Maize Cultivation Practice

By TamilNadu Agricultural University on 14 Dec 2018 | read
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Image title

Season and Varieties


SeasonStrain
Adipattam (July - August)TNAU maize hybrid Co 6, Baby corn Co(Bc) 1
Purattasipattam (September - October) TNAU maize hybrid Co 6, Baby corn Co(Bc) 1
Thaipattam (January - February)TNAU maize hybrid Co 6, Baby corn Co(Bc) 1

Morphological Description


Image titleMaize - HYBRID COH (M)

PARTICULARSCO 1COH(M) 4
ParentageUnit Selection from Indonesian popu­ lation Suwan 1(UMI 90 x xUMI 285) x UMI 112
Duration (days)105 - 11094 (90 – 95 days)
Area of AdoptionCoimbatore, Erode, Tirunelveli, Tanjore and PudukottaiCoimbatore, Dindugul, Erode, Salem, Virudhunagar, Perambalur, Tuticorin, Madurai and Theni districts
Rainfed/IrrigatedBothBoth
Grain yield (kg/ha)
Irrigated52005694
Rainfed33004521
Special featuresResistant to downy mildew Orange flint grainsShorter duration,  suitable for rainfed areas Moderate resistance to downy mildew and stemborer
Sheath colourGreenGreen
Node colourGreenGreen
Mid ribWhiteWhite
Cob sizeBigBig
Husk coverageFullFull
Grain colourDeep orangeYellow
Nature of kernelsFlintFlint


ParticularsTNAU maize hybrid Co 6Baby corn Co(Bc) 1
Parentage(UMI 1200 x UMI 1230)Composite involving UMI 836 and UMI 836-1-2
Duration (days)110 days55 – 65 (fresh cobs harvest)
Area of AdoptionAll maize growing areasAll maize growing areas
Rainfed/IrrigatedBothBoth

Grain yield (kg/ha)

Irrigated74006.7 tonnes of tender cobs & 32.3 tonnes of green fodder / ha
Rainfed50003 tonnes of tender cobs per ha.
Special featuresHigh starch (76.30 %), high protein (11.25%) and high beta- carotein (0.48 mg/100g) with moderate level of fat (4.65 %) and crude fibre (1.25%). High shelling (81%) with high test weight (400 g /1000 seeds). Multiple disease resistance to Sorghum downy mildew, Maydisleaf blight, Turcicum leaf blight, Post flowering stock rot and Banded leaf and sheath blight. Moderately resistant to stem borer. Hybrid seed production is much easier since male and female parents can be sown simultaneously for flowering synchronization.2 to 3 cobs / plant, possessing delightful sweet taste and flavour Suitable for inland and export marketGreen fodder has good forage value.
Stem colourGreenGreenish pink
Leaf: Anthocyanin colouration of sheathPresentNil
Ear: Anthocyanin colouration of silkPresentPresent
Cob sizeBigSmall
Ear: Husk coverageFullFull
Colour of top of GrainsOrange YellowYellow
Type of kernelsSemi dentDent

Irrigated Maize

Field Preparation

Application of Fym or Compost

Spread 12.5 t/ha of FYM or compost or composted coir pith evenly on the unploughed field along with 10 packets of Azospirillum (2000 g/ha) and incorporate in the soil.

Field Preparation

Plough the field with disc plough once followed by cultivator ploughing twice, after spreading FYM or compost till a fine tilth is obtained.

Forming Ridges and Furrows or Beds

  • Form ridges and furrows providing sufficient irrigation channels. The ridges should be 6 m long and 60 cm apart.
  • If ridges and furrows are not made, form beds of size 10 m2 or 20 m2 depending on the availability of water.
  • Use a bund former or ridge plough to economise cost of production.


