ISSUE 15   September 13, 2007

WHEAT SURVEY-PRELIMINARY DISEASE SUMMARY

NDSU IPM field scouts surveyed more than 1100 wheat fields during the growing season of 2007, very similar to the 1150 fields surveyed in 2006. Fields were surveyed from the 1-leaf stage through dough stage of kernel development.

Tan spot fungal leaf disease was the most common disease observed by field scouts. Average severity ranged between 5-15%.

tan spot map

Fusarium head blight, or scab, was at very low levels in 2007, found in only 5.8% of post-flowering fields surveyed, and symptomatic fields averaged a low field severity rating of 0.9%. The majority of occurrence was in the northeast part of the state.

wheat scab severity map

Wheat leaf rust was fairly common in 2007, observed in 11.3% of all fields. Leaf rust was generally observed on most plants throughout the symptomatic fields, but a majority of the fields had low average severities, between 1-5% on the flag leaf. However, a few fields had severity in the 25-50% range by early soft dough.

wheat leaf rust map

Diseases that were a little more common in 2007 than in recent previous years included bacterial leaf blight and barley yellow dwarf virus, both occurring at much greater levels in the eastern 1/3 of the state. Loose smut of wheat was found primarily in eastern counties, with an average of 5.5% tillers infected in those fields showing symptoms. Levels 2% or greater warrant seed treatment.

Field survey results on wheat and other crops are mapped, and these maps are posted to the following web site: http://www.ag.ndsu.nodak.edu/aginfo/ndipm/.

 

SOME EARLY FUNGICIDE RESULTS ON WHEAT

Winter wheat cultivars responded well to fungicides in ND in 2007. The control of a combination of Fusarium head blight in some eastern locations, and leaf rust and leaf spot in all locations, resulted in substantial yield increases. Cultivar differences in disease response also were evident.

Several winter wheat x variety fungicide trials exhibited cultivar differences and variety response to fungicides. For example, at a Lisbon location (data collected and analyzed by Joel Ransom) and at Roseglen and Berthold locations (data collected and analyzed by Kent McKay), two cultivars, Jerry and Millennium, consistently showed less Fusarium head blight, leaf rust, and leaf spot diseases than other cultivars.

For fungicide response: Lisbon location - an early season application of Headline at 3 fl oz, followed by an application of Proline 3 fl oz + Folicur 3 fl oz at flowering, resulted in a 20.6 bu yield increase over untreated, when averaged over all 20 cultivars in the trial. Roseglen and Berthold locations - a flowering application of Proline + Folicur (3 + 3) resulted in a yield increase of 13.8 bu at Roseglen and 15.1 bu at Berthold, when averaged over the 10 cultivars in the trial. Generally, there also were fungicide x variety interactions at these sites.

Further information on the results from these above trials and additional information on winter wheat cultivar performance in 2007 from each of the NDSU Research Extension Centers is posted on the following web page:

http://www.ag.ndsu.edu/smgrains/

Most data from spring wheat, durum wheat, and barley trials are currently being analyzed across ND locations, and DON (vomitoxin) data is not yet available. However, some data from Fargo trials are completed (except for DON data) and the following are examples:

Cropping system study: Yield of Trooper spring wheat increased by 6.5 bu with a flowering application of Proline + Folicur (3+3) under dryland conditions, whereas Glenn only saw a 2.2 bu yield increase. This site had a mid-May planting date and was quite dry later in the season.

Uniform fungicide trial: In a misted fungicide trial with Trooper wheat, a 9.2 - 12.0 bu yield increase was observed with the better flowering fungicide treatments.

This trial was planted May 4th, and had mist irrigation, but high temperatures in July did slow disease development.

Marcia McMullen
Ext. Plant Pathologist
marcia.mcmullen@ndsu.edu

 

CROP PROGRESS REPORT 2007

It is another good year for sugarbeet growers. Southern Minnesota Beet Sugar Cooperative and American Crystal growers will have another bumper sugarbeet crop if all goes well through harvest. Minn-Dak Farmers growers will also have a good crop considering that they were adversely impacted by unusually high amounts of rainfall in May and June that delayed planting significantly. American Crystal grower started their pre-pile harvest in late August; Southern Minnesota growers started their pre-pile on September 5 and Minn-Dak growers commenced their pre-pile harvest on September 12.

