Tag Archive: Evaluation

Evaluation of ESN Controlled Release Fertilizer for Florida Corn Production

Environmentally Smart Nitrogen (ESN) corn trial at the UF/IFAS West Florida Research and Education Center in Jay, FL. Photo: Mike Mulvaney

Dr. Michael J. Mulvaney, Cropping Systems Specialist, WFREC, Jay, FL

Now is the time to start thinking about nitrogen (N) management strategies for corn production in the Panhandle.  This is a follow-up to the March 2016 article:  Environmentally Smart Nitrogen (ESN) as a Controlled-release Nitrogen source for Cotton, or ESN for cotton production.  Researchers now have data on the use of ESN for corn production in Florida.

ESN is a polymer-coated urea formulated as 44-0-0. The reason it contains 2% less N than urea (which is 46-0-0) is due to the weight of the polymer coating.  ESN is commercially available in bulk in some parts of the Panhandle.  Many growers blend ESN with urea, commonly as a 50-50 mix, with the idea that some N is immediately available, while the rest will release slowly over time to “spoon feed” the crop.

How slowly does ESN release N?

The release of N from ESN is temperature dependent under controlled conditions.  That is, the higher the temperature, the faster the release.  So, it stands to reason that ESN release should be slower at corn pre-plant as compared to corn sidedress application.  Likewise, we should see different N release if we broadcast as compared to incorporating ESN.  UF Researchers took this out of the lab, and measured the release rates under field conditions at Jay and Citra, FL during the 2015 and 2016 growing seasons.

The Florida data showed that ESN releases 50% N in approximately 2-5 weeks, with broadcast applications releasing N slower than incorporated ESN.

But does it make a difference in yield?

We used different ESN:urea blends at different times (all pre-plant, or 25% N pre-plant with 75% N sidedress) under corn production at two sites across the Panhandle during 2015 and 2016.  These corn trials were all fertilized at 183 lbs N/ac (except the control, of course) – the only differences were in how it was applied.

Figure 1. Corn grain yields using various ESN:urea blends, applied either all pre-plant or using a 25% N pre-plant, 75% N sidedress split application. 183 lbs N/ac were applied to all plots except the control.

Yield differences were not statistically significant among any of the application treatments.

Cost

Global urea prices are near 5-year lows, but are about the same price as last year (Figure 2).  Locally sourced urea in March of 2016 was selling at $ 380/ton, and ESN was $ 600/ton.  That’s a 65% increase per unit of N for ESN over urea.  March 2015 prices were $ 560/ton urea and $ 687/ton ESN, an increase of 28% per unit of N over urea.  It is expected that prices in March 2017 will be slightly higher those in March 2016.

Figure 2. Global urea prices over the past five years.

Break even cost

If corn prices are $ 3.60/bushel, and 200 lbs N were applied, you would need a 15 bu/ac yield increase to break even for the additional cost of ESN over urea.  If only half of the N was applied as ESN, a 7.5 bu/ac yield increase would be needed to break even.

Summary

During corn production in the Florida Panhandle, 50% of N release can be expected in 2-5 weeks, depending on timing and placement. Although controlled release of N may lead to increased N use efficiency, there was no evidence of significant yield differences among blends, or timing of applications when applied at 183 lbs N/ac at either Jay, FL (a sandy loam) or Citra, FL (sand).

Advantages over urea:

  • It may limit the opportunity for N loss through volatilization, which may be useful under certain conditions where urea-N loss can be high (warm, moist, broadcast conditions). Research on N volatilization from ESN is underway through Dr. Cheryl Mackowiak’s program.
  • It stores better than urea. It won’t gum up unless prills are broken.

Disadvantages compared to urea:

  • It currently costs 65% more per unit of N than urea.
  • In a heavy rainfall, broadcast ESN can be pushed into low spots in the immediate area. You can incorporate ESN to help avoid this, particularly if you are on a slope.
  • ESN should be handled with reasonable care. Damaged prills are as good as urea but considerably more expensive. When the front-end loader scoops from the bottom of the pile, significant damage can occur to the polymer coating.  Also, broadcast applications can damage prills with contact to spreader fins.  Incorporation of ESN may damage prills as well, which may explain why incorporated N release was faster than broadcast N release.

