Pest and Disease Management

Want to regain control over chemical-resistant pests? Aiming to reduce costs while meeting quality assurance requirements? The Soil Wealth ICP extension team has updated a fact sheet to help growers manage Mega Pests.

Rhizoctonia Solani is a fungal pathogen comprised of many species and strains that can cause diseases in vegetable crops such as damping off, root and stem rots, and sometimes leaf blighting or leaf spots.

A series of resources are now available on area wide management (AWM) of vegetable diseases.

AWM strategies for vector-borne diseases help to prevent or minimise the development of insecticide resistance in vector populations, improve the efficiency of biological agents released for control of vectors, and better protect host resistance genes against the emergence of resistance-breaking strains of the viruses.

Blackleg on potato can be caused by either Pectobacterium or Dickeya species, and they often work together in different combinations to cause this disease. Blackleg can result in stem decay, severe seed decay and sometimes lack of plant emergence in severe cases.

This fact sheet provides information on managing blackleg in potato crops, the bacteria which commonly cause the disease and what you can do to prevent and manage it.

This fact sheet provides guidance on the importance of monitoring soilborne diseases, pathogens that can be tested, method for pathogen testing and tips for understanding and managing soilborne disease risks.

A new guide is available on the management of powdery scab in potatoes, highlighting key factors that affect the risks of this disease and opportunities for effective disease management.

Pink rot of potato is an important soil-borne storage disease of potatoes worldwide. It is caused by the fungus Phytophthora erythroseptica and sometimes by P. cryptogea. Pink rot infection is often associated with secondary infection by anaerobic soft rot bacteria.

This fact sheet outlines the symptoms, hosts, risk factors and disease cycle of pink rot, as well as potential management options.

Vegetable crop diseases are often caused by fungi. Examples of foliar diseases caused by fungi include: downy mildew, powdery mildew and white blister. Examples of soilborne fungal diseases include: clubroot and diseases cause by Pythium, Fusarium, Rhizoctonia, Sclerotinia and Sclerotium species.

Fungicide resistance occurs when a fungicide or active-ingredient that was once effective, becomes no longer effective. It can occur when reduced rates of fungicides are used or when fungicides are over-used.

Read this fact sheet to find out more about detection and effective management.

Recent surveys of Tasmanian ryegrass (Lolium spp.) populations have shown a significant increase in Group A herbicide resistance. John Broster (Charles Sturt University) found an increase in resistance from 18% in 2010 to 46% in 2015 to diclofop-methyl ‘Fop’ and sethoxydim ‘Dim’ herbicides.

The selection of resistant weeds can occur in just 3-4 years if herbicide groups (Modes of Action) are not rotated. Read this fact sheet for an overview of herbicide resistance and what you can do to avoid and minimise the risk of resistance developing.

Beet cyst nematode (Heterodera schachtii) can cause considerable yield loss to brassicas, beets, rhubarb and spinach. The nematode severely damages root systems, especially during the summer months. Beet cyst nematode also infects many common weeds such as wild turnip, shepherd’s purse, fat- hen and portulaca, where it can survive and infect the next vegetable crop planted.

Read this fact sheet to find out more about control of beet cyst nematode, as well as key symptoms and life cycle.

Clubroot is one of the most destructive diseases of brassicas globally. Although it was detected in Australia as early as the 1890s, Plasmodiophora brassicae, the pathogen that produces clubroot, caused widespread loss during the 1980s and 1990s due to increasing brassica production and use of transplants.

Read this fact sheet to find out more about why clubroot is a problem, what to do about it, costs, as well as future directions for research.

Since 2016 there have been numerous customer complaints about redback spiders (Latrodectus hasselti) in broccoli. Complaints have mainly come between January and June, and from customers in all Australian states. This suggests that this is not an issue for a single production area, but can occur anywhere that broccoli is grown.

Redback spiders are clearly unacceptable to consumers, and also pose risks to growers, pickers and packers.

Despite their fearsome reputation, redback spiders are generally timid. They are nocturnal, travel only short distances and need protection from wind, rain and extremes of temperatures. Broccoli crops are not their usual habitat.

This fact sheet summarises what we know about the risk of redback spiders contaminating broccoli.

Fusarium is a genus of common soilborne fungi. Most live as saprophytes on decaying plant matter while a few are also important plant pathogens.

While there are many different pathogenic Fusarium species, some of the most damaging diseases are caused by strains of one species complex, Fusarium oxysporum. They cause vascular wilt diseases by entering the roots and colonising the water-conducting tissue (xylem). This causes older leaves to yellow and plants eventually wilt and die.

For more information read this practical fact sheet on fusarium wilt diseases, factors that favour fusarium diseases, and management strategies.

Clubroot is one of the most potentially devastating soil borne diseases affecting brassica vegetables (e.g. cabbages, cauliflower, broccoli, kale and Brussels sprouts) in Australia. Once plants are infected there are no effective control measures.

Read this fact sheet to find out more about identifying clubroot, clubroot management strategies including integrated approaches, as well as evaluating clubroot risk.

