AN EVALUATION OF THE
CALIFORNIA LETTUCE RESEARCH BOARD
1973-74 - 2000-2002
The following information was obtained following a review of the activities of the California Lettuce Research Board (Board) from its inception in 1973 through research funded in 2000-2001, and included in this report. During this period, the Board has invested approximately $9 million in research on iceberg lettuce, and since 1998, over $700,000 in leaf lettuce research. The primary purpose of this evaluation is to provide all handlers and supporters of this program with some of the primary programs, issues, and accomplishments of the Board, and of the researchers funded by the Board, during this period. For reference purposes, please note that the average yield of iceberg lettuce in Monterey County for the 2-year period prior to the initiation of Board funded research (1972-1973) was in the range of 576 to 594 cartons per acre. In 2000 - 2001, the average yield of iceberg lettuce was in the range of 893 to 967 cartons per acre.
The Board annually reviews ongoing research and priorities to meet the needs of the California lettuce industry. Board funds are directed to research aimed at solving both short and long term problems in all areas of California. Research programs have addressed every avenue of lettuce research including: plant breeding; insect, weed, and disease management; nutrient use; cultural production practices; and post-harvest activities related to harvesting, storage, and shipping. In recent years, approximately 50-60% of the annual funds have been allocated for plant breeding and related activities and 40-50% for pest and disease management, nutrient research and cultural production related activities. The primary emphasis of the plant breeding programs is the development of varieties with multiple resistance to pests and diseases such as downy mildew, corky root, lettuce drop, aphids, leafminers, and various lettuce viruses. Nutrient and cultural research is aimed at exploring the use and uptake of nutrients along with the impact of cover crops, compost use, and modified tillage practices. Insect research has focused on the management of aphids, leafminers, whiteflies, and various worms. The primary emphasis of the disease research is related to the development of management techniques for downy mildew, lettuce drop, Verticillium wilt, corky root, anthracnose, and bacterial leafspot.
California is the leading producer of lettuce with an estimated 70-75% of the total U.S. production of iceberg lettuce and 80-85% of the leaf lettuce. Board members have worked together to insure that the current and future needs and problems of the lettuce industry are being met through a strong, scientifically based, research program. The Board feels that the long-term viability of the California lettuce industry requires a continued commitment to funding non-proprietary research that will be of benefit to all California lettuce growers.
We hope that the information summarized on the following pages will provide you an indication of the commitment of the Board, the accomplishments of the researchers, and the value of your contributions to the California lettuce industry. For ease of interpretation, and to allow the reader to see how programs have been modified since 1973, the information is presented in five-year increments starting with the 1974-75 annual report.
1974-75 - 1978-79
Investment in iceberg lettuce research - $1,205,325
Primary Areas of Research:
1 - Plant Breeding.
2 - Post-harvest activities.
3 - Pest and disease management.
4 - Nutrient research.
Primary Issues/Accomplishments:
1 - Release of cultivars Calrey, Calrico, Salinas and Vanguard 75.
2 - Release of UC and USDA germplasm, with desirable horticultural traits and pest and/or disease resistance characteristics, to lettuce seed companies.
3 - Identification of a new strain of downy mildew with ability to overcome resistance in existing cultivars.
4 - Development of data on nutrient use, timing and placement.
5 - Development of data on impact of worm threshold levels on number of pesticide applications.
6 - Development of data to support the registration of pesticides on iceberg lettuce.
7 - Development of data and recommendations related to post-harvest, including:
a - Shipping containers, carton specifications, and handling systems.
b - Shipping and arrival temperatures and other atmospheric parameters.
c - Influence of physiological disorders such as russet spotting, rusty brown discoloration, and brown stain.
d - Impact of film wrapping.
8 - Reapproval of program for 5-year period.
1979-80 - 1983-84
Investment in iceberg lettuce research - $1,632,092
Primary Areas of Research:
1 - Plant Breeding.
2 - Post-harvest activities.
3 - Pest and disease management.
4 - Nutrient research.
Primary Issues/Accomplishments:
1 - Release of cultivars Alamo, Anza, Centennial, Laguna, Ramona, Rita, Sea Green, Thompson, Vega, Vista, and Winterset.
2 - Release of UC and USDA germplasm, with desirable horticultural traits and pest and/or disease resistance characteristics, to lettuce seed companies.
3 - Development of a serological method for screening lettuce seed lots for lettuce mosaic virus infection.
4 - Continued development of data on nutrient use, timing and placement.
5 - Continued development of data on impact of worm threshold levels on number of pesticide applications.
