Trevor and others interested to know single reps vs 4 reps.
In addition to Jerry's comments, regarding statistics designs, variability
and experimental errors.
I would like to add:
There was a significant correlation at the end between the two methods.
However, we found that there were lots of variability when we used one
single replication and compare results to another replicate done few days
ion the same hives. There were several factors identifies as sources of
variability; not enough Liquid N2 applied, Lost counts when you count over
100, bee behaviour, and pupal age. It also takes longer time to count "
oops let me start again,,,," and it requires to take counts after 48 h
sometimes 72 h. To increase precision, Spivak recommended that this test
has to be repeated 2 times to get better results.
In our program, we needed to improve the system to do the job in one day
and have more accurate results without the need to go back to the field to
run another test. We found that 4 small replicates of area of circle 1.5"
diameter (think of stainless steel butter cup with bottom removed)
provided the following:
1. you can easily find areas with pupae of the same age to be used with a
small circle
2. It takes the bees 24 h to do the job.
3. easy to count
4. Better statistical design with less experimental errors
5. You don't have to repeat in few days as recommended by Spivak
6. saved time to travel back in 48 h to those fields. Thus we were able to
do many operations in one location in a day. Next day go back and count
and move on to another location.
I like also to mention that I found that beekeepers are using different
kind of circle size 3 - 7 " diameter. Still they expect the bees to do the
job in 24 or 48 h. I always recommend that a beekeeper needs to first find
the average time for his bees to remove 50% of the cells, specially when
you use large diameters. You need to establish this first as a reference
point. Then, you determine, when you should go 24, 48, 72 h to count
removed cells.
Medhat
Medhat Nasr, Ph. D.
Provincial Apiculturist
Crop Diversification Centre North
17507 Fort Road
Edmonton, AB, Canada T5Y 6H3
Tel: (780) 415-2314 Fax: (780) 422-6096
Mailto:[log in to unmask]
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