Integrated Crop Management News

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Flooding Increases the Risk of Certain Diseases in Corn

June 15, 2008
Image of Pythium stalk rot in a corn plant

By Alison Robertson, Department of Plant Pathology

Infection by a number of pathogens is favored by flooded conditions. Excess soil moisture and anaerobic soil conditions also favor the development of certain diseases.

Root Rots

Over the past week, I have received a number of reports of crown, mesocotyl and root rot of corn. Although root rots of corn occur to some extent every year, under wet conditions, they can cause economic losses.

The Nation’s Wet Spot

June 14, 2008
Map of the US showing the percent of normal precipitation

By Elwynn Taylor, Department of Agronomy

It only takes a glance at the year’s (water year begins in October) precipitation map to identify the region of ABNORMAL wetness. The record setting floods of 2008 are no surprise in light of the records. If it seems that high water years in the Midwest are increasingly common since about 1970; they are.

Corn Size Restriction for POST Herbicides

June 14, 2008
Table of the application restrictions for selected corn post-emergence herbicides

By Mike Owen and Bob Hartzler, Department of Agronomy

Weeds have continued to grow thus making the application of POST herbicides imperative despite the slow development of the corn crop. However, it is also important to follow the size restrictions that exist on the herbicide label, particularly given that corn is under stress due to the poor growing conditions. 

Livestock and Farm Buildings After a Flood

June 13, 2008

By Jay Harmon, Department of Agricultural and BioSystems Engineering
Once the water recedes after a flood there are many things that need to be dealt with before putting a building back in service. These involve dealing with safety issues, service issues and other efforts that will prolong the life of the building. 

Hayfield Lodging – Management Concerns and Guidelines

June 13, 2008

By Stephen K. Barnhart, Department of Agronomy and Mark Hanna, Department of Agricultural and Biosystems Engineering  

Rain, wind, hail, and unavoidable harvest delays have led to lodged and flat hayfields across the state. This is not usually a concern in more normal seasons, but if it occurs, producers have to manage for and around it.  

A ‘bright side’ of delayed harvest is that the forage plants have longer to accumulate carbohydrate ‘stores’ and maintain plant vigor. 

Measuring the Nitrogen Status

June 12, 2008
Image of N-deficient corn and well-fertilized, non-N limiting strips

This year the corn growth is behind, and with the wet soils some fields will be sampled later than normal. Late sampling may complicate test interpretation.

Managing Manure Storage Structures During Wet Weather

June 12, 2008

By Robert Burns, Department of Ag and Biosystem Engineering 

During excessively high rainfall periods Iowa producers with open manure storages should closely monitor manure levels to prevent these structures from over-topping.

Good Seed Supply Available from Most Companies in Iowa

June 12, 2008

By Palle Pedersen and Roger Elmore, Department of Agronomy

Excessive rainfall in Iowa over the last 2 months has challenged most farmers, agronomists, extension workers, and researchers. With another front of storms moving into Iowa today (June 11) we do not know when we will be able to get back into the fields. Our best estimate is that it will first be next week at the earliest.

Estimating Nitrogen Losses

June 11, 2008

By John Sawyer, Department of Agronomy

One method to judge nitrogen (N) loss is to calculate an estimate. Predicting the exact amount is quite difficult as many factors affect losses. However, estimates can provide guidance for supplemental N applications.