IPM Stratergies for Papaya

126 ratings and Nutritional Deficiencies of Papaya Nitrogen Phosphorus Potassium Magnesium Sulphur Boron Manganese IPM...

126 ratings and

Nutritional Deficiencies of Papaya

1. Nitrogen
2. Phosphorus
3. Potassium
4. Magnesium
5. Sulphur
6. Boron
7. Manganese
8. IPM for Papaya

Nitrogen

Nitrogen deficiency causes slow growth and older leaves become paler with reduced leaf area and rate of leaf production. Leaf petioles short, thin and compressed

Correction Measure: Foliar spray of urea @2%.

Phosphorus

The deficiency of P causes complete cessation of elongation, older leaves becoming increasingly irregularly necrotic, leaf production is reduced, and marginal choruses and premature death are caused. P deficiency causes a blue or dark green coloration of leaves.

Correction Measure: Soil application of phosphatic fertilizer as per the recommendation.

Potassium

Deficiency of potassium causes marked reduction in growth, leaves profusely smaller, leaf margins necrosis and premature yellowing of plant. Purplish brown patches appear at the base of the petioles. Fruits are badly shaped, poorly filled and unsuitable for marketing.

Correction Measure: Foliar spray of KCl @2%

Magnesium

Symptoms show green banding around the margin and next to the midrib. Leaves turn yellowish brown margin. Plant height reduced marginal yellowing of leaf margin extends towards the midrib. Purplish mottling of leaf petiole and malformation of leaves.

Correction Measure: Foliar spray of MgSO₄ @ 1-2%.

Sulphur

Deficiency causes chlorosis and delaying of green colour in newly emerging leaves, reduced plant growth and reduced leaf size. The leaf blades become very soft and tear easily.

Correction Measure: Foliar spray of MgSO₄@1%.

Boron

Distortion of newer leaves and the growing point dies. Leaves show chlorotic symptom with inward cupping with stunted growth. Bushy appearance of shoot.

Correction Measure: Soil application of borax @ 2-3 g/plant.

Manganese

Marginal chlorosis of young leaves, which later turn brown. Fruits with raised spots which are dark brown or black in colour. Leaves give striped appearance from the edges.

Correction Measure: Foliar spray of MnSO₄ @1-2%.

IPM for Papaya

To know the IPM practices for Papaya, click here.

Source: NIPHM and Directorate of Plant Protection, Quarantine & Storage

 

3.07   

 

147 ratings

Papaya : Diseases and Symptoms

1. Foot rot of papaya
2. Anthracnose
3. Powdery mildews
4. Papaya ring spot disease
5. Papaya mosaic disease
6. Papaya leaf curl disease
7. IPM for Papaya

Foot rot of papaya

Disease symptoms

• It is characterized by the appearance of water-soaked patches on the stem near the ground level.
• These patches enlarge rapidly and girdle the stem, causing rotting of the tissues, which then turn dark brown or black. Such affected plants withstand strong wind and topple over and die.
• If the disease attack is mild, only one side of the stem rots and the plants remain stunted.
• Fruit if formed are shriveled and malformed. Gradually the plant dies.

Survival and spread

• Resting spore, Oospore, germinates and release zoospores which along with irrigation water spread throughout the field.

Favourable condition

• High relative humidity and rainy condition favors the severe disease development in sick soil.

Anthracnose

Disease symptoms

• Disease occurs both in field and in storage conditions.
• The spots on fruits first appear as brown superficial discolouration of the skin which develops into circular, slightly sunken areas and 1 to 3 cm in dia.
• Gradually the lesions coalesce and sparse mycelia growth appears on the margins of the spots.
• Under humid conditions, an encrustation of salmon pink spores is released.
• Infection at early stages of fruit results in mummification and deformation.

Survival and spread

• The disease is spread through wind-borne conidia.
• Conidia are also spread by rain splashes.
• Severity of the disease on foliage is increased under conditions of excessive moisture. Lesions develop more slowly on the immature fruits than on the mature fruits.

Favourable conditions

• High relative humidity coupled with higher temperatures favour disease development. Maximum disease development takes place at about 26°C under wet weather condition.