Application of Fertilizer
  • Apply NPK fertilizers as per soil test recommendation as far as possible. If soil test recommendation is not available adopt a blanket recommendation of 135:62.5:50 NPK kg/ha. 
  • Apply quarter of the dose of N; full dose of P2O and K2O basally before sowing.
  • In the case of ridge planted crop, open a furrow 6 cm deep on the side of the ridge, at two thirds the distance from the top of the ridge. 
  • Apply the fertilizer mixture along the furrows evenly and cover to a depth of 4 cm with soil. 
  • If bed system of planting is followed, open furrows 6 cm deep at a distance of 60 cm apart. 
  • Place the fertilizer mixture along the furrows evenly and cover to a depth of 4 cm with soil.

When Azospirillum is used as seed and soil application, apply 100 kg of N/ha (25% reduction on the total N recommended by soil test).

Deficiency symptoms

Nitrogen deficiency

:

Leaves become yellow, older leaves show drying at the tips which progress along mid veins, stalks become slender.

Phosphorus deficiency

:

Leaves are purplish green during early growth. Growth spindly, slow maturity, irregular ear formation.

Potassium deficiency

:

Leaves show yellow or yellowish green streaks, become corrugated. Tips and marginal scorch.  Tips end in ears are poorly filled. Stalks have short internode. Plants become weak and may fall down.

Magnesium deficiency

:

Older leaves are the first to become chlorotic at margins and between veins. Streaked appearance of leaves. Necrotic or chlorotic spots seen in leaves.

Zinc deficiency

:

Older leaves have yellow streaks or chlorotic striping between veins. In several cases, unfolding of young leaves, which may be white or yellow.

Iron deficiency

:

Interveinal chlorosis. The entire crop may exhibit bleached appearance

Application of Micronutrient
  • 12.5 kg of micronutrient mixture formulated by the Department of Agriculture, Tamil Nadu, mixed with sand to make a total quantity of 50 kg/ha is to be applied.
  • Apply TNAU MN mixture @ 30 kg /ha as Enriched FYM (Prepare enriched FYM at 1:10 ratio of MN mixture & FYM ; mix at friable moisture &incubate for one month in shade).
  • (or) 5 kg Zn + 40 kg S + 1.5 kg B in deficient soils.
  • Zinc sulphate @ 37.5 kg/ha is recommended for hybrid maize in Zn deficient soils
  • Apply the mixture over the furrows and two thirds in the top of ridges, if ridge planting is followed.
  • If bed system of sowing is followed, apply the micronutrient mixture over the furrows.
  • Do not incorporate the micronutrient mixture in the soil.


Seed and Sowing

Seed Rate

Select good quality seeds and adopt the seed rate of 20 kg/ha for CO 1 and TNAU Maize Hybrid CO 6 and 25 kg /ha for COBC 1.

Spacing

Adopt a spacing of 25 cm between plants in the rows which are 60 cm apart. 
Population :  For varieties and hybrids 6 – 7 plants / sq. m. and 
For baby corn, 8 – 9 plants / sq. m.

Seed Treatment

Step 1:Use pelleted seeds with insecticides (treat one kg of seeds with Chlorpyriphos 20EC or Monocrotophos 36 WSC or Phosalone 35 EC @ 4 ml + 0.5 gram gum in 20 ml of water) for the control of stem borer or seed treatment with imidacloprid 70 WS 10 g/kg of seeds.
Step 2:Seed treatment with Metalaxyl or Thiram @ 2 g/kg of seed for the control of downy mildew and crazy top 
Step 3:Seeds treated with fungicides may be treated with three packets (600 g/ha) of Azospirillum before sowing.

