Thank you Mark and NH for your replies to my questions. I received some further info from a chemist who works with wood preservatives at the Forest Products Research Lab in Madison WI. He suggests a homebrew concoction which will provide temporary protection against fungal growth. It is prepared by making a saturated solution of 20 Mule Team borax and adding a pint (cost about $10.00 at Menards) of home humidifier water treatment which contains quaternary ammonium . The borax is added to 5 gallons of hot water until no more will dissolve, and then the humidifier chemical is them added. The mixture is then sprayed or brushed on. The chemist said that some fungal staining organisms are not inhibited by borax and thus the addition of quaternary ammonium.
He also suggested a commercial product used in sawmills called Kopcoat NP-1. A sawmill near me uses this in a diptank to treat pine lumber. It is also used to treat logs which are sent overseas in the holds of ships. The cost is aboput $50.00 per gallon but it is used in dilution of 1 to 100, so 1 gal of concentrate makes 100 gallons of mixture. It contains borax and an iodine salt and does not stain the wood. One problem is that the smallest quantity sold by the manufacturer is 5 gallon pails. I am going to buy a gallon of concentrate from the local sawmill er who gets it in drums.
NH, I will be slabbing the logs in the first cutting and they will be re sawn to final dimensions later, so I shouldn't have sticker marks. Would like to throw them in a pond but don't have one close by.
I looked up yardguard and it appears to do the same thing as Kopcoat but is considerably more expensive.
Fortunately the wet weather here in WI has delayed cutting of the trees but I will still need to apply a treatment.