A. Research Activities Year 2 Under Major Objectives

Objective 1: To develop pre-harvest strategies that boost natural defence mechanisms in melon, controls diseases and maintain quality.

a. Field trials Systemic Acquired Resistance
In year 1 a number of SAR activators were screened in glasshouse trials in China and Australia for their ability to induce disease resistance. In year 2, the same activators were tested under field conditions in both countries for their effectiveness in controlling postharvest disease. In Australia, field trials were conducted at the University of Sydney Camden Farm and on a growers' property in Griffith. In both trials, preharvest applications of acibenzolar-S-methyl (BTH) and iso-nicotinic acid (INA) provided good protection of harvested fruit against postharvest disease. In China field trials using BTH were conducted in Gansu province and Xinjiang. Results from both trials confirmed that BTH is very effective in controlling postharvest disease when applied preharvest. Other SAR activators such as silica, microbial activators developed in China, Harpin and Kang Du Feng (China) are continuing to be screened where they are available.

b. Combine best SAR & best fungicides
A number of fungicides were applied as postharvest dips to SAR induced fruit, including some strobilurin fungicides. In Australia, a postharvest guazatine dip provided added protection against disease to the SAR induced fruit. In China, some of the strobilurin dips on SAR induced fruit showed promise for postharvest disease control, however these trials will be repeated in 2004. Generally Regarded As Safe (GRAS) chemicals were also applied postharvest including chlorine, iodine, sodium bicarbonate, ammonium molybdate and heat treatment. Of these heat treatment and iodine will be tested further. In China a number of fungicides have been trialled of which Graint (Bayer) and Folicur (Bayer) provided good control of pathogens.

c. Investigate mechanisms of SAR
The pathogenesis related (PR) protein chitinase has been confirmed as a marker of SAR in rockmelon and Hami melon. Leaf chitinase activity increases significantly at each application of BTH but declines after 7 days. Because of the significant reduction in disease in SAR induced plants and fruit we hypothesise that the fruit and leaves are in a "primed" state and able to respond rapidly when infection occurs. We are continuing to investigate the mechanisms. A model host- disease system in melon plants has been developed. Melon varieties were obtained from Yates, SP seeds and Syngenta and were screened for resistance or susceptibility to Fusarium, Alternaria, Colletotrichum and Powdery Mildew. Resistance and susceptibility models were characterized microscopically, looking for lignin, phenolics and suberin, as well as biochemically with peroxidase and chitinase being key target enzymes.

Objective 2: To develop and test postharvest technologies which can be used during storage and transport to minimise disease and improve quality.

a. Send shipments to test packaging and disease control in China
In China 2 trial shipments of melons were sent from Xinjiang to Shanghai and Gansu to Wuhei in Hubbei. The shipments were monitored for temperature, humidity and vibration impact and time to distant markets. Melons were subjected to very high temperatures during harvesting and shipping (up to 30C), resulting in up to 80% loss in melons not treated with fungicide dips. Pink Rot, a major postharvest disease of Hami, melon was controlled by imazalil.

b. Assess cooling technologies, small scale shipment
Extension workshops in Gansu and Xinjiang provinces this year have identified target supply chain systems where cooling technology will be implemented in 2004

c. Test cool storage
Cool storage trails in China showed a significant reduction in postharvest melon disease and was more effective when combined with fungicide dips.

Objective 3: To use supply chain assessment and cost-benefit analysis of potential innovations as drivers of technological adoption in entrepreneurial decision making in melon production and marketing.

a. Supply chain (SC) mapping
A number of different supply chains have been identified and mapped in Australia and China. In China two very successful extension workshops were conducted in September and November with supply chain members and extension officers. SC members took part in a SWOT analysis of their respective systems, identifying issues for improvement. It is evident from the extension workshops that the concepts of SC and participatory research techniques are new to the Chinese system and they are keen to learn more. In Australia, the Australian Melon Association working groups, which include the Australian ACIAR research team, are participating in supply chain analyses and postharvest trials.

b. Conduct consumer surveys
Consumer surveys have been conducted in China and Australia through focus groups and surveys. Conjoint analysis was applied to the data to assess the relative weight of rockmelon quality attributes. Taste (sweetness) is the most important attribute for the consumer in both countries. It has become clear that many growers/wholesalers in both countries are harvesting too early when sugar levels are low, to avoid postharvest losses. However this practice is reducing the market value of the product as well as reducing sales.

c. Update information on melon price, production, marketing and consumption; collect farmer household data for impact study
This data is being collected regularly in both countries.