Powdery mildews

Disease symptoms

• On the undersurface of disease leaves are found patches of whitish powder growth.
• On upper surfaces, leaves at the infection site show blotches of yellow or pale green usually near vein, surrounded by normally colored tissue.
• Occasionally, fungus may attack the stem of young seedling when grown under reduced light condition. The spots enlarge and cover the entire leaf area. Severely infected leaves may become chlorotic and distorted before falling. Affected fruits are small in size and malformed.
• Fungus grow superficially on the undersurface of the leaves with drawing nutrients from the cell of leaf surface by specialized absorbing structure known as haustoria.

Survival and spread

• The powdery mildew fungus overwinters in dormant buds. When conditions are favorable for growth of the fungus in spring, spores are produced, released, and cause new infections. Secondary spread of the disease can occur if spores are produced in these new infections

Favourable condition

• The development of powdery mildew in papaya is favour by relative humidity around 80-85% and temperature range of 24-26°C.

Papaya ring spot disease

Disease symptoms

• Infected plant initially shows cholorsis on youngest leaves followed by vein clearing, rugosity and prominent mottling of laminae.
• Malformation and reduction of the lamina which may become extremely filliform.
• Characteristically elongated dark green streak develop on petiole and upper half of the stems, infected fruits show circular concentric rings causes upto 56-60 % yield loss.
• Pathogen belongs to Potyvirus group of Potyviridae family.

Transmission and favourable conditions

• Disease is aphid transmitted and aphids are more active during warmer conditions.
• PRSV is also easily transmitted via mechanical inoculation but there are no confirmed reports of PRSV transmission through seeds.

Papaya mosaic disease

Disease symptoms

• Causes leaf mosaic and stunting in papaya.
• Young seedlings in the greenhouse show vein-clearing and downward cupping of the leaves about 5 days after inoculation.
• A mottle or mosaic develops after 15-20 days.
• Symptoms appear on the young leaves of the plants.
• The leaves are reduced in size and show blister like patches of dark-green tissue, alternating with yellowish-green lamina.
• The leaf petiole is reduced in length and the top leaves assume an upright position.

Transmission and favourable conditions

• Papaya mosaic diseases is mechanically transmissible viruses associated with other viral disease, from papaya mosaic virus in being aphid-borne and restricted in host range to papaya and cucurbits.

Papaya leaf curl disease

Disease symptoms

• Curling, crinkling and distortion of leaves, reduction of leaf lamina, rolling of leaf margins inward and downward, thickening of veins.
• Leaves become leathery, brittle and distorted. Plants stunted.Affected plants does not produce flowers and fruits.
• Spread by whitefly Bemisia tabaci.
• Sometimes all the leaves at the top of the plant are affected by these symptoms. In advanced stages of the disease, defoliation takes place and the growth of the plant is arrested.
• PLCV is in the family Geminiviridae. It is not transmitted mechanically. The virus vector is the silverleaf whitefly, Bemisia tabaci.

Transmission and favourable conditions

• The virus cannot be transferred mechanical means as in the case of mosaic disease. The virus readily transmitted through grafting and white fly (Bemisia tabaci).

IPM for Papaya

To know the IPM practices for Papaya, click here.

Source: NIPHM and Directorate of Plant Protection, Quarantine & Storage

 

3.04   

 

178 ratings and 21 comments

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Papaya Pests

1. Pests of National Significance
1. Insect pest and mites
2. Diseases
1. Postharvest diseases
3. Nematodes
4. Weeds
1. Grasses
2. Broad leaf
3. Sedge
5. Birds
2. Pest of Regional Significance
1. Insect pests
2. Diseases
3. Nematode
3. IPM for Papaya

Pests of National Significance

Insect pest and mites

• Mealybug: Paracoccus marginatus Williams & Granara de Willink (Hemiptera: Pseudococcidae)
• Grasshopper: Poecilocerus pictus Fab (Orthoptera: Pyrgomorphidae)

Diseases

• Stem or Foot or Collar rot: Pythium spp. Phytophthora spp., Rhizoctonia spp.
• Papaya ring spot disease: Papaya Ring Spot Virus
• Papaya mosaic disease: Papaya mosaic virus (Potex virus)
• Anthracnose: Gloeosporium papayae P Henn / Colletotrichum gloesporioides (Penz.) Penz. &. Sacc

Postharvest diseases

• Anthracnose: Gloeosporium papayae P Henn
• Rhizopus rot: Rhizopus stolonifer (Ehrenb.: Fr.) Vuill.
• Fruit rot: Alternaria alternata (Fr.) Keissl.
• Phomopsis rot: Phomopsis caricae-papayae Petr. & Cif.
• Stem end rot: Botryodiplodia theobromae Leavitt and Munnecke (Lasiodiplodia theobromae)