    ESN prills washed into localized low spots after a heavy rain in 2016. Photo: Mike Mulvaney

PG

Author: Michael Mulvaney – m.mulvaney@ufl.edu

Cropping Systems Specialist, University of Florida, West Florida Research and Education Center, Jay, FL. Follow me @TheDirtDude
http://wfrec.ifas.ufl.edu/people/faculty/dr-michael-mulvaney/

Michael Mulvaney

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2017/01/13/evaluation-of-esn-controlled-release-fertilizer-for-florida-corn-production/

Expected Tight Margins in 2016 Call for Careful Evaluation of Peanut Production Practices

Expected Tight Margins in 2016 Call for Careful Evaluation of Peanut Production Practices

Peanut margins are predicted to be tight this year. According to the UGA Crop Comparison Tool dryland peanuts will struggle to cover production costs. http://agecon.uga.edu/extension/budgets/cct/index.html In tight years the importance of each management decision is magnified. All options should be carefully analyzed to determine the most economically viable production practices. Photo credit: IFAS Communications

Peanut margins are predicted to be tight this year. According to the UGA Crop Comparison Tool, dryland peanuts will struggle to cover production costs.  In tight years the importance of each management decision is magnified. All options should be carefully analyzed to determine the most economically viable production practices.  Photo credit: IFAS Communications

The predictions for 2016 crop prices are, let’s just say, less than ideal. In years like this there is a natural tendency for farmers to look for corners to cut, in an attempt to keep production cost lower. However, more often than not, cut corners lead to a reduction in yield; low prices and low yields are worse for the bottom line than low prices and solid yields. This is not news, we all know that skimping on inputs is not part of the formula for producing a good crop. All that said, in peanuts there are some production factors that can be evaluated and tweaked on a field by field basis, which may allow for some cost savings without sacrificing yield.

Variety Selection

There are many factors to consider here. Yield is only part of the equation; granted, it is a large part. When looking at yield data, I recommend that you consider multiple years and multiple locations. Just because a variety put up ridiculously high numbers in one trial doesn’t mean you should necessarily expect it to do that on your farm. Production practices associated with the variety trials, especially irrigation, should be considered. Look for consistent high production under conditions similar to those on your farm. (See 2016 Peanut Variety Update for the results of trials in Florida).

Data from University of Georgia 2016 Peanut Update By: Monfort, Knox, Smith, Smith, Branch, Tubbs, Porter, Kemerait, Brenneman, Culbreath, Abney, Prostko http://www.caes.uga.edu/commodities/fieldcrops/peanuts/documents/2016PEANUTUPDATE.pdf

Data from University of Georgia 2016 Peanut Update
By: Monfort, Knox, Smith, Smith, Branch, Tubbs, Porter, Kemerait, Brenneman, Culbreath, Abney, Prostko

Seed Size

Seed size is another factor that should be considered. Seed cost is a significant expense (15-20% of the variable cost per acre). Smaller seeded varieties allow for potentially reduced seed cost, without reducing the number of seeds planted. Seeding rates are calculated based on number of seed per acre, but seed is sold by the pound. Smaller seeds equate to more seeds per pound, each bag goes a little further, so fewer bags are needed. A good target is six seeds per row foot. If you are planting much more than that, it is unlikely you will see an increased yield as a result of the extra seeds.

Number of seed per pound varies, ranges and averages shown were compiled from multiple sources. The chart is intended only to illustrate the variation between varieties and how that variation effects seed cost.

Number of seed per pound varies, ranges and averages shown were compiled from multiple sources. The chart is intended only to illustrate the variation between varieties and how that variation effects seed cost.

Disease Resistance

Disease resistance is another important factor to remember when selecting a variety. Yes, we have excellent crop protection products, but it is still advisable to take advantage of the disease resistance packages that are bred into our modern peanut varieties. Not all varieties have the same levels of resistance to all pathogens. Consider selecting varieties that best address your greatest disease concerns on a field by field basis. Below is a disease risk index from Peanut Rx, lower point values equate to grater disease resistance.

"For each of the following factors that can influence the incidence of tomato spotted wilt or fungal diseases, the grower or consultant should identify which option best describes the situation for an individual peanut field. An option must be selected for each risk factor unless the information is reported as “unknown”. A score of “0” for any variable does not imply “no risk”, but that this practice does not increase the risk of disease as compared to the alternative. Add the index numbers associated with each choice to obtain an overall risk index value. Compare that number to the risk scale provided and identify the projected level of risk." From Peanut Rx http://www.caes.uga.edu/commodities/fieldcrops/peanuts/documents/2016PEANUTUPDATE.pdf

For each of the following factors that can influence the incidence of tomato spotted wilt or fungal diseases, the grower or consultant should identify which option best describes the situation for an individual peanut field. An option must be selected for each risk factor unless the information is reported as “unknown”. A score of “0” for any variable does not imply “no risk”, but that this practice does not increase the risk of disease as compared to the alternative. Add the index numbers associated with each choice to obtain an overall risk index value. Compare that number to the risk scale provided and identify the projected level of risk.
From Peanut Rx

Selecting the best variety is a balancing act, there are multiple factors – more than those discussed, that must be considered simultaneously. There is no one right answer, even on the same farm utilizing multiple varieties is often the most efficient course of action.

