Soybeans Growth Stages and Soybean Aphid

Yesterday provided an opportunity to visit some soybean fields and check on growth stages and soybean aphid. The four fields I stopped at were all finished flowering and were in the R6 stage of growth. This is the full seed stage and where on pod on the 4 upper nodes has a seed filling the cavity. Soybean aphid counts were still less than 20 per plant but most all plants had aphids on them. It seems that we are getting to the point that soybean aphid will not be a problem for us in 2009.

Once we get into the R6 stage the plants can tolerate soybean aphid with less effect on yield. The last CORN Newsletter had an article which describe thoughts on higher level thresholds for soybean aphids in bean at these later stages.

The August crop report from USDA gives us the first glimpse of yield estimates for the 2009 crop. If yields for Ohio hold true given the number of acres and estimated yield of 165 bushels per acre Ohio is looking at it largest corn crop ever. The big difference over 2009 from 2008 is the weather with more wide spread and timely rains even with a later planted crop. Soybeans will be 11 bushels higher for the state than in 2008. Below is a snap shot of information on average yield from the report.

	2009 Yield		2008 Yield
Crop	Ohio	US	Ohio	US
Corn	165	159.5	135	153.9
Soybeans	47	41.7	36	39.6
Wheat	71	47.2	68	44.2

This does change the inputs for those who look at the ACRE program. Trend line yield for Ohio corn were 154 and soybean 44. Given the August 2009 yield estimates of the 2009 crop, it will take corn prices on a cash basis (US Marketing Year) of less than $3.40 per bushel and soybean prices of less than $8.95 to generate revenues less than the state guarantee. With good yield and good prices we can certainly live without an ACRE payment but these numbers give some idea of the prices that would trigger payment s for the state of Ohio given the current 2009 production estimates.

The Ohio only report can be found at NASS-Ohio if you would like to see the total US picture that can be found at NASS.

Crop Growth Stages are Behind 2008

During my travels this week, I got a good chance to observe crop growth stages. In 2008, this first week of August was also an observation point, so a comparison can be made between 2008 & 2009 growth stages for both soybeans (Table 1) and corn(Table 3) . The majority of the soybean crop is in the R3 stage which is beginning pod. Most of the corn crop is R1-R2 which is silking to blister.

You can see the GDD accumulation chart matches (Table 4) the expected growth stages for corn based off GDD accumulations. So as we progress through the season we can watch the GDD accumulation and predict corn development. Table 5 shows accumulation at OARDC NW Agricultural Research Station from April 1 and May 15 to August 4. We seem to be about 10 days to 2 weeks behind the 2008 growing season in crop development.

Table 1. Comparison of Soybean Stages for Fulton County in 2009 and 2008 During First Week of August (Numbers Represent Number of Fields at this growth stage).

Year	R1	R2	R3	R4	R5	R6
2009	0	9	28	8	4	0
2008	0	1	5	11	15	10

Table 2. Soybean Reproductive Stages.

Stage		Description
R1	Beginning Bloom	One open flower at any node on the main stem.
R2	Full bloom	Open flower at one of the two uppermost nodes on the main stem with a fully developed leaf.
R3	Beginning Pod	Pod 3/16 inch (5 mm) long at one of four uppermost nodes on the main stem with a fully developed leaf.
R4	Full pod	Pod 3/4 inch (2 cm) long at one of the four uppermost nodes on the main stem with a fully developed leaf
R5	Beginning Seed	Seed 1/8 inch (3 mm) long in a pod at one of the four uppermost nodes on the main stem with a fully developed leaf.
R6	Full seed	Pod containing a green seed that fills the pod cavity at one of the four uppermost nodes on the main stem with a fully developed leaf.
R7	Beginning Maturity	One normal pod on the main stem that has reached its mature pod color.
R8	Full Maturity	Ninety-five percent of the pods that have reached their mature pod color. Five to 10 days away from 15% moisture.

Table 3. Comparison of Corn Stages for Fulton County in 2009 and 2008 During First Week of August ( Number Represent Number of Fields at that growth stage).

Year	RT	R1	R2	R3	R4	R5
2009	1	21	17	2	0	0
2008	0	1	6	21	7	1

Table 4. Corn Reproductive Stages.