We still have the remainder of September for further yield increase and sucrose conversion. Warm days and cool nights in September will be a big boost for higher yields and increased sucrose concentration. Sucrose concentration will be higher in dry conditions than in wet conditions. In addition, defoliation and harvesting will be much easier and more efficient in dry rather than wet conditions.

There are some sugarbeet fields that have a very high population of late emerging weeds. These weeds may be cut using a swather or a stalk chopper to facilitate proper defoliation and harvesting. In addition, the use of steel flails on the front drum of the defoliator while going slowly will help to remove weeds. Clean fields make for easy, problem-free harvesting.

Best wishes for a safe and successful sugar beet harvest.

 

OTHER UPDATES - ROUNDUP READY SUGARBEET

Growers should scout their fields at this time and collect any diseased plants for proper diagnosis, particularly for root diseases. Such information will be useful in variety selection the next time that field will be planted to beets.

In 2008, growers at Minn-Dak Farmers Cooperative and American Crystal Sugar Company will start planting roundup ready sugarbeet. All the roundup ready varieties will have Rhizomania resistance (the level of which will vary based on parent material). Please be aware of disease problems in the fields to which roundup ready varieties will be planted and make sure the varieties selected have acceptable levels of resistance to those diseases – the same principle applies for selecting conventional varieties. Detailed information on growing roundup ready sugarbeet varieties will be provided at the winter growers seminars.

Mohamed Khan
Extension Sugarbeet Specialist
mohamed.khan@ndsu.edu  

 

PRELIMINARY CANOLA SURVEY RESULTS

Data from this year’s canola survey are continuing to trickle in. Most counties have reported some information, so I wanted to give everyone an idea of what was being found. The table below lists the number of fields reported by region , and the level of grasshoppers, flea beetles, blackleg (superficial and penetrating) white mold, aster yellows and blackspot.

I would like to thank all the cooperators in this effort, and thank Dr. Art Lamey for summarizing the data.

Preliminary results of 2007 Canola Survey

Blackleg

Grass Hoppers

Flea Beatles

Penetrating

Superficial

Sclerotinia/ White Mold

Aster Yellows

Black Spot

Region

Fields Reported

Avg of 4 sweeps

Avg of 5 sweeps

% plants

% plants

% plants

% plants

% pod area

Northeast

26

0.29

17.21

23.21

13.15

3.19

2.79

0.24

North Central

35

1.645

13.48

8.8075

6.9925

8.1025

7.7525

0.08

Northwest

46

1.63

28.67

1.70

5.52

11.39

4.11

X

Central

8

1.38

41.75

0.00

6.25

2.50

0.00

1.84

West Central

13

1.62

30.03

16.23

1.69

5.69

5.69

0.06

South Central

1

0.00

6.20

0.00

0.00

0.00

0.00

X

Southwest

4

0.00

22.15

4.50

0.50

0.00

0.00

0.03

 

SOYBEAN DISEASES / SOYBEAN RUST REPORT

Last week we completed our scouting of soybean sentinel plots in North Dakota. This year, twenty sentinel plots were located throughout the eastern half of the state, and assessed for diseases each week.

Bacterial disease was the most common disease found this summer. Despite being frequently recovered, there is little evidence that the amount of bacterial disease observed would translate into a yield reduction. Less frequently observed diseases included Charcoal rot, Septoria brown spot, and Sclerotina (white mold). In general, soybean diseases should not limit yield this year.

The sentinel plot system is designed to monitor soybean rust development and dispersal. Soybean rust developed in several locations near the Gulf of Mexico in May. The disease spread throughout the south and into northern Oklahoma and Arkansas, but has not been found north of the northern Oklahoma and Arkansas borders. The disease continues to be active in the south (see map), and fungicide recommendations are being made for soybeans in states that have reported the disease. I would like to thank all of the growers who allowed my technician and I to scout their fields this year. You’re cooperation is vital for our ability to monitor diseases in ND. Thank you.

Soybean diseases map

Sam Markell
Extension Plant Pathologist
samuel.markell@ndsu.edu


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