Chemical Cost

Chemical cost is generally the largest variable cost associated with peanut production. Fungicides are a large portion of these costs. Selecting a spray program that maximizes your return on investment is key. Each field is different; past disease pressure, cropping history, variety planted, plus other agronomic factors, all effect the potential for various pathogens to become a problem. Pairing the appropriate spray program and products to the anticipated disease pressure will help to maximize return on investment. Remember, there is a difference between cost and value. Value is a factor of cost and effectiveness. There are situations where higher priced products will have a greater value and there are situations where lower priced products will have a greater value. Identifying these situations is essential to maximizing the return on your investment. Assessing the disease risk of each of your fields with the Peanut Rx tool is a great first step to maximizing your return on fungicide investment. Once a disease assessment has been made on each field, an appropriate spray program can be planned.

Pod-blasting and Boarding

Pod-blasting and boarding, or scanning a representative sample from each field to determine optimum harvest time will help to ensure that yield and grade potential of a field is not sacrificed through premature harvest. This is particularly important on dry-land peanuts; the expected days-to-maturity for a specific variety do not account for delays that can be associated with drought stress. Pod-blasting and boarding don’t cost anything but time, while harvesting at optimum maturity can substantially increase grade and yield.

"Blasted" pods prepared for scanning. The scanned image is analyzed to determine maturity and generate a recommended harvest date. Photo credit: Mark Mauldin

“Blasted” pods prepared for scanning. The scanned image is analyzed to determine maturity and generate a recommended harvest date.
Photo credit: Mark Mauldin

For help with variety selection, Peanut Rx, pod-blasting or anything else discussed, contact your county’s agriculture extension agent. Take advantage of any and all available resources that can help reduce costs or increase productivity this crop year.

 

PG

Author: Mark Mauldin – mdm83@ufl.edu

I am the Agriculture and Natural Resources agent in Washington County. My program areas include livestock and forage, row crops, and pond management.
http://washington.ifas.ufl.edu

Mark Mauldin

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2016/02/06/expected-tight-margins-in-2016-call-for-careful-evaluation-of-peanut-production-practices/

Evaluation of Thrip Resistance to Neonicotinoid Insecticides

Evaluation of Thrip Resistance to Neonicotinoid Insecticides

Figure 1. Tobacco thrips injury to seedling peanuts. Joe Funderburk, Danielle Sprague, and Mrittunjai Srivistava, North Florida REC. Quincy, Florida

Figure 1. Tobacco thrips injury to seedling peanuts.  Joe Funderburk, Danielle Sprague, and Mrittunjai Srivistava, North Florida REC. Quincy, Florida

Monitoring to evaluate continued susceptibility of pests to pesticides is an important part of any pest management program. Thrips are known for their ability to develop resistance to insecticides. The western flower thrips, Frankliniella occidentalis, has developed resistance to many of the Insecticide Resistance Action Committee (IRAC) chemical classes.

The development of resistance in Florida of the western flower thrips to field rates of the spinosyn insecticides (IRAC Group 5) is a tremendous concern. The spinosyns provided very high levels of efficacy against thrips pests for over ten years. The neonicotinoid insecticide acetamiprid (IRAC Group 4) has been used for control of the western flower thrips in fruiting vegetables. Recently, we started a resistance monitoring program to evaluate the susceptibility of the western flower thrips to acetamiprid. We have assayed several western thrips populations in Florida to date and these results indicated that each was resistant to acetamiprid.

We also began evaluating susceptibility of the tobacco thrips, Frankliniella fusca, to the IRAC Group 4 neonicotinoid insecticides. Several neonicotinoid insecticides are used as seed treatments on field crops including peanuts, soybeans, and cotton, primarily for control of thrips injury to seedlings (Figure 1). There are reports that the tobacco thrips populations in several Southeastern US states have developed resistance to the neonicotinoid insecticides. So far, we have only assayed populations at the University of Florida’s North Florida Research and Education Center in Quincy.

The objective is to refine our bioassay techniques, namely a bean-dip assay and an assay developed at North Carolina State University that evaluates systemic activity. Both assay techniques yielded similar results, namely that the tobacco thrips population at the North Florida Research and Education Center is resistant to imidacloprid.

Seed treatment for thrips control has long been a contentious issue. Soybeans recover from thrips injury without economic damage. Thrips injury in combination with herbicide burn or drought stress can delay maturity. Planting date and other cultural practices affect damage to cotton from thrips injury. Seed treatment as a preventive treatment for thrips has risks beyond that of economic crop loss, namely the development of pest resistance and potential non-target effects to beneficial insect populations.

