Inside This Issue. Plant Health Applications. Corn and Soybean Disease and Insect Scouting Plant Health Applications

Transcription

1 Plant Health Applications Field investigations have revealed minimal disease presence in corn and soybean up to this point. However, we must consider disease triangle factors which are likely to overlap with recent swings in precipitation. Hybrid / variety susceptibility, percent surface residue, extended leaf wetting periods and disease trends in neighboring counties / states (particularly those to the south) should all be evaluated when implementing management strategies. As an example, this season a stripe rust epidemic occurred throughout much of the wheat crop in IL and IN. Severe outbreaks were being reported in early spring from southern states including: OK, LA, AR and TN. This was a good indication that spring storms with southerly winds would come stripe rust spores. In certain cases growers began spraying fungicides prior to stripe rust lesions spreading to the flag leaf. Others waited for flowering treatments targeting both fusarium head blight and stripe rust, at that time much of the flag leaf was already infected and tremendous yield losses occurred. A proactive strategy in this situation proved beneficial. I am not implying that corn and soybean diseases arising in the south will occur in every Midwestern field this season, but we cannot overlook the importance of monitoring geographical disease trends in addition to examining conditions facilitating disease presence when making application decisions. Insect populations in corn and soybeans have been increasing the past few weeks. Reports of western bean cutworm, corn rootworm adults, European corn borer, Japanese Beetles and Grasshoppers have been materializing in corn. Soybean insects including Japanese beetles, spider mites (to a lesser extent with recent precipitation events), stink bugs, green cloverworms and grass hoppers have also divulged. Visual defoliation is a simple and effective threshold to assist in treatment decisions. However, piercing / sucking, and disease transmitting insects may be more discrete until virus symptoms materialize or yield results transpire. Sweep nets are excellent tools to carry when scouting fields. Insect counts determined by sweep nets will deliver a relative sample to determine the presence of defoliating insects, in addition to those conferring potential for virus transmission, as well those with piercing / sucking mouthparts in order to provide guidance on application decisions. Inside This Issue Plant Health Applications Corn and Soybean Disease and Insect Scouting Technical Service Representative Nick Hustedde (618) Contact your local FMC Representative for more information: Joe Kritenbrink (317) Lonne Fry (309) Jacob Heeren (815) Jen Maruszewski (812) Justin Quear (513)

2 Insecticide / Fungicide Application Benefits University and industry trials have exhibited beneficial results when implementing fungicide and insecticide treatments even in the presence of minimal pressure. Perhaps increased yields pertaining to these circumstances are due to positive physiological effects facilitated by the use of strobilurin fungicides including: increased CO2 assimilation, water use efficiency and stress tolerance during flowering and pod fill. Addressing defoliators as well as piercing / sucking insects that emit digestive enzymes breaking down foliage and developing seeds may have also led to an incremental increase in yield. At any rate, multiple studies have indicated that increasing plant efficiency and reducing stress during critical yield determination stages including flowering and pod fill will likely translate to a positive ROI. Wet and humid conditions have recently transpired which will likely facilitate disease infections. Most soybeans in IL and IN are in the early reproductive stages, representing a critical period for reducing stress. Talk to your local star retailer regarding the 2016 FMC Soybean Yield Assurance program to protect plants and optimize yield. University of Illinois Soybean Omission Plot An omission trial was conducted at the University of Illinois in Five factors were evaluated to quantify the yield increase provided by each. Fertility and foliar protection provided greatest yield benefits with fertility contributing a 4.3 bu/a increase and fungicide and insecticide applications producing 3.6 more bu/a. When splitting out fungicide and insecticide applications in a standard management system (soybean variety, fertility, row spacing), insecticide provided a 3.7 bu/a gain and fungicide provided a 2.1 bushel increase (data not shown). Table 4 provides an average across both standard and high tech management systems. This trial demonstrates consistent yield increases when fungicide and insecticide applications are included in management strategies. Data courtesy of Dr. Jason Haegele University of IL Use Recommendations Soybeans V stages-r5, R3 for best Results: Fungicide 5 oz/a + Hero Insecticide 5 oz Diseases: Frogeye Leaf Spot, Pod & Stem Blight, Powdery Mildew, Cercospera blight, Anthracnose, Altenaria leaf spot, Rhizoctonia aerial blight, Rust, White Mold - suppression. Also labeled for suppression of Sudden Death Syndrome. Must be applied at or prior to R1 stage for SDS suppression Insects: bean leaf beetle, grass hoppers, cloverworms, soybean podworms, dectes stem borer, Japanese beetle, loopers, aphids, thrips, stink bugs. Adjuvants: An adjuvant may be used to increase spray coverage and canopy penetration. Add NIS 0.25% v/v, COC % v/v, or a spreader / sticker. If tank-mixed follow adjuvant requirement for tank-mix partner. PHI 30 days, Rainfast 2 hrs, Do need feed forage or hay to livestock. Influence of Insecticide + Fungicide Applications on Soybean Field Mt. Vernon, IL Nontreated Fungicide 5 R3 Fungicide 5 oz + Hero Insecticide 5 R3 Treatments included NIS 0.25% v/v % Moisture Yield Bu/A

