CORN ROOTWORM PROTECTION MANAGEMENT

Transcription

1 orn rootworm (RW) is one of the most difficult pests to control and can cause substantial annual crop losses. Typically, management practices may include crop rotation and planting corn traits targeting RW with or without insecticides. For farmers who continue to plant continuous corn, Genuity SmartStax RI omplete corn blend with its dual-mode activity against RW is extremely effective and adding a soil-applied insecticide with YieldGard VT Triple or Genuity VT Triple PRO products can help manage fields with high RW pressure. In 212, efficacy of Genuity corn traits with or without insecticide and seed treatments were evaluated for RW protection performance. Materials and Methods This demonstration trial was conducted at the Monsanto Learning enter at Gothenburg, NE in 212 to evaluate root growth, RW damage, and yield of corn products with varying modes of action against RW. This trial was set up in an area of the field that had high RW pressure the previous year. The three DEKL brand corn products, with similar relative maturity (19 RM), selected for this trial are listed in Table 1. The trial was planted on May 7 in 3-inch rows on a corn-corn rotation ground. The field was Table 1. DEKL brand corn products and modes of action against RW. Trademark DEKL brand Mode of ction Genuity SmartStax RI omplete corn blend DK 59-9RI brand blend Dual-mode activity YieldGard VT Triple DK brand Single-mode activity Roundup Ready Figure 2. DK Yield response brand by planting population. None orn 2 Table 2. Soil-applied insecticide and seed treatments applied to DEKL brand corn DK 59-9RI brand blend DK brand DK brand Force 3G apture LFR DK brand + Force 3G DK brand + apture LFR DK brand + Force 3G DK brand + apture LFR DK brand + Poncho 125 DK brand + Poncho Force 3G DK brand + Poncho apture LFR 1 / 5

2 Yield (bu/acre) NIS rating (-3) Yield (bu/acre) NIS rating (-3) Figure 1. Yield and average node injury scale (NIS) ratings across DEKL brand corn products with different modes of action in field with high RW pressure. DK brand DK brand DK 59-9RI brand blend conventionally tilled on pril 2. Seeding rate used was 34, seeds/acre. Plots were fertilized with 1 lbs/acre nitrogen. Pre-plant Degree Xtra herbicide (3.5 qts/acre), Roundup PowerMX herbicide (28 fl oz/acre), and Sharpen herbicide (2 fl oz/acre) were applied on pril 4. In addition, Roundup PowerMX herbicide (28 fl oz/acre) and Warrant Herbicide (2 pints/acre) were applied on June 6. ombinations of insecticides and seed treatments used for this trial are listed in Table 2. Treatments were non-replicated strips. Other agronomic practices were in alignment with local standards. Plots received irrigation water through a drip system as needed. No fungicide was applied because of low disease pressure. Two rows in the middle of four rows were harvested for yield on October 11. root growth & damage ssessment Five randomly selected roots were dug on June 21 from each strip and washed vigorously in a bucket of water. The node injury scale (NIS) of -3 was used to rate the root damage due to RW feeding. To assess the rate of root regrowth, roots from the 12 treatments were evaluated on September 24 by digging two more randomly selected roots from each treatment. Roots were washed in water and individual roots were observed. Two out of five roots from June 21 samples and one out of two roots from September 24 samples were selected for preservation. Roots were dried for 3-5 days before dipping them into a polyurethane solution for few a seconds and then dried under shade. Results and discussion There are substantial differences between the corn products (Figure 1). Roundup Ready orn 2, with no RW.t. technology, yield was the least compared to the traited corn products with RW protection. Genuity SmartStax RI omplete corn blend with dual-mode activity against RW produced the highest yield followed by YieldGard VT Triple with single-mode activity. oth products provided better RW control than the non-traited product, as indicated by the NIS ratings (Figure 1). verage NIS rating ranged between 2.2 for Roundup Ready orn 2 and.3 for both Genuity 2 / 5

