April, 1932] Agricultural Research in N. H. 15 



showing 1.79 per cent, leafroll, were rogued and dug 80, 90, 101, 110 and 

 124 days after planting. When used as seed the next year they showed 

 the following respective per cents, of leafroll: 6.0, 12.1, 14.1, 15.3 and 

 49.7. (Purnell Fund) 



Burgundy Mixtures 



Studies of Burgundy mixtures by O. Butler indicate that calcium ar- 

 senate is an extremely effective stabilizer; arsenate of soda is excel- 

 lent; but lead arsenate is without effect. (Adams Fund) 



Dye Adsorption by Plants 



Hardened plants show a higher adsorption of dyes than do non- 

 hardened plants, finds S. Dunn in studies of cabbage, brussels sprouts 

 and alfalfa. A series of experiments were performed for the purpose 

 of determining the effect of length of time of hardening on colloid con- 

 tent. In general, it was found that dye adsorption increases with 

 length of exposure of the plants to cold up to 4 or 5 days, but that 

 longer exposures cause a decrease, particularly noticeable in plants 

 hardened for 12 days. 



It was observed during the course of the experiments that different 

 parts of a given plant not infrequently reacted dissimilarly following 

 the freezing test, whether or not the plant had been previously 

 hardened. In most cases the leaf -blade was more seriously injured than 

 the petiole, or stem. 



An attempt was also made to identify more particularly the nature 

 of the colloid or colloids responsible for hardiness. (Adams Fund) 



European Corn Borer 



A steady extension of the one-generation phase of the European 

 corn borer into the western border of New Hampshire is reported by 

 W. C. O'Kane. 



In a number of towns the insect now occupies the same territory in 

 which the two-generation phase is found. This brings up the situation 

 anticipated in an earlier report ; namely, the possible effect of this mix- 

 ture of the two phases on future abundance of this insect in New 

 Hampshire. It is possible that the one-generation phase, if it be- 

 comes predominant, may turn out to be more destructive than the two- 

 generation phase heretofore present, because the latter has, apparently, 

 tended to be self-limiting through its inability to accommodate itself 

 to the length of the growing season. 



It will be necessary to watch the developments closely in the western 

 part of the state, therefore, and to plan future work in accordance with 

 the trends observed there. (Adams Fund) 



Contact Insecticides 



Two principal lines of inquiry have been followed up during the 

 3'ear in the studies of contact insecticides conducted by W. C. O 'Kane, 

 W. A. Westgate and E. C. Glover. 