Nematodes

• Reniform nematode: Rotylenchulus reniformis Linford and Oliveira (Tylenchida: Hoplolaimidae)

Weeds

Grasses

• Large crabgrass: Digitaria sanguinalis L.(Scop.) (Poaceae)
• Yellow foxtail: Setaria glauca (L.) P. Beauv. (Poaceae)
• Goosegrass: Eleusine indica (L.) Gaertner. (Poaceae)
• Bermuda grass: Cynodon dactylon (L.) Pers. (Poaceae)

Broad leaf

• Carrot grass: Parthenium hysterophorus L. (Asteraceae)
• Coat buttons: Tridax procumbens L. (Fabaceae)
• Yellow spider flower: Cleome viscosa L. (Capparidaceae)
• Asthma herb/Spurge: Euphorbia hirta L. (Euphorbiaceae)
• Cock's comb: Celosia argentea L. (Amaranthaceae)
• Pigweed: Amaranthus viridis Hook. F. (Amaranthaceae)
• Goat weed: Ageratum conyzoides L. (Asteraceae)

Sedge

• Purple nutsedge: Cyperus rotundus L. (Cyperaceae)
• Flat sedge: Cyperus iria L. (Cyperaceae)
• Umbrella sedge: Cyperus difformis L. (Cyperaceae)

Birds

• Jungle crow: Corrus macrocercus culminates wagker (Passeriformes: Dicruridae)
• Myna: Acridotheres tristis L. (Passeriformes: Sturnidae) 5.3. Roseinged parakeet: Psittacula krameri (Psittaciformes: Psittacidae)

Pest of Regional Significance

Insect pests

• Cotton whitefly: Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae)
• Scale insect: Aspidiotus destructor Signoret (Homoptera: Diaspididae)
• Aphid: Aphis gossypii Glover, Myzus persicae Sulzer (Hemiptera: Aphididae)
• Fruit fly: Bactrocera diversus Coquillett, B. cucurbitae Coquillett (Diptera: Tephritidae)
• Grey weevil: Myllocerus viridans (Coleoptera: Curculionidae)
• Stem borer: Dasyses rugosellus

Diseases

• Damping off of seedling: Pythium spp. Phytophthora spp., Rhizoctonia spp.
• Powdery mildew: Oidium caricae F. Noack
• Papaya leaf curl disease: Papaya leaf curl virus

Nematode

• Root-Gall Nematode: Meloidogyne incognita

IPM for Papaya

To know the IPM practices for Papaya, click here.

Source: NIPHM and Directorate of Plant Protection, Quarantine & Storage

 

3.04   

 

