In this Issue: The Latest on Yellow Starthistle and Fiddleneck Control. The Latest on Yellow Starthistle and Fiddleneck Control

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1 UNIVERSITY OF CALIFORNIA COOPERATIVE EXTENSION FIELD CROP NOTES SISKIYOU COUNTY 1655 S. MAIN STREET YREKA, CALIFORNIA (530) The Latest on Yellow Starthistle and Fiddleneck Control In this Issue: The Latest on Yellow Starthistle and Fiddleneck Control Alfalfa Variety Selection Tips for Dealing with Skyrocketing Fertilizer Prices Does it Pay to Fertilize Perennial Grass Hay with high Nitrogen Fertilizer Prices? Steve Orloff Farm Advisor In accordance with applicable State and Federal laws and University policy, the University of California does not discriminate in any of its policies, procedures, or practices on the basis of race, religion, color, national origin, sex, marital status, sexual orientation, veteran status, age, medical condition, or handicap. Inquiries regarding this policy may be addressed to the Affirmative Action Director, University of California, Agriculture and Natural Resources, 300 Lakeside Drive, 6 th Floor, Oakland, CA (510) To simplify information, trade names of products have been used. No endorsement of named products is intended, nor is criticism implied of similar products that are not mentioned. In late spring or summer I always receive numerous calls on how to control yellow starthistle. The truth is that by that time it is too late. The month of March, however, is a great time to treat yellow starthistle. This timing is ideal because the yellow starthistle is still very small and easy to control, and the soil residual properties of Transline or Milestone prevent subsequent emergence. A trial was established last year to compare the effectiveness of Milestone and Transline for controlling both yellow starthistle and fiddleneck (fireweed). The herbicides were applied at 3 different timings (March 9, April 18, and very late application May 15). A primary objective of the research was to determine whether acceptable control of both weeds could be accomplished at rates as low as 1 or 2 fluid ounces per acre (below the minimum rate stated on the label). Figure 1 below shows the fiddleneck control with the two earliest application timings. Fiddleneck matures earlier than yellow starthistle, so the May application was ineffective because the fiddleneck was already in bloom. As we know from previous experience, Transline did not adequately control fiddleneck. However, Milestone provided effective control especially when used at 2 or 3 ounces per acre. Percent Control Transline 4 oz 9-Mar 18-Apr Milestone 1 oz Milestone 2 oz Milestone 3 oz Figure 1. Fiddleneck control with Transline and Milestone at two different application timings.

2 Percent Control Mar 18-Apr 15-May Transline 4 oz Milestone 1 oz Milestone 2 oz Milestone 3 oz Figure 2. Yellow starthistle control with Transline and Milestone at three different application timings. Application timing had a profound effect on yellow starthistle control (Figure 2). The early March application provided better than 95 percent control of yellow starthistle for both herbicides and all rates. Control dropped off most dramatically for the 1-ounce rate. Control fell from 100% to 70% when application was delayed slightly over one month from March to April. Both the 2- and 3-ounce rates gave excellent control at both the March and April timing. Milestone is generally the better herbicide for use in Siskiyou County because it controls both fiddleneck and yellow starthistle, and its cost per gallon is similar to Transline but the rate used is less. The minimum label rate of Milestone is 3 ounces per acre but this research suggests that even lower rates of Milestone (1 and 2 ounces of product per acre) are very effective as long as the treatment is made early (late February or March). The 2-ounce rate has a longer application window and provides a greater margin of safety that complete control will be achieved. Note that these rates are lower than the label rate so the manufacturer will not guarantee its effectiveness. These rates make Milestone very economical. Alfalfa Variety Selection Alfalfa variety selection has a profound effect on the profitability of an alfalfa operation. There are large differences in yield between alfalfa varieties. We conducted alfalfa variety trials in Scott Valley (at the Hanna Ranch) and at the Intermountain Research and Extension Center (IREC) in Tulelake to compare the performance of both released and experimental varieties of alfalfa. In these trials the yield difference between the top and bottom varieties averaged 0.7 and 1.3 tons per acre per year for the IREC and Scott Valley trials, respectively. Assuming a stand life of 5 years and a hay price of $150 tons, that yield difference equates to $525 and $975 over the life of the stand. Usually the comparison for growers is not between the top variety and the very bottom variety (growers usually do not select the very bottom variety) but it is easy to see that yield differences can equate to a lot of money over the life of a stand. Fortunately, most growers have steered away from planting Vernal. As you can see from these results, Vernal was at or very close to the bottom in both of these trials. When selecting a variety, avoid focusing in on the single top yielding variety in a trial. I would suggest making your selection from the top yielding group in the trial. Also, consider local experience with a variety in your area if there is a track record for how that variety has performed. In addition to yield, pest resistance is also a very important consideration. In the intermountain area, select varieties that have resistance to bacterial wilt, verticillium wilt, fusarium wilt, phytophthora root rot, pea aphid, stem nematode and root knot nematode. Stem nematode resistance is especially important in the Scott and Shasta Valleys and less important in Butte Valley and Tulelake (although stem nematode has been detected in both those areas as well). Fortunately, through plant breeding efforts most of the newer varieties have resistance to these pests. A complete listing of all the certified alfalfa varieties and their fall dormancy rating and pest resistance rating can be found at the following website: This leaflet is very useful and all alfalfa growers and seed salesmen should have a copy.

