436 EXPEBIMENT STATION EECOED. [Vol.38 



glumes until the anthers assumed a pendent posttion occupied an average of 

 10 minutes, uUliough it occasionally required only 8 minutes, while instances 

 were recorded where 30 minutes were required to complete the process. The 

 flowers opened only once, the glumes remaining open 2 to 3 hours. The stigmas 

 remained outside and appeared quite fresh for 24 hours after the glumes had 

 closed. The length of time required for the whole panicle to complete flowering 

 varied with the size of the inflorescence and the number of flowers, but aver- 

 aged about 7 days. 



Cross-pollination between the flowers of the same panicle was the rule, the 

 pollen from the higher and earlier-opening flowers falling on the stigmas of 

 the lower and later flowers. Cross-pollination by foreign pollen can occur 

 only in the flrst flowers to open and possibly in those late-opening flowers 

 whose anthers do not dehisce. Self-pollination can occur only where the stigma 

 remains surrounded by anthers which do not fall out. 



The relative frequency of foreign pollination was found to be 6 per cent 

 in a loose type of panicle with short glumes and only 0.6 per cent in a compact 

 type of panicle. In Tharthur there was 20 per cent foreign pollination. Ball 

 reported 50 per cent as the maxiujum. 



A number of artificial cross-pollinations were made in a study of grain and 

 glume characters. The grain is said to be either red, white, or yellow, while 

 the glumes vary in length in coniparisoii with the grain, from the commoner 

 type which is shorter than the grain to the less common type which is much 

 longer and completely conceals the grain. This latter type, so far as observed, 

 was always associated with a loose type of panicle. In the grain, red and yel- 

 low and red and white behave as simple allelomorphs, red being dominant in 

 both cases. Likewise, yellow and white may behave as simple allelomorphs, 

 or the heterozygote may be red, behaving as a dihybrid with a 9 : 3 : 4 ratio for 

 red, yellow, and white, respectively. The simplest explanation is deemed to be 

 that certain white-grained plants were undeveloped reds, requiring the pres- 

 ence of yellow to cause the red color to develop. The long and short glume 

 characters behave as simple allelomorphs. 



Variety study of the Irish potato, W. H. Wicks (ArJcansas Sta. Bui. 137 

 (1911), pp. 3-32, figs. 24). — This bulletin reports the results of extensive tests 

 conducted at Fayetteville from 1915 to 1917, inclusive, at Van Buren during 

 1916 and 1917, and at Springdale in 1917, together with storage tests and 

 brief notes on approved methods of potato growing and on the production of a 

 second or fall crop in the State. A classification as to season and color has 

 been made of the varieties employed in the test based on the scheme of classi- 

 fication suggested by Stuart (E. S. R., 32, p. 830). Bliss Triumph, the principal 

 commercial variety of the State, was used as a standard for comparison. 



At Fayetteville 62 varieties showed higher average yields than Bliss Tri- 

 umph, Irish Cobbler being first with 187.10 bu. of marketable tubers per acre, 

 as compared with 70.38 bu. for Bliss Triumph. For the July 15 digging, 6 

 red and 16 pink varieties gave a higher average yield than the standard variety, 

 while for the June 16 digging Irish Cobbler, Du.ssex Early Queen, and Early 

 Six AVeeks were the only varieties to exceed the State average, 71 bu. per acre. 



At Van Buren 17 varieties exceeded the standard, Burpee Extra Early 

 being the best with an average yield of 104.23 bu. of marketable tubers per 

 acre as compared with 69.64 bu. for Bliss Triumph. 



The highest yield at Springdale was obtained from White Mammoth, amount- 

 ing to 152.92 bu. per acre on old land. Bliss Triumph gave a yield of 69.74 

 bu. on old land. Potatoes grown on old land gave much higher yields in every 

 case than those grown on new land. 



