IPM strategies for Sorghum

  Management of Fall Army Worm in Sorghum Crop stage : Crop stage: Before sowing Crop stage : Sowing and post sowing cultural a...

 

Management of Fall Army Worm in Sorghum

1. Crop stage : Crop stage: Before sowing
2. Crop stage : Sowing and post sowing cultural and mechanical practices
3. Crop stage : Seedling stage (0 to 30 days old crop)
4. Crop stage : Early whorl stage (30-50 days)
5. Crop stage : Late whorl to boot stage window (50-70 day old crop)
6. Precautions for pesticide use

Crop stage : Crop stage: Before sowing

Intervention : Precautionary measures to be followed before planting of the crop

IPM measures

• Deep ploughing to expose pupae to sun light and predatory birds
• Maintain clean field bunds and plant flowering crop plants, viz.. Tagetes spp. Cosmos spp. etc. to attract the natural enemies.
• Planting Napier grass/hybrid Napier in border and intercropping sorghum with pigeon pea, cow pea in 2:1 to 4:1 ratio is advisable.

Crop stage : Sowing and post sowing cultural and mechanical practices

Intervention : Better sowing method, pheromone installation, clean cultivation and mechanical measures

IPM measures

• Follow ridge and furrow planting method instead of flat sowing Erect bird perches (@25/ha to encourage insectivorous bird soon after emergence.
• Nutritional management: Apply recommended dose of NPK. Balanced application of fertilizers helps to reduce the incidence of FAW
• Clean cultivation by removing weeds which serve as alternate host of FAW.
• Treat the seed with Cyantraniliprole 19.8% + Thiamethoxam 19.8% FS @ 6 ml /kg seed for protection during seedling stage

Crop stage : Seedling stage (0 to 30 days old crop)

Intervention : Application of neem based pesticide, bio pesticides and bioagents; minimize use of chemical pesticides.

IPM measures

• Most vulnerable stage, very crucial period for management. Spray neem formulation (Azadiractin. 1500 ppm) @ 5 ml/I or one lit/acre or 5 % Neem seed kernal estract (NSKE) immediately after observation of one moth/trap/day or 10 % plant infestation at papery windows Stage.
• Hand collection and destruction of larvae and egg in patchy incidence
• Erection of pheromone traps @15/ac for mass trapping of adults (effectiveness of lure last for 30-45 days)
• Release of Telenomus remus (4000/ac) or Trichogramma pretiosum @ 50,000/ac at 7 and 14 days after planting. Parasitoid release may be alternated with neem spray at weekly intervals, but not together.
• For management of early instars, whorl application of Bacillus thuringiensis v kurstaki formulations 2% @ 2g/l or Metarhizium anisopliae or Beauveria bussiana @ 5 g /liter is recommended.
• If incidence is more than 10%, any of the recommended synthetic pesticides. viz. Spinetoram 11.7% SC @ 0.5 ml/l or Chlorantraniliprole 18.5 SC @0.4 ml/l or Thiamethoxam 12.6 % + Lambada Cyhalothrin 9.5 % ZC @0.25 ml/I is recommended.

Crop stage : Early whorl stage (30-50 days)

Intervention : Application of neem based pesticide, bio pesticides and bioagents; minimize use of chemical pesticides.

IPM measures

• Very crucial period for management. Spray neem formulation (Azadiractin, 1500 ppm) @ 5 ml/I or one lit/acre or 5% Neem seed kernal extract (NSKE) immediately after observation of one moth/ trap/ day or 10 % plant infestation at early whorl stage.
• Spray (Whorl application) Bacillus thuringiensis v. kurstaki formulations 2% @2g/l or Metarhizium anisopliae or Beauveria bassiana @ 5 g/ liter at 5-10% infestation. Repeat the spray based on weekly scouting at >10% fresh infestation.
• If incidence is 10 -20 % any of the recommended synthetic pesticides, viz., Spinetoram 11.7 % SC @ 0.5 ml/l or Chlorantraniliprole 18.5 SC @ 0.4 ml/l or Thiamethoxam 12.6 % + Lambda cyhalothrin 9.5 % ZC @ 0.25 mI/l is recommended.

Crop stage : Late whorl to boot stage window (50-70 day old crop)

Intervention : No chemical intervention

IPM measures

• Timely management measures at seedling and early whorl stage reduces FAW damage to greater extent.
• If incidence is more than 20%, any of the recommended synthetic pesticides, viz. Spinetoram 11.7% SC @ 0.5 ml/l or Chlorantraniliprole 18.5 SC @ 0.4 ml/l or Thiamethoxam12.6 % + Lambda cyhalothrin 9.5% ZC@ 0.25 ml / l is recommended.

