Ginger in Queensland
Commercial production

Rodger Broadley, Department of Primary Industries and Fisheries

 

Ginger, (Zingiber officinale) is presumed to have originated from the southern Asian and Indian regions. The crop was first grown commercially in Australia at Buderim in south east Queensland in the early 1900s, mainly for the domestic fresh market. At that time all processed ginger was imported from China. Imports of processed product were disrupted during World War II and consequently the first  processing facility was built in Buderim 1941. Ginger is now grown in the Caboolture, Nambour and Gympie areas.  

Figure 1. A field of ginger plants

Figure 2. Harvested ginger

The Australian industry is currently represented by around 30 growers with an estimated 200-220 hectares under cultivation. The bulk of production is processed with smaller volumes sold on the domestic fresh and export markets. Most growers derive the majority of their income from processed ginger. A few growers supply the domestic fresh market, the organic produce market and the fresh product export market.

Ginger is a capital and labour-intensive industry. Maximum yields are obtained in well-drained friable coastal soils using high inputs of high quality water, fertiliser and organic matter. A high capital outlay is incurred in irrigation, specialised planting and harvesting equipment, and planting materials.

Two businesses operate processing facilities in south east Queensland, Buderim Ginger Ltd at Yandina and The Ginger People Pty Ltd at Caboolture. Ginger growers are represented by the Australian Ginger Growers Association.

Site selection and preparation

Soils must be well drained and free of rocks. Slopes should be less than 1 in 10 and north or north-easterly aspects are preferred. Good supplies of high quality water are essential. Wind protection is advisable in most areas. It is preferable to spell land for two years between crops for the control of nematodes. The use of organic additives is beneficial on sandy soils.

Cover crop

For a September planting, land preparation should begin in November - December of the previous year in order to grow and turn in a green manure crop before planting. Green manure crop examples include maize at 30 kg/ha for summer, rye or oats at 50 kg/ha for winter or forage sorghum at 30 kg/ha for a long term rotation. The winter cover crop should be turned in no later than early July to allow residues to break down.

Soil pH

In normal soils, the pH should be raised to 5.0-6.0. In high manganese soils, the pH should be 6.5-7.0 (see Table 1). Soil pH correction should be completed approximately six weeks before planting, using the rates below. Do not apply more than 2.0 t/ha in any one application (split applications if rates are higher than this and allow 6 months between applications) and be careful not to exceed pH 7. Manganese-induced iron deficiency is known to occur on poorly drained and acidic manganiferous soils. Correction is by improving drainage and increasing soil pH to between 6.5 to 7.0.

Table 1: A guide to lime application rates needed to adjust soil pH into the desired range (normal soil: 5.0 - 6.0; high manganese soil : 6.5 - 7.0)

Soil type	Original pH range	Sandy Soil (t/ha)	Loam (t/ha)	Clay Loam (t/ha)
Normal	4.5-5.0	2.5	3.75	5.0
High manganese	4.5-5.0	6.25	7.5	8.15
	5.0-5.5	3.75	5.0	6.25
	5.5-6.0	1.25	2.5	3.75
	6.0-6.5	0.75	1.5	2.75

Fumigation

Fumigation for nematode control using 1,3-dichloropropene (Telone) is usually a routine practice, but the soil may be tested for nematodes. The success of the fumigation will depend on soil preparation. The soil must be moist and worked to a fine tilth, and free of organic trash and residues from previous ginger crops.

Cultivation

Deep ripping should be used where necessary for drainage, and is recommended on heavy soils such as clay loams and all soils that are frequently cropped. To improve soil drainage, beds are formed approximately 150 mm high and 1800 mm wide. Contour drains may be installed at regular intervals to minimise soil erosion on sloping land. Pre-plant fertiliser may be applied either before or during bed forming.

Planting

Planting material

Success of the crop depends on careful selection of planting material. Material should be nematode and fusarium-free (throw out any suspect pieces). The ginger should be divided into seed pieces as soon as possible after it has been dug. Breaking of pieces is satisfactory, but cutting will give a more even size. Knives should be regularly dipped into methylated spirits or a commercial disinfectant solution, to stop any spread of disease. Clean planting material is very difficult to obtain, it is recommended that nurseries be established from tissue cultured plantlets to bulk up planting material and produce clean seed pieces. 

Seed should be planted as soon as possible after cutting. Store in a well ventilated, cool and shady position in clean or sterilised bags. Special care should be taken with the material to be used for the production of seed ginger. Seed used as mother-seed for planting material should also be hot water treated prior to chemical treatment (45° C for 20 minutes). Hot water treatment reduces yield by up to 20% and should therefore be restricted to the mother-seed. After treatment, use the seed within 2 days. Mother-seed areas should be mulched with sawdust (40 mm deep) to discourage nematodes. Where sawdust is not available, treat the area with a registered nematicide.

