COMPARING SUGAR BEET PRODUCTIVITY, WEED INCIDENCE AND MANAGEMENT IN THREE TILLAGE SYSTEMS.

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0228655
• Project Start Date: Jul 1, 2012
• Project End Date: Jun 30, 2017
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIV OF IDAHO
875 PERIMETER DRIVE
MOSCOW,ID 83844-9803

Performing Department
Plant Soil & Entomological Sci

Non Technical Summary
Sugar beet is an important irrigated crop in Idaho and ranks third nationally in sugar beet production, producing more than 4.78 million metric tons in 2010. Since the introduction of Roundup Ready sugar beet in 2008, weed control in sugar beet has greatly improved for Idaho and eastern Oregon growers compared to non-Roundup Ready sugar beet. Sugar beet grown using strip tillage, a form of reduced tillage, was first tried in Idaho in 2009. Consideration of growing sugar beet using strip tillage was made possible because of Roundup Ready sugar beet. Weed control with conventional sugar beet had long been considered one of the biggest challenges for producing a successful sugar beet crop. With conventional sugar beets, multiple tillage operations during the growing season are usually required in addition to herbicides for weed control. The introduction of Roundup Ready sugar beet has opened the opportunity to commercially grow sugar beet with reduced tillage. Prior to the availability of Roundup Ready sugar beet, conservation tillage research had been conducted in sugar beet dating back more than 35 years. However, it did not generate much interest primarily because of the need to cultivate for weed control in sugar beet due to the ineffectiveness of available herbicides. For the most part, weed control in Roundup Ready sugar beets has been quite successful. Our research thus far shows that weed control with glyphosate alone applied 3 or 4 times during the growing season will control nearly all weeds through the growing season without having to cultivate. However, concerns about glyphosate resistant weeds have prompted evaluating tank mixtures of glyphosate with soil-active herbicides, such as ethofumesate, dimethenamid-P, s-metolachlor, EPTC and cycloate. Field studies thus far show these combinations can be an effective weed management strategy in Roundup Ready sugar beets grown under conventional tillage systems. However, it is not clearly understood if or how weed control in strip tillage or direct-seeded sugar beet using soil-active herbicides, such as acetochlor, dimethenamid-P, ethofumesate, EPTC and s-metolachlor with glyphosate may be influenced by the presence of crop residue on the soil surface.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
213	2010	1140	100%

Knowledge Area
213 - Weeds Affecting Plants;

Subject Of Investigation
2010 - Sugar beet;

Field Of Science
1140 - Weed science;

Keywords

reduced tillage

conservation tillage

direct-seed sugar beets

glyphosate resistance

Goals / Objectives
In order to develop recommendations for using soil-applied herbicides with glyphosate as part of a herbicide resistance management plan in strip-tillage systems, the following objectives will be part of the proposed work: 1. Compare the effect of various soil-active herbicides tank mixed with glyphosate in conventional, strip and no-till sugar beets on weed emergence, control, and biomass production. 2. Compare conventional, strip and no-tillage effects on in-row soil water content, weed seedling emergence and stand establishment levels during the planting through stand establishment period. 3. Compare the effect of conventional, strip and no-tillage on soil-active herbicide movement in soil. 4. Determine the critical time frame for water incorporation of acetochlor, dimethenamid-P, EPTC, ethofumesate and s-metolachlor to obtain optimum weed efficacy.

Project Methods
A field study will be established annually at the University of Idaho Kimberly Research and Extension Center to compare conventional, strip and no-till sugar beet production and weed control. The crop preceding sugar beet will be wheat or barley. After the grain is harvested from the wheat or barley crop, the remaining residue will be removed by baling the straw. The study area will be uniformly irrigated to enable germination of volunteer grain and other weeds. Prior to any tillage, glyphosate + AMS at 0.86 lb ae/A + 2.47 g AMS/100 L spray will be applied to kill all emerged weeds. Conventionally tilled plots will be chisel plowed, disked, roto-tilled and fall-bedded. The strip tilled plots will be tilled with an Orthman Strip Tiller implement. All tillage operations will be conducted in the fall. In the spring before planting, the entire site will be oversprayed with glyphosate + AMS at 0.86 lb ae/A + 2.47 g AMS/100 L spray. The conventionally tilled treatment with the fall-beds will be assessed to determine if a seedbed preparation tillage will be needed before planting. Fertilizer will be applied the same way to all tillage treatments. A starter fertilizer rate will be applied at-planting 5-cm below and 5-cm beside the seeded row. The remaining fertilizer will be applied broadcast to the crop between the four and six leaf growth stage. The experiment will be set up in a split block randomized complete block design. The main plots will be the three tillage treatments (conventional, strip and no-till) and the subplots will be the weed control treatments. Sub-plots will be 2.23 by 9.1 m with 4 replications. Herbicides that will be evaluated in tank mixture with glyphosate include acetochlor, dimethenamid-P, EPTC, ethofumesate and s-metolachlor. In addition, glyphosate alone and an untreated control will be included.

Progress 07/01/12 to 06/30/17

Outputs
Target Audience:Due to the loss of funding from the Idaho Sugar Beet Growers Association, I was forced to terminate studies investigating the production of sugar beet in conventional, strip and no tillage systems. A single study was conducted in sugar beets to evaluate clethodim with various adjuvants in combination with glyphosate for control of volunteer glyphosate resistant corn in glyphosate resistant sugar beet. Volunteer corn has become a bigger problem for sugar beet growers with the increase in field corn acres in Idaho. Clethodim with Class Act NG alone or with Destiny, or Interlock effectively controlled volunteer corn in sugar beet. Previous research had shown that sethoxydim was the least effective of the Group 1 herbicides for controlling volunteer corn in glyphosate resistant sugar beet. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? None of these goals were accomplished this year.

Publications

Progress 10/01/15 to 09/30/16

Outputs
Target Audience:Due to the loss of funding from the Idaho Sugar Beet Growers Association, I was forced to terminate studies investigating the production of sugar beet in conventional, strip and no tillage systems. A single study was conducted in sugar beets to evaluate clethodim with various adjuvants in combination with glyphosate for control of volunteer glyphosate resistant corn in glyphosate resistant sugar beet. Volunteer corn has become a bigger problem for sugar beet growers with the increase in field corn acres in Idaho. Clethodim with Class Act NG alone or with Destiny, or Interlock effectively controlled volunteer corn in sugar beet. Previous research had shown that sethoxydim was the least effective of the Group 1 herbicides for controlling volunteer corn in glyphosate resistant sugar beet. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? nothing to report

Publications

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Growers, crop advisors, crop consultants, and agricultural professionals Changes/Problems:The Idaho sugar beet growers have apparently lost interest in this work. They have indicated they are no longer interested in contributing funds for this study. What opportunities for training and professional development has the project provided?Information from this work has been presented at a field day and will be presented at grower meetings. How have the results been disseminated to communities of interest?Aritcles have been written for the growers. What do you plan to do during the next reporting period to accomplish the goals?Will repeat this study.