Precautions for pesticide use

• Insecticide sprays should be rotated with another recommended chemical in subsequent sprays to avoid build up of resistance in FAW to insecticides.
• Enter the field only 48 hours after spraying the pesticide.
• Harvesting should be done 30 days after last spray of pesticide and the left over fodder may be fed to animals.

Source : Directorate of Plant Protection, Quarantine and Storage

 

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0 ratings and

Nutritional Deficiencies/Disorders of Sorghum

1. Nitrogen
2. Phosphorous
3. Potassium
4. Sulphur

Nitrogen

Little new growth, yellow leaves, this being more pronounced in older leaves and leaf drop. Plants stunted, spindly pale yellow or deep yellow color near the tips and margins progresses toward the base heads small seed numbers reduced.

Correction measure: Apply 8-10 Kg N / acre as top dressing or foliar spray of urea @ 2-3 percent.

Phosphorous

Small root systems;  grain filling inhibited. Growth stunted, spindly, dark green leaves with dark red coloration. Leaf sheaths bend upward with red coloration leaf. Leave appear to be erect and leathery. Roots turn dark brown purple or black.

Correction measure: Foliar spray of 2% DAP 2-3 sprays at an interval of 15 days.

Potassium

Deficiency first seen on older leaves, Irregular necrotic patterns intermingled with red pigmentation. Streaked patterns on the interveinal tissue symptoms at tips and margins move towards the base.

Correction measure: Foliar spray of KCl @ 1%.

Sulphur

Deficiency appears first on younger leaves. New growth is pale yellow.

Correction measure: Foliar spray of CaSO₄ @ 2%

 

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

 

3.05   

 

