Integrated disease management (IDM) for anthracnose, Phytophthora blight and whitefly transmitted geminiviruses in chilli pepper in Indonesia

Summary Statement:
Project activities began in May, 2006. Indonesian partners in IVEGRI, AIAT, and IPB were confirmed. An organizing, Inception Workshop was organized and conducted in September, 2006, in Bandungan, Central Java, with all members attending except our Australian partners. Formal workplans and budgets were discussed and settled, as well as basic reporting responsibilities.
During October and November, pathologists and entomologists conducted surveys of the three targeted production regions, gathering plant and insect samples for isolation and evaluation of pathogen strains, primarily of phytophthora and WTG.
Activities:
Administrative/General:
Inception Workshop, Bandungan, Central Java, September 4-8, 2006
Recruitment and hiring of our project Site coordinator, Dr. Anna Dibyantoro
Objective 1 (Assess socioeconomic and horticultural practices affecting adoption of disease control options in Central Java):
Planning begun for Rapid Rural Appraisal survey of three target areas. Initially scheduled for January, this activity was postponed to March 5-15, 2007, because of schedule conflicts and the transfer of AVRDC socio-economist Dr. Mubarik Ali to new duties in Pakistan).
A consultant, Mr. Joko Mariyono, was contracted to assist in the RRA activity. He will potentially be hired as a research specialist within AVRDC's socioeconomics unit, upon his completion of a PhD degree at Australia National University (Crawford School of Economics and Government) in Australia.
Objective 2 (Characterize biological factors affecting disease incidence and severity):
IVEGRI virologist and entomologist visited the target regions, and collected pepper plant sampled displaying symptoms of geminivirus: Magelang (3), Rembang (4), and Brebes (6). These will be studied further at IVEGRI laboratories. Live plants were also harvested and transferred to IVEGRI-Lembang for further studies. Whitefly samples were also collected, and rearing is underway at Lembang.
Designs were completed for construction of three screened inoculation rooms, to be used in 2007 for transmission studies of the geminiviruses, and for screening germplasm for virus resistance..
Collection surveys for Phytophthora and Colletotrichum pathogens were undertaken in January 2007, and will be reported on in next year's activity report.

Objective 3 (Assess IDM strategies for sustainable disease control):
Initial crop management trials were established in late 2006, in the Brebes area, on Surjan beds 1.5 meters wide x 25 meters long. Shallots were set in the blocks in December, and pepper seedlings were germinated in banana-leaf plugs under protective screen netting, to prevent insect and/or virus infection. These seedlings will be inter-planted among the shallot, and will be followed by disease protective treatments.

Objective 4 (Continue development of locally acceptable varieties carrying resistance to target diseases):
At AVRDC, segregating progenies were advanced and reselected during the fall season, and seed samples are being made available for follow-up testing in Indonesia. These include:
25 F3 progenies of a Kerriting variety crossed with potential sources of WTG resistance. 77 single plant selections were made based on horticultural type and yield potential, and will be shared with IVEGRI and IPB staff for screening with WTG isolates.
21 F4 progenies from crosses between the Phytophthora resistant line PI201238 and several Indonesian varieties (Jatilaba, Kerriting, and Tit Super) were screened a second time for resistance, and 29 single plants were selected for further refinement. Seed bulks of the resistant progenies were also harvested, and these will be sent to Indonesia for additional evaluation, screening, and reselection.
40 F5 and 21 F6 multi-disease resistant progenies based on a Jatilaba background (or Kerriting in some cases) were further reselected on the basis of resistance to anthracnose, yielding 25 F6 and 78 F7selections. Seed of these will also be shared with Indonesian collaborators for screening against local strains, and potentially used in farmer participatory selection trials.
150 accessions of Capsicum frutescens were established in a seed increase block to provide seed for screening in Indonesia for resistance to WTG
At IVEGRI, numerous Indonesian OP varieties are being increased in anticipation of screening them with locally isolated strains of phytophthora and anthracnose, which tasks are being accomplished by the mycologist. Screening of accessions for resistance to geminivirus awaits establishment of isolates, whitefly vectors, and inoculation chambers by the virology group.

