Capsicum (peppers) and chillies
Note Number: AG0467
Published: August 1997
Updated: May 2013
Capsicums (Capsicum annum L.) and chillies (Capsicum frutescens L) originate from South and Central America, they can also be known as peppers. They belong to the family Solanacea along with tomatoes, eggplants and potatoes. Plants are bushy and grow up to 60-80 cm tall. They are semi-perennials but usually grown as annuals in cultivation.
Fruits are rich in Vitamins (A, C & E), folic acid and potassium and low in sodium and calories.
Commercially available varieties produce fruits of varying colours, shapes and pungency*. Pungency or the sensation of heat is caused by a chemical called capsaicin. Most of the capsaicin is in and around the seed baring part of the plant.
Capsicums can be used in several ways. Sweet peppers may be used fresh in salads, as a stuffed, seasoned vegetable or in stews. Hot (pungent) chillies and red peppers when ground into a fine powder are also used to flavour sauces and various meat dishes.
These are the most commonly grown types of capsicum with a large number of varieties and colours available. The main type is bell or block shaped with four lobes. Some of the varieties grown include Tycoon, Santino Bianca, Jaffa, Raptor, Expresso, Predator, Bellbuster, General, Olympicbuster, and Legend. There are a large number of varieties available and more comprehensive lists can be obtained from seed companies.
There are also tapered types of sweet capsicum varieties available including Banana supreme and Supper sweet banana although these are not grown commercially in significant quantities in Victoria.
There are many varieties available including Chainfair, Hot dipper, and Long maxican and Long zippy with a wide range of pungency. Seed companies will provide a list of varieties and their pungency levels.
A long frost-free growing season with high temperatures is desirable. Ideal mean daytime temperatures for growth are 20-25°C and nights below 20°C. Temperatures over 32°C interfere with fruit set and colour development. Adequate water is essential for the crop. Capsicums are sensitive to cold and growth is significantly reduced below 10°C. If the capsicums are to be grown out of season they will need the protection of a polyhouse or glasshouse, preferably heated.
Capsicums are generally planted as seedlings and are planted out when the risk of frosts has passed. Seedlings may be obtained from commercial nurseries or growers can produce their own. Growers should buy seedlings from reputable nurseries to obtain plants that are well grown and free from diseases.
Seedlings for spring plantings in Victoria can be produced by sowing under glass or in polyhouses during winter. Seedlings are most commonly grown as speedlings ® in cell trays.
Capsicums grow best on deep (minimum of 30 cm) loamy and well-drained soils. Soil pH should be in the range of 5.5 – 7.0. They can develop strong deep tap roots (> 1m).
Drainage is important and depending on soil type raised beds may be necessary.
Soils can be prepared in autumn by deep ploughing followed by regular cultivations to keep soils free of weeds and clods. Capsicums are also often grown using plastic mulch together with trickle irrigation. This practice helps in weed control and increases soil temperatures.
Grow windbreak plants in rows where there is a danger of wind damage. Rows of ryecorn and sweetcorn preferably planted at right-angles to prevailing winds will give good protection.
For early plantings of capsicums, plant ryecorn in June so that it will grow tall enough to protect the seedlings when they are planted out.
Animal manure applied before planting will benefit crops grown in the sandy Mallee soils. Apply 30 m 3 of fowl manure or 50 m 3 of compost per hectare at least four weeks before planting.
Apply a base dressing of NPK 6:6:6 or 5:8:4 at the rate of 500 kg per hectare. If using only artificial fertiliser, apply it at the rate of 700 to 800 kg per hectare. Side-dress during the growing season with NPK 20:0:16 at the rate of 225 kg per hectare. If plants are grown using trickle irrigation, fertiliser can be applied through the trickle lines (fertigation).
Farmers should be aware of the potential dangers of using phosphatic fertilisers with high levels of cadmium.
If cadmium in a fertiliser is in excess of 1 mg/kg the label or advice note must contain the statement:
"WARNING––this product contains cadmium. Continued use of this product in agricultural situations may lead to residue levels in plant and animal products in excess of the maximum level specified by the Australia New Zealand Food Standards Code and the accumulation of cadmium in soils."
We are concerned about long-term accumulation of heavy metals in soils and believe that accurate product information assists primary producers to maintain sustainable agricultural practices. Low concentrations of heavy metals generally occur naturally in soils, however, these concentrations occasionally increase due to exposure to industrial sources or contaminants in fertilisers. Compliance of fertiliser products to regulated standards supports sustainable agricultural systems and helps to reduce the potential for accumulation of heavy metals in soils and plants.
Growers should consult fertiliser suppliers or manufacturers for advice on the cadmium levels of fertilisers they are considered using.
