From the Director: Our goal is to provide the faculty with the latest news from the Center research projects and extension activities, and other timely information items. Please feel free to use the contents of the newsletter in your county newsletters and education activities as you wish. If you'd like additional details on newsletter items, contact the faculty member author or our editor, Cheryl Vergot.
Regards, Dr. George Hochmuth, NFREC Director

March 1:  Beef Cattle Management Course Local Extension Office

March 2:  Cotton Production Seminar  Santa Rosa County   9:00 a.m. -  noon

March 2:  Temik Review Meeting  Santa Rosa County   1:00 p.m. – 2:30 p.m.

March 6:  Panhandle Peanut Short Course  Jackson Co. Agriculture Center

March 6:  Small Holders Wrap-up Meeting  Dorothy Oven Park, Tallahassee

March 7-8:  West Florida Livestock Show & Sale  William Inman Agricultural Center, Quincy

March 31:  Escambia County 4-H Chautauqua  And Gulf Coast Agriculture & Natural Resource Association Livestock Show

April 7:  Small Farms Conference  Volusia Co. Fairground, (Deland) 8:30 – 3:00 p.m.

April 17:  Extension Agent In-service Training  Native Wildflowers for Central and South Florida

April 18-20:  Seeds for the Future  Wildflower & Grass Seed Production Conference

May 23:  DDIS In-service Training  University of Florida, Plant Pathology Department, Fifield Hall, Gainesville

June 19-21:  Natural Resources Forum, Watershed Science, Policy, Planning And Management, Tampa Busch Gardens

More Info on Dates

 

We will have a "Cotton Production Seminar"  in Santa Rosa County on March 2,2001.  Meeting speakers include: David Wright, Tim Hewitt, Jim Marois, Bob Kemerait- Univ. of GA, and Mike Donahoe.  The time is 9a.m.-noon. Temik Review Meeting

We will have meeting in Santa Rosa County on March 2, 2001, to review the Temik rule and label. Meeting speakers include: Dr. Elizabeth Braxton -FDACS, Jessica Brown - FDACS, and Mel Kyle - Aventis Crop Science. The time is 1:00 -2:30 p.m. The Panhandle Peanut Short Course to be held March 6 at the Jackson County Ag Center will include topics such as market outlook, variety updates, conservation tillage,weed management and more!! The Small Holders Wrap-up Meeting on March 6 is the final meeting in the small holder (5-50 acre) research planning project.  Summary information from the three regional Florida meetings will be presented.  This information will include a draft source book for small farmers including sections on marketing, alternative production and regulatory issues.  (The Dorothy Oven Park is approximately one mile south of I-10 on Thomasville Road, Exit 30 on I-10.  Park entrance is on the left as you head south on Thomasville Rd.)This is a UF-FSU SARE funded project.

RSVP to Laura Miller-Regalado (850) 942-2952 or Imm9886@garnet.acns.fsu.edu

(Zimet, NFREC News, 3-5)

PROGRAM UPDATES

HORTICULTURAL SCIENCES

Physiological impact of Feeding by the Three Cornered Alfalfa Hopper on Peanut

Peter C. Andersen

University of Florida North Florida Research and Education Center, 30 Research Rd., Quincy Florida

The three cornered alfalfa hopper (TCAH) [Spissitilus festinus (Say)] is a phloem feeder.  TCAH feeds by inserting its piercing-sucking mouthparts circumferentially around the the stem(s) or petioles, thus forming a girdle.   TCAH has a broad host range, and is a common pest of alfalfa, soybean [Glycine max (Merrill)], peanut (Arachis hypogaea L.), and numerous species of vegetable crops.  Although there is an abundance of literature involving the economic or physiological impact of TCAH on soybean, such documentation concerning peanut is nonexistent.  However, there are considerable differences between soybean and peanut (i.e. single stem versus multistem, above ground versus below ground seeds etc.).  