Sowing

  • Dibble the seeds at a depth of 4 cm along the furrow in which fertilizers are placed and cover with soil. 
  • Put one seed per hole if the germination is assured otherwise put two seeds per hole   

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Seed sowing operation 
(25 cm between plants X rows with 60 cm apart)

Weed Management

Apply Atrazine @ 0.25 kg/ha as pre-emergence on 3-5 DAS using Backpack/ Knapsack/ Rocker sprayer fitted with a flat fan nozzle using 500 litres of water/ha followed by one hand weeding on 30-35 DAS. (or)

  • Apply Atrazine @ 0.25 kg/ha as pre-emergence on 3-5 DAS followed by 2,4-D @ 1 kg/ha on 20-25 DAS, using Backpack/Knapsack/Rocker sprayer fitted with a flat fan nozzle using 500 litres of water/ha.
  • In line sown crop, apply PE Atrazine @ 0.25 kg/ha on 3-5 DAS followed by Twin Wheel hoe weeder weeding on 30-35 DAS.
  • Apply herbicide when there is sufficient moisture in the soil.
  • Do not disturb the soil after herbicide application.
  • If pulse crop is to be raised as intercrop, do not use Atrazine. Spray Pendimethalin @0.75 kg/ha as pre emergence on 3-5 DAS.


Unweeded Maize fieldImage title


Hoeing and hand weeding on 

the 17th or 18th day of sowingImage title

After Cultivation

Thinning and Gap Filling

  • If two seeds were sown, leave only one healthy and vigorous seedling per hole and remove the other on the 12-15 days after sowing. 
  • Where seedlings have not germinated, dibble presoaked seeds at the rate of 2 seeds per hole and immediately irrigate.

Hoeing, Hand-Weeding and Earthing Up

  • Hoe and hand-weed on the 30th day of sowing. 
  • Earth up and form new ridges so that the plants come directly on the top of the ridges. This will provide additional anchorage to the plants.

Top Dresssing with N

  • Place half of the dose of N on the 25th day of sowing along the furrows evenly and cover it with soil.
  • Place the remaining quarter of N on the 45th day of sowing
Water Management

Maize crop is sensitive to both moisture stress and excessive moisture, hence regulate irrigation according to the requirement. Ensure optimum moisture availability during the most critical phase (45 to 65 days after sowing); otherwise yield will be reduced by a considerable extent.

Regulate irrigation according to the following growth phase of the crop.
Germination & establishment phase                     1 to   14 days
Vegetative phase                                                 15 to 39 days
Flowering phase                                                   40 to 65 days
Maturity phase                                                     66 to 95 days

Heavy soils
Stage

No. of irrigation                           Days after sowing 
Germination & establishment3After sowing, Life irrigation -4th,12th day
Vegetative225th, 36th day
Flowering (Irrigate copiously)248th,  60th day
Maturity phase (Control irrigation)272nd, 85th day
Light soils
Germination & establishment3After sowing, Life irrigation -4th ,12thday
Vegetative Phase322nd ,32nd & 40th day
Flowering phase (Irrigate copiously)350th ,60th & 72nd day
Maturity phase (Controlled irrigation)285th , 95th day


Harvesting

Image titleUse mechanical threshers to separate the grains from the shank

Stage of Harvest

Observe the following symptoms, taking into consideration the average duration of the crop. 
i.   The sheath covering the cob will turn yellow and dry at maturity. 
ii. The seeds become fairly hard and dry.  At this stage the crop is ready for harvest.

Harvesting the Crop

  • Tear off the cob sheath by using the gunny needle and remove the cobs from the plant. 
  • Carry out harvest operations at a single stage for easy transportation.

Threshing the Cobs

  • Dry the cobs under the sun till the grains are dry. 
  • Use mechanical threshers or by running the tractor over dried cobs to separate the grains from the shank. 
  • Clean the seeds by winnowing 
  • Collect and store the dry grains in gunnies
Stacking Straw for Feeding Cattle

  1. Maize straw can also be used as a good cattle feed when it is green. 
  2. Harvest the crop and cut the green straw into bits with a chaff cutter or chopping knife and feed the cattle.



Image titleDry the cobs under the sun till the grains are dry

Rainfed Maize

1.Field Preparation

Chisel the soil having hard pan formation at shallow depths with chisel plough at 0.5 M interval first in one direction and then in the direction perpendicular to the previous one once in three years. Apply 12.5 t/ha of FYM or compost or composted coir pith besides chiselling, to get an additional yield of about 30% over control.
 