B Other Activities
In February 2003, researchers from both China and Australia attended the International Congress of Plant Pathology in New Zealand
In August 2003, Australian researchers participated in the long distance melon transport trials in China
In August 2003 the Economics researchers participated and presented at the APEC/ASEAN Postharvest Conference in Bali
In September 2003, a USyd Graduate was awarded an AusAID Youth Ambassador scholarship and commenced work in Gansu Province
In September 2003, the annual project coordination meeting took place in Urumqi, Xinjiang, including all team members
In September 2003 a farmer/ wholesaler extension workshop was held at Military Farm 103 in Xinjiang with all team members
In October and November 2003, a project evaluation training course presented by DPI Victoria, was attended
In November 2003, a farmer/wholesaler extension workshop was held in Minqin county for 60 participants with Australian and GAU researchers.

A. Research Activities Year 2 Under Major Objectives

Objective 1: To develop pre-harvest strategies that boost natural defence mechanisms in melon, controls diseases and maintain quality.

a. Field trials Systemic Acquired Resistance
In year 1 a number of SAR activators were screened in glasshouse trials in China and Australia for their ability to induce disease resistance. In year 2, the same activators were tested under field conditions in both countries for their effectiveness in controlling postharvest disease. In Australia, field trials were conducted at the University of Sydney Camden Farm and on a growers' property in Griffith. In both trials, preharvest applications of acibenzolar-S-methyl (BTH) and iso-nicotinic acid (INA) provided good protection of harvested fruit against postharvest disease. In China field trials using BTH were conducted in Gansu province and Xinjiang. Results from both trials confirmed that BTH is very effective in controlling postharvest disease when applied preharvest. Other SAR activators such as silica, microbial activators developed in China, Harpin and Kang Du Feng (China) are continuing to be screened where they are available.

b. Combine best SAR & best fungicides
A number of fungicides were applied as postharvest dips to SAR induced fruit, including some strobilurin fungicides. In Australia, a postharvest guazatine dip provided added protection against disease to the SAR induced fruit. In China, some of the strobilurin dips on SAR induced fruit showed promise for postharvest disease control, however these trials will be repeated in 2004. Generally Regarded As Safe (GRAS) chemicals were also applied postharvest including chlorine, iodine, sodium bicarbonate, ammonium molybdate and heat treatment. Of these heat treatment and iodine will be tested further. In China a number of fungicides have been trialled of which Graint (Bayer) and Folicur (Bayer) provided good control of pathogens.

c. Investigate mechanisms of SAR
The pathogenesis related (PR) protein chitinase has been confirmed as a marker of SAR in rockmelon and Hami melon. Leaf chitinase activity increases significantly at each application of BTH but declines after 7 days. Because of the significant reduction in disease in SAR induced plants and fruit we hypothesise that the fruit and leaves are in a "primed" state and able to respond rapidly when infection occurs. We are continuing to investigate the mechanisms. A model host- disease system in melon plants has been developed. Melon varieties were obtained from Yates, SP seeds and Syngenta and were screened for resistance or susceptibility to Fusarium, Alternaria, Colletotrichum and Powdery Mildew. Resistance and susceptibility models were characterized microscopically, looking for lignin, phenolics and suberin, as well as biochemically with peroxidase and chitinase being key target enzymes.