This project seeks to reduce yield losses associated with selected disease of chili pepper in Indonesia: Anthracnose, Phytophthora blight, and Whitefly Transmitted Geminiviruses (WTG). Three important chili production regions in Central Java were selected (near Brebes, Magelang, and Rembang) for baseline surveys, evaluation of candidate innovations in production practices, and development of resistant varieties. In the past year we have: established a site coordinator's office in Tegal; conducted Rapid Rural Appraisals; established mycology research facilities at IVEGRI; conducted trials in farmers' fields, evaluating several candidate management innovations; and evaluated intermediate and advanced generation disease-resistant selections of peppers.
The Rapid Rural Appraisal (RRA) was implemented in two target villages in each of the three production regions, meeting with ten farmers who have intensively cultivated chili peppers for at least three years. The follow-up baseline study has been implemented to profile the socio-economic context of chili production, with particular focus on pest control strategies. Around 75 farmers (50 chili growers and 25 non-chili growers) are being surveyed in a village in each of three production regions; with 225 farmers in total. Household surveys, are currently being implemented and will be completed by July 2008.
Pathologists at IVEGRI, IPB, and AVRDC - The World Vegetable Center (the Center) have collected isolates of Geminivirus pathogens, which are being used in focused studies of virulence and symptom expression. Surveys of viral disease incidence in chili fields in 2007 found increased Geminivirus incidence almost everywhere, with scattered occurrence of other viruses. Isolates from chili plants from at least five sites in the Magelang area have been comfirmed as WTG via PCR analysis. Characterization of geminivirus isolates based on restriction enzyme patterns has identified at least 6 distinct patterns. Common patterns were found in accessions from Brebes, Magelang, and Yogyakarta areas; unique patterns have been found in collections from the Rembang area, and patterns found in Magelang in 2006 differed from those collected and identified in 2007, indicating a highly fluid situation.
Incidence of the fungal diseases phytophthora and anthracnose has been documented in 20 locations surveyed in Java during 2007-8. Anthracnose was encountered in all sites, while light to moderate incidence of phytophthora was found in only 8 locations. Seventy collected isolates of Colletotricum have been characterized for species and relative virulence. Fifty two isolates were found to be Colletotricum acutatum, ten are C. capsici, six are C. gloeosporioides, and two are C. boniense. C. capsici accessions appear to be the most virulent.
Crop management trials conducted during 2007-8 included evaluation of a combination of plastic mulch, bio-fungicide, or synthetic fungicide. Silver-plastic mulch delayed (but did not prevent) the spread of virus infection, reduced losses due to fruit fly, soft rot, and anthracnose, and produced higher total and marketable yields, compared to non-mulched treatments. The synthetic fungicide (Bion-M) significantly reduced (but did not eliminate) losses due to anthracnose. A second trial compared bio-fungicides to synthetic fungicide on beds with or without rice straw mulch. Mulch delayed and reduced incidence of virus symptoms. Inclusion of bio-fungicides in spray programs significantly reduced anthracnose losses.
Physical barriers to reduce whitefly movement, and consequent virus infection were studied in a farmer's field near Magelang. Plots established with or without Nylon netting either one or 1.5 meters in height, and sub plots were treated with or without insecticidal sprays. Preliminary data suggest that the taller barrier is effective in reducing whitefly entry and disease incidence. Total yields of plots with the high barrier and insecticidal sprays were more than double that of untreated plots that simulated conventional farmer practice. Unfortunately, losses to anthracnose in this trial exceed 50% of the harvested crop, regardless of treatment. We are already seeing local growers imitating this treatment by erecting barrier walls of various sorts around their chili gardens.
Breeding efforts have commenced with seed increase of candidate sources of resistance to Anthracnose or Phytophthora, and numerous intermediate and advanced generation selections carrying disease resistance provided by the Center. Forty four chili lines were screened for resistance against examples of the four Colletotrichum species, and promising entries were identified, especially AVRDC line 0636-6515, which displays resistance to three species. Fourteen chili genotypes were evaluated for geminivirus resistance in an open field planting near Yogyakarta; while all lines developed at least 20% disease incidence after 60 days, a few (especially IPB C46) displayed significantly less incidence than most of the lines tested.
In summary, the project activities are being implemented in farmers' fields and on-station trials in Indonesia, as well as in the Center in Taiwan; and they are on schedule as proposed earlier.