IPM Notes from August 8, 2013

Welcome and a special thanks to the Fernbrook Farm students who were a great help all morning.

Pheromone Trap Results

Trap Report
Trap #1 - Black Cutworm
2 moths (Black Cutworm), 1 spider, 1 mosquito, 1 beetle (click)

Trap #2 - Corn Earworm
8 moths (noctuids) and 1 beetle (click)

Trap #3 - European corn borer
Borer – Inactive

Trap #4 - Fall Army Worm
1 moth – Fall Army Worm

Helios Trap
Inactive

Alfalfa Field
We used 2 sweepers to collect samples of the bugs present in the field. We found leaf hoppers (small but a large number), cucumber beetle, aphids, lace wings, forage loopers, and clover mites.

Hops
The hops are doing poorly with some having the tops dying. We are looking for borers but did not find any holes or other evidence. There are also leaf hoppers.

Sweet Corn
There is borer present in the corn tassels. Evidence includes the presence of frass and broken-over tassels. We found a borer but did not identify it specifically. It is causing the tassel stalk to weaken and fall over. There is also a purple color on the lower stalk that is a stalk disease. Bill says we would need to send it to the lab to get a specific identification. At this time these problems are not a threat to the crop. There is deer damage. They are eating corn silk and tassels.

Soybean Field
This is a late group 3 possibly a 3.8. This means mid to late October harvest.
They are still flowering. Beans are immature. The bean stalks close to the ground have become large and woody (possibly a result of all the rain and the branching of the plants) – this will be difficult for the harvester. We are still seeing Cercosporia and some Septoria. There is also evidence of thrips (leaf puckering).

Wheat/Soybean Field
We were specifically looking for nodule production as the plants show signs of nitrogen deficiency. The plants are just beginning nodule production so probably are nitrogen poor. It is also possible that they are lacking potassium. There are no flowers, so this field would be graded in the vegetative stage. It will probably harvest at the end of October.

Popcorn Field
Bill brought a Minolta Spad Meter to test for nitrogen.
“The chlorophyll meter is a portable, hand-held device that instantaneously measures the greenness (or chlorophyll content) of a plant in the field. Nitrogen (N) is closely associated with leaf chlorophyll; thus chlorophyll meter readings of corn leaves reveal the N status of the corn plants.”

A reader greater than 50 means that there is sufficient nitrogen. Our readings were between 50 and 60. The lower readings were in the areas of the field that have been stressed by flooding. 

There are two varieties of popcorn in the field – one short season and one long season. We are seeing the beginning of tasseling and the formation of ears on the short season variety. Cereal leaf beetle is present. We found a spot of ‘rust’.

Field Corn Field
Today we did the calculation of yield.
Take a full ear of corn. Count the number of kernels in a representative row. Count the number of rows. Multiply to get the average number of kernels per ear.
We did 8 ears as a representative sample and got an average of 638 kernels per ear.
(smallest ear 570,largest ear 720) 

Assume 1 ear per plant. Use the calculation of plants from May 23rd – which is 25,000 plants per acre. Multiply. The result is 15,953,125 kernels per acre.

Divide by 90,000 kernels per bushel. The result is 177.25 bushels per acre. This is the estimated yield for this field. Bill rates it as a ‘good’ yield. It should be profitable when all expenses are deducted.


Note: The identity of last week’s mystery weed is Fall Panicum.


Special thanks to Roger for compiling this weeks notes.