Objective 2: To develop and test postharvest technologies which can be used during storage and transport to minimise disease and improve quality.

a. Send shipments to test packaging and disease control in China
In China 2 trial shipments of melons were sent from Xinjiang to Shanghai and Gansu to Wuhei in Hubbei. The shipments were monitored for temperature, humidity and vibration impact and time to distant markets. Melons were subjected to very high temperatures during harvesting and shipping (up to 30C), resulting in up to 80% loss in melons not treated with fungicide dips. Pink Rot, a major postharvest disease of Hami, melon was controlled by imazalil.

b. Assess cooling technologies, small scale shipment
Extension workshops in Gansu and Xinjiang provinces this year have identified target supply chain systems where cooling technology will be implemented in 2004

c. Test cool storage
Cool storage trails in China showed a significant reduction in postharvest melon disease and was more effective when combined with fungicide dips.

Objective 3: To use supply chain assessment and cost-benefit analysis of potential innovations as drivers of technological adoption in entrepreneurial decision making in melon production and marketing.

a. Supply chain (SC) mapping
A number of different supply chains have been identified and mapped in Australia and China. In China two very successful extension workshops were conducted in September and November with supply chain members and extension officers. SC members took part in a SWOT analysis of their respective systems, identifying issues for improvement. It is evident from the extension workshops that the concepts of SC and participatory research techniques are new to the Chinese system and they are keen to learn more. In Australia, the Australian Melon Association working groups, which include the Australian ACIAR research team, are participating in supply chain analyses and postharvest trials.

b. Conduct consumer surveys
Consumer surveys have been conducted in China and Australia through focus groups and surveys. Conjoint analysis was applied to the data to assess the relative weight of rockmelon quality attributes. Taste (sweetness) is the most important attribute for the consumer in both countries. It has become clear that many growers/wholesalers in both countries are harvesting too early when sugar levels are low, to avoid postharvest losses. However this practice is reducing the market value of the product as well as reducing sales.

c. Update information on melon price, production, marketing and consumption; collect farmer household data for impact study
This data is being collected regularly in both countries.

B Other Activities
In February 2003, researchers from both China and Australia attended the International Congress of Plant Pathology in New Zealand
In August 2003, Australian researchers participated in the long distance melon transport trials in China
In August 2003 the Economics researchers participated and presented at the APEC/ASEAN Postharvest Conference in Bali
In September 2003, a USyd Graduate was awarded an AusAID Youth Ambassador scholarship and commenced work in Gansu Province
In September 2003, the annual project coordination meeting took place in Urumqi, Xinjiang, including all team members
In September 2003 a farmer/ wholesaler extension workshop was held at Military Farm 103 in Xinjiang with all team members
In October and November 2003, a project evaluation training course presented by DPI Victoria, was attended
In November 2003, a farmer/wholesaler extension workshop was held in Minqin county for 60 participants with Australian and GAU researchers.

A. Research Activities Year 3 Under Major Objectives
Objective 1. To develop pre-harvest strategies which boost natural defence mechanisms in melons, control disease and maintain quality.
a. Field trials - Systemic Acquired Resistance