       There are 5 different responses of soybean to TCAH ranging from complete recovery to plant mortality.  In soybean TCAH causes mainstem girdling during the first 2 to 3 weeks after plant emergence. Girdled plants are  less vigorous than non-girdled plants and often break at the point of injury.   Girdled regions of soybean stem are characterized by necrotic epidermal tissue, a random proliferation of vascular bundles interspersed with starch grain containing parenchyma cells.  Girdling appears to restrict the downward movement of assimilates, and TCAH may feed preferentially above the girdles where nutrients are thought to be concentrated.  . The ability of soybean to compensate for TCAH injury has often been shown.   Although mainstem girdling may cause plant mortality or reduce yield per plant, adjacent plants in the stand may compensate by lateral growth filling in the adjacent areas.  It has been reported that reductions in soybean yield did not occur until more than 65% of the mainstems were girdled. The effect of TCAH feeding on the chemistry of phloem fluid or stem tissue has not been thoroughly tested for any plant species.

        Preliminary data indicates that feeding by TCAH had mixed effects (depending upon year of experimentation) on leaf and stem nitrogen and carbon content and dry weight.  Yield of peanut plants will also be assessed as a function of girdling. The greatest influence was on phloem amino acid content and the amino acid profile above and below the girdle.

         Three cornered alfalfa hopper feeding had a substantial effect on the concentrations of amino acids and amino acid profiles of ethanol extracts from peanut stems above and below the girdle of late season but not early season girdled plants (Henceforth late season girdled plants will be referred to as newly girdled plants i.e., girdle less than 1 month old)  The concentration of all amino acids was significantly higher above the girdle with the exception of histidine and cysteine.   The concentration of total amino acids above the girdle was at least 12-fold higher than for any other stem region sampled.  There was no significant difference in the concentration of any amino acid when the stem region below the girdle was compared to nongirdled stems.  Feeding by TCAH also altered amino acid profiles of stems.  The percentage asparagine increased and aspartic acid, glutamine and glutamic acids decreased above the girdle.   The other most notable differences were that proline increased and alanine and tyrosine decreased in the region above the stem.  As mentioned above, few differences were observed for early season girdled plants.

        The most marked effect of TCAH feeding is the resultant accumulation of nitrogenous assimilates above the girdle compared to below the girdle.  This was evident for newly girdled stems; stems girdled earlier in the season recovered from TCAH feeding.  An outcome of this buildup of assimilates above the girdle may be an advantage to subsequent TCAH feeding in this region. The transitory nature of this buildup of assimilates, the multistem compensatory potential of peanut, and the lack of consistent effect on leaf and stem nitrogen, carbon and dry weight content may lead to the hypothesis that the economic impact of TCAH feeding on peanut may be relatively minor.  However, verification of economic impact awaits additional physiological, plant growth and yield data. 

(Andersen, NFREC News, 3-5)

ENTOMOLOGY

New Monitoring Information for Pecan Nut Casebearer  (Russ Mizell, Professor of Entomology)

            The pecan nut casebearer, Acrobasis nuxvorella, is one of the most important early season pests of pecan. The larvae overwinter in hibernacula in pecan trees and emerge to continue feeding in early spring on buds and stems. The first generation larvae are the most devastating, as the female oviposits directly on the developing nutlets. After the eggs hatch the larvae begin feeding on the nutlets. The distinctive signs of the damage are webbing and frass wrapped around the nutlets. A first generation nut casebearer larva can destroy all the nuts in one to several nut clusters and where they occur in high populations they can be devastating. Nut casebearer populations vary widely from year to year and from location to location. Populations fluctuate in response to the availability of nuts and other unknown factors. Usually three generations of nut casebearer occur, but it is the first generation that is usually most damaging.

