INTEGRATED

INTEGRATED PESTS MANAGEMENT

Effective Pest and disease management involves two steps:

1. Prevention

Types of Systemic fungicides

· It is better to prevent than to cure.

· Better managed plants are better able to resist to pests and diseases.

2. Cure

· If, despite all prevention measures, a disease occurs, remedial measures need to be taken.

· It is important to correctly identify the problem to find the most appropriate cure

Powerful Chemical pesticides may seem a good and easy solution. BUT there are several problems:

· Most are extremely toxic; resistant strains of the pest or disease may develop.

· The pest or disease may return, as the real cause of the problem, i.e. the existence of favorable conditions for the pest or disease, is not taken away.

Integrated Pest Management (IPM)

This is the better alternative to the use of chemicals as it blends all effective, economical and environmentally sound pest control methods into a single but flexible approach to managing pests.

Benefits of IPM

· Keep pests populations below economically damaging levels.

· Emphasizes the growth of a healthy crop with the least possible disruption of agro-ecosystems

· Encourages natural pest control mechanisms and least invasive practices, while highly disruptive or environmentally damaging practices (e.g. chemical pesticides) are used only where and when natural methods fail to keep pests below damaging levels.

Pests and Diseases Management Strategies

Regulatory Practices

This refers to all forms of legislation/regulation that might prevent the establishment or reduce the spread of pest and diseases in the national and international levels.

Physical and Mechanical Methods

These methods physically keep pests from reaching their hosts and/or directly remove or kill pests. These include:

· inspection to identify possible points of entry

· Barriers such as screens, plant collars, etc.

· Traps like fly paper, sticky boards, folded burlap around tree trunk, etc.

· crushing pests under your foot, hand-picking, cutting or pruning pest individuals or galls out of a tree, using a fly swatter, etc,

· electronic bug killers

· Temperature extremes to kill pests and diseases or to prevent injury (e.g., cold storage, heat treatments, etc.)

Cultural control

This refers to the use of methods that favor desirable plant growth and make the environment less favorable for pests and diseases.

· Sanitation

This is done by keeping the area clean of plants or materials where pests may live and hide, and of sources of food and water. Examples include: removal of weeds, removal and destruction of crop residues, cleaning of farm equipment.

· Crop Rotation

This method replaces a crop that is susceptible to a serious pest with another crop that is not susceptible, on a rotating basis. This is most likely to be practical and effective when it is used against pest that attack annual or biennial crops, have a relatively narrow host range, cannot move easily from one field to another and are present before the crop is planted.

· Intercropping (mixed Cropping)

This is another way to reduce pest populations by increasing environmental diversity that makes it more difficult for pests to find their favored host crop.

· Adjusting the Time of Planting

· Proper Irrigation and Fertilization

· Flooding to eliminate Soil-borne Pests

· Use of certified Disease-free Mother plants or Seeds

· Variations of Standard Agricultural Practices

Host Resistance/Tolerance

Use varieties that are tolerant to pests and diseases present in the area.

Biological Control

This refers to the use of beneficial organisms to control specific pests.

Chemical Control

This is the use of chemicals to kill pests or to inhibit their feeding, mating or other essential behaviors. However, it must be remembered that chemicals have high toxicity and harmful effects on the environment and non-target organisms. Modern management practices typically reserve synthetic chemical controls as a last resort.

Major banana Diseases

Caused by Fungi

Black Leaf Streak (black Sigatoka)

This is the most economically important leaf disease of banana. It destroys banana leaves which results to yield reduction and premature ripening. It is more virulent, has a wider range, more rapid development and severe defoliation than yellow sigatoka.

Causes:

· The fungus Mycosphaerella fijensis

· Influenced by humidity, temperature, leaf wetness, intensity of infection, plant vigor and light intensity.

Symptoms:

· Stage 1:

Small (less than 1 mm long) whitish or yellow specks on the underside of the leaf, which turn rusty brown.

· Stage 2:

Specks grow into narrow (2 to 5 mm long), reddish or dark brown steaks on the underside of the leaf, with corresponding yellow streaks on the upper side.