143 ratings and

Papaya: Crop Stage-wise IPM

1. Pre-planting*
2. Sowing/Seedling*
3. Vegetative stage
4. Flowering/Maturity stage

Management	Activity
Pre-planting*
	Common cultural practices: • Deep ploughing of fields during summer to control nematodes population and weeds. • Soil solarization • Timely sowing should be done. • Field sanitation, rogueing. • Destroy the alternate host plants • Apply manures and fertilizers as per soil test recommendations. • Plant tall border crops like maize, sorghum or millet to reduce white fly and aphids population. • Crop rotation with graminaceous crops • Adopt ecological engineering by growing the attractant, repellent, and trap crops around the field bunds.
Nutrients	Papaya plant needs heavy doses of manures and fertilizers. Apart from the basal dose of manures fertilizers are also required. • Nutrient should be applied on the basis of soil test values and recommendation for the particular agro--ecological region. • Papaya seedlings are planted in pits of 60 x 60 x 60 cm. size. • The pits are dug in summer about a fortnight before planting. • The pits are filled with top soil along with 20 Kg. of farmyard manure., 1 Kg. neem cake and 1 Kg. bone meal. • Application of 200 g. N/pit is optimum for fruit yield but papain yield increases with increase in N up to 300 g/pit
Weeds	• Plough the field before planting to destroy existing weeds
Soil and seed borne pathogens, nematodes	Cultural control: • Intercropping of marigold reduces nematode population • Nursery should be raised in nematode free sites or fumigated or solarized beds • Application of decomposed poultry manure @ 200 g / sq. m Biological control: • Apply neem cake @ 100 Kg/acre at the time of transplanting for reducing nematodes and borer damage.
Sowing/Seedling*
Nutrients	• Planting is done in pits already filled with top soil and farm yard manure. • Apply 20 g each of Azospirillum and Phosphobacterium per plant at planting and again six months after planting.
Weeds	• Use weed free seedlings for planting. • Remove existing weeds manually in and around the pits at the time of planting. • Mulching with organic materials around the pits. • To suppress the weeds between rows, intercropping of leguminous crops after non-leguminous ones, shallow rooted crops after deep rooted ones are beneficial. No intercrops are taken after the onset of flowering stage. • Use straw or plastic mulch to avoid weed growth and to maintain soil moisture for longer period. In between the rows.
Soil borne diseases	Cultural control: • Seedling raised in insect proof conditions. • Sow 4-5 seeds/bag then retain 3 seedlings. • 2 month old seedling is ready for transplanting • Papaya don’t withstand water logging, hence well drained upland fields should be selected for cultivation. • Under drip, ring method should be followed. • Wind break: should be grown to protect from strong wind also save tree from cold damage Mechanical control: • Remove and destroy virus infected seedlings/plants. Biological control: • Apply Neem seed kernel extract (NSKE) 5%/groundnut oil @ 1-2% on to the plants to manage the vector population.
Nematodes and insects	Cultural control: • Use resistant/tolerant varieties. • Sowing should be completed within recommended periods. • Intercropping with sunnhemp or marigold or daincha. Biological control: • Use mahua [Madhuca longifolia], castor, neem and karanj [Pongamia pinnata] cakes, biogas sludge applied at 1.0 t/acre during pit preparation. • Apply 2 tons of FYM enriched with Pochonia chlamydosporia and Paecilomyces lilacinus/acre before sowing, along with 100-200 Kg of neem or pongamia cake. • Apply neem based products (Neemagon, Bioneem, Neemraj etc.) for controlling this pest.
Vegetative stage
	Common cultural practices: • Collect and destroy diseased and insect infected plant parts. • Provide irrigation at critical stages of the crop • Avoid water stress and water stagnation conditions. • Enhance parasitic activity by avoiding chemical spray, when 1-2 larval parasitoids are observed Common mechanical practices: • Collection and destruction of eggs and early stage larvae • Handpick the older larvae during early stages • The infested shoots may be collected and destroyed • Handpick the gregarious caterpillars and the cocoons which are found on stem and destroy them in kerosene mixed water. • Use yellow sticky traps for aphids and whitefly @ 4-5 trap/acre. • Use light trap @ 1/acre and operate between 6 pm and 10 pm • Install pheromone traps @ 4-5/acre for monitoring adult moths activity (replace the lures with fresh lures after every 2-3 weeks) • Erecting of bird perches @ 20/acre for encouraging predatory birds such as King crow, common mynah etc. • Set up bonfire during evening hours at 7-8 pm Common biological practices: • Conserve natural enemies through ecological engineering • Augmentative release of natural enemies. • Collection and destruction of eggs and early stage larvae • Handpick the older larvae during early stages • The infested shoots may be collected and destroyed • Handpick the gregarious caterpillars and the cocoons which are found on stem and destroy them in kerosene mixed water. • Use yellow sticky traps for aphids and whitefly @ 4-5 trap/acre. • Use light trap @ 1/acre and operate between 6 pm and 10 pm
Nutrients	• Apply 50 g each of N, P and K per plant at bi-monthly intervals from the third month of planting. • The application of 25 % N in organic form, 75 % N in inorganic form along with green manure crops is beneficial. • Apply 20 g each of Azospirillum and Phosphobacterium per plant again at six months after planting.
Weeds	• Inter cultivation is recommended during the first year to check weed growth. Weeding should be done on regular basis especially around the plants. • Earthing up is done before or after the onset of monsoon to avoid water-logging and also to help the plants to stand erect. • In subsequent seasons to suppress the weeds between rows, intercropping of leguminous crops after non-leguminous ones, shallow rooted crops after deep rooted ones are beneficial. No intercrops are taken after the onset of flowering stage. • Use straw or plastic Mulch to avoid weed growth and to maintain soil moisture for longer period.
Mealybugs	Cultural control: • Removal of weeds and alternate host plants like hibiscus, bhindi, custard apple, guava etc in and nearby vineyards throughout the year. Mechanical control: • Detrash the crop on 150 and 210 DAP. Biological control: • Conserve the natural enemies.
