28 MASS. EXPERIMENT STATION BULLETIN 398 



7. Spotted fireworm was generally more abundant than for many years. 



8. Lady beetles were unusually' prevalent. 



9. False armyworm (Xylena) was very prevalent, about as in 1941. 



10. Blossom worm {Epiglaea) was much less than normally abundant. 



11. Spanworms were about as usual. 



12. Cranberry girdler (Crambus) was more harmful than normal. 



13. Cranberry- weevil (Anthonomiis) was about as in other recent years. 



14. Cranberry spittle insect and tipworm were fully as troublesome as usual. 



Control of Cranberry Bog Weeds. (Chester E. Cross.) In all, 155 plots were 

 used during the season to test the value of various herbicides. The more inter- 

 esting results follow: 



Kainit. This potash fertilizer has been advocated as an herbicide for poison 

 ivy and has been used extensively in Europe to destroy charlock and wild mustard 

 in plantings of spring cereals. Results with 56 plots to test its value as a cran- 

 berry bog herbicide were not encouraging. No injury to either cranberry vines 

 or weeds followed its use in amounts up to 1000 pounds an acre when the foliage 

 was dry; and enough to burn weeds like poison ivy, loosestrife, beggar-ticks, 

 horsetail, or asters with their foliage wet damaged cranberry vines also. 



Zotox is widely advertised as a selective weed killer for eradicating crab grass 

 and various broad-leaved perennials from lawns and fairways. Different amounts 

 of solution of this chemical in various concentrations were tried on 46 plots against 

 some of the more common bog weeds. It proved to be valueless as a bog herbicide, 

 not being effective even on crab grass unless enough was used to injure cranberry 

 vines badly. 



Ferrous Sulfate. A solution of this chemical, a pound to a gallon of water, 400 

 gallons to an acre, was ver\' effective on low cudweed, with little injury to cran- 

 berry vines. This weed is often a serious pest on new plantings and on bogs where 

 grubs have caused areas to be bare of vines. 



Kerosene. About 20 plots, on a bog flowed for root grubs till July 15, were 

 treated with kerosene between August 2 and 12. A thick mat of crab grass was 

 almost completely destroyed with 200-300 gallons an acre. The same amount 

 killed barnyard grass, spreading witchgrass, and warty panic grass very eff'ec- 

 tively. Little harm was done to the relatively tender cranberry vines, most of 

 this injury being on plots treated during the middle of the day or when the vines 

 were wet. The time of day the treatments were made did not affect the killing 

 of the weeds. 



Amnwmum Siilfamate. Results of dry applications of this new chemical on 

 cranberry bogs have been reported heretofore. ^ This year it was tried in solu- 

 tion as a spray and gave some promise of being a useful herbicide for poison ivy, 

 loosestrife, chokeberry, feather and sensitive ferns, and asters, when used at a 

 rate of not more than one pound in eight gallons of water. Stronger solutions, 

 unless applied in small amount and with great care, were usually very harmful to 

 cranberry vines. Not enough work has been done with this chemical to justify 

 conclusions. It is peculiar that, when cranberry vines have been injured by its 

 use, new growth is slow to develop and its leaves are discolo.ed and undersized, 

 this perhaps indicating that the injury is greater than appears. Partly grown 

 cranberries sprayed with ammonium sulfamate solutions reddened noticeably in 

 a few days without showing other definite s'gns of injury. 



iMass. Agr. Expt. Sta. Bui. 378:47, 1941. 