Growth Stage	Description	Approx. GDDs	Cum.GDDs	Typical Calendar Date
VT	Tassel	60	1300	Jul 13
R1	Silking	60	1360	Jul 15
R2	Blister	300	1660	Jul 27
R3	Milk	200	1860	Aug 5
R4	Dough	140	2000	Aug 11
R5	Dent	300	2300	Aug 25
	1/2 Milkline	220	2520	Sep 5
R6	Black Layer	200	2720	Sep 17

Table 5. GDD Accumulations from April 1 or May 15 to August 4 of 2007, 2008 and 2009 at Northwest Agricultural Research Station, Custer, OH.

Time Period	2009	2008	2007
April 1-August 4	1921	1939	1968
May 15-August 4	1646	1691	1709

Soybean Aphids Increasing but Not So Fast

Monday and Tuesday afternoon were spent looking at soybean and corn fields along the route I have setup along County Road's B & L. Soybean aphids were an observation to be made in all soybean fields. Basically I do this not to scout a field for threshold information, but get out in the field away from the end rows and look for the presence of aphids.

The route this year has 52 soybean fields. On the 8/3 and 8/4 scouting, 26 fields had aphids and 26 did not have aphids. If you remember back to my last report on aphids on July 17th only 2 of the 52 fields had aphids in them. So aphids are now easier to find. I would not be surprised if you spent time in a field until you found aphids, that you would be able to find aphids in nearly every field.

From my stops the past couple of days though, we still are not close to threshold of 250 aphids per plant. I went to one of the fields that had aphids back on July 17th and population were just 3-4 per plant and only 30% of the plants had aphids on them which was not different than most other fields. Most fields had 3-6 plants out of 20 with aphids on them or 15-30% of the plants. Numbers of aphids per plant were less than 10. As always there was a field that did not fit the mold and had 18 out of 20 plants or 90% of the plants with aphids, but the average was just 15 per plant . This is a field I will go back to over the next couple of weeks.

From a growth stage standpoint, most soybeans are in the R3 growth stage where there is one 3/4 inch long pod at one of the 4 top nodes on the plant.

Western Bean Cutworm in NW Ohio

Since 2007 Ohio State University Extension has been monitoring the progression of Western Bean Cutworm moths as they move from the mid corn belt areas to the east. The first moth catch was in 2007 for Fulton County and the state. In 2008 we caught 13 moths in Fulton County and 105 in Northwestern Ohio. As of August 3rd we have caught 37 moths in Fulton County and 212 in the Northwest Ohio.

Western Bean Cutworm is an economic pest on corn in western states feeding on the ear and more specifically the grain on the developing and mature ear. This pest has a greater capacity to feed than our traditional corn earworm because multiple larvae survive in the case of Western Bean Cutworm versus one larvae per ear with corn earworm. A full description of WBC can be found in this fact sheet from Wisconsin.

We should not expect economic problems from this pest in 2009 but might see evidence of feeding which would be a first time for Ohio. The feeding of larvae on the ear is the most identifiable stage. If you are out in corn this year, whether it is sweet corn, popcorn or field corn and see holes through the husk and multiple worms feeding on the ear please call the extension office 419-337-9210 or send an e-mail to labarge.1@osu.edu. We want to confirm this activity so we can modify recommendations and future monitoring programs.

Dr Ron Hammond has produced a video on identification of injury from Western Bean Cutworm based on a visit to Michigan to observe the injury in 2008.

Pictures in this article are from a University of Nebraska posting on the web.

Wheat Performance Trials Now On-line

The 2009 Ohio Wheat Performance Trials are now available on-line. Sixty soft red winter wheat varieties were included in the trials. A summary of yields and summary of the closest site located in Wood County are below.

Yield information from all test sites.

Location	High Yield	Average Yield	Low Yield
Wood	93.7	85.3	76.9
Crawford	113.6	106.1	98.1
Darke	101.9	88.8	87.1
Wayne	107.7	95.7	83.9

Details from Wood County Site.

	Yield	Test Wt.	Lodging	Powdery Mildew	Head Scab
High	93.7	63.9	19	10	23.4
Average	85.3	61.1	2	6.4	12.6
Low	76.9	58.9	0	2.5	2.8

Full result of the 2009 Trials which can be sorted by different characteristics can be found on the Performance Trial Website. The site also has resistance rating of Ohio common diseases for varieties included in the test as rated by Ohio State University Plant Pathology staff.