            Recently a sex pheromone (attractant) produced by the female nut casebearer was identified, synthesized and tested for its attraction to males with excellent results. Baited Delta traps that intercept flying male nut casebearer were placed in a pecan orchard in Monticello, FL from 1995-1999 (Figure 1).  The data indicate that the date of male emergence can vary dramatically from year to year as a result of weather patterns - mainly temperature, which also affects the pecan tree and nut development. The earliest emergence observed in any year was April 5 while the latest first emergence was observed about 10 May. This is a 35 day spread in the emergence from year to year. This emphasizes how useful such monitoring and detection tools can be to growers for making management decisions. Remember that other areas of Florida, Georgia and Alabama will  have different emergence patterns.  Populations often differ in orchards in close proximity.

            In addition to the timing of nut casebearer emergence, pheromone trap data may indicate the relative population levels of nut casebearer in the orchard. In these test years at Monticello only low populations were observed, as this is the male capture rate averaged for six traps (Figure 1). In another commercial pecan orchard less than 10 miles away, trap counts often were > 10-15 males/night.

            Growers and agents can refer to an article by M. Harris and other pecan entomologists including the author in the 1997 Proceedings of the Southeastern Pecan Growers Association for further information. Based on that article male moths emerge about 3 days before females and females require about 3 days for mating before laying eggs. Eggs require about 4 days before hatch and larvae feed on buds for 2 days before nut entry. Population buildup requires about 2-4 days. Adding all of these stage durations together provides an estimate that first nut entry takes place about 12-16 days after the first male is trapped. Therefore, the decision as to whether the nut casebearer population warrants the application of a control tactic and the proper timing for it can be made appropriately. Based on the trap captures, timing for examination of nutlets for eggs and nut entry can be timed properly (7-12 days after the first capture) and treatment decisions can be better timed. Because nut casebearer occur early in the season, it is wise to select a control measure that will have the least impact on beneficials and spray only when necessary.

            Growers may purchase the pheromone and traps from commercial distributors of such pest management products (ex. Trece, Inc. P.O. Box 6278, Salinas, CA 93912) and a few traps can provide the required data on nut casebearer emergence. Nut casebearer populations in previous years provide some indication of potential current year populations. Using the traps over a period of years should enable the pecan grower to fine tune decision making concerning treatments for nut casebearer. For example low populations in years with high nut set may be advantageous as nutlet removal would reduce heavy nut set to a more appropriate level to enhance nut quality. Use of control measures may not be appropriate in such a situation.

(Mizell, NFREC News, 3-5)

FORAGES

North Florida FORAGE UPDATE 2-2-01

Ann Blount-Forage Breeder, Bob Myer-Animal Nutritionist and Tim Hewitt-Ag Economist

NFREC Marianna Beef Unit

FESCUE TRIAL RESULTS

We have been looking at promising new cool season forages for the Florida Panhandle. One such forage is a new tall fescue variety. Tall fescue is a perennial cool season bunch grass, very similar to ryegrass in quality and tonnage. The concern with fescue has been that it causes some toxicity problems in livestock, such as delayed breeding, poor weight gains, rough hair coats, as well as other symptoms. The cause is actually an endophyte, or fungus, that lives in the plant. The endophyte helps make the plant competitive with other grasses, improves its persistence and gives it better drought tolerance. When forage breeders removed the fungus from the fescue (endophyte-free tall fescue), it lost its ability to persistence. Recently, Dr. Joe Bouton (University of Georgia) and Dr. Gary Latch (AgResearch, New Zealand) killed the fungus infecting the varieties Georgia 5 and Jesup, and reinfected the plants with a new novel endophyte. The novel endophyte helps the fescue maintain good stand persistence and improved animal performance without causing animal toxicity.

At the Marianna Beef Unit and the NFREC, Quincy, we have completed a two-year study with the novel endophyte infected fescue. The verdict is in and is not necessarily favorable for Pennington=s new Max Q fescue. Let us emphasize that THESE TRIALS WERE DONE ON NON-IRRIGATED SOIL. Our reason for such a high interest in fescue is that it has potential for our area because it is a PERENNIAL cool season grass and does not need to be established each year, like all of our annual cool season forages. Unfortunately we don’t yet with have reliable plant varieties and efficient endophyte strains. The studies at the NFREC were done on prepared land and our initial stands were excellent, but we suffered two severe summer drought years and these contributed heavily to the rapid stand losses. We compared fescue varieties Jesup and Georgia 5 that were either infected with the novel endophyte, the wild-type endophyte or were endophyte-free. Observations on the two-year old planting showed a 40-50% stand loss with the novel endophye infected varieties, compared to a 20-30% stand loss in varieties infected with the wild-type endophyte and a 40-70% stand loss on endophyte-free varieties. The % loss varied depending on plant variety and endophyte strain combinations that we used.