Aphids**	Cultural control: • Check transplants for aphids before planting. • Reflective mulches such as silver colored plastic can deter aphids from feeding on plants. • Sturdy plants can be sprayed with a strong jet of water to knock aphids from leaves. Biological control: • Release 1st instar larvae of green lacewing bug (Chrysoperla zastrowi sillemi carnea) @ 4,000 larvae/acre. • Spraying with tobacco decoction (1 Kg tobacco boiled in 10 l of water for 30 minutes and making up to 30 l + 100 g soap). Chemical control: • Organic control includes insecticidal soaps (1%) and horticultural mineral oils (1%)
Whitefly**	Cultural control: • Water sprays may also be useful in dislodging adults. • A small, hand-held, battery-operated vacuum cleaner has also been recommended for vacuuming adults off leaves. Vacuum in the early morning or other times when it is cool and whiteflies are sluggish. Kill insects by placing the vacuum bag in a plastic bag and freezing it overnight. Contents may be disposed of the next day. Fumigating with asmall petrol socked cotton ball. • For biological control follow common practices.
Stem borer**	Cultural control: • Pierce the infested plants with a sharp needle or knife to kill the caterpillar in the stem. • For others see common practices.
Papaya hoppers	• Removal of weeds and alternate host plants such as Hibiscus, bhindi, custard apple, guava etc. • For other practices follow common practices.
Mite	• See common cultural practices • Spray NSKE(5%)
Foot Rot	Cultural control: • The crop should be irrigated by adopting the ring method of irrigation so that the water does not come in direct contact with the stem. • Avoid water logging..
Anthracnose	Cultural control: • Diseased leaves, twigs, gall midge infected leaves and fruits, should be collected and burnt. • Covering the fruits on trees, 15 days prior to harvest with news or brown paper bags.
Powdery mildews**	Mechanical control: • Prune diseased leaves to reduce primary inoculum load. • Keep proper spacing during sowing. Chemical control: • Thiophanate methyl 70% WP @ 286 g in 300-400 l of water/acre (Thiophanate methyl 70% WP @ 0.1% along with sticker @ 0.05%)
Papaya mosaic virus	Cultural control: • Good field sanitation such as removal and destruction of affected plant reduce the spread of the disease. • Losses can be minimized controlling the population of aphid.
Papaya leaf curl virus**,	Cultural control: • Uproot the virus affected plants • Avoid growing tomato, tobacco near papaya. • Control whitefly vector. • Removal and destruction of the affected plants is the only control measure to reduce the spread of the disease. • The field should be kept weed free. Tobacco, tomato. sunnhemp, cape gooseberry, chilli, petunia, Datura stramonium, Zinnia elegans etc. should not be grown nearby papaya field.
Papaya ring spot virus	Cultural control: • Use of yellow sticky strap to control of aphid vector. • Use of resistant varieties. • Early detection of infected plants and prompt removal can check the spread of the disease. • Rogue out infected plants of papaya as early as possible to avoid further infection within the field. • Avoid taking mixed crop of tobacco, chilli, Zinnea, tomato and gooseberry in papaya field or nearby.
Flowering/Maturity stage
Nutrients	• Apply recommended micronutrients, if symptoms are observed. • Micro-nutrients viz., ZnSO4 (0.5%) and H2BO3 (0.1%) are sprayed in order to increase growth and yield characters.
Weeds	• Remove weeds around the plants. • Continue the u straw or plastic mulch to avoid weed growth and to maintain soil moisture for longer period
Fruit fly**	Cultural control: • Prior to harvest, collect and dispose off infested and fallen fruits to prevent further, multiplication and carry-over of population. • Ploughing of orchard during November-December to expose pupae to sun’s heat which kills them. • If infestation is heavy, bait splash on the trunk only, once or twice at weekly interval is recommended. To prepare bait splash, mix 100 g of jaggery in one litre of water and add 1 ml of deltamethrin by using an old broom. • Managing fruit flies also reduces anthracnose disease and prevents late fruit fall. Physical control: • Hot water treatment of fruit at 48 ± 1 ºC for 45 min. • Male annihilation technique: Set up fly trap using methyl eugenol. Prepare methyl eugenol 1 ml/L of water + 1 ml of malathion solution. Take 10 ml of this mixture per trap and keep them at 25 different places in one ha between 6 and 8 am. Collect and destroy the adult flies Biological control: • See common practices.
Scale insects**	Cultural control: • Prune heavily infested plant parts to open the tree canopy and destroy’ them immediately and preferably during summer. • These should be placed in a pit constructed on one corner of the orchard. Allow branches and twigs to dry until the parasites escape. • Burn the remaining debris. • Removal of attendant ants may permit natural enemies to control the insect.
Grey weevil**	Cultural control: • Collection and destruction of infested and fallen fruits at weekly interval till harvest fruit. • Destroy all left over seeds in the orchard and also in the processing industries.
Whitefly**, Mealybug, stem borer**, aphid**, Mite	• Same as in vegetative stage.
Diseases	• Same as in vegetative stage.
Birds	Mechanical control: • Install bird scarers or metallic ribbons to ward off the birds
Post-harvest
Anthracnose, Stem end rot, Aspergillus rot, Rhizopus rot, Fruit rot, Phomopsis	Cultural control: • Avoid harvesting of immature fruits • Cool fruits immediately after harvest and store in well ventilated containers. • The disease can be checked by sorting the fruit at 100 ºC or below but the rot appears after 2-3 days when such fruits are brought back to 20 ºC or above. Physical control: • Hot water treatment at 49 ºC for 20 min. Botanical control: • Postharvest dip treatment of fruits with botanical fungicides could also control the diseases during storage.
*Application of Trichoderma harzianum/ viride and Pseudomonas fluorescens for treatment of seed/seedling/planting materials in the nurseries and field application (if commercial products are used, check for label claim. However, biopesticides produced by farmers for own consumption in their fields, registration is not required). $Pesticides dosage use is based on high volume sprayer. ** Regional pests.

