Source: UNIVERSITY OF CALIFORNIA, DAVIS submitted to
EVALUATION OF FUMIGANT EFFICACY WITH VIF PLASTIC
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0192490
Grant No.
2002-51102-01924
Project No.
CA-D*-PLS-7007-CG
Proposal No.
2002-03535
Multistate No.
(N/A)
Program Code
112.C
Project Start Date
Sep 15, 2002
Project End Date
Sep 14, 2005
Grant Year
2002
Project Director
Ajwa, H. A.
Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671
Performing Department
PLANT SCIENCES
Non Technical Summary
The phase out of methyl bromide by 2005 has created a need for alternative fumigants in crops such as strawberries. Additionally, in California there is concern about offsite movement of fumigants. Soil fumigation technologies are needed that do not pollute the air or cause discomfort to neighbors. This project will attempt to limit movement of alternative fumigants, and improve performance by retaining more fumigant in the soil with impermeable films.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2121122112015%
2121122114015%
2131122116060%
6011122301010%
Goals / Objectives
The primary research objective of this proposal is to identify methods to maximize the effects of alternative fumigants on soil borne pests, while minimizing environmental risk. Specifically, we propose to determine the minimum effective doses of chloropicrin alone and 1,3-dichloropropene (1,3-D) plus chloropicrin on soil borne pathogens, weeds and calla lilly bulbs under virtually impermeable film (VIF). Data on fumigant distribution in the soil and environmental fate will be collected to compare VIF to standard tarps. The crop that will be used as a model is strawberry, with trials addressing fumigant efficacy in commercial berry production fields. Since strawberry is highly susceptible to all the organisms that will be evaluated in this study, it is a good indicator crop to use. Trials will also include evaluation of the herbicidal properties of the treatments for controlling specific flower bulbs, thereby addressing a critical need of the floriculture industry for controlling volunteer plants. In view of the broad host range of the pests under investigation and the common weed species involved, the results of this work will be applicable to many cropping systems that may use these alternative fumigants for pest control. Specific objectives.1. To evaluate the use of VIF in combination with alternative fumigants to determine the minimum effective doses of chloropicrin alone and 1,3-D plus chloropicrin for control of soil borne pathogens, nematodes, weeds and flower bulbs. 2.To evaluate the economic viability of the doses identified in 1. 3.Evaluate fumigant distribution in the bed profile and environmental fate when using standard mulch compared to VIF plastic mulches. 4.Monitor fumigant release into the atmosphere when using different application technologies.5.Demonstrate the scientific and economic performance of key alternative fumigant programs to strawberry producers so that they can make informed decisions during the transition to alternative fumigants.
Project Methods
Fumigation efficacy will be evaluated by placing soil infested with a variety of pathogens and nematodes in nylon mesh bags that will be buried in the beds of a commercial production field prior to fumigation. Bags will be buried at two locations in the plot at depths of 15, 30, and 60 cm. The bags will be retrieved after fumigation and pathogen viability assayed in the participating labs (Verticillium dahliae - Duniway; Phytophthora cactorum - Browne; Pythium ultimum, - Martin; nematodes - esterdahl). Treatments to be evaluated are chloropicrin alone or 1,3-D plus chloropicrin at 50, 100, 200, 300 and 400 lb/A. Fumigants will be applied under standard and VIF mulches and compared to the methyl bromide plus chloropicrin standard. Approximately 28 d after fumigation, strawberries will be transplanted into all plots. Fruit yields will be monitored. Seeds of four weeds: California bur clover, common purslane, little mallow, and prostrate knotweed seed will be buried in nylon mesh packets 5 cm inches deep in the soil before fumigation and will be retrieved prior to transplanting. Mesh bags with calla lilly bulbs will be placed 15 and 30 cm deep at two locations per bed. After sample retrieval, seed and bulb viability will be tested. The effect of treatments on the native weed population will also be measured. Time of hand weeding by crews will be monitored. This data will be used in the economic analysis. Data collected on weeding times will be combined with wages and other employment costs to evaluate differences in weeding costs across treatments. Harvest data will be combined with price data to evaluate the value of production for each treatment. All of this information will be benchmarked to cost and returns data on strawberry production under a standard methyl bromide treatment. Fumigant concentrations will be monitored immediately after fumigant application at 0, 7, 15, 30, 45, and 60 cm deep near where the bags of inoculum, seed and bulbs are buried, to facilitate correlation between fumigant concentration and pest control. Fumigant concentration in the soil will be measured either by a field gas chromatograph or by trapping fumigants on sorbents. The trapped fumigants will then be extracted and determined by gas chromatography in the lab. Water distribution will be determined by monitoring at the same depths where the gas sampling probes are located. Soil gas concentration and water content will be monitored daily until fumigants are no longer detectable. Concentrations of fumigant release into the atmosphere at application also will be monitored. Data analysis will be conducted to calculate fumigant concentrations that kill 50 and 90 percent of the pest sample. This analysis will allow us to determine the minimum effective rates of fumigant to use under each film by pest. Strawberry yield data will be analyzed to determine the maximum yield response to fumigant dose. An important component of this research is technology transfer of the results to the grower community. Since the trials evaluating fumigant efficacy will be conducted in commercial fields and yield data will be collected, the results will be directly relevant for growers.