2. Application of Fym or Compost

Spread 12.5 t/ha of FYM or compost or composted coir pith evenly on the unploughed field along with 10 packets of Azospirillum (2000 g/ha) and incorporate in the soil.

3. Application of Fertilizer

  • Apply NPK as per soil test recommendation as far as possible. If soil test recommendation is not available, adopt a blanket recommendation of 60 : 30 : 30 NPK kg/ha for Alfisols and 40 : 20 : 0 NPK kg/ha for Vertisols.
  • Apply half of N and full dose of P2O and K2O with enriched FYM as basal along with Azospirillum (10 packets/ha).
  • Top dress remaining half of N at tasseling.
  • Apply TNAU MN mixture @ 7.5 kg /ha as Enriched FYM (Prepare enriched FYM at 1:10 ratio of MN mixture & FYM ; mix at friable moisture &incubate for one month in shade).

4. Seed Rate

Select good quality seeds. Adopt the seed rate @ 20 kg/ha for hybrids and 25 kg/ha. for varieties

5. Spacing

Adopt a spacing of 45 cm between rows and 20 cm between plants in the row.
Population   : 10 - 11plants/m­­2

6. Pre-Treatment of Seeds with BioFertilizer

Seeds treated with fungicides may be treated with three packets (600 g/ha) of Azospirillum

7. Sowing

Dibble or drill the seeds at a depth of 4 cm.

8. Cropping Systems

  • Intercropping system of maize + cowpea or maize + blackgram is recommended for higher net returns in the red lateritic soils of Southern districts.
  • For Vertisols of Southern district, maize + redgram intercropping systems is ideal.

9. Crop physiology

  • Foliar spray of TNAU Maize Maxim @ 3 kg/acre in 200 litres of water at tassel initiation and at grain filling stages improves grain filling, grain yield and drought tolerance.

10. Crop Protection

Crop Pest 


  
 Stem fly: Atherigona orientalis Web worm: Cryptoblabes gnidiella
 Stem borer: Chilo partellus Ash weevil: Myllocerus sp
 Pink stem borer: Sesamia inferens Leafhopper: Pyrilla perpusilla
 Corn worm: Helicoverpa armigera Aphid or Plant lice: Rhopalosiphum maidis
 Ear head bug: Calocoris angustatus Shoot bug: Peregrinus maidis
  
Important pests
I. Borer
Stem fly: Atherigona orientalis


Symptoms of damage

  • The maggot feeds on the young growing shoots results in “dead hearts”.

Identification of the pest

  • Adult - Small grey coloured fly.

AdultImage title

Nymph, Larva, Pupa and AdultImage title

Dead HeartImage title

Management

  • Use seeds pelleted with insecticides (see sorghum)
  • Seed treatment with imidacloprid 70 WS 10 g/kg of seeds
  • Plough soon after harvest, remove and destroy the stubbles.
  • Set up the TNAU low cost fish meal trap 12/ha till the crop is 30days old.
  • Soil application of phorate 10%CG 10 kg/ha at the time of sowing

Apply any one of the following insecticides:

  • Methyl demeton 25 EC 500 ml/ha
  • Carbofuran 3%CG 33.3 kg/ha
  • Dimethoate 30%EC 1155 ml/ha
  • Methyl demeton 25% EC 1000 ml/ha
  • Phorate 10%CG 10 kg/ha

Stem borer: Chilo partellus

Symptoms of damage

  • Central shoot withers and leading to “dead heart”.
  • Larvae mines the midrib enter the stem and feeds on the internal tissues.
  • Bore holes visible on the stem near the nodes.
  • Young larva crawls and feeds on tender folded leaves causing typical “shot hole” symptom.
  • Affected parts of stem may show internally tunnelling caterpillars