3 Yield (bu/acre) DK brand DK brand + Force 3G DK brand + apture LFR Force 3G apture LFR DK brand DK brand + Force 3G DK brand + apture LFR DK 59-9RI brand blend Force 3G apture LFR NIS rating (-3) Figure 2. Effect of soilapplied insecticides and seed treatments on yield and average node injury scale (NIS) ratings of DEKL brand corn products with different modes of action planted in field with high RW pressure. SmartStax RI omplete corn blend and YieldGard VT Triple. Generally, combination of insecticide and corn products with RW control trait provided good control of RW (Figure 2). Force 3G insecticide provided good protection from RW feeding in both Genuity SmartStax RI omplete corn blend and Roundup Ready orn 2; however, the latter benefited more and produced an additional 22 bu/acre compared to 12 bu/acre for Genuity SmartStax RI omplete corn blend. dditionally, RW feeding was reduced resulting in a substantial decrease in average NIS rating. Yield advantage, in this case, was closely related to the protected root system. Roundup Ready orn 2 with Force 3G insecticide (Figure 5-bottom) had less RW feeding and larger root system than the untreated plant (Figure 5--top). Within the three corn products, Genuity SmartStax RI omplete corn blend with Force 3G insecticide produced the highest yield and had a low NIS rating average (Figure 2). Similar results from 21 Monsanto Learning enter trial demonstrated that Genuity SmartStax corn products blend provided yield advantage of 2.7 and 1.5 bu/acre over YieldGard VT Triple and Roundup Ready orn 2 with soil-applied insecticide. These results can be contributed to the extra RW protection provided by the dual-mode activity trait found in Genuity SmartStax RI omplete corn blend. The addition of a seed treatment had a mixed effect on corn yield and RW damage. Seed treatment reduced RW feeding compared to non-treated seeds; although, the combination of Poncho 125 and apture LFR provided more protection to Roundup Ready orn 2 than did Poncho 125 and Force 3G insecticide (Figure 2). In this trial, the RW larvae and root damage sampling date was important to help predict yield potential. Figure 3 shows a low yielding Roundup Ready orn 2 with root regrowth that occurred late in the season (R); although, substantial root damage from RW feeding occurred earlier (L). Regardless of root regrowth late in the season, if damage from RW feeding occurs early, yield reduction can be expected due to reduction of water and nutrient uptake by the roots. Under normal growing conditions, sampling would be best conducted as early as the end of June to the 2nd week of July. In addition to root damage from RW feeding, goosenecking symptoms appeared in Roundup Ready orn 2 plants due to RW damage resulted in reduced standability, lodging at the roots, and upward bending of the stalk (Figure 4). 3 / 5

4 ORN ROOTWORM PROTETION MNGEMENT from previous page cross all treatments, Figure 5 clearly illustrates the benefits of using RW.t. technology in high pressure RW areas. Roundup Ready orn 2 had more compact, damaged roots with average NIS rating of 2.2 (Figure 5--top) compared to the protected, healthy roots of YieldGard VT Triple and Genuity SmartStax RI omplete corn blend with.3 NIS ratings shown in Figures 5- & -top, respectively. June 21 Sept. 24 Summary omments cross all treatments, the addition of one or two modes of action against RW resulted in the yield advantage of 36 and 52 bu/acre, respectively, compared to the none- traited corn product. Yield potential can be predicted by conducting early sampling for RW larvae and root damage. Figure 3. Roundup Ready orn 2 roots damaged early in the season (June 21); root regrowth occurred late in the season (September 24). ombination of RW.t. technology and a soil-applied insecticide can help manage high RW population. Force 3G insecticide was more beneficial in reducing RW feeding compared to apture LFR insecticide. This was true only in Genuity SmartStax RI omplete corn blend and Roundup Ready orn 2 and not YieldGard VT Triple. ombination of the seed treatment, Poncho 125 and soil-applied insecticide apture LFR provided more protection to Roundup Ready orn 2 than combination of Poncho 125 and Force 3G. Low NIS ratings in Genuity SmartStax RI omplete corn blend and YieldGard VT Triple confirm the advantages of using corn products with RW trait in high pressure areas. Roundup Ready orn 2 plants showed goosenecking symptoms due to RW feeding. Since Genuity SmartStax RI omplete corn blend provides protection against above ground insects as well, the yield advantage of Genuity SmartStax RI omplete corn blend over Roundup Ready orn 2 would have included this benefit as well. Figure 4: Roundup Ready orn 2 plant with goosenecking symptoms. 4 / 5

