Management of Banana Bunchy Top in Hawaii

Management of Banana Bunchy Top in Hawaii

Summary

Hawaii banana plantings are plagued with several yield-reducing pests, among which, banana bunchy top virus (BBTV) and its aphid vector Pentalonia nigronervosa are of greatest economic concern. In the past, limited field research was being conducted in Hawaii with regards to these organisms. As a result, several “grower myths” developed in Hawaii regarding their management, and changes in production practices resulting from these gratuitous beliefs helped to promote virus spread. Thus, the goal of this project is to help banana growers sustain the economic viability of their operations by obtaining and disseminating trustworthy information on BBTV.

Objectives/Performance Targets

1) obtaining a better understanding of the banana aphid’s biology and ecology,
2) studying the pattern of banana bunchy top virus spread in commercial fields, and
3) determining disease parameters that are important to the development of virus management practices

Accomplishments/Milestones

Monitoring of pest densities allows for informed decision making regarding the judicious use of pesticides. Prior to the start of this project, there were no sampling plans available for monitoring population densities of P. nigronervosa on banana. Thus, field surveys were conducted to develop a sampling plan for this pest. Based on these surveys, a sequential binomial sampling plan has been developed. Further, it was determined that the within-plant distribution of P. nigronervosa is an important factor to consider when sampling for this pest. Specifically, aphids were found more frequently near the base of banana plants, followed by the newest unfurled leaf at the top of the plant. Aphids were least likely to be located on leaves in between the top and bottom of the plant. In the past it was widely accepted among banana growers in Hawaii that banana aphid occurs preferentially on the cigar leaf (newest unfurled leaf). During this study, it was determined that sampling the cigar leaf for aphid presence is not a reliable technique because in 50% of the cases this provides a false negative for their presence This sampling plan is currently assisting in the development of sustainable management practices for banana production and the results from this study were recently published in a manuscript entitled “Within-Plant Distribution and Binomial Sampling of Pentalonia nigronervosa (Hemiptera: Aphididae) on Banana” Journal of Economic Entomology, 99(6): 2185-2190 authored by Robson et al., 2006. Future research needs include evaluating this sampling plan with insecticides and cultural management tactics such as roughing for the further development of disease management strategies.

In an effort to learn more about the distribution of P. nigronervosa and to help disseminate information to growers with regards to BBTV management within banana mats, several farm surveys were conducted. Banana mats usually consist of at least one mature or nearly mature banana plant and some smaller plants or suckers. Banana suckers are vertical shoots that develop from the base of a banana pseudostem. Twenty-nine banana plantings were visited throughout the state of Hawaii and 26 of these farms were surveyed for aphids, nematodes, and BBTV. Afterwards, each farm was given information on how to best manage the banana aphid, BBTV, and nematodes. These visits included commercial growers, banana hobbyists, and individuals whose banana plantings were not their major sources of farm income. In addition to aphids, other banana pests of concerns such as corm weevils, nematodes, and black leaf streak disease were addressed during or after each farm visit. Our preliminary findings from the aphid surveys suggest that P. nigronervosa populations are greater on plants approximately 1.5 meters or less in height and only under conditions of high populations are high numbers found on larger plants (i.e., 3 meters or greater). Additionally, banana aphids are not found on the fruit or flower of banana plants. This would suggest that sampling plants 1.5 meters in height or less would be feasible for scouting banana aphids. These data are currently being analyzed and findings will be used to further advise growers on how to scout their fields for P. nigronervosa and which size plants should be targeted when the economic threshold has been reached. During the surveys, it was noted that many fields were infested with BBTV and nematode pests. This has led us to investigate whether banana plants physiologically stressed by nematodes express BBTV symptoms differently than plants without nematodes.