Planting

Planting occurs from late August through to mid October, with the optimum period mid to late August. Planting is a mechanised operation using modified potato planters. Four persons with one machine can plant about 0.1 hectares per hour. Fully automatic machines only need two operators. The final yield obtained depends mainly on the tonnage planted. For example in a 1.8 metre bed, if using 3 rows, plant 60 g pieces 110-150 mm apart but if using 4 rows, plant 40 g pieces 110-150 mm apart. Both examples require approximately 7-10 tonnes/ha. Plant seed pieces 50-70 mm deep.

Weed management

Apply a registered pre-emergent herbicide by boom immediately after planting. Irrigate in if no rain falls within a day or so. After crop emergence, spot spray with a contact herbicide. Avoid spray drift.

Fertiliser and irrigation

Fertiliser

Pre-plant and side dressing fertiliser applications should be guided by a soil analysis, particularly on new blocks. Most growers apply organic fertiliser such as poultry manure before planting. Once the field has germinated, additional fertiliser is applied as a solid side dressing or as soluble fertiliser in the irrigation. A general guide to fertiliser requirements is listed below:

Nitrogen: It is usually not necessary to include pre-plant nitrogen if organic manures have been incorporated, otherwise apply 60 kg urea/ha, more in areas where sawdust mulch has been used. Side dressings of nitrogen are generally applied through the irrigation system. Rates and timing of applications are related to the growth rate of the crop and this varies from year to year. Generally 500 kg/ha of Urea is required where organic additives have been used and 550 kg/ha where not. It is best to apply approximately 20% of the nitrogen between germination and late December. The remaining 80% is applied in 7-10 applications between early January to April. Where a sawdust mulch is used, more nitrogen may be required.

Phosphorous: Apply pre-plant superphosphate at 200 kg/ha on normal fertile soils and 500k/ha on virgin or infertile soils. Some soils may require up to 1 t/ha of superphosphate. Phosphorus is not required as a side dressing.

Potassium: Ginger is particularly susceptible to potassium deficiency. Apply 90 kg/ha of muriate of potash pre-plant on soils low in potassium or 40 kg/ha of muriate of potash pre-plant on soils with average potassium. Side-dressing potash requirements are based on soil levels established by soil tests or experience. While muriate of potash is safe for basal application, it is advisable to use sulphate of potash for the side dressing (see Table 2).

Table 2: Potassium side dressing requirements

Level of K in soil	Action
Low	apply 210 kg/ha sulphate of potash in mid November and repeat mid January
Medium	apply 105 kg/ha sulphate of potash in mid November and repeat mid January
High	apply 105 kg/ha sulphate of potash in mid November only

Zinc and copper are the two most common trace element deficiencies. They generally occur on sandy loams around Beerwah, Palmwoods, Woombye and occasionally on other soils. Correction is best achieved by pre-plant boom spraying of copper sulphate (18 kg/ha) and zinc sulphate heptahydrate (20 kg/ha).

Irrigation

Careful attention to irrigation is essential to prevent sunburn of newly developed shoots and to prevent water stress in the crop. Any wilting will reduce the final yield.

A low output solid set sprinkler system with an output of 3-4 mm per hour is required. Sunburn is likely to occur with young shoots when shade temperatures reach 32° C. These conditions are most likely to occur between 10am and 3pm. Commence irrigation when the temperature reaches 31° C and wet the top 2 cm or so of soil. Check moisture daily and watch carefully on still days or when dry NE winds are blowing. Where possible, align irrigation NE/SW. Even if a system is automatic regular daily checks may still be necessary.

Ginger requires high quality water for irrigation. Supplies with an electrical conductivity greater than 650 m S/cm require careful management and advice should be sought. Where the water supply is suspect, monthly testing of irrigation water is suggested. An example of a typical schedule for irrigation is shown below in Table 3.