Elongated windowsImage title

Bore holeImage title

Dead heartImage title

Identification of the pest

  • Larva - Yellowish brown with a brown head 
  • Adult - Moth is medium size, straw coloured

 

 

Larva and PupaImage title

MothImage title

Management
  • Mix any of the following granular insecticides with sand to make upa total quantity of 50 kg and apply in the leaf whorls on the 20thday of sowing
  • Phorate 10% CG10 kg/ha
  • Carbaryl 4% G 20 kg/ha.
  •  For stem borer, release egg p[arasitoid Trichogramma chilonis @2,50,000 /ha coinciding egg laying period. Three releases atweekly interval are desirable. Third release is to be accompaniedwith larval parasitoid Cotesia flavipes @ 5000/ha
  • If granular insecticides are not used, spray any one of thefollowing :
  • Carbaryl 50 WP 1 kg/ha on the 20th day of sowing (500 l of sprayfluid/ha).
  • Dimethoate 30% EC 660 ml/ha

Pink stem borer: Sesamia inferens
Symptoms of damage
  • Pink larva enters into the stem causing dead heart symptom .

Identification of the pest

  • Egg - Bead like laid in rows within the leaf sheath
  • Larva - Pinkish brown with dark head
  • Adult - Straw coloured moth with white wings

Management

  • Spray phosaloneb 35%EC at every 20 days interval

EggImage title

Pupa and LarvaImage title

AdultImage title


II. Earhead feeders
Corn worm/Earworm: Helicoverpa armigera

Symptom of damage

  • Larva feeds on silk and developing grains.

Image titleBore hole on the cob

 

Identification of the pest

  • Eggs - Spherical in shape and creamy white in colour, laid singly
  • Larva - Shows colour variation from greenish to brown.
  • It has dark brown grey lines on the body with lateral white lines
  • Pupa - Brown in colour, occurs in soil, leaf, pod and crop debris

Adult 

  • Light pale brownish yellow stout moth.
  • Forewings are olive green to pale brown with a dark brown circular spot in the centre.
  • Hind wings are pale smoky white with a broad blackish outer margin.

Management

  • Set up of light traps
  • Set up sex pheromone traps at 12/ha
  • 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 on the ear heads

Apply any one of the following on 3rd and 18th day after panicle emergence :

  • Carbaryl 10 D 25 kg/ha
  • Malathion 5 D 25 kg/ha
  • Phosalone 4 D 25 kg/ha

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Larva 

NymphImage title

AdultImage title


Ear head bug: Calocoris angustatus

Symptom of damage

  • Nymphs and adult suck the juice from within the grains when they are in the milky stage. 
  • Grains shrink and turn black in colour and ill filled (or) chaffy.
  • Orange and pale green nymphs and adults are seen on the ear head.

Identification of the pest

  • Egg - Blue cigar shaped , laid under the glumes or into the middle of the florets
  • Nymphs - Slender, green in colour
  • Adults - Male is green in colour. Female is green with a brown margin

Management

Apply any one of the following on 3rd and 18th day after panicle emergence :

  • Carbaryl 10 D @25 kg/ha
  • Malathion 5 D @25 kg/ha
  • Phosalone 4 D @25 kg/ha
  • Neem seed kernel extract 5%
  • Azadirachtin 1%
III. Leaf feeders

Image titleWeb worm: Cryptoblabes gnidiella

Symptom of damage

  • larva first feeds on the lemma of the flowers scraping the chlorphyll
  • later on the milky grains.
  • Webbing of maize cobs and feeding on the flowers and the grains.

Identification of the pest

  • Larva - Long and dark brown. It forms silken webs on cobs
  • Adult - Dark grey forewings

Management

  • Spray monocrotophos

 


Image titleAsh weevil: Myllocerus sp.

Symptom of damage

  • larva feeds on the secondary roots and adults on leaves.

Identification of the pest

  • Adult - Grey coloured weevil.

