



c) Silverv-grev leaves 



226 



It is seen from this table that the plants affected by the disease had 

 rough green learves, while those wliich were resistant had grey-green 

 leaves of the intermediate type or silvery-grey leaves of the male t3^pe. If 

 it be considered that only the seeds of those hybrids were used which 

 were not attacked by rust the preceding year and which, in most cases, had 

 grey -green leaves, and also that one is depending on the characteristics of 

 the second generation, it must be recognised : 



(1) that the resistance to rust is a recessive character. 



(2) that it fully obeys the Mendelian law. 



(3) that between this characteristic and the structure of the leaves 

 there does not exist an absolute correlation, since the immune plants are 

 found in all the classes [a, b, and c). 



In the second generation there are types which ma>' also have an in- 

 terest from the agricultural standpoint, and which will serve for the future 

 experiments that it is proposed to make with a view to obtaining a form of 

 sunflower resistant to rust and useful for agriculture. Meanwhile, these 

 initial experiments have given a result of ]^ractical importance, namely 

 that by crossing appropriate parents a variety of Sunflower can be obtained 

 which is resistant, at one and the same time, not only to Homeosoma nebii- 

 lella Hb., and to O/ubanche cnniana ^Vall., but also to Pitccinia Hdianthi 

 Schr. 



073 - Results of 20 Years Experiments on Maize at the Agricultural Experiment 



Station, Ohio. — William, C. G. and Welton, V. A. in Bulletin 0/ the Ohio A -^ri cultural 



F.xpcyiminl Station, Xo. 282, pp. 71-109, 9 fig. Wooster, Ohio, 1915. CROPS 



i) Comparing a five year rotation system with the continuous growing 

 of maize, the former has given an increase of 13 to 14.79 bushels per acre 

 in spite of the heavier use of manure and fertilisers under continuous cul- 

 ture. The five year rotation consisted of maize, oats, wheat, clover and 

 timothy, clover being the fourth year, and timothy, the fifth, both being 

 sown together in the wheat. Comparing a five 3^ear with a three year rotation 

 (maize, wheat, clover) the latter has given an increase of 6 to 8.39 bushels 

 per acre. Comparing a three year rotation with continuous cropping, 

 no fertihsers used in either case, the yield of corn from the former is 127 

 per cent greater, than in the latter, as shown in Table I. The results for 

 the five year and three year rotations are given for an average of 20 and 

 17 years respectively. 



2) The use of phosphorus alone, in the form of acid phosphate, has 

 increased the yield of corn 8.28 bushels per acre. The use of manure alone 

 has increased the yield 31.27 bushels per acre as an eight year average. 



CEREALS 

 AND PULSE 