Few studies have been conducted on the biology and ecology of P. nigronervosa. Thus, studies were carried out to determine the effect of temperature and rearing methods on P. nigronervosa biology. Data on population growth, longevity, and fecundity of P. nigronervosa at different temperatures are useful for developing prediction models for aphid population dynamic under field conditions. During these studies, aphids were evaluated at three temperatures (20, 25, and 30º C). These temperatures represent the temperature range of banana growing areas in the Hawaiian Islands. Banana aphids were reared on six different types of banana leaf cuttings. i) mature leaf >1 m in length, ii) young leaf < 0.5m in length, iii) leaf petiole, iv) leaf midrib, (v) symptomatic BBTV leaf, and vi) cigar leaf (newest unfurled leaf). It was found that the banana aphid performed better when not confined on plantlets, followed by leaf midrib cuttings. Further, their intrinsic rate of increase (r), net reproductive rate (Ro), doubling time (DT), nymphal mortality, and mean offspring per female all showed maximal rates at 25ºC. The r was greater when aphids were reared on intact banana plantlets than on plant cuttings. The results showed that it is important to conduct whole plant experiments when evaluating banana aphid growth features because various growth parameters may be underestimated if various plant cuttings are used. This further implicates the importance of comparing insect-rearing methods for studies such as life tables.

Results of this experiment may help predict at what temperatures banana aphid populations will build to greater numbers, assisting in the development of management practices aimed to control the banana aphid and BBTD. Future studies, need to examine the population thresholds that induce the production of alate (winged) banana aphids because the alates are most responsible for spreading the virus. Additionally, studies are also needed for determining biotic and abiotic factors affecting banana aphid population growth in the field. The findings from this study were justly published under the title “Biology of Pentalonia nigronervosa (Hemiptera: Aphididae) on Banana Using Different Rearing Methods” Environmental Entomology 36(1): 46-52 authored by Robson et al. 2007.

There are ongoing studies to learn more about the biology and ecology of the banana aphid but much of the attention is now focused on how this relates to their ability to transmit BBTV to healthy banana plants. Although, previous research (Robson et al., 2007) indicates that various growth parameters of the banana aphid is significantly reduced on plant cuttings compared to whole plants, we learned that their efficiency in obtaining and transmitting BBTV to healthy banana plants is similar whether they feed on whole plant or leaf cuttings infected with BBTV, respectively (Figure 1).

In controlled experiments, it was also found that BBTV is transmitted by the banana aphid between 20 and 28 hours after feeding on an infected plant (acquisition) including the 12 hour acquisition access time. In two trials, the transmission efficiency for the 28 hour treatment period was 50 and 60%, respectively. Their transmission efficiency for the 36 hour time period was 90 and 100% for trials 1 and 2, respectively (Table 1).

The minimum latent period (i.e., length of time after a plant has been inoculated with a virus that an aphid can acquire and transmit the virus from that plant) of BBTV within banana plants was investigated. The inoculation efficiency was 0 and approximately 75% at the 15 and 20 day test periods, respectively (Figure 2). This indicates that the minimum latent period is somewhere between 15 and 20 days following virus inoculation. These studies are among a few that have been conducted to examine BBTV’s transmission efficiency.

Data on the ability of the banana aphids to transmit BBTV at different temperatures are useful for understanding their transmission biology. Banana aphids were evaluated at three temperatures (20, 25, and 30º C) for their ability to transmit BBTV to healthy banana plants. Additional, studies were conducted to compare the efficiency of adult and nymphs in transmitting BBTV. During these investigations, it was determined that adults can transmit the virus at all three temperatures but they have low efficiency at 20ºC. Nymphs did not do as well compared to adults and could not transmit BBTV to healthy plants when exposed to 20ºC (Figure 3). It was also noted that banana aphids were more settled on the leaves at 25 compared to 30ºC.

An effective management strategy for BBTV is dependent on rapid detection of symptomatic plants so that potential source plants of BBTV can be destroyed promptly.
Thus, field studies were also conducted in Oahu, Hawaii, to identify features of banana bunchy top disease (BBTD) that could be used as pre-symptomatic indicators of BBTV infection. The growth and morphology of banana plants infected with BBTV and healthy controls were investigated. The time interval between aphid inoculation of BBTV and the initial appearance of visual disease symptoms (i.e. incubation period) was also determined. Plants infected with BBTV showed a significant reduction in petiole morphology, plant canopy and height, leaf area, pseudostem diameter, and chlorophyll content compared with control plants. Growth differences between virus infected and control plants were not observed until 40 to 50 days after the plants were inoculated with viruliferous aphids. Other growth parameters such as petiole width and leaf production were not statistically different between infected and control plants. The results show that banana growth parameters may not be suitable as pre-symptomatic indicators of BBTV infection and that PCR assays can provide earlier detection (5 to 10 days in advance) of BBTV in banana plants compared to visual symptoms. It was also found that the initial appearance of observable BBTV symptoms ranged from 25 to 85 days after viruliferous aphid inoculation (Figure 4). The results of this study have been accepted in a peer-reviewed journal following minor corrections.

