PRELIMINARY REPORT ON CHEMICAL WEED CONTROL 

 IN CONIFEROUS NURSERIES 



By p. C. Kitchin 



Forest Assistant, U. S. Forest Service 



The weeding of seedbeds and transplant rows is one of the most 

 expensive items in the administration of the Forest Service Nursery at 

 Haugan, Montana. In the case of two year old seedlings, about 7 per 

 cent of the cost is due to weeding. No satisfactory method of weed 

 eradication, except by hand, has been devised for this location. Even 

 in weeding by hand, m.uch injury is done to the seedlings in pulling 

 the weeds. This is especially true with the redtopped sorrel {Riimcx 

 acetosella L.), which sends out long underground runners, giving rise 

 at frequent intervals to other plants. In removing a medium sized 

 plant of this species from a seedbed, it is no uncommon thing to dis- 

 locate the soil for a radius of several feet, the breaking before being 

 completely disengaged from the bed. This practice results in the 

 pulling up of numerous seedlings and the exposure of the roots of 

 others. Some less destructive method is desirable. However, if the 

 weeding of coniferous nurseries is to be successfully accomplished by 

 the use of chemicals, the problem seems to be one of finding a rela- 

 tively cheap chemical solution which will kill the weeds and not injure 

 the stock or the soil. 



Most of the work which has been done in this country has dealt 

 with the killing of weeds by chemical sprays after the plant has at- 

 tained a considerable size. Apparently, an easier way would be to 

 kill the small seedlings as it emerges from the seed coat in the process 

 of germination. At the Forest Service Nursery at Halsey, Nebraska, 

 the most important secondary factor, following the treatment of the 

 soil for damping oft fungi, has been that of weed control. The 

 records for ]912 show that weeding cost only about 29 per cent as 

 much in beds treated with sulphuric acid as it did in those which had 

 undergone no treatment. Copper sulphate and zinc chloride have 

 proven of value in weed control at several nurseries.^ 



At the Savenac Nursery some work has been done by \\. C Rogers 

 on the control of damping oft' fungi in seed beds through the use of 



'Data taken from United States Department of .Xrgricultnrc Hullctin l.'>:'.. by 

 C. Hartley and R. Pierce. 