These results indicating resistance in western flower thrips and tobacco thrips to the neonicotinoid insecticides should be viewed with caution at this point. Our results with tobacco thrips need to be confirmed by other laboratories. The extent of resistance in different populations of tobacco thrips and western flower thrips in Florida needs to be determined. However, our results combined with those from other states suggest concern.

For more information on thrips and the Insecticide Resistance Action Committee, please see the following resources:

Western Flower Thrips (Frankliniella occidentalis [Pergande])

Tobacco thrips

IRAC’s Insecticide Mode of Action Classification

 

PG

Author: Joe Funderburk – jef@ufl.edu


http://nfrec.ifas.ufl.edu

Joe Funderburk

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2015/07/18/evaluation-of-thrip-resistance-to-neonicotinoid-insecticides/

An Economic Evaluation of Estrous Synchronization and Fixed-Time Artificial Insemination in Suckled Beef Cows

UF/IFAS beef cattle reseach project showed a $ 49 advantage per exposed cow with Timed AI.

Cliff Lamb, UF/IFAS Beef Reproduction Specialist, NFREC

Overview

Estrous synchronization and artificial insemination (AI) are reproductive management tools that have been available to beef producers for over 30 years. Synchronization of the estrous cycle has the potential to shorten the calving season, increase calf uniformity, and enhance the possibilities for utilizing AI. Artificial insemination allows producers the opportunity to infuse superior genetics into their operations at costs far below the cost of purchasing a herd sire of similar standards. In addition, the utilization of estrous synchronization and AI has potential to influence the economic efficiency of cow/calf enterprises by improving a producer’s opportunity to shorten the calving season, increase calf uniformity, have earlier births during the calving season, enhance preweaning growth, and heavier calves at weaning. These tools remain the most important and widely applicable reproductive biotechnologies available for beef cattle operations. However, beef producers have been slow to utilize or adopt these technologies into their production systems.

Our estrous synchronization research has focused on the development of methods that effectively synchronize estrous in postpartum beef cows and replacement beef heifers by decreasing the period of time over which estrous detection is required, thus facilitating the use of fixed-time AI. This new generation of estrous synchronization protocols uses two strategies which are key factors for implementation by producers because they: 1) minimize the number and frequency of handling cattle through a cattle-handling facility; and 2) eliminate detection of estrus by employing fixed-time AI (TAI). 

Research Summary

Our most recent study was the first to be conducted that examined the economic outcomes of the management decision to intervene with estrous synchronization and AI technologies in commercial cow/calf production. The objective of this study was to conduct a partial budget analysis to determine the economic effect of estrous synchronization and TAI on the production of weaned calves in commercial cow/calf operations.

In producer operations, suckled beef cows were assigned randomly within each location to 1 of 2 treatment groups: 1) cows were inseminated artificially after synchronization of ovulation using the CO-Synch + CIDR protocol; and 2) cows were exposed to natural service (NS) without estrous synchronization. Within each herd, cows from both treatments were maintained together in similar pastures and were exposed to bulls 12 h after the last cow in the TAI treatment was inseminated. Overall, the percentage of cows exposed to treatments that subsequently weaned a calf was greater for TAI (84%) than Control (78%) cows. In addition, the cumulative calving distribution differed between the TAI and Control treatments. Weaning weights per cow exposed to treatments were greater (P < 0.01) for cows in the TAI treatment (425.5 lbs) than those cows in the Control treatment (387.0 lbs). Overall, increased returns plus decreased costs ($ 82.32), minus decreased returns plus increased costs ($ 33.18) resulted in a $ 49.14 advantage per exposed cow in the TAI treatment com-pared to the Control treatment.

Previously well-managed herds with relatively short breeding seasons had differing economic outcomes from the intervention of estrous synchronization and TAI. Management factors related to the four areas of the partial budget analysis affected the economic outcomes. Factors influencing costs per exposed cow such as weaning weight, bull costs, labor costs, semen costs, and pharmaceutical costs all contributed to the economic results. Factors that may have influenced calf weight, such as environment, stressors, quality of natural re-sources, and management system may have directly influenced economic outcomes but were not directly evaluated in this study.

Utilizing a partial budget analysis, this study examined the economic implications of the intervention with estrous synchronization and TAI on the value of weaning weight of exposed cows in commercial cow/calf production. This study explored a sub-sample of the total system of cow/calf production and examined the impact of estrous synchronization and TAI on increased and decreased returns and costs. Weaning weight of cows ex-posed to estrous synchronization and TAI was a major driver of profit. The decision to use estrous synchronization and TAI affects many parts of the production system and producers can use partial budget analysis as an aid in defining the success of ES and TAI reproductive management program.

Doug Mayo

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2012/08/24/an-economic-evaluation-of-estrous-synchronization-and-fixed-time-artificial-insemination-in-suckled-beef-cows/