Table 3: Irrigation plan

	Irrigation scheduling - amount and comments
July	Fallow or cover crop.
August	After planting irrigate to maintain soil moisture until emergence. Avoid overwatering before emergence as rots develop easily.
September
October
	During shoot emergence irrigation is used to cool the tender shoots and prevent sunburn (as well as for plant growth), small amounts of water, for example 2mm per hour, is applied during periods of sunny weather. Once shoots have unfurled and significant leaf cover has been established it is necessary to maintain soil moisture for growth apply 5mm every 10 days. However, during periods of very hot sunny weather  keep surface 2 cm of soil moist to help cool the plants and prevent sunburn.
November
December	For normal plant growth and evaporation, apply 5 mm every 2-3 days over a 6 week period. The amount and frequency will vary widely with soil type and weather conditions.
January
	Heavier applications are required for plant growth and evaporation. Apply 10-12 mm every 2-3 days (amount and frequency will vary as above). Avoid plant water stress.
February
March	Apply as required for the late harvest crop (mainly to stop wilting), approx 25 applications of 12-13 mm. Maintain sufficient moisture for growth and to prevent desiccation after tops die off.
April
May
June

Diseases and insect pests

Diseases

Bacterial wilt: A very serious disease that can spread very rapidly through an area, causing complete destruction. Two biotypes have been recorded; biotype III and biotype IV. Biotype III is of little significance, however biotype IV is responsible for very rapid wilting and spreads quickly, causing heavy losses. The plant wilts, and yellowing of the lower leaves spreads upwards, affecting the whole plant. Stems become water-soaked and readily break away from the rhizome at ground level and the plants eventually collapse. When an infected stem or rhizome is cut transversely, and a little pressure applied, a milky white exudate flows freely from the cut surface. Diseased rhizomes are much darker than healthy ones.

Only take planting material from areas known to be free of this disease. Infested areas should not be replanted with ginger, but planted with a perennial grass and fenced off to stop animals and people walking through and spreading the disease. All crop residues where the disease is known to occur should be destroyed, by burning if possible. Implements and boots should be washed down with a commercial agricultural disinfectant.

Fusarium rhizome rot: A very common and serious fungal disease which is specific to ginger. Infected plants are stunted and yellow, lower leaves dry out and turn brown. Eventually all above-ground shoots dry out completely. Plant collapse is very slow (up to several weeks) compared with the rapid collapse associated with bacterial wilt infection. Diseased rhizomes show a brown internal discolouration, are normally shrivelled in appearance and eventually decay leaving the outer shell intact with fiberous internal tissue remaining. Increased nematode infestations are usually associated with fusarium rhizome rot, accentuating yield losses. Fusarium is also responsible for serious loss of planting pieces and poor germination.

Only take planting material from areas known to be free from disease. When cutting up seed, discard any pieces showing shrivelling or brown discolouration and regularly dip the cutting knife in methylated sprits or a commercial disinfectant solution. As soon as possible after preparation, the seed pieces should be dipped for one minute in a benomyl solution. Avoid areas with heavy nematode infestations. Crop rotation of at least 2-5 years between ginger crops will help reduce Fusarium in the soil.

White fungus: This disease has caused serious losses on some farms. Infection first occurs beneath the scales on the rhizomes and may progress to produce a deep brown rot over the entire surface. Affected rhizomes become enveloped in a white fungal mycelial growth which may extend up to the basal stem. Mild infections usually produce no above ground symptoms. Severe infections cause the stems to turn yellow and slowly dry out.

Prepare the ground well in advance of the ginger crop as this fungus will persist on crop residues. The most serious outbreaks of this disease have been encountered in areas previously cropped with sugarcane where a large amount of undecomposed cane trash remained in the soil.

Bacterial soft rot (Erwinia sp.): Normally only a storage rot. The bacteria are present in most soils but field infection usually only occurs in waterlogged areas. Erwinia sp. has caused severe losses of stored rhizomes on some farms, but is not considered a serious storage problem where precautions are taken. Softening of the tissue is accompanied by production of a strong odour and the rhizome eventually collapses completely. Bacterial soft rot differs from other rhizome rots in that this putrid odour is produced.

Make sure the area is well drained. When harvesting ginger for seed purposes, don't commence harvesting until tops have died down naturally, as the stalk scar is an ideal point for infection to occur. Only harvest when it is dry and store in new bags or clean bins in a dry and well-ventilated shed.

Pythium: A fungal disease which is normally only a storage rot. It produces a white fluffy growth on the broken rhizome surface and will penetrate and produce a light brown discolouration internally. The rhizome will remain relatively firm with some shrivelling but not as much as with Fusarium rhizome rot.

Make sure the area is well drained. When harvesting ginger for seed purposes, don't commence until tops have died down naturally, as the stalk scar is an ideal point for infection to occur. Only harvest when rhizomes are dry and store in new bags in a dry and well-ventilated shed.

Armillaria: Caused by the commonly called shoe string (boot-lace) fungus. A common parasite of forest trees, it normally only occurs in recently cleared forest country and causes a yellowing of the stem very similar to Fusarium symptoms. When infected plants are examined, black string like threads can be seen adhering to the rhizomes. All roots and stumps should be removed before planting newly cleared land to prevent infection.