To learn more about the epidemiology of BBTV, GPS units were used to track the movement pattern of the virus in two commercial banana orchards. Monthly data from these farms were initiated in January 2005 and completed in January 2007. Farm 1 used known diseased-free plants (micro-propagated banana plants) for planting material and farm 2 used banana suckers removed from various fields within the farm as planting material. From the data collected from farm 1, it was determined that the virus movement was influenced by wind direction and that the spread pattern was clustered. Additionally, it was found that the virus moved approximately 30 meters per month (Figure 5). Data from farm 2 are still being analyzed but results from the initial analysis indicate that the spread pattern is random and further suggest that field to field spread of BBTV from farm 2 is mostly influenced by the planting of infected plant material throughout the farm. We have established a small field of known disease-free banana plantlets on farm 2 and are now monitoring the spread of BBTV in that field. An additional 1 acre field was established at the Poamoho research station and the pattern of BBTV spread is being monitored at that site. A third field site was established on a midsize commercial farm.

A survey of 50 banana suckers was conducted just after they were transplanted at a major banana producing farm on Oahu. All suckers looked healthy and no obvious BBTV symptoms were present. It was uncovered that 100% of the suckers contained banana aphids, 92% were infested with winged banana aphids, which are the morph most responsible for virus spread, and using PCR methodology it was discovered that 20% of the plants contained aphid carriers of BBTV at time of transplanting. Since some plants may take longer to test positive for the virus this is considered a conservative estimate of the percentage of suckers containing aphids with BBTV.

Thus we are continuously promoting the use of known disease-free planting material (tissue culture banana plantlets) to banana growers so that they can avoid the unintentional planting of infected banana plants throughout their farms. We use data such as mentioned in the latter paragraph to stress the potential risks of using banana suckers as replant material especially if they are in areas where BBTV is prevalent. Workshops, interviews, press releases, and onsite farm visits are ongoing to familiarize banana growers with tissue-cultured banana plants and discuss the benefits of using these plantlets as part of an integrated disease management program. We have noticed a significant jump in the number of growers and banana hobbyist interested in using tissue-cultured banana plants in their gardens and farms. A banana tissue culture facility has been developed on UH Manoa campus to insure that BBTV-free plantlets are readily available to banana growers and BBTV banana plantlets are currently being distributed to commercial growers, banana hobbyists, and home gardeners.

Molecular data (partial sequences of BBTV’s DNA genome) are being used to address specific questions regarding the introduction and spread of this pathogen in Hawaii. The results thus far are summarized in the following three figures.

Figure 6 illustrates the genetic placement of Hawaii BBTV isolates from different islands in relation to BBTV isolates from other regions of the world. It is important to note that Hawaii isolates form a monophyletic clade, suggesting there was only one introduction of this pathogen into the State of Hawaii. Although Hawaii’s BBTV could be grouped with isolates from the South Pacific, its original source could not be pinpointed because there are no BBTV sequences deposited in databases for comparison.

Figure 7 shows the placement of isolates collected from different Hawaiian islands. Interestingly, enough isolates from Maui and Hawaii (Big Island) form monophyletic clades, suggesting only one introduction into those islands. On the contrary, Kauai isolates are located at different branches in the tree, suggesting multiple introductions of BBTV were made into that island. Oahu isolates are present throughout the tree, suggesting that it served as the original BBTV source area for infections into other Hawaiian islands.

Figure 8 illustrates BBTV introduction and spread hypothesis and summarizes the results obtained with the use of molecular tools. It shows that BBTV after being introduced into Oahu in 1989 (one introduction), it then spread to other islands, once into Maui and Hawaii (Big Island), respectively, and multiple times into Kauai.

Much of the data from this molecular work suggest that the spread of BBTV throughout Hawaii was greatly influenced by the movement of infected plant material throughout the islands. Similarly, we have determined that the within-farm spread of BBTV may be more influenced by the planting of infected banana suckers than aphid vectors. This further suggests the importance of using known disease-free banana plants as replant material.