Impacts
What was accomplished under these goals? Previous research has shown that sugar beet recoverable sucrose yields are equal between sugar beet grown in conventional tillage, strip tillage and direct-seed tillage systems. A study was conducted at the University of Idaho Kimberly Research and Extension Center to compare several soil-active herbicides applied in combination with glyphosate for weed control in sugar beet grown in conventional tillage, strip tillage and direct-seed tillage systems. Sugar beet (var. Seedex 1534RR) was planted April 15, 2015, and replanted May 6 due to poor stand from frost and insect damage. Seeding rate was 149,715 seed/ha. Plots were 4 rows by 9.1 m and row spacing was 56 cm. The entire study was sprayed with a preemergence glyphosate application at 0.86 kg/ha on April 20 to control emerged weeds primarily in the strip tillage and direct-seed tillage treatments. The soil-active herbicides applied with glyphosate (0.86 kg/ha) included acetochlor at 1.26 kg/ha, dimethenamid-P at 0.94 kg/ha, ethofumesate at 1.12 kg/ha, EPTC at 3.36 kg/ha, and s-metolachlor at 1.34 kg/ha. All of the soil-active herbicide treatments were applied at the 6-leaf sugar beet growth stage. Broadleaf and grass weeds ranged from 1.25 to 5 cm tall at this application. The primary weed species in this study were common lambsquarters, redroot pigweed, hairy nightshade, and green foxtail. Weed counts between the rows and within the rows were taken 14 and 30 days after the last application (DALA). Sugar beet yield was determined by harvesting the middle two rows of each plot was harvested October 7 with a plot harvester. Sugar beet quality parameters, sucrose content, nitrate content, and conductivity, were determined by collected two 2 11 kg samples of roots for analysis by The Amalgamated Sugar Company Tare Laboratory. Weed populations between the rows or within the rows by species were not different at each of the two counting dates or differed only slightly between the three tillage treatments. There were significant differences in weed populations between and within the rows for all weed species among the weed control treatments. However, the difference was consistently between the untreated control and the herbicide treatments. There was a significant tillage by herbicide treatment interaction for redroot pigweed stand counts between and within the rows at 14 DALA and between the rows at 30 DALA. However, the differences were between tillage treatments with the glyphosate application that did not include a soil-active herbicide. Generally, there were more redroot pigweed in the direct seed treatment than the conventional tillage treatment with glyphosate alone. There were no differences in redroot pigweed populations among the herbicide treatments that included a soil-active herbicide. There were no differences in sugar beet root yield, sucrose yield, sugar content, nitrate concentration, or conductivity between the tillage treatments. There were differences in sugar beet root yield, sucrose yield, and sugar content among the weed control treatments. Sugar content ranged from 17.02% to 18.07% with the untreated control averaging the lowest sugar content. Glyphosate + s-metolachlor had the highest sugar content and was significantly higher than the control, dimethenamid-P, and acetochlor. Interestingly, s-metolachlor, dimethenamid-P and acetochlor have the same mechanism of action and are all Group 15 herbicides. Why there was a difference is unknown. Typically, herbicide treatments do not affect sugar content. Differences in sugar beet root yield and sucrose yield were between the control and the rest of the herbicide treatments. The untreated control root and sucrose yield averaged 34 Mg/ha and 5,366 kg/ha, respectively. There were no differences in root or sucrose yield among the herbicide treatments, which averaged 119 Mg/ha and 19,147 kg/ha, respectively.

Publications

• Type: Other Status: Published Year Published: 2015 Citation: Morishita, D.W., W.H. Neibling, E.J. Wenninger, and K.M. Belmont. October 2015. Effects of fertilizer rate, irrigation and crop residue on diseases, insects and weed control in sugar beets. The Sugarbeet. p. 10-11.
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Belmont, K.M., W.H. Neibling, D.W. Morishita, and E.J. Wenninger. 2015. Effects of irrigation, tillage system and fertilizer rate, on sugar beet root and sugar yields. J Sugar Beet Res. 52:76-77.
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Morishita, D.W., K.M. Belmont, E.J. Wenninger, and W.H. Neibling. 2015. Irrigation, tillage system, and fertilizer rate on weeds, insects and diseases in sugar beet. J Sugar Beet Res. 52:86-87.

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: A field day was held where participants had the opportunity to learn the details of this study and what we have learned thus far. Approximately 120 people attended. Information from this study also was presented at our annual sugar beet conference. Approximately 350 people heard the two presentations that described the results of this study. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? A graduate student has received extensive training from this project. How have the results been disseminated to communities of interest? Information has been presented at a field day and at our annual sugar beet conference. What do you plan to do during the next reporting period to accomplish the goals? We plan to continue this project with an emphasis on objective 1.

Impacts
What was accomplished under these goals? We accomplished objectives 2 and 4.