6 - Continued development of data to support the registration of pesticides on iceberg lettuce.
7 - Development of data on the impact of the sweet potato whitefly and its transmission of the lettuce infectious yellows virus.
8 - Development of data on impact of seed quality and thermodormancy on lettuce seed germination.
9 - Development of data on planter efficacy with raw lettuce seed.
10 - Development of personnel and management training programs and associated workshops.
11 - Continued development of issues related to post-harvest activities.
12 - Reapproval of program for 5-year period.
1984-85 - 1988-89
Investment in iceberg lettuce research - $1,809,946
Primary Areas of Research:
1 - Plant Breeding.
2 - Post-harvest activities.
3 - Pest and disease management.
4 - Nutrient research.
5 - Cultural practices research.
Primary Issues/Accomplishments:
1 - Release of cultivars Autumn Gold, Pacific, and Salinas 88.
2 - Release of UC and USDA germplasm, with desirable horticultural traits and pest and/or disease resistance characteristics, to lettuce seed companies.
3 - Initiation of a project aimed at the development of transgenic lettuce plants including the development of a genetic map for iceberg lettuce.
4 - Initiation of a new project on lettuce viruses.
5 - Identification of multiple fungal pathotypes involved in downy mildew resistance and cultivar development.
6 - Identification of isolates of downy mildew insensitive to Ridomil fungicide.
7 - Identification of the causal agent of corky root.
8 - Continued development of data on the impact of whiteflies and lettuce infectious yellows virus on lettuce production.
9 - Continued development of data to support the registration of pesticides on iceberg lettuce.
10 - Continued development of data on impact of seed quality and thermodormancy on lettuce seed germination.
11 - Continued development of data on planter efficacy with raw lettuce seed.
12 - Initiation of research on drip irrigation.
13 - Development of programs related to the effectiveness of field crew management foremen.
14 - Continued development of issues related to post-harvest activities.
15 - Reapproval of program for 5-year period.
1989-90 - 1993-94
Investment in iceberg lettuce research - $2,089,142
Primary Areas of Research:
1 - Plant Breeding.
2 - Post-harvest activities.
3 - Pest and disease management.
4 - Nutrient research.
5 - Cultural practices research.
Primary Issues/Accomplishments:
1 - Release of cultivars Glacier, Misty Day, and miniature iceberg lettuce cultivars.
2 - Release of UC and USDA germplasm, with desirable horticultural traits and pest and/or disease resistance characteristics, to lettuce seed companies.
3 - Continued development of transgenic lettuce plants and a genetic map for iceberg lettuce.
4 - Continuation of projects on lettuce viruses.
5 - Continued identification of multiple fungal pathotypes involved in downy mildew resistance and cultivar development.
6 - Continued identification of isolates of downy mildew insensitive to Ridomil fungicide.
7 - Involvement in the publication of "Genetic Resources of Lettuce and
Lactuca Species in California."
8 - Review of research priorities with all handlers.
9 - Review of breeding programs and priorities with UC and USDA plant breeders and seed company plant breeders.
10 - Initiation of screening procedures to determine resistance of lettuce cultivars to lettuce drop and leafminers.
11 - Initiation of a project aimed at the use of weather data as a means of predicting fungicide treatment regimes for downy mildew.
12 - Development of new antisera for use in the lettuce mosaic virus seed-testing program.
13 - Initiation of new projects related to the control of lettuce drop.
14 - Initiation of new projects aimed at developing control strategies for
leafminers, the green peach aphid, and the lettuce root aphid.
15 - Continued development of data to support the registration of pesticides on iceberg lettuce.
16 - Continued development of data on the use of drip irrigation.
17 - Development of data on the impact of a new strain of whitefly on lettuce production.
18 - Development of data on impact of nutrients and cover crops on nitrogen availability and use.
19 - Continued development of issues related to post-harvest activities
20 - Reapproval of program for 5 year period.
1994-95 - 1996-97
Investment in iceberg lettuce research - $1,246,965
Primary Areas of Research:
1 - Plant Breeding.
2 - Pest and disease management.
3 - Nutrient research.
4 - Cultural practices research.
Primary Issues/Accomplishments:
1 - Release of cultivar Tiber.
2 - Release of UC and USDA germplasm, with desirable horticultural traits and
pest and/or disease resistance characteristics, to lettuce seed companies.
3 - Continued development of transgenic lettuce plants and a genetic map for
iceberg lettuce.
4-Continuation of projects on lettuce viruses.
5 - Continued identification of multiple fungal pathotypes involved in downy
mildew resistance and cultivar development.
6 - Continued identification of isolates of downy mildew insensitive to Ridomil
fungicide.
7 - Initiation of lettuce cultivar field performance and demonstration trials.
8 - Review of breeding programs and priorities withUC and USDA plant
breeders and seed company plant breeders.
9 - Involvement in the publication of a compendium on diseases of lettuce.
10 - Continuation of the project aimed at the use of weather data as a means of
predicting fungicide treatment regimes for downy mildew.
11 - Continuation of projects related to the control of lettuce drop.
12 - Continuation of projects aimed at developing control strategies for
leafminers,the green peach aphid, and the lettuce root aphid.
13 - Continued development of data to support the registration of pesticides on
iceberg lettuce.
14 - Continued development of data on impact of nutrients and cover crops on
nitrogen availability and use.
15 - Development of data on the economic impact of herbicides and weed
control on lettuce.
16 - Initiation of a project to determine the impact of bacterial leafspot.
17- Identification of a Verticillium wilt as a new disease of iceberg lettuce, and
initiation of lettuce resistance screening program.
18 - Development of methods to determine the degree of specific viruses in
lettuce cultivars.
19 - Development of data on influence of irrigation methods on incidence of
lettuce drop.
20 - Development of data on impact of minimum tillage and composting on
lettuce production.
21 - Reapproval of program for 5 year period.
1997-98 - 2001-02
Investment in research - $2,614,269
Iceberg - $1,898,354
Leaf-$715,915
Primary Areas of Research:
1 - Plant Breeding.
2 - Pest and disease management.
3 - Nutrient research.
4 - Cultural practices research.
5 - Food safety research.
Primary Issues/Accomplishments:
1 - Addition of research on leaf lettuce (i.e., romaine, green and red leaf and
butterhead) to the program in 1998.
2 - Recipient of the "IPM Innovator Award" from the California Department of
Pesticide Regulation in 1998.
3 - Recipient of a $58,000 grant from the California Department of Pesticide
Regulation to allow additional IPM research on leatminers and downy mildew in
1998-99.
4 - Development (1998) and up-date (2001) of "Crop Profiles" for both iceberg
and leaf lettuce as apart of the federal "Pesticide Impact Assessment Program."
5 - Cooperation with the University of California on a project funded by the
Pew Charitable Trust for the development of IPM information for leatminers and
the lettuce aphid.
6 - Establishment of a Board web site @www.calettuceresearchboard.org.
7 - Release of UC and USDA germplasm, with desirable horticultural traits and
pest and/or disease resistance characteristics, to lettuce seed companies.
8 - Continued development of transgenic lettuce plants and a genetic map for
lettuce.
9 - Continuation of projects on lettuce viruses.
10 - Completion of a review of LMV seed testing protocols.
11 - Continued identification of multiple fungal pathotypes involved in downy
mildew resistance and cultivar development.
12 - Completion of identification of isolates of downy mildew insensitive to
Ridomil and Aliette fungicides.
13 - Completion of the project aimed at the use of weather data as a means of
predicting fungicide treatment regimes for downy mildew.
14 - Continuation of projects related to the management of lettuce drop,
including the impact of crop rotation, cover crops, and a lettuce cultivar
resistance screening program.
15 - Continuation of projects related to the management of Verticillium wilt ,
including a lettuce cultivar resistance screening program.
16 - Initiation of research on the lettuce aphid.
17 - Continuation of projects aimed at developing management strategies for
leatminers, the green peach aphid, and the lettuce root aphid.
18 - Continuation of the project to determine the impact of bacterial leafspot.
19 - Initiation of a project to determine the impact anthracnose.
20 - Initiation of a project to determine the impact crown rot.
21 - Initiation of a project to determine the impact bottom rot.
22 - Initiation of a project to determine the impact a new virus of lettuce (i.e.,
Lettuce die-back).
23 - Initiation, and completion, of a project to determine lettuce crop tolerance
for the fungicide Actigard.
24 - Initiation, and completion, of a project to determine the impact powdery
mildew.
25 - Initiation, and completion, of a project to determine the impact gray mold.
26 - Initiation of aproject on weed management.
27 - initiation and completion of the development of data on the efficient use of
nitrogen on lettuce.
28 - Initiation of the development of food safety information.
29 - Development of crop production costs for both iceberg and leaf lettuce.
30 - Continued development of data to support the registration of pesticides on
lettuce.
31 - Reapproval of program for 5 year period