Big bud (bunchy top): The mycoplasma-like organism which causes this disease also causes big bud on a wide range of plants and is similar in characteristics to a virus. The disease is spread by leafhoppers. All diseased plants should be detected and rogued out.

Root-knot nematodes: Heavily infested plants are stunted, have chlorotic leaves with marginal necrosis and swollen, distorted roots. Infested rhizomes have wart-like growths on the surface. Heavy nematode infection will greatly reduce yields. Select planting material as free from nematodes as possible. Take soil samples to determine nematode infestations prior to planting. Fumigate with a registered nematicide pre-plant if required.

For production of nematode-free planting material, seed pieces should be placed in hot water (48° C) for 20 minutes, and then cooled prior to dipping in fungicide. The treated seed pieces should be planted within 2-3 weeks of treatment. Grow the crop under sawdust mulch, preferably 80-90 mm deep. If sawdust is not available, sprinkle granules of a registered nematicide over the soil between plants in mid November and mid January.

Insect pests

The major pests of ginger are cutworm and heliothis after planting, and African black beetle during early growth.

Cutworm: The primary shoot is eaten just below or just above ground level. The first leaf may also be eaten. Feeding is done at night and larvae can be found in the ground at the base of the shoot during the day. Larvae grow up to 40 mm long, are grey, brown or pink and curl up when disturbed. Spray when first damage is evident. Spraying in the late afternoon will give better control.

Heliothis: Young shoots are eaten off at ground level. The caterpillar grows up to 40 mm long and varies in colour from pinkish-brown to light green, with a variable number of dark markings and longitudinal stripes along the body. Control with a registered insecticide.

African black beetle: Ginger stems are gnawed approximately 5 cm below ground level, causing plant collapse. Adult beetles are dark brown to black and approximately 12 mm long. Spray when first damage is evident. Spraying in the late afternoon will give better control. Insecticide should be applied with sufficient water to wet the soil down to 5 cm.

Symphilids: these feed on the root tips, stimulating the production of many short branching roots, the characteristic "witches broom" effect. This root damage can affect growth and yield.

Harvesting and marketing

Table 4: Yield expected

Harvest	Time of harvest*	Yield t/ha***
Early	Late feb - early March**	12-50 (average 30)
Early-late	April	20-50 (average 35)
Late - late	Mid June - Early Aug	38-75 (average 45)
Seed (must be approved)	August

* dependent on region.
** Regular plant samples required to establish correct time of harvest for early ginger. Contact factory for more details.
***Yields quoted are for costal areas. Crops grown in elevated regions have lower yields as temperatures are lower.

At early harvest, tips are still green and firmly attached to the rhizomes. Mechanical harvesters are available for pruning and removing most of the top. Hand labour is still required to clean ginger of excess soil, roots and stems. In smaller areas stools are pulled by hand and tops snapped off. Surplus soil and roots are removed before rhizomes are placed in bulk bins.

Methods vary for late harvest, but most growers use adapted potato diggers to lift rhizomes. These lift a bed of rows at once. Rhizomes are then picked up by hand and, after surplus soil and roots are removed, the ginger is bulk handled to the factory. Weight loss is minimised during harvesting by quick handling and by covering the bins or storing in the shade.

Grade standards: early harvest is not to fall below 35% choice (fibre free) grade - usually harvesting starts around 45% choice grade. Early harvest product must be free of rhizome roots, rots and nematodes. Late harvest product must be free of rhizome roots and rots.

Figure 3. Selecting premium grade ginger

Figure 4. Selected cut of fibre-free ginger

Packaging is mostly in bulk bins to the factory. Growers are paid on quality and quantity. A hiring charge is paid on the bins. Green ginger (fresh market) is packed in 18 L cartons.

Further information

Australian Ginger Growers Association: phone 07 5447 8469

Buderim Ginger Ltd: phone 07 5447 8469

The Ginger People Pty Ltd: phone 07 5495 2045

For commercial enquiries on ginger, contact the DPI&F on telephone 13 25 23 between 8 a.m. and 6 p.m. weekdays; non-Queensland residents phone (07) 3404 6999. E-mail: callweb@dpi.qld.gov.au

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Information contained in this publication is provided as general advice only. For application to specific circumstances, professional advice should be sought. The Department of Primary Industries and Fisheries Queensland has taken all reasonable steps to ensure the information in this publication is accurate at the time of publication. Readers should ensure that they make appropriate inquiries to determine whether new information is available on the particular subject matter.

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Last updated 7 September 2007