3 Images courtesy of Iowa State University Herbicide Tank-Mixtures Growers may be inclined to include insecticide + fungicide applications with herbicide tank-mixtures to save a trip across the field. We can reference a trial that was conducted in Southern Illinois in 2015 for a better understanding of insecticide + fungicide applications with herbicide tank-mixtures. In this trial, a tank-mixture of fungicide + Marvel herbicide + glyphosate was applied. Data indicated a slight increase in crop response (likely due to additional solvents) but the combination provided adequate disease protection. This trial suggests no adverse affect on disease efficacy when fungicide was tank-mixed with a burner herbicide. As we get later in the season it is predictable that this treatment will not be timed correctly and we do not anticipate many of these tank-mixtures being employed. However the trial information is reported below. Combinations with Liberty herbicide Evaluation of Marvel herbicide + fungicide Combinations for Disease Efficacy and Yield Illinois Ag Research Mason, IL Roundup PowerMAX herbicide 32 oz + Marvel herbicide 7.25 R Roundup PowerMAX herbicide 32 oz + Marvel herbicide 7.25 oz + fungicide 5 R2 Septoria Brown Spot % LAA 9-22 Frogeye Leaf Spot % LAA 9-22 CI% 6 DAT Yield Bu/A Liberty herbicide is loaded with a surfactant system. Tank-mixtures including Preemptor SC fungicide and Hero Insecticide encompass more solvents and emulsifiers potentially causing a flash response (we occasionally see this with Liberty herbicide alone). This is cosmetic and plants will recover rapidly. Liberty herbicide can be applied postemergence to transgenic soybeans from emergence up to but not including bloom stage, which will not facilitate optimal results with Preemptor SC fungicide on most soybean diseases. Soybean Diseases to Watch For Septoria Brown Spot Cercospora Blight, Purple Seed Stain Frogeye Leaf Spot Powdery Mildew

4 Soybean Growth Stages When making fungicide applications it is important to abide by label suggestions based upon soybean growth stage. Below is a guide from Iowa State University that will help distinguish in the field. Soybean Insect Complex Soybean Aphid Two Spotted Spider Mite Three-cornered Alfalfa Hopper - Overwinters as an egg on buckthorn - Multiple generations per year - Damage from feeding on sap - Indirect damage from spread of soybean mosaic virus and alfalfa mosaic virus - Varies with several factors insecticide cost, application cost, infestation timing, current timing, expected yield and price of soybeans - During drought conditions they will move to soybeans - Foliar coverage is critical - Assess mite movement into fields along corners and edges to prevent heavy infestations within the field - None, easier to manage the population than rescue a heavy infestation - Generally cause problems on beans less than 12 tall - Feed on main stem near the soil line - Seedling plants my be girdled and die, larger damaged plants may lodge - Later feeding on pod petiole will cause pod abortion - 1 per sweep

5 Potato Leafhopper Corn Earworm (Podworm) Soybean Stem Borer - Overwinters near the Gulf - Adult females insert eggs into soybean plants 2-3 per day - Feed on phloem - Cause distorted leaf veins, yellowbrown leaves (hopper burn) and may stunt the plant Approximate - 5 leafhoppers/plant - Moths lay eggs in the upper canopy, 1 female can lay up to 1800 eggs - Caterpillars (4 pairs of prolegs) feed on leaves, blossoms, and pods [cost of trt/(price/bu x 1.93)]/ At $12 beans and $7 chemical cost, it is 0.44 worms/ft row - Overwinters as a larva in the base of the stem - Adults emerge in late June and lay eggs through August - Control is difficult the larva are in the stem and cause lodging, proper timing is key to adult control Approximate - 1 per 10 sweeps Japanese Beetle Bean Leaf Beetle Stink Bugs - Adults emerge in early June and feed most of the summer - They group feed and stay exposed to sunlight making them easier to control - Grubs from these adults can cause problems next year in field corn - 30% defoliation at pre-bloom stage - 15% defoliation from bloom to pod-fill - Overwinters as an adult - Two in-season generations per year - Direct damage from feeding on leaves and pods - Indirect damage from spread of bean pod mottle virus (see photo) - Difficult to determine depending on direct or indirect damage. Scout earliest planted soybeans first. Guideline: - $7 insecticide cost, $12 bu soybeans - 9 beetles/20 sweeps - Move into the north from the south on weather fronts - Females lay eggs per cluster - Depending on species it takes 23 days to 2 months from egg to adult - Feed directly on pods and seeds Approximate - 1 per ft of row

