Electric fence tape. Not wire. You've seen the stuff, looks like a 30m/100ft tape measure.  Used around cattle yards, horse fences, strip grazing areas, etc.
 
From tree to tree, to keep it on/above the poly pipe, put loops/cable ties (something like an o-ring maybe) on/over/around the pipe, thread the tape through the loops and tension it between the trees, so it pulls upwards and sits just above the poly pipe.
 
They'll have to contact the tape before they contact the poly pipe when landing.
 
Any type of petroleum product applied to the pipe will progressivley wash off as you irrigate/when it rains and will contaminate the ground. Not good.
 
A shotgun works well, but you'll be repairing shot holes in the poly pipe all the time 
 
POLY TAPE 400M X 12MM - ELECTRIC FENCE POLYTAPE WIRE | eBay
 
Fencing wire braid and tape | Fences, Australia, Standard, Fence, Hishock | Electric Fence Australia - online electric fencing
				
			 
			
		 
			
				
			
			
				Kev..
 
Going ... going ...  almost gone ... GONE !! ... 2004 D2a Td5 Auto "Classic Country" Vienna Green
2014 MUX LST with fruit
2015 Kimberley Kamper "Classic"
			
			
		 
	
Bookmarks