Overview. SAR elicitors were screened in glasshouse trials in Year 1, and tested under field conditions in Year 2, in both Australia and China. In year 3, further field trials of SAR elicitors were conducted in order to confirm their efficacy in controlling pre- and postharvest disease. In Australia, the SAR elicitors BTH, ReZist and Silica were tested at a commercial property in Mildura, Victoria. In China, the SAR elicitors BTH and Kangdufeng were tested at both two farm sites in Xinjiang; while BTH and Harpin were tested at a farmer's property in Minqin, Gansu. Treatments were assessed for effects on the development of pre-harvest disease and postharvest disease during transport and/or storage regimes. Biochemical changes e.g. enzyme activities of pathogenesis-related proteins, levels of antifungal compounds, and the production of volatiles, were examined in some experiments, as indicators of SAR induction, and may help to explain enhanced disease resistance in following SAR induction.
Pre-harvest disease. The effect of treatments on pre-harvest disease severity could not be reliably assessed in Mildura and Xinjiang, due to unusually low disease pressure; however, there is evidence from the Xinjiang trial that BTH (50 ppm) treatment reduced the incidence and severity of bacterial spot and powdery mildew infections.
Postharvest disease. In the Mildura trial, BTH (50 ppm) 3 weeks before harvest, ReZist (44 ppm) weekly, and Silica (500 ppm) weekly, all enhanced postharvest resistance to disease and enhanced melon quality. In the Minqin storage study, BTH (100 ppm) and Harpin (50 ppm), applied 4 times during the growing season, reduced the incidence of disease caused by latent Alternaria and Fusarium infections. In the Xinjiang storage experiments, there were no statistical differences between treatments and controls, due to problems with fruit maturity and inadequate care of fruit during postharvest handling. These results emphasised the need for adequate postharvest management to take place in conjunction with any adoption of technology for disease control.
Biochemical changes. In the Mildura trial, SAR treated plants (BTH, ReZist and Silica) displayed increased chitinase and peroxidase activities in fruit and leaves, compared to the control plants. Similarly, in the Minqin trial, BTH and Harpin treatments led to increased chitinase and peroxidase activity, as well as increasing the quantity and diversity of pre-formed antifungal compounds and peroxidase isoenzymes in treated leaves and fruit. Furthermore, a decrease in the range of volatile compounds produced, and a delay in their release was observed in fruit from BTH/Harpin treated plants. In one Xinjiang trial, assessment of peroxidase activity found no differences between treatments, corresponding with the results for disease incidence and severity.
Fruit yield and quality. No treatment effects on physiological parameters were detected, although some symptoms of phytotoxicity were recorded on treated plants in the Mildura trial after ReZist application at the highest concentration (88ppm). Treatments had no apparent effects on fruit yield or sugar content in the Mildura trial. In one Xinjiang trial, SAR-treated fruit generally tended to have higher sugar levels, which may have reflected healthier foliage and greater photosynthetic capacity; however data to support this were limited. SAR treatments had no apparent effects on the marketability of fruit in the Chinese trials. In the Mildura trial however, the marketability of fruit from plants treated with the highest concentration of Silica (1000 ppm), dual BTH application (3 and 5 weeks before harvest), and surfactant only (Sett 1%) was substantially reduced due to brown discolouration of the skin. The physiological cause of the browning was not clear.
b. Greenhouse/glasshouse trials - Systemic Acquired Resistance
Glasshouse trials of SAR elicitors were conducted at Xinjiang Agricultural University and Gansu Agricultural University to test SAR elicitors and further elucidate the mechanism of SAR during the melon off-season. Difficulties were experienced due poor temperature control and therefore results were not conclusive.
c. Combined SAR elicitor and fungicide
Pre-harvest SAR/postharvest fungicide combination treatments were tested in the Minqin storage and transport studies, one Xinjiang transport study, and in storage experiments at Sydney Postharvest Laboratory. BTH/azoxytrobin combined treatment reduced the severity of postharvest disease on fruit in the Minqin storage study, but there were no significant differences between treatments in postharvest disease on fruit in either transport study. In the Australian study, postharvest dipping of melons in guazatine had an additive effect on postharvest disease control recorded on fruit from plants receiving pre-harvest SAR applications (BTH or INA). It is speculated that poor postharvest management, e.g. high temperature and humidity conditions that promoted the development of disease, may have negated the benefits of SAR applications for disease control. This requires further investigation.
Objective 2. To develop and test postharvest technologies which can be used during storage and transport to minimise disease and improve quality.
a. Screening of fungicides
In the Chinese field trials, fungicides were tested as either sole treatments or in conjunction with pre-harvest SAR applications, and assessed for effects on pre- and postharvest development of disease. Azoxystrobin (Amistar) was applied as a pre-harvest spray in the Xinjiang trials, and as a postharvest dip in the Minqin field trial. Results from the Xinjiang trials indicate that pre-harvest fungicide treatment reduced the severity of powdery mildew and bacterial spot infections on leaves. Postharvest azoxystrobin application controlled postharvest rots during cool storage, but not during transport, possibly due to the high temperature and humidity conditions (mean T~30C, RH~80%).
In vitro and in vivo screening of the fungicides prochloraz (Sportak), iprodione (Rovral) and azoxystrobim (Amistar) were conducted at China Agricultural University. Prochloraz and azoxystrobin postharvest dips gave the best control of postharvest disease caused by Trichothecium roseum, Alternaria alternata, Fusarium sp., and Rhizopus stolonifer. Combining fungicide dips with heat treatment generally increased the suppression of disease development.
In vivo testing of the fungicides imazalil, kresoxim-methyl, azoxystrobin, and imazalil/azoxystrobin combinations were conducted at Gansu Agricultural University. The fungicides were applied as postharvest dips, and some treatments were combined with hot water dipping. Treated fruit were assessed for lesion size after inoculation with Fusarium sp. or Trichothecium sp., or after storage at ambient temperature to allow natural development of disease. The results indicated that all of the fungicide treatments reduced the severity of Trichothecium sp. and Fusarium sp. rots, with the best disease control from imazalil and imazalil/azoxystrobin combined treatments.
b. Transport studies - Urumqi to Shanghai, Lanzhou to Beijing
A study of Hami melon transported by train from Xinjiang to Shanghai and of honeydew melon transported by truck from Minqin, Gansu to Beijing was completed during the 2004 season. Postharvest disease development was assessed upon arrival at the transport destination and during subsequent storage at ambient temperature. Shipments were also monitored for temperature, humidity, and vibration impact (Minqin study only) during transport. Poor conditions during transport, exacerbated by fruit over-maturity (particularly in fruit from the Xinjiang study) led to rapid development of disease, and are suggested to negate the capacity of SAR and postharvest treatments to control disease. Recommended disease control strategies will have to encompass adequate management practices in addition to pre- and postharvest technologies for improving disease resistance.
c. Assess small-scale postharvest technology for Chinese melon industry
Two extension workshops were held in Wu Jia Qu and a third in Shanshan, Xinjiang with farmers, wholesalers, extension officers and researchers, in order to develop a better understanding of supply chain issues and feasible improvements that can be made along the supply chain. Topics included pre-harvest spraying for disease control (e.g. SAR technology), harvest aids, packing sheds, inexpensive pre-cooling equipment, postharvest dipping, and simple methods of improving ventilation and reducing temperature within loads during long-distance transport. Farmers expressed interest in some of the technology discussed; however the fragmented and transaction-based nature of the supply chain is a major impediment to adoption of technology, as farmers/wholesalers must be able to realise benefits of improved fruit quality and shelf-life beyond their immediate transaction. Also, the lack of stable land tenure in the Military Farm system means that the allocation of land changes from one season to the next, and there is no incentive to invest in infrastructure e.g. packing sheds. The concept of horizontal integration in the form of farmer groups or co-operatives was discussed as a way to start improving industry relationships and begin development of a more integrated supply chain. After some discussion about WTO, the rise of supermarkets in China and their implications for Xinjiang melon growers, participants were convinced of the need to work together and expressed interest in being involved in a pilot farmer group, if assistance from a third party was available.
Objective 3. To use supply chain assessment and cost benefit analysis of potential innovations as drivers of technological adoption in entrepreneurial decision making in melon production and marketing.
a. Consumer surveying and sensory evaluation - Shanghai
A consumer focus group was held at Jiao Tong University, Shanghai, and a consumer survey of over 200 cases was completed in selected venues, including three universities and a multinational company. Participants were surveyed on their consumption patterns, purchase preferences, knowledge of Hami melon, and perception of melon fruit quality e.g. visual and eating quality. The results indicated that there was a good but underdeveloped market for Hami melon in Shanghai (over half the surveyed consumers ate Hami melon), supermarkets are a growing market sector, consumers prefer to store Hami melon for 3 or more days at ambient temperature, supplying full maturity melons that are sweet with no defects will increase sales and demand, and that poor consumer knowledge meant that product differentiation, better marketing, and consumer education will be important to compete with other provinces and imports.
b. Update information on melon price, production, marketing and consumption; collect farmer household data for impact study
Data on the costs of production and marketing of melons in Xinjiang and Gansu were collected for future use in cost-benefit analysis of changing current production or management practices, and/or adopting new technology.
c. Farmer workshops focussing on supply chain issues
Workshops were conducted in Lu Ke Qing in Shanshan County, Xinjiang and Shousheng in Minqin, Gansu to deliver project trial results, results from consumer surveys in Beijing, Wuhan and Shanghai, and explore feasible supply chain improvements in preparation for a possible project extension. Participants included farmers, extension officers, Head of the Bureau of Agriculture (in Minqin), Chinese team members, and Australian team members. In Minqin, a melon association has been in operation since early 2004, so there is no need to develop a new farmer group there. However, farmers would like the project to assist them improve the operation of the farmer association in implementation of supply chain improvements and establishing a quality assurance system.
d. Cost-benefit analysis for adoption of disease control technology
The cost-benefit of adopting pre-harvest BTH treatment and postharvest heat treatment in Australia was analysed on a grower, supply chain and industry level. At the grower level, there are three sources of benefits: reduced average growing costs due to improved marketability, increased revenue due to improved marketability, and higher profits due to improved quality. At the supply chain level, the existing and new value chains were analysed. At the industry level, benefits are likely to come from three sources: improved production, improved quality, and the ability to export via sea-freight. Based on data purchased from the Australian Bureau of Statistics (data to mid-2004), estimated benefits worth $14.4M could be possible if the technologies are taken up by the whole industry now (based on 10% increase in annual production, 10% receiving $4 price premium per tray, and current sea and air freight costs).
B. Other Activities
Project associated travel went ahead as scheduled with 2 additional travel by 2 Australian scientists to China in the reporting period.
From September 2003 to August 2004, an Australian Youth Ambassador for Development assisted in research at Gansu Agricultural University and Xinjiang Agricultural Universities.
In January to March 2004, 3 Chinese scientists visited Australia for research training.