Publications

• Type: Other Status: Accepted Year Published: 2014 Citation: Morishita, D.W., W.H. Neibling, E.J. Wenninger, O.T. Neher and K. Belmont. 2014. First year report on the effects of fertilizer rate, irrigation and crop residue on diseases, insects and weed control in sugar beets. The Sugarbeet. p. 26-27

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Farmers, crop advisors, crop consultants, and extension educators Changes/Problems: We will address objectives one and threeof this project in a separate study beginning in 2015. What opportunities for training and professional development has the project provided? Kelli Belmont, graduate student, was hired in May 2013 to begin her M.S. studies on this project. She is currently living in Moscow taking courses and will be back in southern Idaho at the conclusion of the 2014 spring semester. Her progress academically and on this project has been excellent. How have the results been disseminated to communities of interest? A report of progress was submitted to the Idaho Sugar Beet Growers Association since they have partially funded this project. What do you plan to do during the next reporting period to accomplish the goals? We will be repeating the study where we are comparing the effects of tillage treatment, irrigation rate and nitrogen fertilizer level on weed speciesseedling emergence.

Impacts
What was accomplished under these goals? Due to an error tilling the specific treatments, we were not able to compare various soil-active herbicides tank mixed with glyphosate in three tillage systems. We did establish another study to compare the effects of the different tillage treatments, irrigation rates and nitrogen fertilizer levels on weed species seedling emergence. We also conducted a study to address the critical time frame for water incorporation of various soil-active herbicides.

Publications

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: A field experiment was conducted at the University of Idaho Research and Extension Center near Kimberly, Idaho to compare weed control with various herbicide treatments in three sugar beet tillage systems- conventional tillage (CT), strip tillage (ST) and direct seed (DS). Herbicide treatments are focused on tank mixtures with glyphosate. Oher herbicides included: acetochlor, dimethenamid-P, EPTC, ethofumesate and s-metolochlor. Experimental design was a 3 by 8 factorial split plot randomized complete block with four replications. Tillage treatments were the main plots and were 32 rows by 40 ft. Herbicide treatments were the sub-plots and were four rows by 30 ft. Kochia (KCHSC), common lambsquarters (CHEAL), redroot pigweed (AMARE), green foxtail (SETVI) and hairy nightshade (SOLSA) were the major weed species present. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Farmers, crop advisors, crop consultants, extension educators. A field day was held in June 2012 to show this study to stakeholders. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Green foxtail was the most abundant weed species averaging 43 and 46 plants/ft2 in the row and between the row, respectively. When the weed species counts were compared by counting date, no differences were observed within the main effects, tillage or herbicide treatment, nor were there many significant interactions between tillage and herbicide treatment (data not shown).When the weed species counts were pooled across each counting date, there were still not many differences in weed species densities within the main effects or interactions between tillage and herbicide treatment. There was a significant herbicide by tillage treatment interaction for total counts of common lambsquarters within and between rows and for total counts of redroot pigweed between the rows. These differences were due to higher weed densities in the conventional tillage treatment with dimethenamid-P, direct seed with EPTC There were no differences in weed densities for kochia, hairy nightshade or green foxtail. Weed control among tillage treatments ranged from 93 to 100%, with the lowest weed control ratings in the direct seed treatments. Weed control compared between herbicide treatments pooled across tillage treatments ranged from 89 to 100%. The lower weed control ratings were associated with the glyphosate only treatment applied two times at 0.75 lb ae/A with ammonium sulfate (AMS) at 2.55 lb ai/A and glyphosate applied at 2 leaf followed by glyphosate + dimethenamid-P at 1.13 lb ae/A + 0.75 lb ai/A. Where dimethenamid was applied at 0.98 lb ai/A with glyphosate, weed control was equal to all other herbicide treatments. There was a significant tillage by herbicide treatment interaction for kochia control at the 121 DALA evaluation. Kochia control with dimethenamid-P at 0.75 lb ai/A with glyphosate in the direct seed treatment averaged 85%, compared to 100% in the strip tillage and conventional tillage treatments. There were no other significant tillage by herbicide interactions for weed control, yield, sugar content or conductivity. Sugar beet yield in the tillage treatments pooled across herbicide treatments ranged from 34 to 38 ton/A. Conventional tillage was highest at 38 ton/A and was significantly greater than direct seed, which was 34 ton/A. There was no difference in estimated recoverable sugar, sugar content or conductivity among the tillage treatments. When comparing sugar beet yields and ERS among herbicide treatments, all herbicide treatments were greater than the untreated control. There was no significant difference among the herbicide treatments.

Publications

• No publications reported this period