Source: NIPHM and Directorate of Plant Protection, Quarantine & Storage

 

3.05   

 

156 ratings and

Papaya: Insect, Mite and Nematode Pests Management

1. Papaya mealybug
2. Whitefly
3. Aphid
4. Red Spider mite
5. Fruit fly
6. Grasshopper
7. Reniform nematode
8. Root knot nematode
9. IPM for Papaya

Papaya mealybug

Biology

• Egg: Females usually lay 100 to 600 eggs. Eggs are greenish yellow and are laid in an ovisac sac that is three to four times the body length and entirely covered with white wax. Egg-laying usually continuous over a period of one to two weeks.
• Nymph: Eggs hatch in about 10 days, and nymphs or crawlers begin to actively search for feeding sites.
• Adult: The adult female is yellow, approximately 3 mm long and 1.4 mm wide and is covered with a white waxy coating. Adult males are pink, especially during the pre-pupal and pupal stages, but appear yellow in the first and second in stars. Adult males are approximately 1.0 mm

Damage symptoms

• Initially the affected portion will be cholotic, later changed to brown and dry away.
• These bug excrete honey dew and as a result infested portion becomes shiny and moist and to this, secondary infection by sooty fungus, Capnodium occurs results in black covering the affected parts.
• Papaya mealy bug is polyphagous pest. Symtopms can be observed on ground parts of leaves, stem and fruits as clusters of cotton like masses

Natural enemeis of papaya mealybugs

• Parasitoids: Acerophagus papaya, Phygadium spp.
• Predators: Spalgis epius (West wood), Cryptolaemus montrouzieri, Rodolia fumida
• The entomogenous fungus Beauveria bassiana.

Whitefly

Biology

• Egg: The females mostly lay eggs near the veins on the underside of leaves. Each female can lay about 300 eggs in its lifetime. Eggs are small (about 0.25 mm), pear-shaped, and vertically attached to the leaf surface through a pedicel. Newly laid eggs are white and later turn brown.
• Nymph: Upon hatching, the first instar larva (nymph) moves on the leaf surface to locate a suitable feeding site. Hence, it is commonly known as a “crawler.” If then inserts its piercing and sucking mouthpart and begins sucking the plant sap from the phloem. Adults emerge from puparium through a T-shaped slit, leaving behind empty pupal cases or exuviae.
• Adult: The whitefly adult is a soft-bodied, and moth-like fly. The wings are covered with powdery wax and the body is light yellow in color. The wings are held over the body like a tent. The adult males are slightly smaller in size than the females. Adults live from one to three weeks.

Damage symptoms

• Both the adults and nymphs suck the plant sap and reduce the vigor of the plant. In severe infestations, the leaves turn yellow and drop off. When the populations are high they secrete large quantities of honeydew, which favors the growth of sooty mould on leaf surfaces and reduces the photosynthetic efficiency of the plants.