Once a banana plant has been diagnosed as being infected with BBTV, the general recommendation is that the plant be destroyed as soon as possible to prevent it from serving as a source for continuous virus spread. The most popular method being used to destroy infected banana plants is injecting them with a bananacide (i.e., herbicides that can be used to kill banana plants). However, it was not known how long banana plants remain virulent after a bananacide injection. Three on-farm field experiments were conducted to investigate this question. It was discovered that banana plants can remain virulent up to six weeks after being injected with a bananacide at the highest label recommended rate and that aphids are capable of acquiring the virus from plants up to 6 weeks after injections. Similarly, it was determined that aphids feeding on plants 6 weeks after injection can transmit BBTV to healthy banana plants. Thus growers are beginning to treat their plants with an insecticide after injection. The importance of this finding is that many growers believed that an infected plant was no longer a threat after being injected with a bananacide. Additional, studies are needed to determine non-chemical/organically acceptable methods for destroying infected banana plants and determining if injecting plants with a bananacide causes greater production of winged morphs. Future plans are underway to determine how BBTV titer levels change in a plant following a bananacide injection.

Several field experiments were conducted to determine if the two most economically important banana cultivars [apple/dwarf Brazilian (AAB Group) and Williams (AAA Group)] grown in Hawaii differed in their susceptibility to BBTV. Results of these studies indicated that several growth (e.g., plant height, canopy, leaf area, etc.) and physiological features (chlorophyll and moisture levels) of both cultivars were similarly impacted by BBTV. The chlorophyll content was significantly less in plants of both cultivars infected with BBTV compared with control plants (Figure 9). However, Williams appeared to have a wider incubation range than apple (Figure 10). Despite morphological and physiological similarities, significantly fewer dwarf Brazilian became infected compared to the Williams banana (Table 2). These findings differed from results obtained from a laboratory study in which similar numbers of apple and Williams banana plants became infected (Table 3). Also, on average 1 additional leaf were produced prior to the appearance of symptoms in apple compared to Williams banana plants during both laboratory and field trials. It is generally believed by commercial banana growers in Hawaii that apple is more resistant to BBTV than Williams. Findings from the field investigation added some credence to this belief. However, results from the study dispelled the myth that apple is more tolerant of BBTV or masks its symptoms better than Williams banana. More research is needed to determine what factor(s) responsible for lower virus incidence in apple bananas.

Recently, imidacloprid a systemic insecticide was registered for managing P. nigronervosa in bananas. A field study was conducted to determine how long after application does imidacloprid residual activity remain effective in controlling P. nigronervosa and to compare the residual activity of imidacloprid with two rates below the recommended label rate. Additional data were taken on its impact on aphid reproduction. The data from this study are currently being analyzed but preliminary results suggest that its effectiveness is short lived in plants when used as a foliar application. Current plans are to determine how long after applications is it effective in preventing viruliferous aphids from infecting healthy banana plants.

Impacts and Contributions/Outcomes

Our results are being disseminated to banana stakeholders through workshops, farm site visits, collaborative research projects, websites, conferencesc and email action groups. Each year, we highlight relevant findings at the local banana conference and from stakeholders’ comments and questions to determine additional research needs. In the past, Hawaii growers were given limited information regarding the virus and vector and thus relied on their own guesswork on how to best manage this virus. Thus, one of the leading constraints to greater adoption of IPM strategies for BBTV management in Hawaii was the availability of trustworthy information. Through our collaborative research and outreach efforts, we have been able to give stakeholders creditable information on the virus and its associated vector and have thus removed some of the questionable myths regarding Banana bunchy top virus.

We have also built a diverse team of collaborators that includes administrators, extension agents/personnel, researchers, farmer cooperators, non-profit agencies (e.g., Hawaii Banana Industry Association, Oahu Banana Growers Association, Maui Invasive Species Committee), students, and service providers. This team is also multi-disciplinary and includes Plant Pathologists, Nematologists and Entomologists.

Thirty banana plantings have been visited throughout the state of Hawaii and 26 of these farms and have been survey for aphids, nematodes, and BBTV. Each farm was given information on how to best manage the banana aphid and BBTV. These visits included commercial growers, banana hobbyists, and individuals whose banana plantings were not their major sources of farm income. In addition to BBTV, other banana pests of concern such as corm weevils, nematodes, and black leaf streak disease were addressed during or after each farm visit.