Sclerotinia rot, also known as white mould, is one of the major diseases of green beans in Australia. Sclerotinia rot can cause significant yield losses during the cropping season as well as post-harvest damage.

Read this fact sheet to discover more about identyfing slerotinia, management options, important irrigation timings and further reading.

Sclerotinia rot is also known as white mould, cottony rot, drop of lettuce and nesting of beans after harvest.

Sclerotinia rot can also cause significant yield losses during cropping and as a post-harvest disease.

This factsheet outlines the disease life cycle and managment options.

Spinach crown mites live in the topsoil; they thrive in a cool, moist environment. They feed mainly on partly decomposed organic material and on fungi living off decomposing material. They also feed on young spinach leaves which are close to the soils surface. Leaves become distorted which reduces the marketability of the crop.

The national distribution and identity of the mites in Australian spinach crops has not been confirmed. Effective, product based control methods are currently limited.

Read this fact sheet to find out more about identification, life cycle and available control measures.

Biopesticides are a diverse group of pest control products based on naturally occurring biochemicals, minerals and microbes. They generally have very low toxicity to humans and are sustainable with minimal environmental impacts. Many can be used in organic production.

Biopesticides often require a good understanding of pests and diseases to be used effectively. They help to manage, rather than completely control pests. Biopesticides are therefore best used in an integrated approach rather than as simple replacements for conventional pesticides.

Read this fact sheet to find out more about plant extracts, microbial pesticides, natural chemicals/minerals and biochemicals, including their availability, application, developments, challenges, advantages and disadvantages.

Issues with damping off in spinach? This useful fact sheet provides an overview of the symptoms and conditions that favour different pathogens causing damping off such as Pythium spp, Phytophthora spp, Fusarium spp and Rhizoctonia spp. Knowing the causal pathogen can aid selection of effective management and control strategies.

There's also handy information on how the fungi spread, susceptibility and severity, diagnosis, and how to manage damping off, including practices to keep in your 'toolbox'.

Two Pythium species are mostly responsible for forking and cavity spot of carrots in Australia. In most cases, P. sulcatum cause the symptoms.

While some general rules apply, especially the need for managing soil moisture, pH, soil calcium and crop maturity; carrot producers should find their own optimum combination of additional management strategies that fit their production systems and growing conditions.

Read this useful fact sheet to find out more about what causes cavity spot and forking in carrots, as well factors affecting cavity spot development and management approaches.

Adjuvants are additives that enhance or modify the action of a chemical. They are commonly classified into broad categories including oils, surfactants, buffers, acidifiers and fertiliser adjuvants. Adjuvants can modify how a chemical forms, spreads or behaves within the spray solution and/or on the target pest.

This fact sheet provides insights into how adjuvants work, what types are available, and recommendations on what one to choose to make sure it's compatible with your pesticides active ingredients.

Onion Maggot (Delia platura), also known as seed corn maggot, is an agricultural pest that damages seeds and seedlings in a wide range of crops including corn, beans, onions, garlic, brassicas, potatoes and spinach.

Reports of damage by this pest are usually following cool wet spring conditions. This fact sheet provides practical advice on the damage caused by Onion Maggot, its life cycle, and the cultural, biological and chemical control options. There are also some tips for great further reading if you want to know more.

Brassica whitefly (Aleyrodes proletella) is a pest of crops in the brassica family. This insect is not restricted to brassicas, although it prefers them. Its host range includes cabbages, cauliflowers, broccoli, kale and Asian vegetables, especially wombok (Chinese cabbage).

In NSW, the brassica whitefly has only become a pest of significance in the last 2-3 seasons but were first reported in Australia in 1997 in South Australia.

This fact sheet provides you with important information on damage, ecology, and management options including monitoring, cultural practices, biological control and chemical control.

This easy to read fact sheet provides information on control options (both chemical and non-chemical) for high priority pests in capsicums and chillies. This fact sheet is the last in a series of seven publications that provide details on the currently registered and permitted pesticides for key diseases, insects and weeds in your crop.

This easy to read fact sheet provides information on control options (both chemical and non-chemical) for high priority pests in lettuce. This fact sheet is the sixth in a series of seven publications that provide details on the currently registered and permitted pesticides for key diseases, insects and weeds in your crop.

This easy to read fact sheet provides information on control options (both chemical and non-chemical) for high priority pests in cucumbers. This fact sheet is the fifth in a series of seven publications that provide details on the currently registered and permitted pesticides for key diseases, insects and weeds in your crop.

This easy to read fact sheet provides information on control options (both chemical and non-chemical) for high priority pests in celery. This fact sheet is the fourth in a series of seven publications that provide details on the currently registered and permitted pesticides for key diseases, insects and weeds in your crop.

This easy to read fact sheet provides information on control options (both chemical and non-chemical) for high priority pests in carrots. This fact sheet is the third in a series of seven publications that provide details on the currently registered and permitted pesticides for key diseases, insects and weeds in your crop.

This easy to read fact sheet provides information on control options (both chemical and non-chemical) for high priority pests in brassica vegetable crops. This fact sheet is the second in a series of seven publications that provide details on the currently registered and permitted pesticides for key diseases, insects and weeds in your crop.