118 ratings

Sorghum : Crop Stage-wise IPM

1. Pre-sowing*
2. Sowing*
3. Vegetative
4. Flowering

Management	Activity
Pre-sowing*
	Common cultural practices: · Deep summer ploughing · Use resistant/tolerant varieties · Follow crop rotation with non-host crops · Destroy the alternate host plants · Sow the ecological engineering plants · Sow sorghum/maize/bajra in 4 rows all around the main crop as guard/barrier crop · Soil solarization to prevent soil borne pathogens. · Timely sowing should be done. · Field sanitation, rogueing · Destroy the alternate host plants · Apply manures and fertilizers as per soil test recommendations · Adoption of crop rotation Common mechanical practices: · Uproot and burn infected plants parts early to avoid spread of the disease. · Collection and destruction of larvae.
Nutrients	· Apply FYM @ 5 t/ acre and incorporate in the soil 2 to 3 weeks before sowing.
Weeds	· Remove existing weeds at the time of sowing. · Weed species: Cyperus iria, Digera arvensis, Convolvulus arvensis, Trianthema sp.,Tridax procumbens, Euphorbia hirta, Phyllanthus niruri are controlled by 2,4-D dimethyl amine salt 58% SL 612 ml in 200-240 l of water/acre and 2,4-D ethyl ester 38 % EC (having 2,4-D acid 34 % w/w) 400 ml in 170 l of water/acre.
Soil borne pathogens, resting stages of insects	Cultural control: · Effective weed control. · Trimming of bunds · Early planting minimizes shoot fly, midge and ear head bug damage. · Planting sunhemp as trap crop to control the pest. Biological control: · Application of neem cake@ 80 Kg/ acre for nematode control. · Controlling adult beetles feeding on neem. · Acacia like trees on field bunds by shaking trees and destroying the beetles.
Sorghum loose Smut**	Cultural control: · Collect smutted ear-heads in cloth bags and destroy by dipping in boiling water or bury in soil. · Avoid ratooning. Chemical control: · Spray thiram 75% WS @ 10-12 g/acre in 400 ml of water.
Grain smut**	Cultural control: · Collect smutted ear-heads in cloth bags and destroy by dipping in boiling water. · Avoid ratooning Chemical control: · Seed treatment with sulphur 80% WP 1.2-1.6g/Kg seed in 400 ml of water.
Sowing*
	Common cultural practices: · Use healthy, certified and weed free seeds. · Follow proper spacing · Crop rotation with pulses or oilseed crops. Common mechanical practices: · After harvest, plough to remove and destroy the stubbles. · Collection and destruction of white grub.
Nutrients	· Apply NPK fertilizers as per soil test recommendations as far as possible. If soil test recommendations are not available, adopt a blanket recommendation of 30 N, 18 P2O5, and 18 K2Kg/acre. · Application of bio-fertilizers: When Azospirillum is used apply only 75% of recommended N for irrigated sorghum. · Mix 12.5 Kg of micronutrient mixture formulated with enough sand to make a total quantity of 50 Kg. · Basal application of 10 Kg ZnSO4/acre-1 for the deficient soils or 5 Kg Zn SO4 acre -1 + FYM for the Zn deficient soils · Basal application of FeSO4, 20 Kg/acre along with 5 t/acre FYM for iron deficient soils.
Weeds	· Weed Species: Cyperus iria, Digera arvensis, Convolvulus arvensis, Trianthema sp.,Tridax procumbens, Euphorbia hirta, Phyllanthus niruri are controlled by2,4-D dimethyl amine salt 58% SL 612 mlin200-240 l of water/acre and 2,4-D ethyl ester 38 % EC (having 2,4-D acid 34 % w/w)400 ml in 170 l of water/acre.
Shoot fly	Cultural control: · Early sowing to avoid the active period of shoot fly population. · Planting date in kharif 7-10 days onset of monsoon and in rabi end of September to 1st week of October is ideal to escape the shoot fly · High seed rate 1.6 – 2.0 Kg/acre. · Tall variety with yellow glossy stem less attacked. Mechanical control: · Removal of the seedlings with dead hearts. · Set up the low cost fish meal traps @4/acre till the crop is 30 days old. Chemical control: · Seed treatment with imidacloprid 48% FS @12ml/Kg seeds · Seed treatment with imidacloprid 70% WS@ 10g/Kg seeds · Spraying carbaryl 50%WP@ 600g/acre in 200-400 l of water. · Soil application carbofuran 3% CG @13320g/acre. · Spraying oxydemeton-methyl 25% EC @400ml/acre in 200-400 l of water. · Soil application phorate 10% CG @ 7500g/acre. · Spraying quinalphos 25%EC @ 600ml/acre in 200-400 l of water. · Seed treatment with thiamethoxam 30% FS @ 10 ml/Kgseeds.
Sorghum white grub	Mechanical control: · See the common mechanical practices Chemical control: · Apply phorate 10% @ CG 10 Kg/acre.
Sorghum downy mildew**	Cultural control: · Grow moderately resistant varieties. Chemical control: · Seed treatment with metalaxyl 35% WS @ 6-7 g/Kg seed.
Vegetative
	Common cultural practices: · Collect and destroy crop debris · Collect and destroy disease infected and insect damaged plant parts · Provide irrigation at critical stages of the crop · Avoid water logging · Avoid water stress during flowering stage · Judicious use of fertilizers · 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 and seed capsules 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 @ 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
Nutrients	· Apply N @ 50:25:25 % at 0, 15 and 30 DAS and full dose of P2O5 and K2O basally before sowing and if basal application is not possible the same could be top dressed within 24 hours.
Weeds	· Apply 2,4-D @ 400g/acre on 20-25 DAS on the plants surface, using Backpack/Knapsack/Rocker sprayer fitted with a flat fan nozzle using 80 l of water/acre (or) if herbicides are not used, hand weeding twice on 10-15 DAS and 30-35 DAS.
Stem borer	· Follow common cultural, mechanical and biological practices Cultural control: · Select and grow varieties resistant to spotted stem borer. Sow the lablab or cowpea or pigeon pea as an intercrop (Sorghum: Lablab 4:1) reduces the damage by stem borers. Biological control: · Egg parasitoids: Trichogramma chilonis @ 30,000/acre/ week Chemical control: · Spray carbaryl 50%WP @ 800g in 200-400 l of water/acre. · Application of carbofuran 3%CG @ 3320gm/acre. · Apply quinalphos 5% G 6000 @ g/acre.
Sorghum downy mildew	· As mentioned above in the sowing stage
Flowering
Midge	· Follow common cultural, mechanical and biological practices Cultural control: · Removal of Johnson grassy weed Biological control: · Neem seed kernel extract 5% · Azadirachtin 1% · Parasitoids: Aprostocetus sp. Chemical control: · Spray quinalphos 1.5% DP @ 10640 g/acre; phosalone 4% DP @ 10000g/acre; phosalone 35% EC @ 457.2 ml in 200-400 l of water/acre; malathion 50% EC @ 400ml in 200-400 l of water/acre.; malathion 5% DP@ 8000 g/acre; dimethoate 30% EC @ 660 ml in 200-400 l of water/acre; carbaryl 5% DP @ 8000 g/acre.
Sorghum ear head caterpillar**	· Follow common cultural, mechanical and biological practices Biological control: · Two applications of NPV at 10 days interval at 1.5 X1012 POB along with crude sugar 2.5 Kg + cotton seed kernel powder 250 g.
Sorghum earhead bug**	· Follow common cultural, mechanical and biological practices Biological control: · Neem seed kernel extract 5% · Azadirachtin 1% Chemical control: · Quinalphos 1.5% DP 10kg/acre.
Sorghum grain mould	· Follow common cultural, mechanical and biological practices
Sorghum charcoal rot	· Follow common cultural, mechanical and biological practices Cultural control: · Plant varieties with good stalk strength · Plant in fertile soil. · Avoid high plant populations unless irrigating. · Rotate with cotton.
Sorghum anthracnose**	· Follow common cultural, mechanical and biological practices Cultural control: · Eliminate other susceptible plants such as Johnson grass. · Rotate crops. · In poorly rotated fields, plough under infested residue where erosion is not a problem. Chemical control: · Treat the seeds with thiram at 4 g/Kg.
Sorghum rust**	Follow common cultural, mechanical and biological practices Cultural control: · Remove the alternate host Oxalis comiculata
Sorghum ergot**	· Follow common cultural, mechanical and biological practices
Sorghum loose smut**	· Same as mentioned in the above pre-sowing stage
Grain smut**	· Same as mentioned in the above pre-sowing stage
Birds**	Mechanical control: · Use bird scarer · Use reflecto-ribbon surrounding sorghum field Botanical control: · Apply NSKE5% on panicle to save the damage from birds
Note: Apply Trichoderma spp./ harzianum and Pseudomonas fluorescens as seeds/ seedling/ planting material treatment and soil 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).