3 TABLE YIELDS, UC TULELAKE ALFALFA CULTIVAR TRIAL. TRIAL PLANTED 5/21/04 FD Yield Yield Yield Yield Average Dry t/a % of Vernal Released Varieties Expedition ( 6) 9.1 ( 2) 9.1 ( 10) 7.8 ( 5) 7.8 ( 1) A WL357HQ ( 30) 8.9 ( 6) 9.2 ( 3) 8.0 ( 1) 7.8 ( 2) A B Xtra ( 23) 9.2 ( 1) 9.4 ( 1) 7.4 ( 22) 7.8 ( 3) A BC DS309Hyb ( 10) 8.8 ( 16) 9.1 ( 9) 7.9 ( 3) 7.8 ( 4) A BCD Rebound ( 16) 8.9 ( 7) 9.3 ( 2) 7.5 ( 17) 7.7 ( 5) A BCD Alfa Star II ( 18) 8.9 ( 8) 9.2 ( 4) 7.7 ( 9) 7.7 ( 6) A BCD WL319HQ ( 25) 8.9 ( 9) 9.0 ( 11) 7.8 ( 6) 7.7 ( 7) A BCDE WL325HQ ( 7) 9.0 ( 5) 9.2 ( 5) 7.3 ( 26) 7.7 ( 8) A BCDEF MasterPiece ( 12) 8.8 ( 15) 9.1 ( 8) 7.6 ( 13) 7.7 ( 9) A BCDEF Recover ( 9) 8.8 ( 12) 8.9 ( 20) 7.7 ( 8) 7.7 ( 11) A BCDEFG Vitro ( 13) 8.7 ( 17) 9.1 ( 7) 7.5 ( 15) 7.6 ( 12) A BCDEFG Mountaineer 2.0 (4M124) ( 1) 8.8 ( 13) 8.9 ( 17) 7.4 ( 23) 7.6 ( 13) A BCDEFG C 316 Lot ( 31) 9.0 ( 4) 9.1 ( 6) 7.5 ( 18) 7.6 ( 14) A BCDEFG LegenDairy ( 32) 8.9 ( 11) 9.0 ( 12) 7.7 ( 7) 7.6 ( 15) A BCDEFGH Boulder (4M125) ( 27) 8.9 ( 10) 8.9 ( 18) 7.6 ( 10) 7.6 ( 16) A BCDEFGHI Dura ( 29) 8.6 ( 19) 8.9 ( 19) 7.9 ( 4) 7.6 ( 17) A BCDEFGHIJ Hybriforce-420/Wet ( 15) 8.6 ( 18) 8.8 ( 22) 7.5 ( 19) 7.5 ( 19) BCDEFGHIJK Q ( 21) 8.5 ( 21) 9.0 ( 15) 7.5 ( 21) 7.5 ( 20) CDEFGHIJKL Blazer XL ( 28) 8.3 ( 28) 8.7 ( 26) 8.0 ( 2) 7.5 ( 21) DEFGHIJKL LM 459 WD ( 20) 8.4 ( 24) 8.7 ( 27) 7.6 ( 11) 7.5 ( 22) EFGHIJKLM DS ( 14) 8.5 ( 22) 8.7 ( 25) 7.4 ( 25) 7.4 ( 23) F G HIJKLM CW ( 24) 8.4 ( 25) 8.7 ( 24) 7.5 ( 16) 7.4 ( 24) F G HIJKLMN SW435(SW4A135) ( 17) 8.6 ( 20) 8.5 ( 32) 7.3 ( 27) 7.4 ( 25) G HIJKLMN Reward II ( 26) 8.3 ( 27) 8.8 ( 21) 7.3 ( 29) 7.4 ( 27) HIJKLMN ( 34) 8.3 ( 30) 8.9 ( 16) 7.5 ( 20) 7.4 ( 28) I J K L MN Magna ( 5) 8.4 ( 26) 8.6 ( 29) 6.9 ( 35) 7.3 ( 30) K L MNO Plumas ( 33) 8.1 ( 33) 8.6 ( 30) 7.6 ( 12) 7.3 ( 31) L MNO Innovator +Z ( 35) 8.3 ( 29) 8.4 ( 35) 7.3 ( 28) 7.2 ( 34) N O P Vernal ( 36) 8.0 ( 35) 8.4 ( 33) 7.3 ( 31) 7.1 ( 35) O P Experimental Varieties CW ( 19) 9.0 ( 3) 9.0 ( 13) 7.6 ( 14) 7.7 ( 10) A BCDEF CW ( 22) 8.8 ( 14) 9.0 ( 14) 7.4 ( 24) 7.6 ( 18) BCDEFGHIJK SW ( 11) 8.4 ( 23) 8.5 ( 31) 7.3 ( 30) 7.4 ( 26) HIJKLMN SW ( 2) 8.2 ( 31) 8.8 ( 23) 7.0 ( 34) 7.3 ( 29) J K L MNO SW ( 8) 8.0 ( 34) 8.7 ( 28) 7.1 ( 32) 7.3 ( 32) L MNO SW ( 3) 8.1 ( 32) 8.4 ( 34) 7.1 ( 33) 7.2 ( 33) MNO SW ( 4) 7.8 ( 36) 8.0 ( 36) 6.7 ( 36) 7.0 ( 36) P 98.1 MEAN CV LSD (0.1) Trial seeded at 25 lb/acre viable seed at UC Intermountain Research and Extension Center, Tulelake CA. Entries followed by the same letter are not significantly different at the 10% probability level according to Fisher's (protected) LSD. FD = Fall Dormancy reported by seed companies.

4 TABLE YIELDS, UC SCOTT VALLEY ALFALFA CULTIVAR TRIAL. TRIAL PLANTED 5/04/ Yield 2007 Yield Average % of Vernal FD Dry t/a % Xtra ( 1) 9.7 ( 2) 7.6 ( 1) A Integra ( 21) 10.1 ( 1) 7.4 ( 2) A B Magnum VI ( 2) 9.4 ( 8) 7.4 ( 3) A B MasterPiece ( 11) 9.6 ( 5) 7.2 ( 4) A B C Dura ( 6) 9.4 ( 11) 7.1 ( 5) B C D FSG ( 19) 9.6 ( 3) 7.1 ( 6) B C D HybriForce ( 4) 9.2 ( 22) 7.1 ( 7) B C D PGI ( 7) 9.4 ( 10) 7.1 ( 8) B C D E HybriForce420/wet ( 3) 9.1 ( 24) 7.1 ( 9) B C D E Mountaineer ( 10) 9.4 ( 12) 7.1 ( 10) B C D E Rebound ( 12) 9.4 ( 7) 7.1 ( 11) B C D E Power 4.2 (PI + Alleg) ( 23) 9.6 ( 4) 7.1 ( 12) B C D E PGI ( 15) 9.4 ( 6) 7.1 ( 13) B C D E WL 357HQ ( 5) 9.2 ( 21) 7.0 ( 14) B C D E Mariner III ( 9) 9.2 ( 19) 7.0 ( 15) B C D E Power 4.2 (Coated) ( 16) 9.3 ( 15) 7.0 ( 16) B C D E Masterpiece ( 17) 9.3 ( 14) 7.0 ( 17) B C D E CW ( 8) 9.1 ( 23) 7.0 ( 18) B C D E Boulder ( 22) 9.3 ( 13) 6.9 ( 19) B C D E Whitney ( 18) 9.2 ( 17) 6.9 ( 20) C D E WL 325HQ ( 20) 9.2 ( 18) 6.9 ( 21) C D E DKA ( 25) 9.2 ( 16) 6.8 ( 22) C D E F AmeriStand 407TQ ( 27) 9.2 ( 20) 6.8 ( 23) C D E F G GrandStand ( 30) 9.4 ( 9) 6.8 ( 24) C D E F G WL 319HQ ( 26) 9.0 ( 25) 6.8 ( 25) D E F G H Expedition ( 24) 9.0 ( 26) 6.7 ( 26) D E F G H WL 355RR ( 13) 8.7 ( 29) 6.7 ( 27) D E F G H FSG 408DP ( 14) 8.6 ( 30) 6.7 ( 28) E F G H WL 343HQ ( 31) 8.8 ( 27) 6.5 ( 29) F G H Vernal ( 28) 8.4 ( 32) 6.4 ( 30) G H RRALF 4R ( 32) 8.7 ( 28) 6.4 ( 31) H 99.4 DKA41-18RR ( 29) 8.4 ( 31) 6.3 ( 32) H 99.1 MEAN CV LSD (0.1) NS Trial seeded at 25 lb/acre viable seed at Scott Valley, CA. Entries followed by the same letter are not significantly different at the 10% probability level according to Fisher's (protected) LSD. FD = Fall Dormancy reported by seed companies. 4

5 Tips for Dealing with Skyrocketing Fertilizer Prices Rob Wilson and Steve Orloff If you purchased fertilizer lately, you likely passed out after you heard the price quote. Fertilizer prices are at record highs, and they have more than doubled compared to prices a few years ago. Two nutrients with a dramatic price increase are nitrogen and phosphorus, and unfortunately, these nutrients are needed on almost all intermountain farms. Below are some tips to help ease the pain and keep fertilizer costs as low as possible. Start soil and tissue sampling to determine crop nutrient needs. The importance of this cannot be overstated. Soil and plant tissue tests are very inexpensive considering the cost of fertilizer or the cost of lost yield. Many farmers unknowingly over apply fertilizer to prevent deficiencies. They often use a recipe that has worked in the past and apply the same amount each year. Some nutrients could be building up over years while others could be gradually depleted. Soil and plant tissue sampling allows farmers to accurately estimate current soil nutrient levels and only apply enough fertilizer to satisfy crop needs. For most nutrients, tissue sampling is the more accurate method. Phosphorus and potassium levels can be estimated with a soil test but plant tissue tests are still more accurate and are FAR more accurate for sulfur, boron, and molybdenum. Below is a brief list of some of the more commonly used CA labs that will analyze your samples. If you have questions about nutrient sampling, call me! o o A&L Western Ag. Laboratories Modesto, CA Dellavalle Laboratory, Inc. Fresno, CA o Monarch Laboratory Chico, CA Don t skip applying fertilizer if the crop needs it. Many people have mentioned they plan to forgo applying fertilizer this year. This approach is appropriate if soil and tissue samples suggest fields have adequate nutrient levels. But, if fields have nutrient deficiencies, yield loss will likely greatly outweigh any savings in fertilizer cost. Most crop prices are expected to be up again this year, so yield increases should outweigh the high fertilizer cost. The Lassen UCCE office has several publications discussing crop nutrient needs and fertilization practices. Become a stripper. If fields soil or plant tissue samples come back in the marginal category, test strips are an effective way to estimate the potential for an economical yield response with fertilizer. This spring apply a couple fertilizer test strips in questionable fields with different fertilizer rates including an untreated strip. Did the fertilizer increase yield? Apply fertilizers in the most efficient way. Fertilizer application methods differ in their efficiency (% of fertilizer that becomes available to the crop). For nitrogen fertilizer, it s important to irrigate or incorporate the fertilizer into the soil within a couple days of application to prevent volatility losses. Fertilizer sources differ in their potential for volatilization loss and environmental, but banding nitrogen fertilizer a couple inches into the soil may also improve efficiency with some crops. For phosphorus, banding P fertilizer can improve efficiency compared to broadcast applications especially on high ph soils where some of the phosphorus can become fixed or tied up. Consider split applications of N for pasture or grass hay. Split applications of nitrogen are more efficient than a large single application. A large single application does not last long enough to supply the crop what it needs for the season. With a single large application the possibility of leaching some of the N out of the root zone is greater and there is a greater likelihood of luxury consumption where the plant takes up more than what is needed for maximum yield. See the article Does It Pay to Fertilize Perennial Grass Hay with High Nitrogen Fertilizer Prices in this newsletter for more information on split applications for grass crops. Fertilize alfalfa at the optimum time. Fertilize alfalfa at least 60 to 90 days before the first cutting. This is how long it takes to get maximum uptake and benefit from the fertilizer. Fertilizing closer to a cutting or between alfalfa cuttings is not as efficient. The first cutting is typically the highest yield cutting and soil temperatures are lower at this time so there is less microbial activity in the soils. Therefore, you get the most bang for your buck fertilizing in spring (or fall) rather than between cuttings. Continued 5

6 Buy the cheapest source of fertilizer per lb. of nutrient. Several studies have shown that fertilizer type (liquid vs. granular, and formulation) usually has little influence on fertilizer efficiency. For this reason, buy fertilizer products with the lowest price per lb of nutrient. Since fertilizers contain different nutrient concentrations, always price fertilizer by price per lb of nutrient instead of price per ton. For example, ammonium sulfate has 21% nitrogen and urea has 46% nitrogen. This means that each ton of ammonium sulfate contains 420 lbs of N, and each ton of urea contains 920 lbs of N. Use the formula below to convert price per ton to price per lb of nutrient. o Price per ton of fertilizer lbs of nutrient in a ton = price per lb o Example: Urea at $575/ton 920 lbs/ton = $0.62 per lb N Apply the appropriate amount of irrigation water. Fertilizer use efficiency declines considerably if the crop is not adequately irrigated. In other words, if the crop is underirrigated the full benefit of the fertilizer is not realized. If you have adequate water supplies, make sure the irrigation water applied keeps pace with the crop demand. However, if you know that irrigation water will be inadequate, fertilize for the realistic expected yield rather than the maximum theoretical potential yield. Buy stock in fertilizer companies. In 2007, some of the greatest returns in the stock market came from companies that produce fertilizer. Many companies posted gains of 44% to 394%. If you can t beat them, join them! Does It Pay to Fertilize Perennial Grass Hay with High Nitrogen Fertilizer Prices? Rob Wilson and Steve Orloff Present record high nitrogen fertilizer prices have many producers contemplating their fertilizer plans for Some producers may be tempted to reduce their nitrogen fertilization, while others may wonder if they should fertilize at all. Before farmers make decisions, they should consider that nitrogen fertilization of grasses is very important to high yields. In UC trials, nitrogen fertilization often more than doubles grass hay yield. With elevated hay prices and soaring feed