59 



light, however, each evening, heginning just after sunset and con- 

 tinuing for a few hours for about 12 weeks, and, as a result, ripe 

 seed was obtained on many of the plants in the latter part of 

 March. It was possible to plant this seed out of doors and thus 

 secure the second generation crop during the same season. The 

 utilization of artificial illumination is particularly valuable in such 

 work, especially for the relatively small number of first genera- 

 tion plants. These occu])y little space and, since they can lie 

 lirought to maturity in sufficient time to plant a second crop out 

 of doors in the early spring, an entire season may be gained. 



Sorghum smut investigations 



The main studies during the past year have been in connection 

 with the resistance of various hybrids to the covered kernel smut. 

 The second generation progenies of sixteen dififerent crosses of 

 cjuite diverse parentage were inoculated with this smut and grown 

 to maturity, and quite divergent results were obtained with many 

 of the hybrids. A cross between the two susce]Jtible varieties 

 Dawn Kafir X Red Amber Sorgo gave 60.9 per cent, infection. 

 This corresponded rather closely to the per cent, of infected plants 

 obtained with the Dawn Kafir and was somewhat higher than 

 that obtained wnth the other parent. Red Amber Sorgo. The hy- 

 brids Feterita X Sumac Sorgo and Feterita X Dawn Kafir gave 

 percentages of infection approaching or somewhat above 50 per 

 cent., but lower than that secured with the susceptible parent. 

 Feterita X Brown Durra, Feterita X Manchu Kaoliang and Fe- 

 terita X Red Amber Sorgo, gave comparatively low percentages 

 of infection, ranging between 13.8 to 22.8 per cent. In all the 

 combinations in which varieties of Milo were used as the resistant 

 parent, low ]iercentages were secured. Black Amber Sorgo 

 crossed with varieties of IMilo gave 14.2 to 19.2 per cent, infection 

 and Dawn Kafir crossed with the same varieties gave 6.5 to 12.2 

 per cent, infection. It is not at all clear just what is the actual 

 mode of inheritance of the resistant quality. The results are 

 complicated by failure to secure practically 100 per cent, of in- 

 fection of the susceptible parents, since this depends upon various 

 environal factors which greatly influence the process. However, 

 the results seem to indicate that the mode of inheritance is some- 