Since the start of the project, growers have gained a better understanding of the virus and are now changing their production practices in an effort to better manage the disease. We now expect to see a reversal in banana acreage lost because of this intrepid virus. In addition to accomplishing the original objectives of the project, we instituted additional goals that will substantially benefit the banana industry in Hawaii. Further, a graduate student received her Master of Science degree in May 2006 on research conducted in accomplishing the objectives of the project and another graduate student completed her Master of Science degree in August 2007 on research work related to this project. A third graduate student who contributed to various aspects of the project completed his Master of Science degree in December 2007. An undergraduate whose directed research project allowed her to participate on the project will graduate in 2008.

Research from this project has been highlighted in a USDA-CSREES movie and collaborators of this project have contributed to the design of a BBTV awareness poster. Our goal to slow the spread of BBTV is currently being highlighted on the front page of the University of Hawaii main web page “http: //www.hawaii.edu/” and the front page story of the December issue of the College of Tropical Agriculture and Human Resources news magazine “http://www.ctahr.hawaii.edu/acad/Research/ResearchNews.html”. Interviews and press releases regarding BBTV were conducted with several local newspapers on the islands of Oahu, Lanai, and Hawaii. An interview was also conducted with Hawaii Public Radio. Three papers will have been published in peer-reviewed journals, two additional manuscripts are accepted following minor revision, one has been submitted for publication and another is being prepared. Slide presentations highlighting some of our work are posted online http://www2.hawaii.edu/~snelson/HBIA/. Thirty onsite farm visits have been conducted on 5 Hawaiian Islands. Two demonstration plots have been set up at two collaborative farm sites. Additionally, we have communicated with ~ 80 persons through phone and email conversations with regards to BBTV management.

Results from molecular laboratory procedures show that the main driving factor behind the Hawaiian BBTV epidemic was most likely the transportation of contaminated plant material among islands from Oahu. The total number of established inter-island invasions observed (n=6) in less than 20 years highlights the difficulty in controlling the movement of infectious hosts if those are cultivated plants that remain asymptomatic for many weeks after infection. Since the planting of infected plant material is a major contributor to BBTV spread, we rank our achievement in promoting the use of known disease-free banana planting material, establishing a facility to produce tissue cultured banana plantlets, and the distribution of known BBTV-free banana plantlets to the public among our greatest accomplishments. We currently have 11 different banana cultivars in culture and ~ 55,000 banana plants have been micro-propagated. This has a potential impact of 100 acres of banana thus far. Our goal is to make available all banana cultivars currently being grown in Hawaii so as to eliminate the need to use field collected suckers as planting material.

Publications:

Robson, J.D., Wright, M.G. and Almeida, R.P.P. 2006. Within-plant distribution and binomial sampling of /Pentalonia nigronervosa/(Hemiptera, Aphididae) on banana. Journal of Economic Entomology, 99(6): 2185-2190.

Robson, J.D., Wright, M.G. and Almeida, R.P.P. 2007. Biology of Pentalonia nigronervosa/(Hemiptera, Aphididae) on banana using different rearing methods. Environmental Entomology, 36(1): 46-52.

Robson, J.D., Wright, M.G. and Almeida, R.P.P. 2007. Effect of imidacloprid foliar application on banana aphid /Pentalonia nigronervosa/ (Hemiptera, Aphididae) survival. – New Zealand Journal of Crop and Horticultural Science 35: 415-422.

Hooks, C. R. R., Wright, M.G., Kabasawa, D. S., Manandhar, R., Almeida, R. P. P. Effect of Banana bunchy top virus infection on morphology and growth characteristics of banana. – Annals of Applied Biology. In revision

Anhalt, M.D. and Rodrigo P.P. Almeida 2008. Effect of Temperature, Vector Life Stage and Plant Access Period on Transmission of Banana bunchy top virus to Banana. Phytopathology In revision

Almeida, R. P.P. G.M. Bennett, M. D. Anhalt, C.W. Tsai and P. O’grady. 2008 Spread of an Introduced Vector-Borne Banana Virus in Hawaii. Molecular Ecology Submitted.

C. R.R. Hooks, R. Manandhar, E. P. Perez, K.-H. Wang, R.P.P. Almeida, and M.G. Wright Comparative susceptibility of banana cultivars dwarf Brazilian and Williams to Banana bunchy top virus. In preparation

Abstracts:

Almeida, R.P.P. 2006. Molecular epidemiology of /Banana bunchy top virus/ in Hawaii. Phytopathology 96 (Supplement): S5.