costs, high grass yields are an important consideration probably more important than high fertilizer prices. This article discusses the economics of nitrogen fertilization and answers some questions about the yield/fertilizer cost trade-off. From 2004 to 2007, UC farm advisors in Northeastern California conducted experiments investigating nitrogen fertilization of orchardgrass and tall fescue. Results showed nitrogen fertilization was critical to maximize grass-hay yield and economic return. Yield and net return reached a plateau around 400 lb N/acre for both grass species in a 3-cut system. Under-irrigated fields with only two cuts had lower yield and economic return compared to fully irrigated fields with 3- cuttings, however N fertilization, albeit at lower rates, was still beneficial in a 2-cut system where plants were drought-stressed in mid-summer. Split fertilizer applications applied in early spring and after each cutting gave the highest yield and efficiency. Fertilizing with 100 to 150 lb N/acre applied at spring grass green-up was best for firstcut yield. Then depending on irrigation and summer growth rates, lower fertilizer rates, 75 lb N/acre after 1 st cutting and 50 lb N/acre after 2 nd cutting, maximized second and third cut yield. Table 1 shows a partial economic budget for nitrogen fertilization of retail grass hay considering fertilizer price, application cost, forage yield, and hay price. Under current economic conditions, the benefit of nitrogen fertilization greatly outweighs the cost of fertilizer. Although fertilizer prices have skyrocketed in recent years, fertilizer price is still below the breakeven point. At current hay prices, fertilizing with the recommended fertilizer program increased net returns $100 to $400 per acre compared to not fertilizing. Table 1 shows net returns (gross return fertilizer cost) for different hay prices and fertilizer costs. The value of increased crude protein (CP) from fertilization was not factored into this economic evaluation because grass hay in the West is normally not sold based on forage quality analysis as is alfalfa. Although CP was not factored into returns, fertilization increases CP content by 2 to 4% at each cutting. Since higher CP increases daily weight gain for most livestock, producers should consider this as an additional benefit of nitrogen fertilization of hay and pasture. 6

7 Table 1. Economics of nitrogen fertilization of orchardgrass and tall fescue at different hay and fertilizer prices. The nitrogen fertilizer program used in this table was based on results from UC trials and equals (150 lb of N/acre applied at spring grass green-up 75 lb of N/acre applied after 1 st cutting 50 lbs of N/acre applied after 2 nd cutting) Hay price ($ per ton) Urea fertilizer price ($ per ton) Gross return a Fertilizer cost b Net return c (fertilized) Net return d (unfertilized) Increase in return from fertilization Under-irrigated Orchardgrass (2-cut $ per acre system) Orchardgrass (3-cut system) Tall fescue (3- cut system) a b c d Gross return was calculated as total DM yield (tons per acre) * hay price ($ per ton). Fertilizer cost was calculated as urea fertilizer price per acre + fertilizer application cost ($8 per acre per application). Net return was calculated as gross return fertilizer cost. Net return above fertilizer cost does not reflect other costs such as irrigation, harvest, and pesticides. These costs were assumed to stay the same. Net return if the field was not fertilized. 7

8 FIELD CROP NOTES DATED MATERIAL Cooperative Extension NON-PROFIT University of California STANDARD MAIL 1655 South Main Street PERMIT #3 Yreka, CA YREKA, CA 8