Agronomy notes
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Permanent Link: http://ufdc.ufl.edu/UF00066352/00143
 Material Information
Title: Agronomy notes
Uniform Title: Agronomy notes (Gainesville, Fl.)
Physical Description: v. : ill. ; 28 cm.
Language: English
Creator: Florida Cooperative Extension Service
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida.
Place of Publication: Gainesville
Publication Date: January 2012
Subjects / Keywords: Crops and soils -- Florida   ( lcsh )
Crop yields -- Florida   ( lcsh )
Agriculture -- Florida   ( lcsh )
Agronomy -- Florida   ( lcsh )
Genre: serial   ( sobekcm )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
periodical   ( marcgt )
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Additional Physical Form: Electronic reproduction of copy from George A. Smathers Libraries, University of Florida also available.
General Note: Description based on: January 1971; title from caption.
Statement of Responsibility: Florida Cooperative Extension Service, University of Florida, Institute of Food and Agricultural Sciences.
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notis - AER9014
System ID: UF00066352:00143


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Agronomy Notes Jan 2012 Volume 36:1 Features: Forage: The Timing for Forage Fertilization...........................Page 6 Agronomy Notes is prepared by: Maria Gallo Chair and Y. Newman, Extension Forage Sp ecialist (ycnew@ufl.edu); J. Ferrel, Ext ension Weed Specialist (jferrel@ufl.edu); F. Fishel, Pesticide Information O fficer (weeddr@ufl.edu); D.C. Odero, Extension Weed Specialist (dcodero@ufl.edu); The use of trade names does not constitute a guarantee or warrant of products named and does not signify approval to the exclusion of similar products. The Institute of Food and Agricultural Scienc es (IFAS) is an Equal Employment Opportuni ty-Affirmative Action Employer authorized to provide research, educational information and other services only to indi viduals and institutions that function without regard to race, color, sex, age, handicap or national origin. For information on obtaining other extensi on publications, contact your coun ty Cooperative Extension Office Florida Cooperative Extension Service/Institute of Food and Agricultural Sciences /University of Florida/Millie Ferrer-Chancy, Interim Dean. Miscellaneous: Weeds and Pesticides: For Palmer Amaranth, Scout Early and Often.........Page 3 Nutsedge control in sugarcane ...................................Page 4 Review Security Procedures for Pesticide Storage ......Page 5 New Hires in Agronomy ..........................................Page 2 Calendar of Events...................................................Page 7


4 2 Agronomy New Faculty Hires The Agronomy Department is very pl eased to announce and introduce to our agronomy community two new faculty members that have recently joined the department: Dr. S. Luke Flory (flory@ufl.edu ) Assistant Professor in Invasion Ecology, Gainesville campus. Dr. Flory joined the Agronomy Department in August, 2011. He received his Bachelor of Science degree in Biological Sciences, from DePauw University in 2001. He received his MS in Enviro nmental Science with focus on Applied Ecology from the School of Public a nd Environmental Affairs at Indiana University (2003) and his PhD in Ecol ogy and Evolutionary Biology from the Department of Biology, Indiana University (2008). His appointment is 70% research and 30% teaching. Dr. Fl orys work has focused on cropping systems and management for enhanced environmental sustainability. New projects under development will investigate the invasi on risk of biofuel crops and the interaction between invasions and climate change. For additional information on Dr. Florys research and interests, please visit The Flory Lab Invasion Ecology website! http://www.florylab.com/research/ Dr. Lyn A. Gettys (wlgettys@ufl.edu ) Assistant Professor of Aquatic and Wetland Plant Science, Fort Lauderdale REC (Fort Lauderdale). Dr. Gettys joined the Agronomy Department in January 2012. She received her bachelors degree in Horticulture from the University of Florida (1996), her MS in Plant Breeding/Horticultura l Science from North Carolina State University (2000) and her PhD in Plant Breeding and Genetics/Agronomy from the University of Florida in Gainesville (2005). Dr. Gettys brings expertise in the areas of aquatic plant reproduction and biology, aquatic weed science, experimental herbicide evalua tion and lake restor ation methods and techniques. Her appointment is 60% re search and 40% extension. Dr. Gettys will evaluate methods to control Florid as aquatic invaders and improve the success rate of lake restoration effort s in Florida; she will also provide leadership for the University of Flor idas annual Aquatic Weed Control Short Course in Coral Springs. Miscellaneous