Natural enemies of whitefly

• Parasitoids: Encarsia formosa, Eretmocerus spp., Chrysocharis pentheus
• Predators: Dicyphus hesperus , Lacewing, Ladybird beetle, Big-eyed bugs (mirid bug) (Geocorissp).

Aphid

Biology

• Egg: Eggs are very tiny, shiny-black, and are found in the crevices of bud, stems, and barks of the plant. Aphids usually do not lay eggs in warm parts of the world.
• Nymph: Nymphs (immature stages) are young aphids, they look like the wingless adults but are smaller. They become adults within 7 to 10 days.
• Adult: Adults are small, 1 to 4 mm long, soft-bodied insects with two long antennae that resemble horns. Most aphids have two short cornicles (horns) towards the rear of the body

Damage symptoms

• Infesting tender shoots and under surface of the leaves.
• Curling and crinkling of leaves
• Stunted growth
• Development of black sooty mould due to the excretion of honeydew

Natural enemies of aphid

• Parasitoids: Aphidius colemani, Aphelinus sp.,
• Predators: Fire ant, Robber flies, Big-eyed bug (Geocoris sp), Earwig, Ground beetle, Cecidomyiid fly, Dragon fly, Praying mantis, Lacewing, Ladybird beetle, Spider etc.

Red Spider mite

Biology

• Egg: Eggs reddish, spherical and provided with a small filament. Incubation period is 4-6 days, before hatching becomes light orange colour.
• Nymph: Upon hatching, it will pass through a larval stage and two nymphal stages before becoming adult. Developmental stages include six legged larva, protonymph and deutonymph.
• Adult: Adult female elliptical in shape, bright crimson anteriorly and dark pruplish brown posteriorlym. Mites spin a web of silken threads on the leaf. Each developmental stage is followed by a quiescent stage and life cycle completed in 10-14 days.

Damage symptoms:

• Spider mites usually extract the cell contents from the leaves using their long, needle- like mouthparts. This results in reduced chlorophyll content in the leaves, leading to the formation of white or yellow speckles on the leaves.
• In severe infestations, leaves will completely desiccate and drop off. The mites also produce webbing on the leaf surfaces in severe conditions.
• Under high population densities, the mites move to using strands of silk to form a ball-like mass, which will be blown by winds to new leaves or plants, in a process known as “ballooning.”

Natural enemies of red spider mite:

• Predators: Anthocorid bugs (Orius spp.), mirid bugs, syrphid/hover flies, green lacewings (Mallada basalis and Chrysoperlasp.), predatory mites (Amblyseius alstoniae, A. womersleyi, A. fallacies and Phytoseiulus persimilis), predatory coccinellids (Stethorus punctillum), staphylinid beetle (Oligota spp.), predatory cecidomyiid fly (Anthrocnodax occidentalis), predatory gall midge (Feltiella minuta), Predatory thrips etc.

Fruit fly

Biology

• Egg: Female flies insert eggs under the skin of fruit in clusters of 10 to 50 about 1/25 to 1/8 inch below the fruit surface. The eggs measure about 1/25 by 1/250 inch and are white, elongate, and elliptical. They hatch in 1-1/2 days.
• Larva: The white larva is legless, and resembles an elongated cone. The mouth is at the pointed end of the body. There are 3 larval stages, or instars. The third instar is about 2/5 inch long. The entire larval stage lasts for 11-15 days.
• Pupa: When mature, larvae drop to the ground and pupate in the soil. The puparium is yellowish-brown and seed-like. Adults emerge in about 10 days.
• Adult: Generally, the abdomen has two horizontal black stripes and a longitudinal median stripe extending from the base of the third segment to the apex of the abdomen. These markings may form a "T" shaped pattern, but the pattern varies considerably. Females begin to lay eggs about 8 days after emergence from the puparium. Under optimum conditions, a female can lay more than 3,000 eggs during her lifetime, but under field conditions approximately 1,200 to 1,500 eggs per female is considered to be the usual production. Ripe fruit are preferred for egg laying, but immature ones may be also attacked.