· Stage3:

Streaks become longer (20 to 30 mm long) and may coalesce to cause leaf necrosis.

· Stage 4:

Individual streaks broaden to form brown spots on the underside of the leaf, with corresponding black spots on the upper side.

· Stage 5:

Elliptical black spots, usually surrounded by a yellow halo, on both sides of the leaf.

· Stage 6:

Centre of the spot dries and fades to clear gray, surrounded by a black border and water soaked or yellow halo.

· The leaves turn brown-black, dry quickly and die within 1 to 4 weeks.

· Symptoms usually first seen on leaves 3 and 4, later also on younger leaves.

· Few or no viable leaves at harvest.

· Reduction in quality and quantity of fruit.

Prevention and Control

Cultural Control for Black Sigatoka

Reduce inoculums levels on farms by:

· Removing leaves with extensive necrosis.

· Removing or cutting the small areas of necrotic leaf tissue as soon as they appear.

Reduce relative humidity inside the crop by:

· Maintaining an efficient drainage systems; and

· Maintaining adequate balance between distribution and numbers of plants, to avoid overlapping of foliage.

Use of Resistant Cultivars

Very susceptible cultivars include:

· Cavendish, Gros Michel (AAA)

· All known plantain Cultivars (AAB)

Resistant cultivars are:

· ABB cooking banana cultivars (Bluggoe, Pelipita, saba)

· Mysore AAB, T8 (bred hybrid, AAAA), Pisan Lilin (AA), FHIA-03 (AABB), FHIA-18, FHIA-21 (AAAB), FHIA-25

Chemical Control for Black Sigatoka

This disease can be controlled by two types of fungicides:

· Protectant Fungicides

These remain on the leaf surface and do not penetrate the underlying tissues. Approved protectant fungicides are dithiocarbamates and chlorothalonil.

Types of Protectant Fungicides

Gallons per hectare

· Systemic Fungicides

These penetrate the leaf and have a specific mode of action, which makes them phytotoxic to banana. They exert a toxic effect in the pathogen after infection has taken place. They belong to the benzimidazole, morpholine, triazole and strobilurin group of fungicides.

Types of Systemic fungicides

Petroleum oil

This has been shown to have an effect on disease development. Oil application rates range from 5 to 15 liters per hectare, and it can be applied straight or in an oil-water emulsion. All systemic fungicides are applied in oil. The oil helps the fungicides penetrate the leaves.

Preventing Build-up of Resistance

· Limit the use of fungicides.

· Base fungicide applications on a disease-forecasting system and/or on crop growth and weather conditions.

· Limit the use of systemic fungicides.

· Always apply systemic fungicides in mixtures with protectant fungicides.

· Alternate between systemic and protectant fungicides.

· Use a rate of oil close to 10L/ha.

· Do not use reduced rates of systemic fungicides.

· Maintain all cultural practices that will reduce the amount of inoculums.

Sigatoka (Yellow Sigatoka)

This used to be the most important foliar disease of banana and caused widespread disruption to the export trade until the discovery and spread of black Leaf Streak (BLS). Sigatoka causes the premature death of large areas of leaf tissue leading to yield loss and premature ripening.

Cause

· The fungus mycosphaerella musicola, ascomycete

· Influenced by environmental conditions, host resistance and intensity of infection

· Has a lower temperature optimum than BLS

Symptoms

· Light green, narrow specks (1 mm long) on the upper surface of the leaf.

· Develops into a streak (several mm long and less than 1 mm wide) running parallel to veins.

· Elongates and expands laterally to become elliptical, turns rusty red.

· Centre appears sunken and turns grey, while halo becomes darker brown.

Prevention and Control

Cultural Control for Yellow Sigatoka

Reduce by inoculums levels on farms by:

· Removal and destruction of badly spotted leaves (trash).

· Burial or pilling of heavily diseased leaves.

Reduce relative humidity inside the crop through:

· Correct design of blocks to ensure rapid removal of water and good air flow.

· Avoid planting bananas in wet areas or near areas of permanent water.

· Under-tree or drip irrigation is recommended instead of overhead irrigation

Use of Resistant Varieties

Very susceptible varieties:

· Cavendish, Gros Michel, Lakatan, Pisanf Susu (AAA)

· Sucrier, Inarnibal (AA)

· Plantain (AAB) at elevations

Resistant alternatives:

· Yangambi Km 5(AAA)

· Pisang Lilin. Pisang Tongkat, Paka (AA)

· Ney Poovan (AB)

· Plantain (AAB) at sea level

· Bluggoe, Pisang Awak, Kluai Terapot (AAB)

Chemical Control for Yellow Sigatoka

· Application of protectant fungicides before infection.

· Application of systemic fungicides to stop or arrest the fungus after it has infected the leaf (up to the speck or early streak stage, not later).

· Petroleum oil should be included in all sprays since it can arrest infection up to about 2 weeks after it has entered the leaf.

· The frequency of chemical application must be based on:

* Disease development, monitored by competent consultant

* Weather conditions

* A time-based regular schedule such as:

¾ Ten to 14 day intervals during wet season;

¾ Extended to 3 to 4 weeks during dry period; and

¾ Reduced to 2 to3 weeks before the next wet season.

· Chemical applications must be aimed at the younger leaves since these are the most prone to new infections.


Preventing Chemical Resistance

In order to prevent chemical resistance, there must be a:

· Combination of cultural and chemical methods.

· Limited use of systemic fungicides (use when conditions are conductive to infection, not when symptoms are obvious).

· No application of systemic fungicides to heavily diseased plants (de-leaf diseased leaves bfore applying the systemic fungicide).

· Observation of systemic-free periods.

· Monitoring of the sensitivity of the leaf spot population.

· Limited use of a fungicide from the group to which a particular population of leaf spot is resistant until that particular population has been controlled.

Fusarium Wilt (Panama Wilt)

This is regarded as one of the most destructive plant diseases in recorded history. It colonizes the xylem and causes a lethal vascular wilt.

Cause

The fungus Fusarium oxysporum f.sp. cubense

There are four races of this fungus that attack specific varieties:

· Race 1: attacks Gros Michel (AAA), Maqueno (AAB), Silk (AAB), Pome (AAB), Pisang Awak (ABB), I.C.2 (AAAA)

· Race 2: attacks ABB cooking bananas (e.g. Bluggoe), some bred AAAA tetraploids

· Race 3: attacks Heliconia (before)

· Race 4: attacks some clones as race 1 and 2 + Cavendish (AAA), plantain (AAB), Pisang Mas (AA)

· Subtropical Race 4: plants are usually attacked only when stressed

· Tropical Race 4: can attack unstressed plants

Transmission

· Infection via root tips

· In susceptible varieties, the fungus moves in xylem vessels via the plant’s transpirational flux

· In resistant varieties, the mechanical host defenses to stop systemic colonization of the xylem.

· Dissemination through: infected rhizomes, soil, running water, farm implements and machinery.

· Long-term survival in soil.

· Parasite of non-host weeds species.

Symptoms

Internal

· Reddish to dark brown discoloration of vascular system

· First in feeder roots and the rhizome and later also in the pseudostem

External

· Yellowing of oldest leaves

· Longitudinal splitting of lower portion of the outer leaf sheaths pseudostem splitting

· Wilting

· Collapse of leaves at petiole base

· Gradually younger leaves collapse, until the entire canopy consists of dying or dead leaves

Distinction from Moko (bacterial wilt)

· Yellowing starts from older leaves

· Symptoms do not develop on plants and suckers less than 4 months old

· No brown discoloration in fruit

Control

There is no cure for Fusarium Wilt. Prevention and immediate eradication once detected is your only option.

Prevention

· Disinfection of farm tools and machinery

· Use of pathogen-free planting material (tissue culture) in uninfested soil.

· Immediate eradiction of diseased plants (6-m radius) and removal of diseased plants part from the farm

· Rice hull burning

· Quarantine measures

Cultural control for Fusarium Wilt

· Good drainage system

· Annual cropping

Use of Resistant Varieties

· Natural sources of resistance in wild species and cultivars.

· Synthetic diploids developed by breeding programs (using resistance in Pisang Jari Buaya, Pisang Lilin and Musa acuminata ssp, burmannicoides ( Calcutta 4): FHIA-01, FHIA-03 à R r1, r4; FHIA-17 à R r1, FHIA-23 à T

· Somaclonal variant selection (Taiwan): GCTCV 119. GCTCV 215 à R r1

Caused by Bacteria

Moko/Bugtok (Bacterial Wilt)

This is a major disease of banana. Filipino farmers wait for 18 to 21 months to harvest cooking banana Saba (ABB/BBB), only to find out that 80 percent is Bugtok infected.

Cause

Caused by the aerobic bacterium Ralstonia solanacearum (race 2) – syn. Pseudomas solanacearum

Transmission

· Moko

* Infection is via roots or rhizome

* Soil to root transfer is slow but may be hastened by the presence of excess water in the field.

* Mechanical transmission through contaminated tools during pruning, desuckering, removal of male buds or damaged leaves (wounds in: roots, rhizomes, male buds, leaves).

· Bugtok

* Infection via insect vectors via male bud of cooking banana cultivars.

Symptoms

· Moko

* Yellowing and wilting of oldest leaves.

* Oldest leaves become necrotic and collapse.

* Younger leaves develop pale green or whitish panels.

* Younger leaves become necrotic.

* Suckers may wilt, without foliar symptoms.

* Fruit development is arrested.

* Fingers may ripen prematurely or spilt.

* Internally, fruits become discolored and eventually rot.

* Pockets of dry gelatinous grayish black or yellowish red tissues in the fruit.

* Vascular tissues become progressively discolored.

* Bacterial ooze exuded from vascular tissues, when cut.

Bugtok

* First symptoms in flowers, buds and peduncles, which become blackened and shriveled.

* Bacterial ooze may be observed at the base of the bracts where localized blackening may also occur.

* If male flower is removed, external symptoms may not be observed.

* Bacterium spreads to fruit, which may ripen prematurely and rots.

* Infection continues to pseudostem, causing blackening of the vascular tissue.

Prevention and Control

There is no cure, so early detection and prompt eradiction of infected mats is your only option.

Prevention, Eradication and Quarantine Measures

· Use clean materials in uninfested soil in starting a new banana plantation.

· Once an infection has been identified, eradicate diseased plant and quarantine the area.

* Eradication can be done by injecting a herbicide (glyphosate) or by completely cutting and digging out the diseased plant.

* Vampire method: the mother plant is cut down, bamboo sticks (15-20 cm long with shiny part removed) are soaked in 100% glyphosate for 24 hrs and inserted in the trumk of the cut mother plant, which will kill the suckers.

· Ensure that the cut suckers will not regrow.

· Treat surrounding healthy plants (including weeds) with herbicide

· No bananas or anyalternative host such as Heliconia are grown in the area.

· Fallow the area or plant with wilt-suppresive crops such as maize for a period of 6 to 12 months.

· Burn rice hull to reduce the necessary fallow period:

* Put rice hull on top of the infected field at 1,500 kg/case and burn.

* Three to four weeks later, burn another 750 kg/case and do a third of 750 kg/case for another 3 to 4 weeks later.

* The area will be ready for planting 3 to 4 months after the first burning.

Cultural Control

· The spread of Moko can be prevented through good drainage conditions and disinfection of used tools and shoes of workers (10% formaldehyde for 10s, or 5% formaldehyde for 30s).

· Bugtok infection can be prevented by removing the male buds by hand at an early stage and bagging the inflorescence with polyethylene, muslin cloth or fine nylon mesh.

· Debelling or debugging: This is the removal of the bell or male bud about 10cm below the last hand soon after it is set. This procedure helps to increase the size of the lower hands and bunch weight and reduces bird activity and damage. More importantly, this is an effective control measure to prevent infection by insects with the bacteria that causes Moko or bacteria wilt.

* Cut off the male bud by a knife or machete.

* Disinfect cutting tools in a formaldehyde solution (10% solution for 10s or 5% solution for 30s) or a 5% sodiumhypochlorite solution to prevent spread of diseases or to avoid this problem, break the peduncle by hand or use or forked stick.

* Remove small fingers or false hands to increase finger length, reduce time between shooting and harvesting as well as increase percentage of first class fruit.

* Leave one finger in the last removed hand to prevent bunch stalk and withering back.

Caused by Viruses

Banana Bunchy top Disease

Banana bunchy top disease is the most serious virus disease on banana.

Cause

Banana Bunchy Top Virus (BBTV)

Transmission

· Transmitted by an aphid vector, Pentalonia nigronervosa or black aphid.

Look out for alternative hosts for the virus and aphids.

· Can be transmitted through vegetative planting materials.

· Beware of regrowth of suckers of incompletely destroyed infected mats and undetected infection in suckers used to plant new areas.

· Can be transmitted through tissue culture.

· Not transmitted through mechanical inoculation.

Symptoms

· Dark green streaks or dots on the minor veins (form ‘hooks’ as they enter the midrib) and sometimes on the petiole (easily seen when viewed against the light).

· Whitish streaks along the secondary veins, that becomes dark green as the leaf unfurls.

· Leaves turn pale green to whitish, cholorotic margins that tend to turn necrotic.

· Leaves turn thin and papery, harsh and brittle.

· Successive leaves are stiffer and narrower than the preceding leaf and stand more erectly, becoming rosette and with a bunchy-top appearance.

· Pseudostem does not develop further.

· Small and distorted bunch and fruit when infected late; no bunch production when infected early.

· Infection may be mild or go symptom-less.

Prevention and Control

There is no cure for Banana Bunchy top Disease. Prevention and eradication, once detected is your only option to prevent further spread.

· Eradicate infected plants from both lightly and heavily affected areas.

· Restrict or quarantine the movement of planting materials.

· Restrict the use of planting materials; use tissue-cultured planting materials instead of suckers.

· Conduct regular inspections for early detection and prompt eradication.

Steps in eradication

· Spray with paraffin or insecticide to kill aphids.

· Chop down plants.

· Dig out corn with all suckers.

· Chop all plants materials into small pieces to prevent re-growth.

· Inject herbicide (24-, glyphosate, dicamba)

Vampire method to prevent re-growth of suckers

· Soak 15 to 20 cm bamboo sticks (with shiny part removed) in 100% glyphosate or roundup for 24 hrs.

· Insert bamboo stick in the centre of cut mother plant.

Use of resistant varieties

· There are no confirmed reports of immunity to BBTV in any Musa species or cultivar.

· Differences in reaction:

* AA and AAA highly susceptible (e.g. Gros michel)

* Some cultivars containing B-genome show how levels of infection or total absence of symptoms after aphid inoculation e.g. Pisan Raja (AAB), Bungaoisan (AAB),Pelipita (ABB), Turangkog (ABB).

Watch out for the hosts of virus e.g. (Canna, Heliconia, Strelitzia) and other hosts of aphids. Control of aphids with insecticides has only limited success.

Major Banana Pests

Nermatodes

Banana nermatodes which are microscopic worms, attack the root system of the banana plant. The root system is responsible for the anchorage of the plant in the soil and for the uptake of water and nutrients from the soil.

As a result, nermatode infestation reduces the root system. Thus, the plant will be less able to take up water and nutrients and to anchor itself in the soil. This will result to less vigor, wilting symptoms, increased harvest-to-harvest time, toppling and susceptibility to Fusarium wilt.

Types of nermatodes

· Burrowing nermatodes or Radophulus similis

· Lesion nermatodes or Pratylenchus

· Root nermatodes or Meloidogyne spp

· Spiral nermatodes, the most widespread and numerous nermatodes but are generally considered as less serious panthogen.

Diagnosis

· Above-ground symptoms

* Stunted plant growth, lack of vigor

* Reduction in number and size of leaves

* Leaf yellowing

* Premature defoliation

* Increased susceptibility to wilt

* Reduced yield, small bunches

* Increased harvest-to-harvest time

* Plant toppling

· Under-ground symptoms

* Reddish-brown necrosis of roots, not in stele

* Galling of roots

* Reduced root system: lower number of secondary and tertiary roots and root hairs.

* Root proliferation

* Reddish-brown necrosis of corm

Nermatode management

Often, application of large quantities of nermaticides is the only control measure taken. However, nermaticides are very expensive, and thus beyond the reach of small-scale farmers. Furthermore, these are very toxic and have grave effects on non-target organisms, the environment and the farmer. As such, alternative management practices are needed.


Preventive Control measures

Nermatodes are chronic problem. However, by themselves, nermatodes can only move about one meter per year. Thus, prevention of infestation and spread should be a priority.

· Use clean planting materials:

* Tissue-cultured plantlets – only planting material source guaranteed to be absolutely free of nermatodes.

* Planting materials from clean nursery blocks- start a nursery block with tissue-cultured plantlets.

· Check the status of the soil in the nursery area (e.g. no prior history of banana growing).

· Prevent movement of nermatodes into the nursery area through tools, vehicles and footwear.

· Treat planting materials through;

* Cleaning and pairing

* Hot-water treatment: 52 to 55 °C for 15 to 20 min

* Cold fenamiphos (Nemacur® 400) dip: 100 ml of in Nemacur® 400100 liters of water, for 10 minutes.

* Nermaticide-mud coating (pralinage)

· Implement quarantine measures.

· Clean machinery and equipment.

· Avoid contaminated irrigation water.

· Remove plants with symptoms.

Types of Physical Control

· Pre-planting heat treatment of soil through:

* Steam

* Black polyethylene cover during summer

* Deep ploughing during summer.

· Pre-planting flooding

Types of Cultural Control

· Fallowing:

* Bare fallow: no plants at all

* Non-host crop fallow: only non-host plants

* Pay attention to weeds, remains of bananas

· Crop rotation:

* e.g. with low-land rice; anaerobic conditions due to flooding

* panola grass, maize, sugarcane, marigold against Meloidogyne spp.

· Intercropping:

* Antagonistic crops: e.g. marigold, mustard, neem production of chemicals

* Trap crops: e.g. cowpea for Meloidogyne spp.

* Cover crops

· Adjustment of date of planting and harvest

Use of resistant varieties

· Varieties resistant to R. similis:

* Pisang Jari Buaya (AA) and Yangambi Km 5 (AAA), Pisang Batuau (AA), Pisang Pli (AA), Ney Poovan (AB), several wild Musa balbisiana (BBw), Rimina, Menei (Fe’i), Figue Pomme Ekonah (Silk, AAB), Pisang Kelat (AAB), Pisang Ceylan (Mysore, AAB), FHIA-01 (AAAB), Ducasse, etc.

· Varieties resistant to Pratylenchus spp:

* Calcutta 4 (AA), Yangambi Km 5 (AAA), Paka (AA), Kunnan (AB)

· Varieties resistant to Meloidogyne spp:

* There are no widely confirmed sources of resistance however in the Philippines, the following varieties showed resistance: Viente Cohol (AA), Paka (AA), Dakdakan (AA), Pogpogon (AA), Alaswe (AAA), Inambak (AAA), Pastilan (AAA), Sinker (AAA), Maia Maole (Maia Maole Popoulu subgroup, AAB), and Pa-a Dalaga (AAN).

Extracts of the following plants are shown to have nermaticidal effects as they prevent eggs from M. incognita from hatching:

· Root extracts of: marigold (Tagetes erecta), ipil-ipil (Leucaena leucocephala), Bermuda grass (Cynodon dactylon), and makahiya (mimosa pudica)

· Leaf extracts of: kaatoangbangkal (Anthrocephalus chiensis) and water lily (Eichornia crassipes)

· Extracts of garlic (Allium sativa) and onion (Allium cepa)

Chemical Control Methods

There are two major chemical groups of nermaticides namely: organophosphates and carbamates. However, their mode of action is mainly nermatostatic since they do not kill nermatodes but rather, act on nermatodes’ nervous system and interfere with its ability to hatch from eggs, move, penetrate roots, feed and reproduce.

Nermaticides used for the control of Musa nermatode