ADVANTAGES OF SOIL FUMIGATION IN STRAWBERRY CULTURE 



(Talk presented by Joe Teeling, Middleboro, Massachusetts at the Small 

 Fruit Meeting held on University of Massachusetts campus in January, 1959) 



For some years growers have been frequently plagued with poor yields because 

 of one or more contributing factors. One of the major causes, which often may 

 have been unrecognized, is root rot or black root. Its severity varies with the 

 seasons. Black root destroys root tissues thus preventing the plant from securing 

 sufficient water to mature all its fruit. The causal factor or factors in black 

 root may attack the root at any point. The root tissue below this point then dies. 

 In severe cases almost the entire root system is destroyed. Black root should not 

 be confused with red stele, another, even more serious root disease, which also 

 destroys the plant root system. Red stele is caused by a member of the soil fungi 

 which apparently works its way up the root destroying it. 



At first, black root was blamed on various types of soil fungi. However, 

 later investigations indicated that tiny microscopic worms called nematodes might 

 be a contributing agent. There are two of these nematodes that seem serious in 

 strawberry plantings. One is called the root knot nematode, which at present, is 

 more of a pr9blem in the Maryland area than in Massachusetts, although it can 

 exist here. The more harmful one in Massachusetts is the common meadow nematode. 



With the "spotlight" turned on nematodes, it was natural to try some form of 

 soil fumigation which might destroy many of these pests in the land to be set with 

 strawberries. Two of the first materials tried, and still used, were ethylene 

 dibromide (E.D.B.) and D-D which were injected into the soil by special tractor- 

 drawn applicators- These materials become a gas when released and as they move 

 upward through the soil destroy many of the nematodes. 



In 1954, I hired a commercial applicator to treat about 3 acres with E.D.B. 

 at a cost of about $50 per acre. Two of these acres did well. One did very 

 poorly. There seemed to be little difference between the treated area and a 

 check plot which had no treatment. In no field did E.D.B. eliminate black root. 

 However, I repeated the treatment on another piece of land in 1955. At the 

 same time, I fumigated approximately ^ acre with methyl bromide which was applied 

 under a plastic cover. This material was very expensive and laborious to apply. 

 However, it offered much more than the E.D.B. or D-D in that it had some fungi- 

 cidal action as well as serving as a nematocide. It, also, destroys all weed 

 seed in the soil. The superiority of the plants grown on the methyl bromide 

 treated soil was very evident in both appearance and yield. This plot was also, 

 nearly weed free. 



In the fall of 1956 I decided to treat an acre with methyl bromide which 

 I did at a cost of over $500. It was a tedious task involving the moving of a 

 plastic cover about 25 times. On the same piece of land I treated a small area 

 with chloro picrin. Although results were the same, the higher cost of this 

 material precluded its further use. The field previous to fumigation was heavily 

 infested with weed seed and considerable "witch grass." Red stele had been 