Presentations at conferences:

Wright, M.G., Almeida, R.P.P., Hooks, C.R.R. and Robson, J.D. Aphids and banana bunchy top virus in Hawaii. Invited presentation. 2005 Pacific Entomology Conference, Invasive Species Symposium.

Almeida, R.P.P. Biology and epidemiology of banana bunchy top virus. WERA20 Regional Meeting. May 8-9 2006. Victoria, Canada.

Robson, J.D., Wright, M.G. and Almeida, R.P.P. Biology and ecology of
Pentalonia nigronervosa/ Coq. (Hemiptera: Aphididae) in Hawaii. Annual Meeting of the Entomological Society of America. December 15-18 2005. Fort Lauderdale, FL.

Anhalt, M.A. and Almeida, R.P.P. Transmission of Banana bunchy top virus to banana by Pentalonia nigronervosa (Hemiptera: Aphididae). Annual Meeting of the the Entomological Society of America. December 2006, Indianapolis, IN.

Hooks, C.R.R., Wright, M.G., Kabasawa, D. S., Manandhar, R., Almeida, R P.P. The influence of Banana bunchy top virus infection on the morphology and growth of banana. 37th Annual Hawaii Banana Industry Association Conference. August 25th, 2006. Hilo, Hawaii.

Almeida, R.P.P. and Vorsino, A. Spread of Banana bunchy top in Hawaii. 37th Annual Hawaii Banana Industry Association Conference. August 25th, 2006. Hilo, Hawaii.

Anhalt, M.A and R.P.P. Almeida, Transmission biology of banana bunchy top virus: viral acquisition and latent periods in aphids and banana plants. 37th Annual Hawaii Banana Industry Association Conference. August 25th, 2006. Hilo, Hawaii.

Wright, M.G., Pest biology, sampling, management decisions and provado for the management of banana aphids. 37th Annual Hawaii Banana Industry Association Conference. August 25th, 2006. Hilo, Hawaii.

Mandy D. Anhalt, Rodrigo PP Almeida, Mark G. Wright, Cerruti RR Hooks, & Jane M. Tavares, Transmission Biology of Banana bunchy top virus by Pentalonia nigonervosa (Hemiptera: Aphididae). 38th Annual Hawaii Banana Industry Association Conference. August 2007. Oahu, Hawaii.

Cerruti RR Hooks, Steve Fukuda, Eden A. Perez, Derek Kabasawa, Mark G. Wright, Roshan Manandhar, Koon-Hui Wang, & Rodrigo PP Almeida, The virulence of Banana bunchy top virus in Banana Plants After Injection With a Bananacide. 38th Annual Hawaii Banana Industry Association Conference. August 2007. Oahu, Hawaii.

Eden A. Perez, Cerruti RR Hooks, Mark G. Wright, Mandy Anhalt, & Rodrigo PP Almeida, Integrated BBTV Management: Using a Combination of Strategies to Control the Virus and its Aphid Vector. 38th Annual Hawaii Banana Industry Association Conference. August 2007. Oahu, Hawaii.

Koon-hui Wang, Cerruti RR Hooks, & Roshan Mandahar, Preliminary Investigation of Nematodes Inhabiting Banana Fields in Hawaii and Their Management Options. 38th Annual Hawaii Banana Industry Association Conference. August 2007. Oahu, Hawaii.

Mark G. Wright, Sequential Sampling: How to Decide When to ‘Take Action’ Based on Threshold Counts. 38th Annual Hawaii Banana Industry Association Conference. August 2007. Oahu, Hawaii.

Workshops/Moderated Discussion:

Jari Sugano, Cerruti R2 Hooks, Mandy Anhalt, Derek Kabasawa, Update of findings from current banana research. Banana growers on Oahu. May, 2006. Kaneohe Extension Office, Oahu, Hawaii.

Kabi Neupane, Cerruti R2 Hooks, Eden Perez, Derek Kabasawa, Introduction to Banana Tissue Culture and Disease-Free Planting Material. July 13, 2006. Leeward Community College,Oahu, Hawaii.

Cerruti R2 Hooks, Mandy Anhalt, Mark Wright, Banana workshop: Update and future direction of banana research. May, 2007. University of Hawaii at Manoa, Oahu, HI.

Jim Hollyer, Banana tissue culture plant distribution policy, moderated discussion. 38th Annual Hawaii Banana Industry Association Conference. August 2007. Oahu, Hawaii.

Collaborators: