CONSIDERATIONS WHEN REPLANTING WALNUTS USING FUMIGANTS. Carolyn DeBuse Farm Advisor Solano & Yolo Counties

Transcription

1 CONSIDERATIONS WHEN REPLANTING WALNUTS USING FUMIGANTS Carolyn DeBuse Farm Advisor Solano & Yolo Counties

2 REASONS TO FUMIGATE Replanting Walnut to Walnut Very old orchard with established nematode problems Time restrictions reduce fallow time Can not change rootstock

3 ECONOMIC CHOICE Bruce Lampinen, UC Extension Specialist

4 Bruce Lampinen, UC Extension Specialist After nine years at a seasonal average midday stem water potential of: -5 bars -7 bars -9 bars Yield (tons/ac) Cum. yield Cum. dollars $36,000 $28,000 $21,600 Per acre loss -$8,000 -$14,400 80% 64% 48%

5 ECONOMIC CHOICES ~30% midday light interception Potential for 1.5 ton/acre ~45% midday light interception Potential for 2.2 tons/acre Bruce Lampinen, UC Extension Specialist

6 TESTING FOR NEMATODES Take multiple soil samples from the old orchard at depths of inches deep. Include various soil types Include live roots in sample Sample when soil is moist Combine soil samples that are similar in depth and soil type Send to Lab for nematode count of each species

7 UNDERSTANDING YOUR NEMATODE SAMPLE Nematodes Species Lesion nematode- Pratylenchus vulnus- A count of one is too high Ring nematode- Mesocriconema xenoplax- Also bad for walnuts Root-knot nematode-meliodogyne spp.- Can be problematic but not severe Decision: 85 % of walnut orchards have too high of a nematode population and fumigation is needed

8 SOIL TYPE CONSIDERATIONS AND FUMIGATION In light sandy loam soil the fumigation moves through the soil freely In heavy silt y clay soil fumigation moves slower and not as far G t i l Gas movement is also dependant on dryness of soil

9 SOIL TYPE CONSIDERATIONS AND FUMIGATION Fumigants move 10,000 to 30,000 times faster in soil-air than soil-water Methyl bromide works in heavy soil Colder soil temps (42-80 F) & works well in high moisture soils 1,3 Dichloropropene (Telone II )does not! Need > 55 F soil temps & locks up in soil-water Want soil moisture at 12-18%

10 SOIL MOISTURE REQUIRED FOR DIFFERENT TREATMENTS AND SOIL TYPES FUMIGANT NAME Methyl bromide (restricted use only) 1,3 Dichloropropene (Telone II) 1,3 Dichloropropene+ chloropicrin (Telone C- 35) Telone II plus Metamsodium (Vapam HL) Telone II plus chloropicrin Telon II plus cholorpicrin APPLICATION AMOUNT lb/ac injected at 10 in gpa gpa Telone 33.7gpa plus Metsod 110lb/ac incorporated in top 5 inches Telone broadcast at 33.7gpa with Pic stripped at 170lb/ac Telone 33.7gpa apply using Buessing shank at 20 in. plus lb/ac Pic at 28 in. SOIL TYPE SOIL MOISTURE any 12-18% sandy-sandy loam sandy-sandy loam sandy-sandy loam sandy-sandy loam silty or clay loam <12% <12% <12% <12% <12-18%

11 TIMELINE FOR PREP AND FUMIGATION Year one October November 15 th : kill roots 60 days; remove trees Year two March-May: plant or leave fallow August: Soil ripping and cultivation September-November: Fumigate Plant: January -April Total time= months

12 TREE REMOVAL By November 15 th Cut trees Paint stumps with 50ml Garlon plus 50ml MorAct. Wait 60 Days Note: Prunus species you can use glyphosate (Roundup) plus MorAct

13 TREE REMOVAL 60 Days after trees were killed remove stumps and rip ground Within 5 months 99% of nematodes inside roots have been killed By next summer the roots left in the soil will disintegrate It takes 2 ½ years of fallow to lower nematode populations p to the same level as 1 year with Garlon

14 SOIL PREPARATIONS 1. Starve the remaining soil borne nematodes 2. Drying out the soil 3. Texture of soil at fumigation needs to be loose 5 feet deep

15 SOIL PREPARATIONS Starve the remaining soil borne nematodes Fallow- Reduces nematodes 50% Plant alternative crop Sudan grass- (reduce nematodes 85%) Safflower Wheat Any other crop other than beans

16 SUDAN GRASS Peach RD, Parlier: effects of fumigation treatments x sudan rotation Fumigation treatment Fumigant /treated A Fumigant/ orchard A Sudan grass rotation Trunk dia. increase by 30 Aug 2008 (Oct 2007) (lbs) (lbs) (Jul Sep 2007) (mm) Control 0 no 7.9 yes 14.1 MB, by conventional shanks no *22.6* to 8 wide row strips yes *20.4* Telone C35, by conventional no *28.3* shanks to 8 wide row strips yes *31.9* Telone C35, by GPS controlled shanks to 5x 6 tree spots Inline, by single drip emitters to 4 dia. tree spots CP, by GPS controlled shanks to 5x6 tree spots no *21.4* yes *24.2* no *20.8* yes *21.3* no *24.2* yes *26.5* Minimum i significant ifi tdiff difference (according to 95% confidence intervals): Greg Browne; 2007

17 INTERIM CROP DIFFERENCES Peach RD, Parlier: effects of fumigation treatments x sudan rotation Trunk Pre plant rotation Disease severity rating Diameter 30 Aug 2008 Pre Fumigation treatment treatment 7 July 2008 (mm) No fallow Control 1 year fallow Mustard Wheat Sudan No fallow Chloropicrin 400 lb/a 1 year fallow Mustard Wheat Sudan Greg Browne; 2007

18 SOIL PREPARATIONS Drying out the soil Heavy soils need to be at 12-18% by fumigation Plant a crop to dry soil Fallow and rip and disc down to 4-5 feet Repeat ripping and tilling through out summer Test soil moisture Sample soil at different depths 1-5 feet; weigh sample, then dry, and weigh again Goal is 12% to 5 feet deep > 12% will require more fumigant

19 SOIL PREPARATIONS

20 FUMIGATION TIMING Before Nov 15 th Soil Temperatures >55 F- Not a problem in California (at one foot depth) Before 2 inches of rain fall

21 FUMIGATION CHOICES For heavy walnut soils Methyl bromide is hard to find and too expensive Telone II- 13 1,3 Dichloropropene Chloropicrin- not to be used alone but in tandem Telone C ,3 Dichloropropene plus Chloropicrin Metam-sodium (Vapam) not a true fumigant but can be used at soil surface levels to sterilize the top layers if tarp is not used (check w/ ag com)

22 Methyl Bromide Alternatives Trial-Kings County Bob Beede, UC Kings Co. Farm Advisor Dan Kluepfel, USDA-ARS Davis Mike McKenry, Extension Specialist Riverside Lani Yakabe, Graduate Research Assistant, UCD Plant Pathology Tony Garcia, Kings Co. Ag. Assist.

23 Gold Top Ranch Alternate Fumigation Trial (2008) Trunk Caliper Measurements in (MM) Thur in M M. Methyl Br omide broa 4000 lb/ac 33.7 gal/ /ac strip trea ted 10' swath) & shanked at 20" Telon e 33.7 g al/ac broad cast & shanked at 20" al/ac broadc ast & 20" Plus 175 lb/ac cast and shanked at 28" Telone 33.7 gal/ac broadcast and shanked a t 20" Plus M ethyl Brom 125 lb/ac at 28" depth 15.0 A vg. C a lipe r M eas. treated Con trol Telonee 33.7 g shanked at Chlorop icrin broad Buff er Trees 10.0 Un Telone II ( Treatments Number 7 is the Buffer rows Bob Beede, UCCE Kings County

24 35 RING NEMATODE AVERAGE POPULATION PER FIVE FOOT DEPTH Bob Beede, UCCE Kings County 30 NEMA ATODES/2 250cc control MeBr TELONE II- STRIP TELONE II- BROAD TELONE II + C-PI TELONE + MeB ring pre ring 21d ring 119d ring 410d ring 560d

25 350 LESION NEMATODE AVERAGE POPULATION PER FIVE FOOT DEPTH Bob Beede, UCCE Kings County 300 ATODE/2 250cc NEM control MeBr TELONE II- STRIP TELONE II- BROAD TELONE II + C-PI TELONE + MeB lesion pre lesion 21d lesion 119d lesion 410d lesion 560d