This easy to read fact sheet provides information on control options (both chemical and non-chemical) for high priority pests in brassica leafy vegetable crops. This fact sheet is the first in a series of seven publications that provide details on the currently registered and permitted pesticides for key diseases, insects and weeds in your crop.

Anthracnose is a foliage disease of lettuce that causes significant crop losses in iceberg, cos and babyleaf lettuce. It is an intermittent disease in Australia, driven mainly by extended periods of wet weather, particularly in mild-cool wet periods, during which crop losses can be severe. This fact sheet outlines control options available to Australian lettuce growers to control anthracnose.

This Agnote developed by the Northern Territory Government describes the technique of grafting snake beans to control Fusarium wilt.

In the higher rainfall zones, slugs in vegetable production systems can be a problem. As no single control method will provide complete protection, an integrated approach is best. Read this useful fact sheet to find out more, and learn from what other industries are doing.

This vegenote provides useful information on how to identify white blister and options for managing the disease.

Tobamoviruses—tobacco mosaic virus (TMV), tomato mosaic virus (ToMV) and pepper mild mottle virus (PMMV) — are stable and highly infectious viruses that are very easily spread from plant to plant by contact. These viruses can survive for long periods in crop debris and on contaminated equipment. Although these viruses affect field crops, they are more often a problem in greenhouse crops where plants are generally grown at a higher density and handled more frequently.

The majority of viruses infecting plants are spread by insects, and aphids are the most common group of virus vectors or carriers. All potyviruses (the largest group of plant viruses) are transmitted by aphids.

Aphids are sap-sucking insects and have piercing, sucking mouthparts. Their mouthparts include a needle-like stylet that allows the aphid to access and feed on the contents of plant cells. During feeding, aphids simultaneously ingest sap contents and inject saliva, which can contain viruses if the aphid has previously fed on an infected plant.

The structure of aphid mouthparts, their searching behaviour for host plants, the range of available host plants and high reproductive rates contribute to the efficiency of aphids to act as virus carriers.

Insects are potential contaminants of processed leafy vegetables. Pest and beneficial species, in both the juvenile and adult stages of their life cycles can become unwanted contaminants if they make their way from the field into the final packaged product and to the end consumer.

Spraying not working? Have a look at this helpful fact sheet to improve your pesticide resistance management.

The popularity of Asian vegetables has increased in recent years amongst consumers with a range of uses, including salad and baby leaf mixes. With increased demand has come the need to manage losses caused by pests and disease. Critical to the successful management of pest and diseases in any vegetable crop, is an understanding of the main pests and diseases known to affect each crop

Cucurbits include watermelons, cantaloupes, cucumbers, zucchini, pumpkins, squash, bitter melons, gourds, and hairy melons.

Sole reliance on fumigants like Metham Sodium often changes soil conditions and reduces inherent disease suppressive soil properties, reinforcing continued reliance on fumigation to deal with soilborne diseases, pests and weeds.

Powdery mildew has been found on a carrot crops in three states of Australia. The first finding of the disease was in the Murrumbidgee Irrigation Area (MIA) of New South Wales in 2007. It has subsequently been found in Tasmania and South Australia in 2008. While the organism causing the disease is commonly found in parsnip crops, powdery mildew has not previously been recorded on carrots in Australia.

Four page fact sheet on managing diseases of carrots.

This fact sheet contains information on the identification and management of thrips in green beans.

New management strategies for lettuce drop and white mould of beans.

This technical reference note has been produced by Denis Persley and Cherie Gambley (DEEDI) as part of Horticulture Australia Limited project VGO 7128-Integrated management of virus diseases in vegetables.

Helpful four page fact sheet on integrating pest management in lettuce.

This helpful fact sheet outlines the key information required to get the best out of your chemical application.

Want to regain control over chemical-resistant pests? Aiming to reduce costs while meeting quality assurance requirements? The Integrated Crop Protection (ICP) extension team has developed a series of five fact sheets to assist growers manage Mega Pests.

Want to regain control over chemical-resistant pests? Aiming to reduce costs while meeting quality assurance requirements? The Integrated Crop Protection (ICP) extension team has developed a series of five fact sheets to assist growers manage Mega Pests.

Want to regain control over chemical-resistant pests? Aiming to reduce costs while meeting quality assurance requirements? The Integrated Crop Protection (ICP) extension team has developed a series of five fact sheets to assist growers manage Mega Pests.

Want to regain control over chemical-resistant pests? Aiming to reduce costs while meeting quality assurance requirements? The Integrated Crop Protection (ICP) extension team has developed a series of five fact sheets to assist growers manage Mega Pests.

The key messages of this fact sheet are:
- Plant resistant varieties.
- Irrigate crops in the morning to reduce leaf wetness and infection.
- Manage nutrients as they impact on disease.
- Use disease forecasting models when cropping susceptible varieties.

Viruses are a major cause of loss in many Australian vegetable crops. Often the intricate relationships between the virus, host plants and the vector, or carrier, create problems in developing effective management systems. This reference note provides information on plant viruses and how they are transmitted, and lists viruses of importance to the Australian vegetable industry.