5 from previous page Figure 5. Root systems and average NIS ratings of corn products with varying modes of action, none (), single (), dual (), for RW protection with and without soil-applied insecticide and seed treatments*. orn Traits w/o Insecticide/Seed Treatment NIS = 2.2 NIS =.3 NIS=.3 Roundup Ready orn 2 + Seed Treatment + Insecticide Poncho 125 Poncho apture LFR Poncho Force 3G NIS =.9 NIS =.5 NIS =.4 NIS = 1.4 orn Traits + apture LFR insecticide NIS =.3 NIS=.3 *None = Roundup Ready orn 2 (DK brand) Single-mode activity = YieldGard VT Triple (DK brand) Dual-mode activity = Genuity SmartStax RI omplete corn blend (DK 59-9RI brand blend) NIS =.4 orn Traits + Force 3G insecticide NIS =.3 NIS=.3 The information discussed in this report is from a single site, non-replicated, one-year demonstration. This informational piece is designed to report the results of this demonstration and is not intended to infer any confirmed trends. Please use this information accordingly. Monsanto ompany is a member of Excellence Through Stewardship (ETS). Monsanto products are commercialized in accordance with ETS Product Launch Stewardship Guidance, and in compliance with Monsanto s Policy for ommercialization of iotechnology-derived Plant Products in ommodity rops. This product has been approved for import into key export markets with functioning regulatory systems. ny crop or material produced from this product can only be exported to, or used, processed or sold in countries where all necessary regulatory approvals have been granted. It is a violation of national and international law to move material containing biotech traits across boundaries into nations where import is not permitted. Growers should talk to their grain handler or product purchaser to confirm their buying position for this product. Excellence Through Stewardship is a registered trademark of iotechnology Industry Organization..t. products may not yet be registered in all states. heck with your Monsanto representative for the registration status in your state.importnt IRM INFORMTION: Genuity RI omplete corn blend products do not require the planting of a structured refuge except in the otton-growing rea where corn earworm is a significant pest. Genuity SmartStax RI omplete corn is a blended seed corn product. See the IRM/Grower Guide for additional information. lways read and follow IRM 5 / 5 requirements. Roundup Technology includes Monsanto's glyphosate-based herbicide technologies. Individual results may vary, and performance may vary from location to location and from year to year. This result may not be an indicator of results you may obtain as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible. LWYS RED ND FOLLOW PESTIIDE LEL DIRETIONS. Roundup Ready crops contain genes that confer tolerance to glyphosate, the active ingredient in Roundup brand agricultural herbicides. Roundup brand agricultural herbicides will kill crops that are not tolerant to glyphosate. Warrant Herbicide is not registered in all states. Warrant Herbicide may be subject to use restrictions in some states. Degree Xtra is a restricted use pesticide and is not registered in all states. The distribution, sale, or use of an unregistered pesticide is a violation of federal and/or state law and is strictly prohibited. heck with your local Monsanto dealer or representative for the product registration status in your state. Degree Xtra, DEKL, Genuity, RI omplete, Roundup PowerMX, Roundup Ready 2 Technology and Design, Roundup Ready, Roundup Technology, Roundup, SmartStax, Warrant and YieldGard VT Triple are trademarks of Monsanto Technology LL. Leaf Design is a servicemark of Monsanto ompany. LibertyLink and the Water Droplet Design is a registered trademark of ayer. Herculex is a registered trademark of Dow grosciences LL. Respect the Refuge and orn Design and Respect the Refuge are registered trademarks of National orn Growers ssociation. Poncho is a registered trademark of ayer. ll other trademarks are the property of their respective owners. 212 Monsanto ompany SMK