 

Management

    • Mix any of the following granular insecticides with sand to make upa total quantity of 50 kg and apply in the leaf whorls on the 20thday of sowing
    • Phorate 10% CG10 kg/ha
    • Carbaryl 4% G 20 kg/ha.
    •  For stem borer, release egg p[arasitoid Trichogramma chilonis @2,50,000 /ha coinciding egg laying period. Three releases atweekly interval are desirable. Third release is to be accompaniedwith larval parasitoid Cotesia flavipes @ 5000/ha
    • If granular insecticides are not used, spray any one of thefollowing :
    • Carbaryl 50 WP 1 kg/ha on the 20th day of sowing (500 l of sprayfluid/ha).
    • Dimethoate 30% EC 660 ml/ha

IV. Sap feeders

Image titleLeafhopper:  Pyrilla perpusilla

Symptom of damage

  • Leaves become yellow
  • Covered with black sooty mould
  • Top leaves get dried up and lateral buds germinate

Identification of the pest

  • Nymph - Soft, pale brown dorsally and pale orange ventrally
  • Adult - Straw coloured, head pointing forward as a snou

 

Management
  • Avoid excessive use of nitrogenous fertilizers
  • Set up light trap
  •  Detrash: 150 and  210th  DAP
  •  Release lepidopteran parasitoid:
  • Epiricrania melanoleuca @8000 -10,000 cocoon /ha (or) 8 - 10 lacs egg/ha.
  • Spray any one of the following on the 150th and 210th day (1000 l spray fluid)
    • Malathion 50 EC 2000 ml
    • Monocrotophos 36 WSC 2000 ml

Aphid or Plant lice: Rhopalosiphum maidis

Symptom of damage

  • Yellowing of leaves
  • Colonies of aphids found in central leaf whorl.

Identification of the pest

  • Yellow with dark green legs

 

AphidsImage title

Winked AdultImage title

Colony of aphidsImage title

NymphImage title

NymphImage title

Management
  • Mix any of the following granular insecticides with sand to make upa total quantity of 50 kg and apply in the leaf whorls on the 20thday of sowing
  • Phorate 10% CG10 kg/ha
  • Carbaryl 4% G 20 kg/ha.
  •  For stem borer, release egg p[arasitoid Trichogramma chilonis @2,50,000 /ha coinciding egg laying period. Three releases atweekly interval are desirable. Third release is to be accompaniedwith larval parasitoid Cotesia flavipes @ 5000/ha
  • If granular insecticides are not used, spray any one of thefollowing :
  • Carbaryl 50 WP 1 kg/ha on the 20th day of sowing (500 l of sprayfluid/ha).
  • Dimethoate 30% EC 660 ml/ha

Shoot bug: Peregrinus maidis

Symptom of damage

  • Plants become unhealthy stunted and yellow.
  • The leaves wither from top downwards.
  • Panicle formation is inhibited and the plants die if attack is severe. 
  • Honeydew secreted by the bug causes growth of sooty mould onleaves.
  • The midribs of the leaves turn red due to egg-laying and may dry up subsequently.

Identification of the pest

  • Egg: Laid inside the leaf tissue and covered with a white waxy substance.
  • Adult: Yellowish brown to dark brown with translucent wings.

Management

Spray any following insecticides

  • Diazine0.04%
  • Dimethoate (or) 0.02%,
  • Phosphomidon @ 250 ml in 450-500 litres water/ha

NymphImage title

AdultImage title

Diseases Maize

Downy mildew / Crazy top: Peranosclerospora sorghi

Symptoms:

  • Chlorotic streaks appear on the leaf and white fungus growth is seen on both the surfaces of leaf.
  • Affected plants become stunted and exhibit bushy appearance due to shortening of internodes.  
  • Sometimes leafy growths in the tassel and proliferation of axillary buds on the stalk of the tassel are noticed.

