Archive for category: Uncategorized

Understandably most growers are still concerned about getting all of their corn planted and debating when they should switch their corn relative maturity (Corn Hybrid Relative Maturity Switch Dates for 2011). This coupled with cool soil temperatures has delayed the progress of our 2011 soybean plantings. Many resources suggest that soybean should not be planted until soil temperatures reach 50° F and to tell the truth we were nervous to start planting our soybean variety trials until those temperatures where achieved (Table 1). With that said I, like many, saw the calendar date and have recently experienced several week delays in May due to wet weather so decided to start planting soybean on May 4^th (This is called the do as I say not as I do paradigm). Given the soil temperature and lack of accumulated gdu’s (28 based on soil temp and base 50° F) I was surprised to see how far the soybean development has progressed to date. This furthers my thought that the base temp for soybean germination is less than 50° F. That is a topic for another day.

For more detailed information regarding soybean emergence please see Predicting When Soybeans Will Emerge.

Table 1. Soil temperature monitored at 2 inch depth at the Arlington Agricultural Research Station in 2011.

Image 1. Developmental images of soybean planted on May 4^th at Arlington, WI in the long term-rotation study.

While today’s (Monday) weather has been the sort of day we have been lacking recently, the USDA-NASS Wisconsin Crop Progress for April 25th indicates that in almost all of the reporting districts, subsoil moisture is either adequate to surplus! As we get itchy to be in the fields planting, a very relevant question to ask is if seed treatment fungicides will be effective in soybean in 2011. Our experience over the past few years has been that these products can be a cost-effective management tool. We have seen consistent responses in both inoculated and non-inoculated trials for some products. Several factors drive this response including soil temperature and soil moisture. Below are the soil temperature and soil moisture levels for Arlington and Chilton over the past 30 days. What should be rather obvious is that the soil temperature dropped steadily as the month progressed. Temperatures have only recently begun to increase but are still holding in the mid-40’s. Soil moisture has been good at both locations and increased with either recent snows or rain. As such, right now conditions are at such where the use of a seed treatment may be warranted and effective, especially in reduced tillage to no-till environments.

Arlington soil temperature and soil moisture.

Chilton soil temperature and soil moisture.

A visual survey of our Arlington, Janesville, and Lancaster winter wheat variety trials suggest that green-up of the 2011 winter wheat crop is occurring 5-7 days later than last year. We were unable to accurately assess our Chilton site last week due to delayed crop development. Our green-up assessment at the southern locations suggest very little winter-kill occurred (Image 1). Given the calendar and the inclement spring weather-to-date growers and retailers are anxious to apply nitrogen. It is important to remember that the functional purpose of spring N is to 1. stimulate tillering and 2. provide crop nutrition. If ample tillering (> 70 tillers per square foot) has occurred growers can delay N applications up to pre-joint (Feekes 4-5; Zadoks 30). This practice will aid in minimizing early spring N loss. Applications of N made after this growth stage may lead to wheel track damage. If growers have < 70 tillers per square foot it is important to get across those fields as soon as possible to minimize yield loss due to low tiller/head counts.

(Lancaster variety trial – T. Wood)

I just wanted to take this opportunity to announce that we have a new and integrated website for diseases of field crops. This new website is called: Field Crop Pathology. The URL for this site is: fyi.uwex.edu/fieldcroppathology. For those who have used the Soy Health webpage (and we know that it has been a lot of you), please be assured that the content that was on that website will be fully integrated into our new site. We have been working to standardize the presentation of the material on Soy Health with our new website.

On the new Field Crop Pathology website will be information about diseases of corn, soybean, wheat, and alfalfa. We have tested the search function on the main page and are quite happy with the results for finding materials on this site. We also linked from our main page to several of UW-and UW-Extension associated websites (among others) that we know you are also interested in using. On the Main Page, I will try to write periodic updates about new information available on the website.

Please feel free to contact me with any questions that you have about the new website. We welcome your feedback. We will not be taking down our current websites until we have fully integrated our materials.

Thanks and have a great weekend!

Paul

The U.S. Wheat & Barley Scab Initiative FHB Alert System will again be active in 2011. In addition to adding two more states, there will be options for users to customize the system to target their geographical area better. The goal of the alert system is to enable users to have improved notice (i.e., more timely) about the potential for scab outbreaks. The alert system is tied to the Fusarium Head Blight Risk Assessment Tool and integrates information from predictive models with commentary from state extension specialists. The forecasting system will be available in early March.