So, where are we with developing a fescue to fit into our forage systems? We have just planted a large acreage study at Marianna to look at Max Q under irrigation. In order to improve our fall period forage production, which is often limited by seasonal drought and cooler weather,  a perennial forage would be ideal. We lack reliable forages since we rely on annual cool season forages. The new trial at the Marianna Beef Unit will look at Max Q’s establishment under irrigation, persistence under grazing, animal performance and carrying capacity. An economic analysis of the study will also look at the cost per pound of gain.

COOL-SEASON FORAGE STUDY

Growing winter forage on prepared land has a major advantage over the common practice of overseeding our perennial summer grass pastures. At the Marianna Beef Unit there is a demonstration of winter forages that have either been planted on prepared soil or overseeded on Argentine bahiagrass pastures. The differences are striking. Animals were grazing the rye and oats by the third week in December that were planted on prepared land. It is early February, and the overseeded pastures are not yet ready to graze. The study at the Beef Unit will measure pasture performance in terms of forage tonnage, animal gains and number of grazing days. A comparison of the cost of using winter forages will be compared to that of hay and supplements.

READY MADE SLIDE SHOWS

Doug Mayo reminded me that we have some good slide sets available to the agents on our livestock web page. We added this level to our original page so that we could post some ready-made slide shows for you to use.  Please e-mail me any forage related slide sets that you might like to have added to the list. The web site for the livestock page is:

http://livestock.ifas.ufl.edu        and for the slide sets:       http://livestock.ifas.ufl.edu/agents.htm

Also, let us know if there are specific topics that you would like to have covered and put into EDIS.

(Blount, Myer, Hewitt, NFREC News, 3-5)

PAPER MULCH STUDY

Interest in paper mulch research on the part of paper manufactures has increased greatly in the last five years.  Active research programs are currently ongoing in at least three private paper companies and the USDA, Plant Polymer Research Unit in Peoria, Illinois.  The paper manufacturers include: International Paper, Cascades, and Appleton.  Over the past five years, the quality of the paper products has increased greatly.  We have evaluated test rolls of products that easily lay with a Kennco plastic layer with almost no modifications to the machine set-up.  Each company approaches the coating issues differently, but all have technology available to increase the longevity of the paper product in the field.  The issue appears to downguage the product to make it less expensive and this appears to be a great challenge.  Research programs appear to be continuing and improvements occur each year.  I have included here the results of the watermelon and USDA paper mulch trial from last year.

Field Evaluation of Watermelon Produced On Paper Mulch 
Coated with Polymerized Vegetable Oil  2000-01
Robert C. Hochmuth, Multi-County Extension Agent - NFREC-Suwannee Valley

Material and Methods

    The paper mulch study was conducted during the spring, 2000 season at Live Oak, Florida on Lakeland fine sand.  Plowing and disking prepared soil for the experimental area.  Beds were formed on 7.5 foot centers with each 24 inches wide at the top.  On March 16, 2000 beds were fertilized and formed with a bedpress.  Treatments included paper mulch and black polyethylene mulch.  The black polyethylene mulch was a Sonoco high-density film (0.6 mil).  The paper used was a brown kraft paper coated with a polymerized vegetable oil provided by Randal Shogran, Plant Polymer Research Unit, National Center for Agricultural Utilization Research, ARS, USDA, Peoria Illinois, 61604.  All mulches were applied to the beds with Kennco mechanical mulch application mulch application machine.  One-half of each plot was fumigated with a methyl bromide and chloropicrin mixture (67:33) at a rate of 400 lbs per treated acre.  Drip irrigation tubing was Roberts row drip tubing with a 8-mil wall thickness and emitter spaced 12 inches apart.  Pre-bed fertilizer application was 500 lbs/A 13-4-13 (N-P2O5-K2O).  Remaining N and K2O was fertigated weekly to result in N and K2O rates for the season of 150 lbs/A.

