Lebanon Crop Management Video


19 May 2016

Slug Management and Options-

 Del Voight Penn State Extension
SLUG RESOURCES  Slug Resources

There are numerous pests of corn and as the plants emerge it is important to scout to determine if there any insect issues that need to be addressed.  There are two pests that are active that we have received calls this week regarding leaf feeding  those being slugs and cutworms.
Right of center with residue and 1 stage earlier than left of center with vertical tillage graphic difference in level of slug injury no yield difference at the end of the season.

 Slugs – Slugs are active and small the gray garden slug is measuring about ¼ but can be found easily now under surface residue… They  can severely impact the development of corn if prolonged wet weather is occurring. If we get dry windy weather the slug issue will go away as quickly as it emerged with the exception of side wall compaction when they feed under the soil line and are not subject to weather.  My experience with slugs is that leaf feeding is not a huge issue provided dry weather returns,  however,  if the slugs attack the seed due to sidewall compaction they can kill plants and set seedlings back weeks before recovering. To avoid this pest here are some methods.
Avoid sidewall compaction
Utilize Starter and trash cleaners
Check in the fall and the spring for activity

Step up field visits when wet prolonged weather exists.
Monitor populations
An open slit with sidewall compaction ideal for the worst injury from slugs in the row with the seed.
If one looks closely about 2 inches below my finger you will see two grey garden slugs huddled together on a windy day they will seek moisture and no air movement.
Treatments  - There are numerous methods to deal w
An example of field with sidewall compaction and tremendous slug population that is feeding right in the row with the seed
ith slugs and results will vary in control.  Likewise the cost of these materials and methods can impact the management option.
Trash cleaners, zone tillage
Deadline MP or other baits in row under severe infestation. Cost - @$2.20/lb would require 10lb if banded and 40 lbs if broadcast.($22-84/acre)
Broadcast or band over the row as rescue.  Here is what Galen Dively found in his work from the early 90’s.
Liquid UAN half and half sprayed at night. (Growers report success when the slugs are visible during application). Cost - @2.00/gal at 10 gallon per acre= $20/acre
Galen Dively from University of Maryland did some experimenting with this tactic and this is what he found many years ago.

Tillage – this practice disrupts hiding places and also allows the soil to dry. Replanting is required so this would be the most expensive. Below are some preliminary reports from Joanne Whalen related to slug management and trends in tillage.
Tillage Demonstration to Determine the Impacts of Various Tillage Treatments on Corn Plant Feeding Injury from Slugs
      Tillage demonstration plots were established with one cooperator in two different fields near Middletown, Delaware to evaluate the impacts of various tillage treatments in reducing corn injury from slug feeding.  Tillage has been used as a control or management strategy to reduce the risk and severity of slug damage to crops.  To determine the effectiveness of tillage in reducing slug damage, demonstration plots were established by dividing a field into thirds and performing three different tillage treatments prior to planting including; 1) no-Till, 2) disking and 3) chisel plowing and disking.  Prior to performing the tillage treatments, three shingle traps 1’ x1’ were randomly placed in each of the plots to establish an estimate of slug densities within the plots.  Using line transect methods, the percentage of crop residue remaining on the soil surface was also estimated prior to performing the tillage treatments.  The percent of plants with slug feeding injury was estimated by dividing each tillage treatment plot into four quadrants and evaluating 5 consecutive plants for a total of 20 plants in each of the plots.  The presence or absence of slug feeding injury and a damage rating was assigned for each plant on a scale of 0-4.  The percentage of damaged plants and average plant injury rating was then calculated for each plot.