4 3 For Palmer amaranth, scout early and often Over the past 30 years, increasingly effective herbicides have been released for weed management in peanuts. These compounds permitted us to forgo soil applied herbicides and rely totally on postemergence sprays. They also would kill big weeds which allowed us to catch up if we got behind and the weeds got a little too big. But as everyone is now aware, Palmer amaranth has changed everything. Palmer amaranth possesses two qualities that have required us to renovate our weed management strategies. These are: 1) Resistance to ALS inhibitors like imazapic (Cadre, others) a nd 2) growth rates up to 1 inch per day. If imazapic cant be used for this weed, the program of choice is overlapping residuals (Prowl + Valor, followed by Dual, etc) and early postemergence applications of paraquat or other burners like Cobra, Ultra Blazer, or Storm. But in order to make a timely application, these fields must be scouted regularly. I have scouted fields for years by driving by and looking out the truck window. This can be a quick and effective way of managing coffeeweed and crabgrass, but simply will not cut it if Palmer is in the field. By the time you see a Palmer plant from the window, it is likely too late to kill it. So when should a more intense scouting schedule start? Our experience is that Valor will provide 30 to 45 days of effective control, if you get an activating rainfall within 5 days of application. Personally, I would scout a few times after planting to ensure proper activation of my preemergence herbicide. Then around 30 days after planting I would start scouting on a 4-5 day schedule until you see the Palmer seedlings emerge. A newly emerged seedling will grow relatively slow for 10-14 days depending on temperature and soil moisture. After emergence, I would recommend scouting those fields on a 2-3 day schedule with plans to spray when the average weed height is 2-3. When the weeds are ready to sp ray, what product should you choose? After ex tensive testing we have concluded that if you target small weeds, Cobra, Ultra Blazer, and Storm are all equa lly effective and will provide >95% control. However, when Palmer reaches 3 the growth really takes off. Missing this wi ndow by a mere 3 days will result in 6 weeds. What are the options at this point? Again, extensive testing has shown that Cobra, Ultra Blazer and Storm are equally ineffective at this height. Will adding 2,4-DB help? It will help, but not enough to clean up a field of overly-tall Palmer amaranth. At this point, the only viable option is paraquat in a wiper. For this weed, we have no backup plan. It is vitally importa nt to use our residual herbicides and then be ready when the weeds begin to escape. Early intervention from a peanut producer is the best wea pon we have for Palmer amaranth control. Weed Science Dr. Jason Ferrell, Extensio n Weed Specialist jferrell@ufl.edu Ms. Sarah Berger, Graduate Student sberger@ufl.edu Above: Palmer sprayed at 3. Note carcass in bottom right .. Below: Palmer sprayed at 6. Note injury and regrowth. Photos by Jason Ferrell