Progress 09/15/02 to 09/14/05

Outputs
The impending methyl bromide phase out emphasizes the immediate need for development of alternative fumigation systems to provide disease, nematode and weed control. We conducted field evaluations of drip-applied fumigants and impermeable films to reduce rates and improve the efficacy of alternative fumigants on soil borne pests. Field studies were initiated near Oxnard, CA on Sept. 16, 2002 and August 20, 2003 and near Watsonville, CA on Oct. 1, 2002 and Sept. 16, 2003. Fumigants applied were chloropicrin (Pic) and 62 percent 1,3-dichloropropene (1,3-D) plus 35 percent chloropicrin (Inline) each at 50, 100, 200, 300 and 400 pounds per acre though the drip irrigation system. The commercial standard was shank applied 67 percent methyl bromide plus 33 percent chloropicrin (MbPic) at 350 lb/A. One half of the length of each plot was covered with high density polyethylene film (HDPE) and virtually impermeable film (VIF) covered the other half. Mesh bags containing pathogen and weed seed samples were installed before fumigation and removed 2 to 3 weeks after fumigation. Soil gas concentrations were measured to 24-inches deep for 1 week after fumigation to monitor fumigant distribution and dissipation. Fumigant emissions over the 400 lb/A Inline and Pic treatments were monitored over both the VIF and HDPE tarps. Hand weeding times and strawberry fruit yields were monitored. All studies have been completed. The 1,3-D or Pic concentrations (emissions) directly over the VIF tarp were reduced by 90 to 97 percent compared to the fumigant concentrations over the HDPE 24 hours after application. Conversely, directly under the tarp the 1,3-D or Pic concentrations at 24 hours after application were 148 to 358 percent higher under VIF than HDPE. At Watsonville, VIF tarp reduced weeding times in all Inline treatments by 34 to 56 percent and Pic treatments by 13 to 42 percent compared to the standard tarp. Based on regression analysis, Inline at 257 and 350 lb/A applied under VIF at Oxnard and Watsonville, respectively, had hand weeding times equivalent to MbPic at 350 lb/A, while the Inline rate under standard film equivalent to MbPic was 761 to 770 lb/A. At Oxnard, 360 lb/A Pic applied under VIF had weeding times similar to MbPic, while 556 lb/A Pic was necessary to realize weeding times equivalent to MbPic at Watsonville. More than 1000 lbs/A of Pic would be necessary to provide weed control equivalent to MBPic under standard tarp at both Oxnard and Watsonville. These results indicate that Inline and Pic applied under VIF controlled weeds better than the same treatments applied under HDPE. Overall control of nematode, and Pythium ultimum, verticillium wilt was better under VIF than HDPE. Control of Phytopthora cactorum was not different between the two films. Strawberry fruit yields were generally higher under VIF than HDPE for both Inline and Pic. Field days were held at Oxnard on March 27, 2003, March 23, 2004 where about 50 growers and industry personnel attended each year and at Watsonville on June 11, 2003 and June 24, 2004 where about 75 growers and industry personnel attended both years.

Impacts
Methyl bromide is the basis for control of soil-borne diseases, nematodes and weeds in California's 1.1 billion dollar strawberry industry. Use of VIF may allow growers to reduce fumigant emissions and rates as well as improve control of soil borne diseases and weeds.

Publications

  • AJWA, H., FENNIMORE, S., KABIR, Z., MARTIN, F., DAUGOVISH, O., ROTH, K., and RACHUY, J. 2004. Weed response to chloropicrin and Inline dose under VIF and standard film. Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. Orlando, FL. Abstract 004.
  • FENNIMORE, S., KABIR, Z., AJWA, H., DAUGOVISH, O., ROTH, K., and RACHUY, J. 2004. Weed response to chloropicrin and Inline dose under VIF and standard film. Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. Orlando, FL. Abstract 004.
  • GOODHUE, R., FENNIMORE, S., and AJWA, H. 2004. Economics of VIF used with Pic and Inline in California strawberries. Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. Orlando, FL. Abstract 099.