The seedlings may be planted out in the open once the risk of frost has passed. Crops planted too early will grow poorly until the weather and soil warms up and run the risk of being damaged or killed by late frosts. Growing in plastic covered beds will increase the soil temperature and plants can therefore be panted out earlier. Plant the seedlings in rows 75cm to 1 m apart and about 30 to 50cm apart in the row (about 30 000 plants per hectare). Close densities give smaller fruit.
The availability of herbicides for use on capsicum crops is limited.
For the registration status of these products, please refer to Australian Pesticides and Veterinary Medicines Authority, your chemical reseller or your local chemical standards officer. Ensure you meet the relevant Maximum Residue Limits (MRLs) for the chemical in the end market, be it domestic or export.
Chemical users must ensure they read and understand all sections of the chemical label prior to use.
Depending on the range of weeds, hand hoeing may be essential. Plastic mulch will help reduce the need for weed control. Appropriate disposal of plastic will have to be considered as part of post crop management.
Trickle or drip irrigation is increasingly popular and is very effective in maintaining even soil moisture. The incidence of blossom-end rot (a calcium deficiency that looks like a sunken, dry, black rot at the base of the fruit) can be reduced by maintaining uniform soil moisture. This is most important when the weather is hot. Water stress can also cause flowers and small fruit to drop off the plant, greatly reducing yield. Trickle irrigation which helps to reduce leaf wetness is beneficial in controlling some diseases such as bacterial spot.
Pest and diseases
Perhaps the most likely disease problems for capsicum are viruses. Particularly Tomato Spotted Wilt Virus (TSWV) which leaves the fruit with an uneven ripening colour, rings, spots and possibly distortion. There is no treatment for virus infection and prevention of infection is the best control. Keep areas around the crop free from weeds (which may be host to virus) and control insects (which spread disease) if numbers build up. Capsicums can be infected with Tobacco Mosaic Virus (TMV) so it is important that anyone who has been smoking washes their hands before coming into contact with the particularly before picking.
Insects may attack leaves, stems and fruit. Minor feeding damage when fruit is small can grow into large scars as the fruit grows and may mean it is unmarketable.
Nematodes may also cause problems to roots which will show up above ground as wilting and stunting and below ground as reduced root systems and roots with nodules.The APVMA maintains a database of all chemicals registered for the control of pests (including weeds) in Australia . Refer to the APVMA (www.apvma.gov.au) or your chemical reseller for chemicals registered for the control of pests. Ensure you meet the relevant Maximum Residue Limits (MRLs) for the chemical in the end market, be it domestic or export.
Chemical users must ensure they read and understand all sections of the chemical label prior to use.
Harvesting and marketing
The stage of maturity at which capsicums are picked depends on the purpose for which they are grown. For market, the large sweet capsicums are usually picked at the green or coloured (usually red) mature fruit stage. Capsicums for processing or drying are often allowed to mature to their full colour.
When harvesting capsicums, care should be taken not to injure the plants, as the stems are brittle and will snap off very easily. A picking knife may help in removing fruit safely.
Capsicums usually begin flowering 1-2 months after planting and will take up to around 110 days from planting to first harvest which then continue until cold weather reduces yield or frost stops growth. An average yield is around 18 tonnes per hectare.
Capsicums are usually packed in 6 kg and 12 kg cartons or the standard black supermarket crates if being sent directly to the supermarkets.
Ideal post harvest treatment includes washing (with water treated with iodine, chlorine, etc) and cooling to 10°C. Storage should be at between 7-13°C and 90-95% humidity. Capsicums are sensitive to chilling injury and ethylene. Shelf life deterioration is often because of moisture loss.
What's a Scoville Heat Unit?
A measure to test the pungency levels of chillies was developed by Wilbur Scoville in 1912. Heat units are actually determined by how many parts of sugar-water it takes to dilute a sample so that the heat of a chilli can no longer be detected. The chilli sample is provided in the form of an extract. The original tests were performed by a large panel of human testers who would taste each sample with increasing pungency levels. Currently it's done in laboratories with High Performance Liquid Chromatography (HPLC) testing.
The generally accepted ratings of Scoville Heat Units are:
For information relating to the safe and appropriate use of chemicals, including management of chemical residues and licensing requirements, contact us and ask to speak to your local chemical standards officer or visit our Chemical use page.
This Agnote was developed by Rob Dimsey, Farm Services Victoria, in August 1997.
It was reviewed by Rob Dimsey and Neville Fernando, Farm Services Victoria, in November 2009.
Published and Authorised by:
Department of Environment and Primary Industries
1 Spring Street
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The advice provided in this publication is intended as a source of information only. Always read the label before using any of the products mentioned. The State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication