Full report
This short report is a summary of a full report Chinese Broccoli (Kailaan)in southern Australia (RIRDC Publication Number 02/ 161,UCQ-10a) by Professor David Midmore et al. who can be contacted on: Phone 07 4930 9770, Fax:07 4930 9255, Email:d.midmore@cqu.edu.au, Web:http://science.cqu.edu.au/psg/
The full report is available in hardcopy for $15 from RIRDC (Phone:02/6272 4819) or can be downloaded for free from RIRDC ’s website: www.rirdc.gov.au/reports/Index.htm
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Cooperative trials on Chinese broccoli show it can be grown all year in Victoria with the research identifying options for cultivars for various seasons and locations.

The trials, funded in Tasmania by the Rural Industries Research and Development Corporation (RIRDC)and in Victoria by the Victorian Department of Primary Industries, also looked at the potential for growing Chinese broccoli in Tasmania, but failed to provide any firm conclusions on likely success.

Chinese broccoli,(commonly known as kailaan – Brassica oleracea var..alboglabra) is harvested for its flowering stems with compact florets.Harvest time and post- harvest conditions are critical in order that the flowering heads do not contain opened flower buds.

Used extensively in Asian cuisine,Chinese broccoli is one of the top five Asian veg- etables sought by Australian supermarkets.

Demand from these retail outlets,Chinese restaurants and Asian grocery shops is satisfied through limited production by growers of Asian background and by a small number of specialist growers.

Open pollination (OP) lines developed by growers meet the requirements of these particular markets.

The Study

The aim of the research was to identify national production capability and supply and productiv- ity issues for development of domestic and future export markets.The project was headed by Pro- fessor David Midmore (Plant Sciences Group at Central Queensland University in Rockhampton) with participation from a range of other industry and research groups.The Victorian trials and the national report were coordinated by Dr Wendy Morgan.

In 1998/99,cultivar trials were undertaken to evaluate seven varieties of Chinese broccoli in replicated field trials at the TAFE farm in Burnie, Tasmania.

Simultaneously eight cultivars were trialled in five Victorian regional locations:Lindenow (Gippsland), Boneo on Mornington Peninsula (Melbourne), Geelong (south west), Tatura (north central), and Myrtleford (north east).

The plantings commenced from mid-April 1998 and continued approximately bi-monthly until mid-March 1999.

Trials sought to determine which sites and varie- ties provided optimal production,taking advan- tage of varied climatic conditions in the two States.The research assessed the primary stem production,sideshoot production,and quantified quality parameters of the respective harvests.

Commercial practice with Chinese broccoli is to harvest both the main shoot and the subsequent side shoots from plants.This required further evaluation of eight commercial cultivars – carried out in 1999/00 in Victoria.

The cultivars, including the best from the 1998/99 evaluation,were assessed in replicated trials at four locations. There were four sowing dates at eight-week intervals between August and February, the optimum sowing window having been previously identified.

Agronomic measurements were expanded to include both the terminal shoots and the side shoots.Side shoot harvests continued for up to six weeks.

A number of yield and quality components, including those identified as important to grow- ers,were measured and used to identify the relative merits of cultivars.A comparison with a grower’s open pollinated line was undertaken at one site.

The Results

There was an inverse relationship between crop duration and marketable yield across sites.Slower longer periods of growth in colder plantings did not compensate for the shorter season faster growth of warmer plantings within the same site.

August sowings appreared to be the least suit- able across most locations,and October to January the best.

Yields of shoots ranged from 0.3-21 t/ha,and from 1-42 t/ha when side shoot harvests were included.The average and best of these are higher than reported yields elsewhere.

The cultivar which performed well in the Victorian series of trials over the two-year period and which proved suitable for sequential harvest- ing was Kailaan White,which showed consist- ent high yield across sites (but not at all sowing dates)and was variable in terms of harvest date within a sowing.It was a high performer in summer sowings.

Others trialed in two years but which had poor yield or poor quality in one or more locations or plantings included OP Kailaan,Green Lance and Tai Nan.

In Tasmania,all varieties bolted (very early flowering)in both summer or autumn.While low temperatures induce bolting,it may be that the practice of transplanting seedlings (52 days old in summer and 63 days old in autumn)further induced bolting.

The OP variety Mandy was more tolerant to bolting than other varieties but is not a recom- mended variety due to its appearance.

Location and sowing dates in Victoria (all trials were established by direct seeding)affected yield and time to harvest.Crop duration was greater in the north of the state in the winter (sown April to August –110-150 days),and least in early summer (sown December)when the crop duration (about 60 days)did not markedly differ between locations.

Pests and Diseases Slug damage occurred with the October planting in the north east of Victoria,particularly on Green Lance,OP Kailaan,Thainan and Cultivar A.

Downy mildew was present at all plantings in the Melbourne region.OP Kailaan,Green Lance and Cultivar A were the most susceptible cultivars with King,4502 and Cultivar B showing a high degree of resistance.In the north central and east Gippsland regions downey mildew was present in planting 1 on OP Kailaan (moderate to severe levels)and Green Lance (less severe).

Aphids and/or leafminer were observed at low levels in East Gippsland in the August/September planting; aphids on Green Lance, both on OP Kailaan and leafminer on BBT 37.

Clubroot was not present in East Gippsland during the trials,but they did not take place in the clubroot season.

Summary

Essentially,harvests of Chinese broccoli could be achieved throughout the year in Victoria by selec- tively choosing variety and location.Marketable yields as a percentage of total yield (based on numbers of marketable shoots per total number of shoots)were consistently low in a number of site-by-sowing-date combinations,and those combinations were not considered suitable for commercial production.

For August and February sowings,Boneo (Melbourne),the only site with current commer- cial production,would appear the most suitable for production of main and side shoots.

But October sowing was better in Myrtleford north east of Victoria, January/February in Mornington Peninsula (Melbourne), September/ October in East Gippsland, July in the south west (Geelong),and February for Tatura in north central Victoria.


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