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

 

3   

 

140 ratings

Sorghum Pests

1. Pests of National Significance
1. Insect pests
2. Diseases
3. Weeds
1. Broad leaf
2. Grasses
3. Sedges
4. Parasitic weeds
4. Nematode
5. Vertebrates
2. Pests of Regional Significance
1. Insect and mite Pests
2. Diseases
3. IPM for Sorghum

Pests of National Significance

Insect pests

• Shoot fly: Atherigona soccata (Rondani) (Diptera: Muscidae)
• Stem Borer: Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae)
• Midge: Stenodiplosis sorghicola (Coquillett) (Diptera: Cecidomyiidae)
• White grub: Holotrichia consanguinea (Hope) (Coleoptera:Scarabaeidae)

Diseases

• Grain mold: Fusarium sp.,Phomasp. (Saccardo) Curvularia sp.
• Charcoal rot: Macrophomina phaseolina (Tassi, Goid)

Weeds

Broad leaf

• Cock'scomb: Celosia argentea L. (Amaranthaceae)
• Common purselane: Portulaca oleraceaL.( Portulacaceae)
• False amaranth: Digera arvensis (Forssk) (Amaranthaceae)
• Horsepurslane: Trianthema portulacastrum L. (Aizoaceae)
• Pigweed: Amaranthus viridis (Hook. F.)(Amaranthaceae)
• Swinecress: Coronopus didymus L. Sm. (Brassicaceae)
• Black nightshade: Solanum nigrum L. (Solanaceae)
• Sessilisjoywood: Alternanthera sessilis L DC (Amaranthaceae)
• Punarnava: Boerhavia diffusa L. (Nyctagnaceae)
• Tropical spiderwort: Commelina benghalensis L (Commelinaceae)
• Whitetop Weed: Parthenium hysterophorus L (Asteraceae)
• Bullhead: Tribulus terrestris L (Zygophyllaceae)
• Coat button: Tridax procumbensL(Asteraceae)

Grasses

• Rabbit/crow foot grass: Dactyloctenium aegyptium (Willd) (Poaceae)
• Goosegrass: Eleusine indica L. (Gaertner) (Poaceae)
• Barnyard grass: Echinochloa crusgalliL. (Scop) (Poaceae)
• Crabgrass: Digiteria sanguinalis L. (Scop) (Poaceae)
• Burmuda Grass: Cynodon dactylon (Poaceae)
• Johnson grass: Sorghum halepense L Pers (Poaceae)
• Gamba grass: Brachiaria ramose L (Poaceae)
• Finger grass: Chloris barbata Sw (Poaceae)