6 As corn nears tasselling, the decision to apply a fungicide for disease control, improved standability at harvest, and higher yields is upon us. fungicide from FMC provides outstanding disease control in corn with excellent residual. Preemptor SC fungicide: flutriafol (triazole) + fluroxastrobin (strobilurin) Preemptor SC fungicide has excellent curative as well as some of the longest residual control and preventive control available for row crops. It is and highly systemic fungicide and provides long-lasting disease protection Rainfast in 2 hours Outstanding translaminar movement. Both actives are very mobile in plant xylem for leaf protection Excellent Plant Health Benefits: Reduced Ethylene, Higher Yields, Greater Standability Corn Diseases Controlled: Common & Southern Rust, Gray Leaf Spot, N. Corn Leaf Blight, N. Corn Leaf Spot, S. Corn Leaf Blight, Anthracnose Leaf Blight, Eye Spot Application Guidelines Corn: V5 thru R4 (early dough) stage Recommended Use Rates: 270 Dr. Jason Bond 2015 Southern IL Univ. Corn Yield - Bu/A (Grey Leaf Spot, Southern Rust, Common Rust) 5-6 oz (V5 - V8 stage) + NIS 0.25% 4-5 oz after tassel + NIS 0.25% Do not include adjuvants from V8 to VT stage corn PHI: 30 days grain, forage, stover Minimum of 2 gpa aerial or 10 gpa ground application volume 250 fungicide 5 oz + V8 Headline AMP fungicide10 oz + V8 fungicide 5 oz + VT Headline AMP fungicide 10 oz + VT Check Gray Leaf Spot Corn Diseases to Watch For Description Lesions are narrow, rectangular and usually are restricted by leaf veins Lesions initially are tan and later turn gray. Lesions coalesce to kill entire leaves Scouting tip Disease may be more prevalent in fields where previously infected corn residue is present. High RH (above 90%) during silking and early kernel-fill stages can lead to increased disease. Extended periods of leaf wetness >13hrs allow infection Fog each morning for a week will increase severity Common Rust Description Brick-red pustules(raised bumps), oval or elongated, approximately 1/8 long. Scattered sparsely or clustered together on both upper and lower leaf surfaces in the mid to upper canopy. Leaf tissue surrounding the pustules may become yellow.

7 FMC-AG FMCCROP.COM Always read and follow label directions. NOTE REGARDING RESTRICTED USE PESTICIDES: Anthem ATZ herbicide; Athena insecticide, Brigade 2EC Insecticide/Miticide, Brigade WSB Insecticide/Miticide, Brigadier Insecticide Capture 3RIVE 3D insecticide, Capture LFR Insecticide, Declare insecticide, Hero Insecticide, Mustang Insecticide, Mustang Maxx Insecticide, Pounce 25WP Insecticide, Stallion Brand Insecticide, Ethos XB Insecticide/Fungicide and Gladiator Insecticide/Miticide are Restricted Use Pesticides. VGR Soil Amendment is not a pesticide. NOTE FOR CALIFORNIA: Accurate Extra herbicide, Aim EC herbicide, Anthem herbicide, Anthem ATZ herbicide, Anthem Flex herbicide, Anthem Maxx herbicide, Authority Assist herbicide, Authority Elite herbicide, Authority First DF herbicide, Authority Maxx herbicide, Authority MTZ DF herbicide, Authority XL herbicide, Cadet herbicide, Chisum Herbicide, Command 3ME microencapsulated herbicide, Crusher Herbicide, Edition Broadspec herbicide, Edition Tankmix Herbicide, Marvel herbicide, Nimble Herbicide, Nuance Herbicide, Preemptor SC, Report Extra Herbicide, Solstice herbicide, Spartan 4F herbicide, Spartan Charge herbicide, Spartan Elite herbicide, Zeus Prime XC herbicide, Zeus XC herbicide, Capture 3RIVE 3D insecticide, Ethos XB Insecticide/Fungicide, Hero Insecticide, Mustang Maxx Insecticide, Topguard Terra Fungicide, Specialty Crops fungicide, Display cotton harvest aid are not registered for sale or use in California. Topguard Fungicide is only registered for apples and soybeans in CA. Beleaf and Carbine are trademarks of Ishihara Sangyo Kaisha, Ltd. Cercobin is a trademark of Nippon Soda Co., LTD. Sovran is a registered trademark of BASF. Fortix is a trademark of Arysta LifeScience North. FMC, 3RIVE 3D, Accurate, Aim, Anthem, Athena, Authority, Brigade, Brigadier, Cadet, Capture, Chisum, Command, Crusher, Declare, Display, Edition, Ethos, Fracture, Fyfanon, Gladiator, Hero, Koverall, LFR, Marvel, Mustang, Nimble, Obey, Pounce, Preemptor, Report, Rhyme, Rovral, Shark, Solida, Solstice, Spartan, Stallion, Topguard, Topguard Terra and Zeus are trademarks and HatchTrak and Investing in farming s future are service marks of FMC Corporation or an affiliate FMC Corporation. All rights reserved. Roundup and Roundup Ready are trademarks of Monsanto Technology LLC. Liberty Link and Liberty are trademarks of Bayer Crop Science. Headline AMP is a trademark of BASF Agro B.V. HT-CCB-SOYBEAN-NVH