Tunnnelling in corm
Tunnelling in corm
Roots on soil surface
Roots on soil surface
Water-logging
Cause: Soil erosion or too much water in the soil from rainfall or irrigation.
Solution: Avoid planting in wet areas and heavy soils. Install and maintain a drainage system for your plantation.
Roots discoloured internally
Roots discoloured internally
Burrowing nematode, other nematodes
Cause: Burrowing nematode Radopholus similis feeding on the cells in the root cortex. Many species of nematodes in the soil also parasitise the roots of bananas.
Solution: Nematodes other than burrowing nematode are not usually a problem in the tropics. Check a random sample of roots over the whole field to determine the extent of the problem and if a nematicide treatment is necessary.
Damaged roots or no root hairs
Damaged roots or no root hairs
Fertiliser burn, drought or water-logging, poor drainage, air burn, soil compaction.
Cause: There are several causes of root tip burn. They include fertiliser burn from too much fertiliser or poor placement; aluminium or manganese toxicity caused by low soil pH; and soil drying out or staying too wet for too long. As well as these causes, air burn or soil compaction can cause root hairs to be lost.
Solution: Determine the cause with soil and tissue analyses. Broadcast fertiliser evenly and at recommended rates. Watering heavily to leach salts out of the root zone can alleviate problems of excess fertiliser. Maintain soil pH between 5 and 6 and avoid planting in areas with poorly drained soils.
Greyback cane beetle
Cause: Chewing by larvae (cane grubs) of Dermolepida albohirtum.
Solution: Correct timing of insecticide application is crucial. The chemical must be applied when larvae are close to the surface between November and January.
Root-knot nematode
Cause: Meloidogyne spp. Root-knot nematode invades the root when young. When mature the females form special feeding cells that appear as galls within the roots.
Solution: Root-knot nematode is not usually an economic problem to banana production in the tropics. Most mature banana plants with adequate irrigation and fertilising can compensate for any damage. Root-knot nematode may become a problem in very young plants, or on very sandy soils.
Leaves bunching at top of plant
Leaves bunching at top of plant
Choking of leaves
Cause: Choking can be due to a genetic abnormality related to a particular variety or off-type, or from stresses (water-logging, cold, water or nutrient shortage, 2,4-D, banana streak virus and bunchy top). These causes limit the normal elongation of the true stem so that the leaves appear ‘bunched up’.
Solution: Choose varieties less prone to choking and cull tissue-cultured off-types showing these symptoms. Check for diagnostic virus indicators. Improve management to limit stresses on plant.
Green leaves dropping
Green leaves dropping
Panama disease (Fusarium wilt)
Biosecurity Alert
Cause: The fungus Fusarium oxysporum f. sp. cubense which is a soil-borne organism. It is spread in water, soil and planting material. It enters the plant through the roots, and blocks the conducting tissue within the plant resulting in wilting, yellowing of leaves, splitting of pseudostem and death of the plant.
Solution: There is no cure for affected plants. Use only approved planting material and do not plant in previously infested areas.
Biosecurity obligation: Panama is a notifiable disease and you must report any suspicious plants. If you suspect Panama disease you must notify Biosecurity Queensland immediately (13 25 23).
More info:
Bacterial corm rot
Cause: The bacteria Pectobacterium spp (formerly known as Erwinia spp.) are widespread in most soils. Plants that are stressed from heat or lack of water during the dry season can succumb to bacterial invasion during the early part of the wet season.
Solution: No chemical treatments are available. Ensure adequate moisture levels are maintained during the dry season and provide good drainage during prolonged wet seasons.
Water stress
Cause: Mild water stress during periods of high evaporation.
Solution: Apply more water during periods of high demand.
Internal stem discolouration
Internal stem discolouration
Panama disease (Fusarium wilt)
Biosecurity Alert
Cause: The fungus Fusarium oxysporum f. sp. cubense which is a soil-borne organism. It is spread in water, soil and planting material. It enters the plant through the roots, and blocks the conducting tissue within the plant resulting in wilting, yellowing of leaves, splitting of the pseudostem and death of the plant.
Solution: There is no cure for affected plants. Use only approved planting material and do not plant in previously infested areas.
Biosecurity obligation: Panama is a notifiable disease and you must report any suspicious plants. If you suspect Panama disease you must notify Biosecurity Queensland immediately (13 25 23).
More info:
Moko disease
Biosecurity Alert
Cause: The bacteria Ralstonia solancearum race 2. Moko is a soil-borne disease and is spread with soil, in water, on implements, in planting material and by insects from flower to flower. The infection enters the plant through the roots and spreads through the host, blocking conducting tissue and resulting in plant yellowing, wilting and death.
Solution: There is no chemical control for Moko. All plants plus an adequate buffer zone around the diseased plants must be destroyed. The area must be quarantined and only non-host plants grown.
Biosecurity obligation: If you suspect Moko disease you must notify Biosecurity Queensland immediately (13 25 23).
More info:
Stem shatters
Stem shatters
Panama disease (Fusarium wilt)
Biosecurity Alert
Cause: The fungus Fusarium oxysporum f. sp. cubense which is a soil-borne organism. It is spread in water, soil and planting material. It enters the plant through the roots, and blocks the conducting tissue within the plant resulting in wilting, yellowing of leaves and death of the plant.
Solution: There is no cure for affected plants. Use only approved planting material and do not plant in previously infested areas.
Biosecurity obligation: Panama is a notifiable disease and you must report any suspicious plants. If you suspect Panama disease you must notify Biosecurity Queensland immediately (13 25 23).
More info:
2,4-D damage
Cause: Injection of 2,4-D will kill the plant. Overspray or drift from herbicide application may cause lesser symptoms.
Solution: Be extremely careful with chemical applications.
Tissue-cultured off-type
Cause: A genetic abnormality that occurs in tissue-cultured plants.
Solution: Remove affected plants and set additional following suckers on nearby plants.
Banana streak virus
Cause: The banana streak virus (BSV). Symptom expression is sporadic. Symptoms of cucumber mosaic are similar.
Solution: Do not take planting material from infected plants. Eradicate infected plants where symptoms are observed. Confirm diagnosis by looking for yellow black streaks or flashes on leaves or by laboratory tests.
Frost
Cause: Frost during the growing season.
Solution: No cure for damaged plants. Slightly damaged plants may grow out of it.
Small and stunted plants
Small and stunted plants
Tissue-cultured off-type
Cause: A genetic abnormality occurring in tissue-cultured plants.
Solution: Remove affected plants and set additional following suckers on nearby plants.
Burrowing nematode
Cause: Severe root damage caused by burrowing nematode affects the plant’s ability to take up water and nutrients from the soil.
Solution: Check a random sample of roots from the whole field to determine if nematodes are the problem and if a nematicide treatment is necessary.
Banana weevil borer
Cause: Tunnelling by larvae of Cosmopolites sordidus in the corm. Sever infestation reduces plant vigour.
Solution: Use stem baits (traps) to establish the severity of the infestation. If numbers exceed an average of 4 weevils per trap, treat with appropriate insecticide. Pheromone traps are also available.
Banana bunchy top
Biosecurity Alert!
Cause: The banana bunchy top virus (BBTV) which is spread on infected planting material and by the banana aphid, Pentalonia nigronervosa. BBTV is not present in tropical Australia, and movement of planting material is controlled by legislation.
Solution: There is no cure for this disease and all infected plants must be eradicated.
Reporting: Under state legislation, banana bunchy top disease must be reported. If you have seen plants with banana bunchy top symptoms within the Southern Queensland banana biosecurity zone, or the NSW Banana Bunchy Top Virus Control Zone contact the Banana Bunchy Top Hotline on 1800 068 371.
If you have seen banana bunchy top outside of these areas, you must report it within 24 hours to the Biosecurity authority in your state (Biosecurity Queensland on 13 25 23, or NSW DPI Biosecurity Hotline 1800 680 244) or the Exotic Plant Pest Hotline on 1800 084 881.
More Information:
Not enough water/dry conditions
Cause: Insufficient water for plant growth.
Solution: Use water scheduling techniques to supply sufficient water to meet the plant’s requirements.
Plants turn yellow and die
Plants turn yellow and die
Bacterial corm rot
Cause: The bacteria Pectobacterium spp. (formerly known as Erwinia spp.) that are common soil inhabitants. Plants that are stressed during the dry season can succumb to invasion during the wet season.
Solution: No chemical treatments are available. Ensure adequate moisture levels are maintained during the dry season and provide good drainage during prolonged wet seasons.
Water-logging
Cause: Not enough oxygen for the roots caused by too much water in the soil from rainfall or irrigation.
Solution: Avoid planting in areas that are often water-logged and in heavy soils. Install and maintain the drainage system for your plantation.
Panama disease (Fusarium wilt)
Biosecurity Alert
Cause: The fungus Fusarium oxysporum f. sp. cubense which is a soil—borne organism. It is spread in water, soil and planting material. The fungus enters the plant through the roots and blocks the conducting tissue within the plant, resulting in wilting, yellowing of leaves, splitting of pseudostem and death of the plant. There are several “races” of the disease which affect different varieties.
Solution: There is no cure for affected plants. Use only approved planting material and do not plant in previously infested areas.
Biosecurity obligation: Panama is a notifiable disease and you must report any suspicious plants. If you suspect Panama disease you must notify Biosecurity Queensland immediately (13 25 23).
More info:
Herbicide damage (glyphosate)
Cause: Glyphosate spray drift onto green parts of the plant. The first symptom is yellowing of leaves.