Sedges

• Purplenutsedge: Cyperus rotundus L (Cypraceae)
• Flat sedge: Cyperus iria L. (Cypraceae)

Parasitic weeds

• Witchweed: Striga asiatica L. (Kuntze) (Orobanchaceae)

Nematode

• Lesion Nematode: Pratylenchus spp. (Tylenchida: Pratylenchidae)
• Cyst nematode: Heterodorasorghii

Vertebrates

• Rodent: Springhare sp. (Rodentia)
• Parrot: Psittacines sp. (Psittaciformes)
• Crow: Corvus spp. (Passeriformes: Corvidae)

Pests of Regional Significance

Insect and mite Pests

• Armyworm: Mythimna separate (Walker) (Lepidoptera: Noctuidae) Karnataka, Maharashtra
• Cutworms: Agrotisipsilon (Ochsenheimer) (Lepidoptera: Noctuidae)
• Grasshopper: Hieroglyphus sp (Krauss) (Orthoptera: Acrididae) Karnataka, Rajasthan, Tamil Nadu, Madhya Pradesh, Uttar Pradesh, Haryana, Delhi
• Pyrilla: Pyrilla perpurilla (Linnaeus) (Hemiptera: Lophopidae) Maharashtra, Madhya Pradesh
• Shoot bug: Peregrinus maidis ( Ashmead) (Hemiptera: Delphacidae) Andhra Pradesh, Madhya Pradesh, Karnataka, South India, Tamil Nadu, Bihar, Maharashtra
• Earhead caterpillars: Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) Eublemma spp,(Lepidoptera: Noctuidae) Crytoblabes spp. (Lepidoptera: Pyralidae) Gujarat, Andhra Pradesh, Tamil Nadu, Haryana, Madhya Pradesh, Delhi, Maharashtra
• Earhead bug: Calocoris angustatus (Hemiptera: Miridae) Karnataka, Andhra Pradesh, Tamil Nadu, Uttar Pradesh
• Sugar cane aphid: Rhophalosiphum maidis Koch (Hemiptera: Aphididae) Andhra Pradesh, Delhi, Gujarat, Maharashtra
• Spider mite: Oligonychus indicus Hirst (Trombidiformes: Tetranychidae) Karnataka, Punjab, Maharashtra, Tamil Nadu

Diseases

• Downy mildew: Peronosclerospora sorghi (Weston & Uppal, C.G. Shaw) Rajasthan, Tamil Nadu, Karnataka, Andhra Pradesh, Maharashtra, Haryana
• Anthracnose: Colletotrichum graminicola (D.J. Politis)
• Loose smut: Sporisorium cruenta (de Bary)
• Ergot: Claviceps sorghi (B.G.P. Kulk)Tamil Nadu, Karnataka, Andhra Pradesh, Maharashtra
• Grain smut: Sporisorium sorghi (Ehrenb ex. Link)
• Red leaf spot : Helminthosporium turcicum Madhya Pradesh, Bihar, Maharashtra
• Rust : Puccinia purpurea (Cooke) Karnataka, Madhya Pradesh, Tamil Nadu, Uttar Pradesh, Maharashtra, Andhra Pradesh, Bihar, Central Provinces

IPM for Sorghum

To know the IPM practices for Sorghum, click here.

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

 

3.06   

 

155 ratings and

Sorghum: Diseases and Symptoms

1. Sorghum grain mould
2. Sorghum charcoal rot
3. Sorghum downy mildew
4. Sorghum anthracnose
5. Loose smut
6. Rust
7. Ergot
8. IPM for Sorghum

Sorghum grain mould

Damage symptom

• If rains occur during the flowering and grain filling stages, severe grain moulding occurs. The most frequently occurring genera are Fusarium, Curvularia, Alternaria, Aspergillus and Phoma. Fusarium semitectum and F.moniliforme develop a fluffy white or pinkish coloration. C. lunata colours the grain black. Symptom varies depending upon the organism involved and the degree of infection.

Survival and spread

• The fungi mainly spread through air-borne conidia.
• The fungi survive as parasites as well as saprophytes in the infected plant debris.

Favourable conditions

• Wet weather following the flowering favors grain mould development.
• The longer the wet period the greater the mould development.
• Compact ear heads are highly susceptible.