4 Weed Science Dr. D. Calvin Odero, Extension Weed Specialist dcodero @ufl.edu Nutsedge control in sugarcane Nutsedges are common weeds in sugarcane fields in south Florida. The two common species of nutsedge in south Flor ida are yellow nutsedge ( Cyperus esculentus) and purple nutsedge ( Cyperus rotundus ) with the former being the most prevalent. Nutsedges are grass-like perennial plants that have triangular stems and leaves that grow in three vertical ro ws from the base of the plant. The leaves of yellow nutsedge taper gradually unlike purple nutsedge that taper abruptly to a sharp point. Both nutsedges have much branched fibrous roots and rhizomes with underground tubers that grow from rhizomes. Yellow nutsedge produces solitary tubers that arise either from the basal bulb or from a rhizome in contrast to purple nutsedge that produces chains of tubers that develop alon g the entire rhizome. There are several new plant cane fields that are presently infested with nutsedges. This has mainly been attributed to heavy rains at planting and poor control during the summer fallow months. Infestations of nutsedges ar e also presently high in stubble cane fields. Contro l of these nutsedges in the fall is very important to minimize their interference in sugarcane in the spring. To control nutsedges in plant or stubble cane, Sandea (75% halosulfuron by weight) should be applied at a broadcast rate of 1.0 to 1.33 oz/A with a nonionic surfactant at 1 to 2 qt/g al (0.25 to 0.5% v/v) or crop oil concentrate at 4 qt/100 gal (1% v/v). Sandea can be tank-mixed with glyphosate for preplant burn down of emerged annual grasses, broadleaf weeds, and nutsedges in sugarcane. Sandea can also be tank-mixed with Atrazine, Asulox (asulam), Evik (ametryn), or 2,4-D to provide additio nal control of broadleaf weeds and grasses in addition to nutsedges. The choice of tank-mix partner(s) should made after scouting the field to assess the type and number of weeds present. Always refer to labels of these herb icides for use instructions, additive requirements, weeds controlled, the size range of weeds that should be treated, and applic ation restrictions. Yukon, a premix of halosulfuron (12.5% by weight) and dicamba (55% by weight) can be applied at 4 to 8 oz/A to control nutsedges. The dicamba in the premix is helpful in controlling sm all broadleaf weeds. Yukon shoul d be applied with either crop oil concentrate at 4 qt/100 gal (1% v/v) or nonionic surfactan t at 1 to 2 qt/gal (0.25 to 0.5% v/v). Yukon may be tank-mixed with Atrazine, Asulam, Evik, or 2,4-D to broaden the spectrum of w eed control in addition to nutsedges. Application of either Sand ea or Yukon should be made on actively gr owing nutsedges at the 3 to 8 leaf stage. Generally, control of nutsedges in fields to be planted to new cane should be first implemented during the fallow period using a systemic herbicide such as glyphosate that can move to nutsedge tubers. Above: Yellow nutsedge in plant cane. Photos by D. Calvin Odero Below: Yellow nutsedge in stubble cane


4 5 Pesticides Dr. Fred Fishel, Pesticide Information Director weeddr @ufl.edu Review Security Procedures for Pesticide Storage There continue to be reports of ag richemical thefts. Most recently over the Thanksgiving weekend, in Hendry County, a large operation was targeted despite locked gates. Such unfortunate occurrences serve as a reminder to continue or step up your vigilance of your storage facility. Recommended considerations in ev aluating agrichemical security: Securing buildings, manufacturing facilities, storage areas and surrounding property: its fundamental, but prevention of intrusion can include elements such as fe ncing or other barriers, lighting, locks, detection systems, signage, alarms, cameras and trained guards. Securing pesticide application equipment and vehicles: consider using an authorization process for persons who have access to such equipment before their use. Also consider specifically marking equipment as well as other tool s kept in the operation so that you can identify them. Aerial application equipment: th e FBI has requested that aerial applicators be vigilant to any suspicious activity relevant to the use, training in, or acquisition of dangerous chemicals and their application. Such activit y includes, but is not limited to, threats, unusual purchases, suspicious behavior and unusual contacts with the public. Protection of confidential info rmation: as businesses have grown more reliant on comput ers and communication technology, the need to secure these systems has grown. Efforts to include contingency planning for power losses, monitoring access ports, adherence to password and backup pro cedures, and maintaining access for au thorized personnel only should be taken into account. Developing procedures and policies that support secur ity needs: even the best hardware and staffing budgets are only as effective as the procedures and policies that control their use. Effective hiring and labor relations are important to obtain and retain good em ployees who will support and follow safety precautions. For example, the hiring process should ensure that pesticide handlers have all requisite training necessary to handle pest icides safely. Background checks of sta ff who have access to secure areas, particularly those areas wh ere pesticides may be stored, are also necessary. Inventory management policies can help limit the am ount of potentially hazardous pe sticides stored on site, reducing the risks of accidental or intentional release or theft. Take control of your inventory: request that chemicals be delivered on the days you need them and not before. Return excess chemicals to the chemical distributor. Not having a stockpile of chemicals in y our facility will decrease the opportunity for theft. Effective advance emergency response procedures can be critical. Business official s and employees need to have an understanding of how to respond and w ho to contact in the case of an emergency. Establish a procedure for locking up the f acility at the close of the business day. Finally, buy only from reputable dealers and do not be tempted to buy "cheap" chemicals from unknown sources you are only supporting a th ief and you may be next. Look out for your neighbor, and if you witness suspicious individuals, activities, and vehi cles, contact your local sheriffs office.