Favourable Conditions :

  • Low temperature (21-33˚C);High relative humidity (90 per cent) and drizzling
  • Young plants are highly susceptible.

Management:

  • Rogue out affected plants.
  • Use resistant TNAU maize hybrid COH-6
  • Soil application of   P. fluorescens (or) T. viride @ 2.5 kg / ha + 50 kg of well decomposed FYM (mix 10 days before application) or sand at 30 days after sowing
  • Spray Metalaxyl @ 1000g(or) Mancozeb 2g/lit at 20  days after sowing

Chlorotic streaks on leavesImage title

Leaf  Blight: Exserohilum  turcicum & Helminthosporium maydis

a.Turcicum Leaf Blight Symptoms:

  • The fungus affects the crop at young stage.
  • Early symptoms are oval, water-soaked spots on leaves.
  • Mature symptoms are characteristic cigar shaped lesions that are 3 to 15cm long.
  • Lesions are elliptical and tan in color, developing distinct dark areas as they mature that are associated with fungal sporulation.
  • Lesions typically first appear on lower leaves, spreading to upper leaves and the ear sheaths as the crop matures.
  • Under severe infection, lesions may coalesce, blighting the entire leaf.

b.Maydis Leaf Blight Symptoms: 

  • Small yellowish round or oval spots appear on the leaves. 
  • These spots enlarge, become elliptical and the center becomes straw coloured with a reddish brown margin. 
  • Conidia and conidiophores are formed in the center.

Blighting of leavesImage title

Favourable Conditions :

  • Optimum temperature for the germination of conidia is 8 to 27˚C provided with free water on the leaf; Infection takes place early in the wet season.

Management

  • Rogue out affected plants.
  • Resistant cultivers  – Deccan, VL 42, Prabhat, KH-5901, PRO-324, PRO-339, ICI-701, F- 7013, F-7012, PEMH 1, PEMH 2, PEMH 3, Paras, Sartaj, Deccan 109, COH-6.
  • Soil application of   P. fluorescens (or) T. viride @ 2.5 kg / ha + 50 kg of well decomposed FYM (mix 10 days before application) or sand at 30 days after sowing
  • Spray Matalaxyl 1000 g / Mancozeb 2 g/liter at 10 days interval after first  appearance of the disease
Charcoal rot: Macrophomina phaseolina         

Symptoms:

  • The pathogen affects the plant mostly after flowering and the disease is named as Post Flowering Stalk Rot (PFSR).
  • The stalk of the infected plants can be recognized by greyish streak.
  • The pith becomes shredded and greyish black minute sclerotia develop on the vascular bundles. 
  • Shredding of the interior of the stalk often causes stalks to break in the region of the crown.
  • The crown region of the infected plant becomes dark in colour.
  • Shredding of root bark and disintegration of root system are the common features.
  • High temperature and low soil moisture (drought) favours the disease

Shredding of StalkImage title

Management

  • Follow crop rotation
  • Avoidance of water stress at flowering time reduced disease incidence
  • Avoid nutrient stress.
  • Apply potash @ 80 kg/ha in endemic areas
  • Soil application of   P. fluorescens (or) T. viride @ 2.5 kg / ha + 50 kg of well decomposed FYM (mix 10 days before application) or sand at 30 days after sowing

Corn rust: Puccinia sorghi  

Symptoms:    

  • On both the surfaces of the leaf, brown pustules are seen.
  • These represent the uredosori of the fungus.
  • The alternate host is Oxalis corniunlata.
  • Cool temperature and high relative humidity favours the disease.

Favourable condition:

  • Optimum temperature for the germination of conidia is 10 to 12˚C

Management:

  • Destroy altrenate plant host
  • Soil application of   P. fluorescens (or) T. viride @ 2.5 kg / ha + 50 kg of well decomposed FYM (mix 10 days before application) or sand at 30 days after sowing
  • Spray Mancozeb 1.25 kg/ha

Brown pustules on leafImage title

 

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