On March 23, 2000, watermelon transplants were planted in the field.  Watermelon, cultivar ‘Royal Sweet’ plants were placed in a single row on each bed with 36 inches between plants in a row.  Transplants were planted with a mechanical-aid transplanter “water-wheel” and water was applied with each transplant for aid in transplant establishment.  Recordings were made of the soil temperature at the 4-inch depth in the beds on March 27.
    Watermelon fruit were harvested only once, on May 31, due to severe crow damage.  All data was analyzed by analysis of variance and means were compared using Duncan’s Multiple Range Test.

Results and Discussion

    Mulch application of polyethylene mulch was excellent and paper mulch was fair to good.  The paper mulch tore occasionally during application.  Paper mulch application would have improved at a slower speed.  The speed of the application was set at 3 miles per hour for both polyethylene and paper.
    Transplants were planted using a water wheel transplanter.  Holes were punched in the paper without any serious problems.  The holes in the paper tended to tear an additional 1-2 inches but no more.  The paper mulch laid tightly to the bed and resulted in an acceptable mulched bed.
    Soil temperature measured on March 27 showed very little difference between paper and plastic mulched plots.  The paper was brown but was somewhat opaque allowing some light through the paper.  Soil temperatures were also similar between fumigated and non-fumigated plots.  Weeds in the non-fumigated plots pushed up on the paper mulch.  The primary weed was yellow nutsedge, which pierced through the black plastic mulch.  Weed growth made heat transfer less efficient in both non-fumigated mulch treatments.

Yield of watermelon fruit number and weights were similar on paper and plastic mulched plots (Table 1).  Average fruit weights were also similar from paper and plastic mulched plots.
    Fumigation had no effect on number of fruit per acre (Table 2).  Fumigation with methyl bromide and chloropicrin eliminated weeds from the plots early in the season.  Yield of 35,164 lbs/A was found in the fumigated plots and 26,864 lbs/A in the non-fumigated plots.  The difference between these treatments, however, was not significant.  The same trend of higher average fruit weight was found in fumigated plots, but again was not significant.

    The first signs of initial degradation of the buried tuck area of the paper mulch was noticed on May 7, 52 days after application.  The integrity of the paper mulch was adequate for a single crop of watermelon transplanted in a spring season in North Florida.
    The paper mulch treatments performed in a very similar manner in this trial to the standard black polyethylene mulch.

Table 1 – Effect of mulch type on yield, fruit size, and soil temperature at Live Oak, Florida.

Mulch Type	Total Fruit Number (No./acre)	Total Market Weight  (lbs/acre)	Season Average Fruit Weight (lbs/fruit)	Soil Temperature (oF)
Paper	2,435	31,678	13	91
Plastic	2,186	30,350	14	89
Significance  (p=0.05)	NS	NS	NS	NS

Table 2 – Effect of fumigation on yield, fruit size, and soil temperature at Live Oak, Florida.

Mulch Type	Total Fruit Number (No./acre)	Total Market Weight  (lbs/acre)	Season Average Fruit Weight (lbs/fruit)	Soil Temperature (oF)
+	2,324	35,164	15	91
-	2,296	26,864	12	89
Significance  (p=0.05)	NS	NS	NS	NS

(BHochmuth, NFREC News, 3-5)

Thought for the Day:  Adopt the Pace of Nature:  Her Secret is Patience.   

Cheryl Vergot, Public RelationsNFREC - Quincy, U/F IFAS
E-Mail: cvergot@ifas.ufl.edu
Phone: (850) 875-7112

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