Progress 01/01/03 to 12/31/03

Outputs
The impending methyl bromide phase out emphasizes the immediate need for development of alternative fumigation systems to provide disease, nematode and weed control. We are conducting field evaluations of drip-applied fumigants and impermeable films to reduce rates and improve the efficacy of alternative fumigants on soil borne pests. Field studies were initiated near Oxnard, CA on Sept. 16, 2002 and August 20, 2003 and near Watsonville, CA on Oct. 1, 2002 and Sept. 16, 2003. Fumigants applied were chloropicrin (Pic) and 62% 1,3-dichloropropene (1,3-D) plus 35% chloropicrin (Inline) each at 50, 100, 200, 300 and 400 pounds per acre though the drip irrigation system. The commercial standard was shank applied 67% methyl bromide plus 33% chloropicrin (MBPic) at 350 lb/A. One half of the length of each plot was covered with high density polyethylene film (HDPE) and virtually impermeable film (VIF) covered the other half. Mesh bags containing pathogen and weed seed samples were installed before fumigation and removed 2 to 3 weeks after fumigation. Soil gas concentrations were measured to 24-inches deep for 1 week after fumigation to monitor fumigant distribution and dissipation. Fumigant emissions over the 400 lb/A Inline and Pic treatments were monitored over both the VIF and HDPE tarps. Studies initiated in 2002 have been completed and most results are available. The 1,3-D or Pic concentrations (emissions) directly over the VIF tarp were 1.7 to 5.6% of the fumigant concentrations over the HDPE during 0 to 48 hours after application. Conversely, directly under the tarp the 1,3-D or Pic concentrations were 153 to 844% higher under VIF than HDPE. At Watsonville the season-long weeding time with MBPic at 350 lb/A was 60.6 hours per acre. The rate of Inline at Watsonville with weeding time equal to MBPic was 152 lbs/A under VIF and 424 lbs/A under HDPE. The rate of Pic with weeding time equal to MBPic was 412 lbs/A under VIF and 573 lbs/A under HDPE. These results indicate that VIF tarp improves weed control with Inline compared to HDPE, and VIF did not improve weed control provided by Pic as much as Inline. Overall control of nematode, Phytopthora cactorum and Pythium ultimum was better under VIF than HDPE. Strawberry fruit yields were generally higher under VIF than HDPE at Oxnard, but there was no clear trend between VIF and HDPE on fruit yields at Watsonville. A field day was held at Oxnard on March 27, 2003 where about 50 growers and industry personnel attended and at Watsonville on June 11, 2003 where about 75 growers and industry personnel attended. For studies initiated in 2003, we are still in the process of analyzing most of the gas, pathogen and weed seed samples. We are currently monitoring the weeding times at the Oxnard and Watsonville sites. Fruit harvest monitoring will begin at Oxnard in early January and early April in Watsonville. Field days are planned for both sites in 2004.

Impacts
Methyl bromide is the basis for control of soil-borne diseases, nematodes and weeds in Californias $991 million strawberry industry. Use of VIF may allow growers to reduce fumigant emissions and rates as well as weeding costs with the alternative fumigants such as 1,3-D.

Publications

  • AJWA, H., FENNIMORE, S., KABIR, Z., MARTIN, F., DUNIWAY, J., BROWNE, G., TROUT, T., GOODHUE, R., and GUERRERO, L. 2003. Strawberry yield under reduced application rates of chloropicrin and Inline in combination with metam sodium and VIF. Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. San Diego, CA. Abstract 2.
  • BROWNE, G., BECHERER, H., McGLAUGHLIN, S., FENNIMORE, S., DUNIWAY, J., MARTIN, F., AJWA, H., WINTERBOTTOM, C., and GUERRERO, L. 2003. Integrated management of Phytopthora on strawberry without methyl bromide. Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. San Diego, CA. Abstract 128.
  • FENNIMORE, S., KABIR, Z., AJWA, H., DAUGOVISH, O., ROTH, K., and VALDEZ, J. 2003. Chloropicrin and Inline dose response under VIF and HDPE: weed control results. Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. San Diego, CA. Abstract 3.


Progress 01/01/02 to 12/31/02

Outputs
The impending methyl bromide phase out emphasizes the immediate need for development of alternative fumigation systems to provide disease, nematode and weed control. We have begun field evaluations of drip-applied fumigants and impermeable films to reduce rates and improve the efficacy of alternative fumigants on soil borne pests. Field studies were initiated near Oxnard, CA on Sept. 16, 2002 and near Watsonville, CA on Oct. 1, 2002. Fumigants applied were chloropicrin (Pic) and 62% 1,3-dichloropropene plus 35% chloropicrin (Inline) each at 50, 100, 200, 300 and 400 pounds per acre though the drip irrigation system. The commercial standard was shank applied 67% methyl bromide plus 33% chloropicrin at 350 lb/A. One half of the length of each plot was covered with standard polyethylene film and virtually impermeable film (VIF) covered the other half. Mesh bags containing pathogen and weed seed samples were installed before fumigation and removed 2 to 3 weeks after fumigation. Soil gas concentrations were measured to 24-inches deep for 1 week after fumigation to monitor fumigant distribution and dissipation. We are still in the process of analyzing most of the gas, pathogen and weed seed samples. However, we have processed yellow nutsedge tubers that were buried in the Oxnard study. The yellow nutsedge tuber 50% lethal doses (GR50) in lbs/A for Pic were: VIF 185.4, standard 362.3, and GR50s for Inline were: VIF 101.3 and standard >400. This suggests that the use of VIF increased the efficacy of Pic and Inline on yellow nutsedge by 95 percent or more. We are currently monitoring the weeding times at the Oxnard and Watsonville sites. Fruit harvest monitoring will begin at Oxnard in early January and early April in Watsonville. Field days are planned for both sites in 2003.

Impacts
Methyl bromide is the basis for control of soil-borne diseases, nematodes and weeds in California's $889 million strawberry industry. Use of VIF may allow growers to reduce fumigant emissions and rates.

Publications

  • No publications reported this period