Sorghum charcoal rot

Damage symptom

• Charcoal rot is a major disease in the dry sorghum growing regions. The disease is particularly destructive on high yielding, sorghum that mature during hot and dry weather if the vigorously growing crop is subjected to moisture stress during the pre-flowering period. Infected stalks show an internal shredding at and above the ground line. The shredding can be observed by splitting the stalk and molting the deteriorated soft pith tissue leaving the tougher vascular strands

Survival and spread

• Survival of microsclerotia is several years in dry soil but only a few weeks in wet, saturated soils.

Favourable conditions

• Charcoal rot is caused by Macrophomi naphaseolina, a disease that appears in hot and dry weather.
• When soil temperatures are 80-95°F (27-35°C) for 2 to 3 weeks.

Sorghum downy mildew

Damage symptom

• The fungus causes systemic downy mildew of sorghum. It invades the growing points of young plants, either through oospore or conidial infection. As the leaves unfold they exhibit green or yellow colouration. Abundant downy white growth is produced on the lower surface of the leaves, which consists of sporangiophores and sporangia. Normally three or four leaves develop the chlorotic downy growth. Subsequent leaves show progressively more of a complete bleaching of the leaf tissue in streaks or stripes. As the infected bleached leaves mature they become necrotic and the interveinal tissues disintegrate, releasing the resting spores (oospores) and leaving the vascular bundles loosely connected to give the typical shredded leaf symptom.

Transmission

• The primary infection is by means of oospores present in the soil which germinate and initiate the systemic infection.
• Secondary spread is by air-borne sporangia

Favourable conditions:

• Maximum sporulation takes place at 100 per cent relative humidity.
• Optimum temperature for sporulation is 21-23⁰C during night.
• Light drizzling accompanied by cool weather is highly favourable.

Sorghum anthracnose

Damage symptom

• The fungus causes both leaf spot (anthracnose) and stalk rot (redrot). The disease appears as small red coloured spots on both surfaces of the leaf. The centre of the spot is white in colour encircled by red, purple or brown margin. Numerous small black dots like acervuli are seen on the white surface of the lesions. Red rot can be characterized externally by the development of circular cankers, particularly in the inflorescence. Infected stem when split open shows discoloration, which may be continuous over a large area or more generally discontinuous giving the stem a marbeled appearance.

Survival and spread

• The disease spread by means of seed-borne and air-borne conidia and also through the infected plant debris.

Favourable conditions

• Continuous rain.
• Temperature of 28-30˚C.
• High humidity.

Loose smut

Damage symptom

• The affected plants can be detected before the ears come out. They are shorter than the healthy plants with thinner stalks and marked tillering. The ears come out much earlier than the healthy. The glumes are hypertrophied and the earhead gives a loose appearance than healthy. The sorus is covered by a thin membrane which ruptures very early, exposing the spores even as the head emerges from the sheath.

Transmission

• The pathogen is externally seed borne.

Favourable conditions

• Optimum environmental conditions for maximum infection include: temperatures between 20 and 25°C and slightly acidic soils favour the disease developments.

Rust

Damage symptom

• The fungus affects the crop at all stages of growth. The first symptoms are small flecks on the lower leaves (purple, tan or red depending upon the cultivar). Pustules (uredosori) appear on both surfaces of leaf as purplish spots which rupture to release reddish powdery masses of uredospores. Teliopores develop later sometimes in the old uredosori or in telisori, which are darker and longer than the uredosori. The pustules may also occur on the leaf sheaths and on the stalks of inflorescence.

Survival and spread

• The uredospores survive for a short time in soil and infected debris. Presence of alternate host helps in perpetuation of the fungus.

Favourable conditions

• Low temperature of 10 to 12⁰C favours teliospore germination.
• A spell of rainy weather favours the onset of the disease.

Ergot

Damage symptom

• The disease is confined to individual spikelets. The first symptom is the secretion of honey dew from infected florets. Under favourable conditions, long, straight or curved, cream to light brown, hard sclerotia develop. Often the honey dew is colonised by Crerebella sorghivulgaris which gives the head a blackened appearance.

Survival and spread

• The primary source of infection is through the germination of sclerotia which release ascospores that infect the ovary.
• The secondary spread takes place through air and insect-borne conidia. Rain splashes also help in spreading the disease.

Favourable conditions

• A period of high rainfall and high humidity during flowering season.
• Cool night temperature and cloudy weather aggravate the disease.

IPM for Sorghum

To know the IPM practices for Sorghum, click here.

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

 

3.01   

 

142 ratings and

Sorghum: Pests Management

1. Shoot fly
2. Sorghum stem borer
3. Sorghum midge
4. Cutworm
5. White grub
6. IPM for Sorghum

Shoot fly

Biology

• Egg: Eggs are cigarette shape, white coloured laid generally singly parallel to the midrib on the under surface of the 3rd to 5th leaf. Under high shoot-fly pressure, there may be several eggs on the same leaf. Sometimes, as many as 25 eggs may be laid on the same seedling. They hatch in 2-5 days.
• Maggot: Yellow in colour migrate to the dorsal surface of the leaf, enter the space between the leaf sheath and the axis and make a clean cut at the base of the leaf. The larval period lasts for 6 - 10 days.
• Pupa: Pupation takes place inside the stem and the adults emerge in about a week.
• Adult: The adults are dark brown and similar to domestic housefly, but nearly half the size with the males smaller than the females. The adults usually live for 10 to 20 days.

Favourable conditions

• The late sown crops generally suffer greater shoot fly damage because of high humidity and moderate temperature.
• Infestation is normally high in the post rainy season crop, which is sown in September- October temperature above 35^oC and below 18^oC reduces shoot fly survival.

Damage symptoms

• Damage by at the seedling stage (5 to 30 days after seedling emergence) will lead to the typical dead heart symptoms.
• The larva migrates to the upper side of the leaf, and moves along the leaf whorl until it reaches the growing point where the larvae cut the growing point. As a result the central leaf dries up forming a dead heart, which can be pulled out easily and produces a rotting smell.
• Normally the damage occurs 1 to 4 weeks after seedling emergence. Seedlings of 5 to 30 days old are generally susceptible to shoot fly damage.
• Older plants (>30 days after seedling emergence) are not usually damaged by A. soccata however, under conditions of high humidity during the rainy season, infestation may occur.
• Under these conditions the infested plants do not produce the typical dead heart symptoms. In this instance, the damaged leaf becomes thin and papery, wrapping around the other leaves. The plants may fail to grow normally.
• Late infestations may also damage the panicle in the formative stage, resulting in rotting or drying up of a portion of the panicle affected by shoot fly damage.
• The damage plants produce side tillers
• Infestation is especially high when sorghum planting is staggered due to erractic rainfall.

Natural enemies of shootfly

• Parasitoids : Trichogrammatoidea simmonalsi, Trichogramma chilonis, Neotrichoporoides nyemitawus
• Predators: Spiders, Coccinellids, lace wings etc.

Sorghum stem borer

Biology

• Egg: The eggs are laid on the underside of a leaf near the midrib in 3-5 rows, in groups of 10-100. They are flattened, oval, and about 0.8 mm long. Hatching takes place after 7-10 days.
• Larva: The young caterpillars produce characteristic leaf windowing. Sometimes the early stages mine in the leaves, causing yellow streaks. After a few days they bore down inside the tunnel. They also may move down outside the stem and then bore into it just above an internode. In older plants the caterpillars sometimes live in the developed heads. In general appearance the larvae look like Busseola fusca larvae (= Maize Stalk Borer). They are creamy pink with groups of dark spots along the back. The head capsule is brown. When mature they are about 25 mm long. The caterpillars can be distinguished from B. fusca and from Sesamia calamistis (= Pink Stalk Borer) by the hooks on its prolegs. In C. partellus these hooks are arranged in a complete circle. In B. fusca and S. calamistis they are arranged in a crescent. The larval period takes 28-35 days.
• Pupa: Pupation takes place in a small chamber in the stem. The pupal period takes 7 10 days.
• Adult: Adult moths have a wingspan of 20-30 mm. Males are smaller and darker than females. The forewings of males are pale brown. The forewings of the females are much paler and the hind wings are almost white.

Damage symptoms

• Damage occurs as a series of small holes in lines (pin holes) in younger leaves and/or patches of transparent leaf epidermis (window panes) in older leaves.
• Holes in stem caused by larvae tunnelling into the stem can result in broken stems or drying and eventual death of the growing point (deadheart).

Natural enemies of stem borer

• Parasitoid: Cotesia sesamiae, Cotesia chilonis
• Predators: Chrysoperla zastrowi sillemi, ladybird beetle, reduviid bug, spider, fire ant, robber fly, black drongo (King crow), common mynah, big-eyed bug (Geocoris sp), earwig, ground beetle, pentatomid bug (Eocanthecona furcellata), preying mantis, Dicyphus hesperus etc.

Sorghum midge

Biology

• Eggs: Each white, cylindrical egg, 0.3 by 0.6 mm, is attached to the host spikelet by a slender, tapering stalk.
• Maggot: The newly hatched larva is colorless. As it feeds on the developing grain, it gradually becomes pale pink to a deeper pink, then orange, and finally a darker orange or red-orange. The full-grown larva, 1.5 to 2.0 mm long, is slightly flattened and spindle-shaped, tapering to a point at the head.
• Pupa: At first, the pupa is uniformly dark orange, but after a few hours the head, antennae, legs and thorax darken until they become black. Only the abdomen retains the orange color.
• Adult: The sorghum midge is an orange fly, the male measuring approximately 1.3 mm in length and the female 1.6 mm.

Damage symptoms

• Maggot feed on the developing ovary inside the glumes: this results in empty or chaffy spikelets as shrivelled grains fail to develop.
• During the grain filling or milk stage, if damaged spikelets are pressed between the finger and thumb or between a pair of forceps, they produce a red ooze: the body contents of the midge larva or pupa.
• In the mature crop, damaged spikelets become empty or chaffy, and the sorghum panicles present a blasted appearance.
• Damaged panicles have small, transparent midge pupal cases attached to the tip of the damaged spikelets.

Natural enemies of sorghum midge

• Parasitoids: Aprostocetus spp.

Cutworm

Biology

• Egg: The egg is white in color initially, but turns brown with age. It measures 0.43 to 0.50 mm high and 0.51 to 0.58 mm wide and is nearly spherical in shape, with a slightly flattened base. The egg bears 35 to 40 ribs that radiate from the apex; the ribs are alternately long and short. The eggs normally are deposited in clusters on foliage. Females may deposit 1200 to 1900 eggs. Duration of the egg stage is three to six days.
• Larva: There are five to nine instars, with a total of six to seven instars most common. the larva is rather uniformly colored on the dorsal and lateral surfaces, ranging from light gray or gray-brown to nearly black. The head is brownish with numerous dark spots. Larvae usually remain on the plant until the fourth instar, when they become photo-negative and hide in the soil during the daylight hours. In these latter instars they also tend to sever plants at the soil surface, pulling the plant tissue belowground. Larvae tend to be cannibalistic.

• Pupa: The pupa is 17 to 22 mm long and 5 to 6 mm wide and dark brown. Duration of the pupal stage is normally 12 to 20 days. Pupation occurs belowground at a depth of 3 to 12 cm.
• Adult: The adult is fairly large in size, with a wingspan of 40 to 55 mm. The forewing, especially the proximal two-thirds, is uniformly dark brown. The distal area is marked with a lighter irregular band, and a small but distinct black dash extends distally from the bean-shaped wing spot. The hind wings are whitish to gray, and the veins marked with darker scales.

Damage symptoms

• Cutworms usually feed at night or during overcast days. Newly hatched larvae feed on weeds, and/or young maize plants if present, leaving small irregular holes in the leaves. Such early feeding is of little significance to plants.
• Larger larvae may completely cut through stalks, which can cause plants to wilt and die. Severe stand reductions can result. They sometimes drag cut plants under soil clods or into small holes in the soil to continue their feeding during the daylight hours.
• In other crops like potatoes and root vegetables, damage can take the form of unsightly holes in the subterranean tubers, which may allow the penetration of secondary fungi.
• When numerous, cutworms can destroy as much as 75% of a crop.

Natural enemies of cutworm

• Parasitoids: Cotesia spp., Meterorus spp., Campoletis spp.
• Predators: Chrysoperla zastrowi sillemi, ladybird beetle, reduviid bug, spider, fire ant, robber fly, black drongo (King crow), common mynah, big-eyed bug (Geocoris sp), earwig, ground beetle, pentatomid bug (Eocanthecona furcellata), preying mantis etc.

White grub

Biology

• Egg: A female lays on an average of 27 eggs in the soil, which are pear like white enclosed in earthen cells.
• Grub: Fleshy ‘C’ shaped, whitish yellow in colour found close to the base of the clump.
• Pupa: Pupae are tan to brown, and occur deeper in the soil in earthen chambers.
• Adult: Adult beetles are a rusty-red color just after emerging from the pupal stage, but turn nearly black.

Damage symptoms

• Yellowing and wilting of leaves.
• Drying of entire crown.
• Affected stem come off easily when pulled.
• Cause extensive damage to roots and base of shoot.

Natural enemies of white grub

• Parasitoids:Typhia (parasitic wasp)
• Predators: Ground beetle, red ant etc.

IPM for Sorghum

To know the IPM practices for Sorghum, click here.

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

 

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