A review of PHT/1998/140 was held in June 2005. An abstact of the review report states "The project was clearly well conceived, managed and executed by the project research teams in China and Australia, and also by ACIAR staff from Canberra and Beijing. The research team members worked closely within and across countries. They generated a large amount of new and important information, much of which has already been collated, analysed and either published or about to be published.

The most obvious success of the project was development and extension of supply chain relationships in China. Farmers in two melon growing regions of China became acutely aware of marketing issues and their role and responsibility in meeting consumer needs and forging strong links and good relationships with other supply / value chain members. As a direct result of this project, the melon farmers from the Gansu site now work more closely together, adopted branding of their fruit, are drafting quality management guidelines, and are developing a (partial) cold chain. They now appreciate the importance of total quality management, particularly fruit and foliage disease control.

A further very tangible area of success for the project teams was development and/or demonstration of relatively novel and socio-environmentally sound postharvest disease management technologies, such as heat and iodine treatments and cool chain benefits. These technologies were of great interest to both Chinese and Australian melon growers. One Australian melon grower has already installed an iodine-treatment plant. One group of Chinese growers, with potential support from Rotary (Australia), hope to build a pre-cooling facility and another is raising support to do likewise. The commercial benefits (in yield and fruit quality terms) of an effective integrated pre- and postharvest disease management strategy were demonstrated clearly by the research teams.

The 'jewel in the crown' of this project, however, is the parallel work conducted in China and Australia on treatments with environmentally benign chemical (e.g. Bion or BTH) and biological (e.g. biological extracts) elicitors of natural plant defence reactions. This research work has shown that elicitors can be used to reliably manage both leaf (viz. powdery mildew) and fruit (i.e. rot) of hami, honeydew and rockmelons. In addition to demonstrating the applied commercial efficacy of such treatments, the teams have elucidated the biochemical mechanisms involved. These include up-regulation of defence enzymes (e.g. chitinase) and structural defence compounds (viz. lignin).

An extension of 2 years (from July 05-June 07) was recommended, sought and approved in December 2005. Publication of research and ongoing research were conducted during this approval period.

The results of the work on plant defense stemulators is a bit sketchy.