CULT:Borer

re:Cygon 2E for borer

Yes, it is a systemic and a very powerful one.  It is important to use
protective clothing(rubber boots & gloves, respirator; definitely NOT bermuda
shorts!), to spray when there is no wind, and to wash yourself, clothing,
sprayer, etc. when finished.  In a windy site, using a larger droplet will
minimize drift.  Follow ALL label directions, because it can be absorbed thru
the skin and cause SERIOUS liver damage.  Once the material is on the plant
and dry, it won't injure you, but I certainly wouldn't spray it near food
plants.

Yes, you should apply in the spring, when plants are 3 - 6 " tall, and soak
the plant--drenching the soil is of doubtful value.  The point of applying in
the spring is to get better coverage on still-small plants and also to get the
borers when they first hatch and begin their trip down the inside of the leaf.
You should try to arrange your application when there will not be rain for 24
hours; the material needs to dry on the leaves and get into the plant's
system.  A second application 10 days later is recommended.

Some reasons why you don't get 100% control:  

Crowded or taller foliage is more difficult to cover thoroughly.

The moth(s) may fly more than once, or the hatch may be earlier or later due
to weather conditions.

If you use a water softener, or have very alkaline water, Cygon will degrade
very fast.  John (my husband) learned in pesticide applicator training that a
high water pH can cause it to lose 1/2 its efficacy within 20 minutes of being
mixed.  The solution is to test your water for pH and add sufficient pool
acidifier to bring it to neutral BEFORE adding the Cygon.

When used properly, Cygon will give 80%+ control.  Assuming a heavy
infestation, it may take you two years to get the borer under control.  Then
the key is to watch your irises carefully after bloom.  The farther down the
leaf or stalk it goes, the larger the borer gets.  You need to be looking for
borer sign in the 2 to 4 week period after bloom, so that you can get the
stragglers before they reach the rhizome. We've not found any data on how long
the Cygon stays in the plant.  It must be in the rhizome, but may not be
strong enough (or persistent enough) to overcome the fast rate of borer growth
once it gets there.

Three other caveats:

Clean up and cut back after frost (to catch eggs of late flying moth) and do
not compost the waste.  (We put iris waste in plastic bags, treat with Cygon,
and leave for a season before dumping.  Where legal, burn it, or send it away
to the dump.)

There's no substitute for keeping careful watch & recognizing early signs,
because I. pseudacorus is naturalized all over North America in borer
territory and they LOVE those big, fat rhizomes, so there is always a
reservoir of infestation.  At least in our part of the world, pseudacorus is
more of a problem than versicolor.

In recent years we have seen what we think may be a late hatch--borers still
in the leaf or rhizome at transplant time, when we normally expect them to
have pupated and gone into the soil.  Hope we're wrong about this, or that it
is a weather-related phenom, not permanent.

I understand that this material may have already been covered, but people seem
to be willing to speculate.  Our information comes from the Cygon 2E labeling
and from the NYS Dept of Environmental Conservation & Cornell Co-operative
Extension.

It is because we have a healthy respect for this material that we are so
interested in the nematodes.  I'm working on retreiving that info--I'm still
pretty inept on the Web.  Thanks for the pointers, Claire and Webmaster.

Helen Schueler.  at Phoenix NY prox 20 
miles north of Syracuse and south of Oswego, Zone 4b-5a, lots of snow cover
most years.
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index