26 APPLICATION CONSIDERATIONS Sealing Shank cut immediately Buessing shank- has wings to seal the behind injections Follow shank with disc and roller Tarp inches inches

27 APPLICATION CONSIDERATIONS At <12% 332 lbs/a Telone equal at both depths At >12-15% 332 lbs/a Telone at 18 plus 150 lb/a Chloropicrin at 26 At >15-19% 332 lbs/a Telone at 18 plus 250 lb/a Chloropicrin at 26 Consider 12 strip application to tree row with double the Telone but equal to 332Lbs/A inches inches Michael McKenry, 2002

28 APPLICATION CONSIDERATIONS Reality check Telone 18 inches ($) Telone 18 inches ($$) Methyl bromide ($$$) if available still the top choice even if cost is high Buessing Shank southern California hires for acres ($$$) 18 inches Followed by roller to seal the soil

29 Soil Fumigant Regulatory Update Even more restrictions coming gyour way! Methyl Bromide phase-out under the Montreal Protocol/Clean Air Act (EPA - Office of Air) To prevent destruction of stratospheric ozone layer Telone Township Caps (CDPR) To protect bystanders/neighbors from chronic exposure VOC Soil Fumigant regulation in the SJV (CDPR/SJVAQCD/ARB/ EPA Office of Air) To reduce ground level ozone formation Reregistration of Soil Fumigants (EPA -Office of Pesticide Programs) To protect bystanders/neighbors from acute and chronic exposures Gabriele Ludwig (Almond Board of California)

30 Soil Fumigant Regulatory Update EPA s Reregistration Eligibility Decision (RED) EPA reviewed the risks from all soil fumigants: Methyl Bromide, Chloropicrin, Metam Sodium, Dazomet, Methyl Iodide Telone reregistered in 1998 so not part of this RED. In new labels with new restrictions Major requirements include: Major buffer zones for MeBr and Pic Credits for certain kinds of tarps or soil types or soil seals Notification of neighbors in advance of fumigation OR - Extensive, costly monitoring outside of buffer Need to break up fumigations into smaller blocks Can t overlap buffer zones Must have written OK for any buffer zone that extends onto neighboring public or private land. Fumigant Management Plan required Gabriele Ludwig (Almond Board of California) c

31 Notification OR Monitoring Requirement Notification depends on size of buffer: If buffer zone is: Then neighbors within distance from edge of buffer must be notified: < 100 ft within 50 ft If 100<buffer< 200ft within 100 ft If 200< buffer< 300within 200 ft If >300 ft within 300 ft OR Need to monitor space between bufferzone outer edge and neighbor every hour during application and entire buffer zone period (5 days min). If exceed certain limits must start fumigation evacuation plan. Gabriele Ludwig (Almond Board of California) c

32 ROOTSTOCK CHOICES Paradox Clone: VX211 Preliminary findings that VX211 tolerates nematode feeding If population too high tolerance disappears California Black supports fewer nematodes than Paradox seedling, but less vigorous E gli h t l g l ti f English supports large populations of nematodes

33 35 GOLD TOP RANCH FUMIGATION ALTERNATIVE TRIAL (2008) CALIPER MEASUREMENTS IN MM THUR. DEC. 12, 2008 M A V G. IN M PARADOX VLACH VX-211 Bob Beede, UCCE Kings County

34 Average Diameter (mm) Jan 2010 a b c c 35 a d RESULTS FROM SOLANO COUNTY ROOTSTOCK TRIAL PLANTED Vlach 2 VX211 Vlach 1 Pdx. Seedling Burbank RX1 Estimated Height (ft) Aug a b b c cd 5 d 0 Vlach 2 Vlach 1 VX211 RX1 Pdx. Seedling Burbank

35 NUTRIENT ADDITIONS Soil micro and macro nutrients can be depleted Previous orchard Fumigation can lower Phosphorous and Zinc Some debate over adding nutrients to just planted walnuts studies showed 1/6 lb plus 8.3 ml of Super Micro with 2 gallons of water at planting doubled the size of trees in first year spoon feed nitrogen through out season Leaf sample in July

36 THANK YOU