Damage symptoms

• The female punctures outer wall of mature fruits with the help of its pointed ovipositor and insert eggs in small clusters inside mesocarp of mature fruits.
• On hatching, the maggots feed on fruit pulp and the infested fruits start rotting due to further secondary infection

Natural enemies of fruit fly

• Parasitoids: Opius fletcheri, Fopius arisanus, Diachasmimorpha kraussi
• Predator: Ants

Grasshopper

Biology

• Egg: Adult females lay eggs along the midrib and lateral veins of the leaves. The egg period is 4 to 11 days.
• Nymph: The nymphs resemble the adults, but lack wings. Instead, they have slightly extended wing pads. They are pale green in color. They tend to move sideways when disturbed. The nymphal period varies from one to four weeks depending on the temperature.
• Adult: The adults are wedge-shaped, pale green insects. They have fully developed wings with a prominent black spot on each forewing. The adults may live for one to two months

Damage symptoms

• Both nymphs and adults suck the sap from the lower leaf surfaces through their piercing and sucking mouthparts. While sucking the plant sap, they also inject toxic saliva into the plant tissues, which leads to yellowing. When several insects suck the sap from the same leaf, yellow spots appear on the leaves, followed by crinkling, curling, bronzing, and drying, or “hopper burn”.

Natural enemies of grass hopper

• Parasitoids: Lymaenon empoascae (egg), Anagrus flaveolus, Stethynium triclavatum
• Predators: Birds, praying mantis, blister beetle, ground beetle, spider, hoverfly etc.,

Reniform nematode

Biology

• The predominant reniform species found on papayas in most of the world is R. reniformis.
• Many commonly cultivated crops as well as weeds are hosts of the reniform nematodes.
• Because of their small size, they do not travel distances of more than a few inches in their lifetime.
• Juveniles that hatch from eggs are less than 500 μm long.
• After undergoing several molts, female juveniles become young adults and penetrate the root cortext and become sedentary.
• The portion of the body that remains outside the root enlarges and becomes kidney-shaped, hence the name "reniform." After maturation the female secrets a gelatinous substance around her body (the sand-like bodies referred to above) into which she lays about 100 eggs.
• A complete life cycle is possible in about 25 days. The reniform nematode feeds near the phloem in papaya roots inducing the formation of giant cells.
• These are centers of high metabolic activity that compete with other parts of the plant for food and nutrients.
• The nematode also may feed in the root cortex and cause mechanical breakdown of the cortical cells, thus providing suitable sites for attack by fungi.

Symptoms

• Above-ground symptoms of plants infected by the reniform nematode are similar to those associated with one or more of the following conditions: 1) lack of proper nutrients, 2) chronic moisture stress, and/or 3) poor soil aeration.
• The above-ground symptoms appear as moderate to severe leaf chlorosis and plant stunting. Some wilting may occur during periods of peak transpirational stress on the plant.
• Below ground symptoms are not readily detectable by the untrained observer. However, reniform nematode presence on the roots may be observed with the aid of a 10x hand lens.
• The small sand-like bodies which remain attached, after the root system is carefully washed, are egg masses of the nematode.
• Fruits produced are smaller than normal and may be slightly insipid.

Root knot nematode

Biology

• Most species of plant parasitic nematodes have a relatively simple life cycle consisting of the egg, four larval stages and the adult male and female.
• Development of the first stage larvae occurs within the egg where the first molt occurs. Second stage larvae hatch from eggs to find and infect plant roots or in some cases foliar tissues.
• Under suitable environmental conditions, the eggs hatch and new larvae emerge to complete the life cycle within 4 to 8 weeks depending on temperature.
• Nematode development is generally most rapid within an optimal soil temperature range of 70 to 80°F.

Damage symptoms

• Infected plants in patches in the field
• Formation of galls on host root system is the primary symptom
• Roots branch profusely starting from the gall tissue causing a ‘beard root’ symptom
• Infected roots become knobby and knotty
• In severely infected plants the root system is reduced and the rootlets are almost completely absent. The roots are seriously hampered in their function of uptake and transport of water and nutrients
• Plants wilt during the hot part of day, especially under dry conditions and are often stunted
• Nematode infection predisposes plants to fungal and bacterial root pathogens

Survival and spread

• Primary: Egg masses in infected plant debris and soil or collateral and other hosts like Solonaceous, Malvaceous and Leguminaceous plants act as sources of inoculums.
• Secondary: Autonomous second stage juveniles that may also be water dispersed.

Favourable conditions

• Loamy light soils.

IPM for Papaya

To know the IPM practices for Papaya, click here.

Source: NIPHM and Directorate of Plant Protection, Quarantine & Storage