Re: [compost_tea] little microscope

From: <soilfoodweb_at_aol.com>
Date: Tue, 22 Jun 2004 18:34:38 EDT

Hi Laura -

I'm jus getting back to the list serve after a break too.

The hand-held microscope didn't pan out. Sigh. The UV light source proved
to be too expensive, and too heavy to carry into the field. The intensity of
light needed was more than reasonable.

So, instead, we developed a small microscope - the least expensive is about
$400, up to the upper end of the scale of $1200.

You need a microscope that has 4X, 10X (or 20X), 40X objective lenses. 10X
WF eyepieces. Numerical Aperature 2.5 ABBE condensor (needs to have an iris
diaphragm).

Ther are some available to buy on occassion on E-bay. But microscopes don't
lose much just because they are 5 or 10 or 20 years old. In fact, my
grandfather's microscope is worth more today than when he bought it as a student.

This is a microscope that you could take in the field with you, if you had a
battery operated light source. So, attachment to the car battery is possible.
 Otherwise, you bring the samples back to your house, or business.

The standard curve for the superb to bad tea is in the Compost Tea Quality:
Light Microscope Methods manual, available from SFI. You could just buy the
manual and work through the method, or you can come to a course here at SFI.
Paul Wagner will offer the course sometime, as will Ted Leischner in Canada in a
few weeks, I believe.

I'm working on the red dye method for assessing coverage of leaf surfaces.
It's pretty easy, but people seem to like to have instructions, so that manual
is next.

Elaine R. Ingham
Soil Foodweb Inc., Corvallis, Oregon
Soil Foodweb Inc., Port Jefferson, New York
Soil Foodweb Institute, Lismore Australia
Soil Foodweb Institue Cambridge, New Zealand
Soil Foodweb Inc., Hilversum, The Netherlands
Laboratorios de Soil Foodweb, Culiacan, Mexico
Soil Foodweb Inc., Jerome, Idaho




Received on Tue Jun 22 2004 - 20:50:34 EDT

This archive was generated by hypermail 2.3.0 : Tue Feb 07 2012 - 14:15:23 EST