4 6 The Timing for Forage Fertilization Pasture fertilizati on is profitable if timely done but if the timing is wrong you may not see the benefits it provides. Before making any decision, an important reminder to any rancher or grass farmer is to soil test their pastures. A soil test is a low cost investment that can actually save you money by letting you know what soil nutrients you already have and do not need to add. A soil test will also let you know those nutrients that are deficient but critical to your forage plant and will need to be added. Soil test results include the recommendations of the type of nutrients and the levels or amounts needed. When pasture fertilization is not timely done it may result in more costs than benefits Below are some examples: There will be a slow response to fertilizer application wh en the plant is not ready to absorb the nutrients because the soil is too cold and the roots are not growing. Root growth for most warm-season grasses requires consistent soil temperatures of 65F. When there is a high weed population in the area to be fertilized, a fertilizer application will make the weed problem worst. Take care of the weeds first, then fertilize. When there is over application because the roots are not fully developed, only a sma ll amount of fertilizer is taken up by the plant. Early stage plants require less amount of fertilizer than a full stand. If a fertilizer application is made prior to having soil test results and re commendations, nutrients (and fertilizer) will be over or under applied. Or if pH is too low, lime may be re quired for better upt ake of soil nutrients. When applications are excessive and fer tilizer is lost to run-off or leaching, there will be more costs than benefits from fertilization. Fertilization of forage plants is an in vestment when there is a need to increas e the number of animals that are grazing, or the production in a hay field. In this case, proper and timely fertiliz ation will result in high production of dry matter, which will allow for a higher stocki ng rate, hay production, and economic returns. Forage fertilization is very specific depending on forage type. Fertilization recommen dations for legumes are different from those of grasses. For example, nitrogen is used in small amounts as a start up fertilizer for legumes that should not exceed 25 lb N/acre/season. While for gra ss production nitrogen recommendations depending on the situation may well be three or more times that amount. ... (Continues next page) Forages Dr. Yoana Newman, Extension Forage Specialist ycnew @ufl.edu


4 7 The Timing for Forage Fertilization (...continued from previous page) What are the nutrients needed in a forage plant? Nitrogen, Phos phorus, and Potassium (major nutrients), calcium, magnesium, and sulfur (secondary nutrients), and manganese, iron, boron, copper, molybdenum, chloride, zinc, and nickel (Micronutrients), which are required in very small amounts Nitrogen this nutrient is required in large amounts, and because of its mobility in the soil it should be applied in two or more applications during the growing season. Low nitrogen in the soil will likely limit root growth and the ability of roots to access soil nutrients. Neverthel ess, excess nitrogen is not desirable either b ecause of the nutritional imbalances that produc e in the plant making them susceptible to di seases, insects, freeze damage lodging, etc. In addition, the potential for N losse s (runoff, leaching, denitrification) incr eases with excess nitrogen applications. Phosphorus this nutrient is involved in fruit and seed formati on, and proper root growth. Phosphorus is not usually leached from the soil. Potassium a major nutrient needed by fora ge plants in large amounts. It is involved in rhizome production in grasses, and it is also needed for adequate winter survival and root grow th. Movement in the soil is intermediate between nitrogen and phosphorus. For additional information on Forage Fertili zation or any other forage related topic, please check the Forages of Florida website at: http://agronomy.ifas.ufl.edu/ForagesofFlorida/index.php or just Google Forages of Florida. Forages Dr. Yoana Newman, Extension Forage Specialist ycnew @ufl.edu Calendar of Events To follow the link, press Ctrl and put cursor over link, and click. Jan. 9-11 2012 American Forage and Grassland Council (AFGC). Louisville, KY http://www.afgc.org/events.html Jan. 26 29th Annual Florida Cattlemen & Allied Tradeshow. Kissimmee, FL http://www.floridacattlemen.org/d/2012_FCIATS_ad.pdf Feb. 5-7 American Society of AgronomySouthern branch. Birmingham, AL https://www.agronomy.org/membership/branches/southern Feb. 14 Best Management Practices Class. Fort Myers, FL http://lee.ifas.ufl.edu/Hort/H ortClasses/BMP2012Agenda.pdf Feb. 15-16 Uf Water Institute Symposium. Gainesville, FL http://www.floridacattlemen.org/d/ufwatersavethedate071211r2.pdf Feb. 29 The second Generation (G2) of Be st Management Practices (BMPs) for Crop Production. Apopka, Fl. For information, contact 352-273-4814