Chart 9.  Pretreatment Slug Counts, Plot A

Chart 10. Pretreatment Slug Counts, Plot B

Chart 11. Slug Damage Evaluations: Percent of Damaged Plants for Plot A & Plot B, 3 Leaf Corn
Chart 12.  Slug Damage Evaluations: Average Damaged Rating for Plot A & Plot B, 3 Leaf Corn
Conclusions: The pre-treatment slug counts varied greatly across the tillage plots for both locations by slug species and in the presence of adults and juveniles.  This variability is consistent with what has typically been found in crop production fields.  Despite this variability, as expected, there does appear to be a trend of a higher percentage of plants with slug feeding injury in the no-till plots compared to the disked and chisel plowed plots for both locations.  The average damage rating for each plot also follows the same trend in that the no-till treatment plots exhibited more severe feeding injury that the disked and chisel plowed plots.     
The use of Lannate insecticide is another option however it comes with some baggage related to beneficial insect reduction and is the last resort option at this time.
Visual Slug Counts, Feeding Injury Percentages and Shingle Trap
Treatment Timing
5/21 (2 Days After Treatment)
5/25 (5 Days After Treatment)
Grey Garden Slugs
Marsh Slugs
% of Plants with Slug Feeding Injury
Shingle Trap Slug Counts
# of Grey Garden Slugs
# of Marsh Slugs
Early Evening - 6:55 PM
Lannate LV (2.4 SL)
1.5 pt
Late Evening - 9:40 PM
Lannate LV (2.4 SL)
1.5 pt
Early Morning - 5:15 AM
Lannate LV (2.4 SL)
1.5 pt
Untreated Check
<Means in the same columns followed by the same letter are not significantly different (Tukey’s; P=0.05)
<Conclusions:  At two days after treatment, there were significantly fewer grey garden slugs in each of the treatments compared to the untreated. However, there were no significant difference between the treatments and the untreated check for the marsh slugs.  At five days after treatment, there were no significant differences between the treatments and untreated check for the percentage of plants with slug feeding injury and slug counts under the shingle traps for either the grey garden slug or the marsh slug.  Overall, grey garden slugs appeared to be the most prominent species causing damage to the corn plants and the marsh slug densities were low based on visual observations at night.  The level of control that was obtained 2 days after treatment is promising; however, additional studies will need to be conducted to determine the efficacy of Lannate (methomyl) to control slugs in field corn. Additional information is also needed to determine the best time of application and the length of control.

11 May 2016

Soybean Replanting Decisions

As the soybeans begin emerging growers might find some stands might need to be replanted due to a number of factors.  The soybean plant has the ability to branch and fill in however there are limits to the lowest population established without losing top end yield.   The Agronomy Guide Soybean replant worksheet offers details on determining the relative benefit of replanting.

We are early in the planting of soybeans but I have seen several stands planted back in early April that are beginning to be rowed and populations can be conducted now.  To illustrate this here is a table with the relative impact on yield by planting date as the season progresses. This illustrates the ability of the soybean to respond to varying planting date.
                                              1.       May 10 – 100%
2.       May 20- 98%
3.       May 30 – 95%
4.       June 10- 88%
5.       June 20 – 76%

Replanting is one of those thankless jobs in farming, so it pays to take time to evaluate stands carefully before replanting.  Consider some of these issues in deciding to replant.

1.  Soybeans have a tremendous capability to recover from reduced stands.  Data from various states would indicate that near maximum yields are possible with stands at 100,000 plants per acre.  At 70,000 plants, yields will still be in the range of 90-95% of optimum.  A recent Purdue study showed that across four locations, final stands of 46,000 plants per acre averaged 66 bushels /acre compared to 79.0 bushels /acre for 171,000 stands. That’s 83% of the maximum yield with a fairly sparse stand.

2. Soybeans cannot compensate for large gaps in the stand.  Many Pennsylvania fields with varying soil types are prone to uneven soil conditions which could lead to many gaps in the rows.  More gaps in the stand lead to a lower yield potential.  In a field with 40% gaps, at 70,000 plants, we’d estimate the yield to be 83% of optimum. Where large gaps are or in fields where large patches occurr replanting might be the best option.

3. It is important to identify the cause of poor emergence before replanting.  Seed depth, crusting, dry seedbeds, cold wet seedbeds, seedling disease insects, hail or seed quality are possible culprits. Stands with significant number of injured seedlings may have limited yield potential.
4. The one great aspect of soybean replanting is that one does not have to eliminate the existing stand. It can be replanted directly with only slight differences in seed set at the end of the season.  I had a grower a few years ago that we had just shy of 60,000ppa in the field so he chose to replant with an additional 100,000 seed drop per acre and at the end of the season he had about 120,000ppa final stand 70bu/acre yields.  

So what should you do to conduct a stand assessment?

First you will need to determine the population as it stands in the field. To do this utilize the following table below. Otherwise there is a simple method I use to estimate populations.  To determine populations you must first know the width of planting. 6”, 7”, 8” for small grains 7”, 15” or 30” for beans and 15” or 30” for corn.
  1. Now to determine population you simply convert the row width from inches to feet by dividing by 12.
  2. Then divide the square feet per acre(43560) by the foot of row. This gives you linear feet
  3. Then, take the number of plants you find per foot in the field and multiply by the linear feet number to get the ppa.
  4. For an example. Thirty-inch rows divided by 12 is 2.5 feet. 43560 square feet in an acre divided by 2.5 gives us 17424 linear feet. Now if you get 3 plant in a foot you have 17,424 plants per acre. If you get 2 then you have 34,848. To simplify this you could now take 17424 and divide by 1000 to get the number of feet you need to represent 1/1000th of an acre. In this case it would be 17.4 feet. So you could go to the field measure 17.4 feet count the plants multiply by 1000 and you will have your plants per acre. Do this in several places and you could find the average of the field.
Table 1.6-1. Seeding rates and plant population estimates for soybean.
Row width
Number of seeds planted/ft row¹
Number of plants/25ft row

Full Season²
Double Crop
Full Season
Double Crop








Based on 85% germination (full season = 176,000 seed/A, double crop = 235,000/A.

