In February 1974, a commercial rabbit and deer repellent (active ingredient: 

 tetramethylthiuramdisulfide) was tested on transplants of bitter panicum and sea oats. The 

 repellent was sprayed without dilution at the rate of 12 ounces per 100 plants. Cost of 

 treatment per plant was 1.8 cents (1974), not including labor costs. The period between 

 planting and collecting the data was without rainfall. Results (Table 52) showed a significant 

 reduction of rabbit damage to panicum, but none for sea oats. The repellent would have to 

 be nearly 100 percent effective for economical use. A more effective method against damage 

 to sea oats was to plant the trimmed culms 14 inches deep, so that only a few inches of 

 leaves were exposed. 



Table 52. 



Effects of commercial rabbit repellent on jackrabbit damage tc 



transplants. 1 



Repellent 2 



Culm chewed off near ground 



Culm pulled from ground 



Total damage 



Bitter panicum (8 inches deep) 



Treated 

 Untreated 



34 

 63 



4 



4 



38 3 

 67 



Sea oats (8 inches deep) 



Treated 

 Untreated 



22 

 27 



8 

 14 



30 4 

 41 



Sea oats (14 inches deep) 



Untreated 



1 



.... 



l 5 



1. Number of plants: 100. 



2. Chaperone (brand) rabbit and deer repellent, Sudbury Laboratory, Inc., Sudbury, Massachusetts. 

 Active ingredient: Thiram (tetramethylthiuramdisulfide). 



3. Significant difference at P„ Q - level. 



4. No significant difference. 



5. Significant at P„ ^ level from other treatments. 



Another deterrent to beach plantings was from free-ranging cattle before their removal. 

 Usually they remained in mid-island, but mosquito infestations during wet, warm weather 

 forced the cattle to the beach, especially at night. These circumstances resulted in cattle 

 bedding down on the 1,200-foot sea oats planting. In November 1969, the cattle consumed 

 nearly all exposed vegetation, which allowed winter winds to remove sand from around the 

 plants. Damage was still noticeable in June 1970. To prevent more damage, a two-strand 

 barbed-wire fence was constructed, which was partially effective. Cattle showed a preference 

 for bitter panicum over shoredune panicum or sea oats; however, they ate the sea oats when 

 a more palatable species was not available. 



Human damage from vandalism and from apparent ignorance, has been a disturbing 

 problem. Protective fences, both posts and wire, have been torn down, chopped down, and 



144 