  • ²Full season = 150,000 plants/A; double crop = 200,000 plants/A
  • * Double-crop beans should be planted in row widths of 15 inches or closer.

  • The number of seeds planted per foot of row is based on 85 percent germination and an optimum population of approximately 150,000 plants per acre for full-season beans and 200,000 plants per acre for double-cropped beans.

    Know that Final Stands for high level yields need to be between 100-120,000 ppa.  If you count a stand and it is below 100,000 as of today it may be advantageous to replant.

    For early plantings it is particularly important to treat the seed to avoid potential pest problems.  Placing seed in a cold environment “naked” no insecticide or fungicides will open numerous doors for pest issues to surface most notably disease organisms.   My advice here is that at this late planting the soybeans could remain untreated since most likely the seed will germinating rather quickly.  It would not be wasted money to treat these soybeans as well particularly for soybean aphid and other insect management benefits of systemic treatments that contain chloronicotynil compounds.  Many times growers can add more soybeans to the field without terminating the existing soybeans.  The planter will terminate some soybeans and that will need to be accounted for when no tilling more soybeans into the existing stand.    In many cases in the past growers have replanted with roughly half the amount of seed per acre to thicken thin stands of soybeans.  Now is the time to be looking at these stands and not when the beans are 6 inches tall and will cause issues with replanting.

    09 May 2016

    Head Scab Condition ripe for infection in the Lebanon Area

    Here we go with conditions favorable for infection at the time wheat is pollinating.. The key is the weather  The most favorable conditions for infection are prolonged periods (48 to 72 hours) of high humidity and warm temperatures (75 to 85 degrees Fahrenheit). However, infection does occur at cooler temperatures when high humidity persists for longer than 72 hours. Early infections may produce air-borne spores, which are responsible for  secondary spread of the disease, especially if the crop  has uneven flowering due to late tillers.  This is the web address for the current forecast month.  http://www.wheatscab.psu.edu/riskTool_2012.html This is a  guide not to replace the conditions observed as above. Right now about the whole state is red indicating the best conditions for infection. Keep this in mind with Barley as well as some heads have emerged last week.
     Early Maturing Wheat in the Lebanon area  is beginning to flower and conditions are favorable for infection. I talked to a local grower. From his spray records last year he sprayed May 25th when flowers were out this year might be somewhat different.  Prosaro and Caramba, only provide about 50-60% suppression when applied at flowering. Depending on the weather conditions, and the baseline level of disease and toxin, 50-60% suppression may be sufficient to avoid or reduce price discounts and dockage. For instance, 50-60% suppression would bring vomitoxin levels from 4-6 ppm to 2-3 ppm, or under more favorable weather conditions, from 8-10 ppm to 3-5 ppm. So, this is what you can expect, suppression, not 100% control. Efficacy is greatly reduced when applications are made before or after flowering, so expect little or no vomitoxin suppression from application made for foliar disease control between flag leaf emergence and heading.
    Flowering is when anthers (the yellowish male part of the flower) are seen sticking out of the heads(see picture below). This typically occurs 3 to 5 days after heading. Anthers first emerge in the central portion of the head – this is called early anthesis or early flowering and is the growth stage at which fungicides should be applied for best results against scab and vomitoxin. If conditions are warm, it takes less time between heading and flowering, however, under cooler conditions, it may take longer, up to 5 or more days after heading, and flowering may last for several days. Main tillers (main stems) usually flower first, followed by secondary tillers (side stems). So, the flowering pattern may vary from field to field, depending on the variety and local weather conditions. This variation affects the risk for scab and vomitoxin and fungicide efficacy against the disease and toxin. In general, a well-timed application to a field with a narrow flower window will likely provide better scab and vomitoxin suppression than a poorly timed application or an application made to a field that flowers over several days.
    Prosaro and Caramba are the two choices for application at this time. 
    Prosaro 421 SC 6.5–8.5 ounce/acre  30 days HI
    prothioconazole + tebuconazole
    Caramba 10.0–17.0 ounce/acre  30 days HI


     Applications with twin jet nozzles and or increased  gallonage (20gpa) is critical to coat the heads with the material.  The point here is the target is a vertical head so the product needs to be applied at an angle to the head to coat all the spikelets.  Angling the nozzles and treating two different directions is also an option.