Friday, January 28, 2011

Blast (Leaf and Neck)

ImageSigns and symptoms
  • initial symptoms are white to gray-green lesions or spots with dark green borders
  • older lesions elliptical or spindle-shaped and whitish to gray with necrotic borders
  • lesions wide in the center and pointed toward either end
  • lesions may enlarge and coalesce to kill the entire leaves
  • symptoms also observed on leaf collar, culm, culm nodes, and panicle neck node
  • internodal infection of the culm occurs in a banded pattern
  • nodal infection causes the culm to break at the infected node
  • few, no seeds, or whiteheads when neck is infected or rotten





Image
  • presence of the blast spores in the air throughout the year
  • upland rice environment and high elevation in the tropics
  • cloudy skies, frequent rain, and drizzles
  • high nitrogen levels like ammonium sulfate
  • high relative humidity (90% and higher) and wet leaves
  • temperature from 25-28°C
    Pyricularia grisea (Cooke) Saccardo (anamorph)
    P. oryzae Cavara (anamorph)
    Magnaporthe grisea (T. T. Hebert) Yaegashi & Udagawa (teleomorph)
    cultural practices:
    There are some cultural practices that are recommended against the rice blast. Early sowing of seeds after the onset of the rainy season is more advisable than late-sown crops. Early sowing allows escape from the build-up of inoculum originating from neighboring farms. Excessive use of fertilizer should be avoided as it increases the intensity of blast, indirectly by promoting luxuriant crop growth which in turn increases the relative humidity and leaf wetness of the canopy. Excessive application of nitrogen at the start of the cropping season should be minimized to avoid luxuriant crop growth which favors the disease. Split application of nitrogen based on the actual requirements of the crop is recommended to manage the disease.
    Soils known to be low in plant-available silicon should be amended with calcium silicate slag.
    Planting resistant varieties against the rice blast is the most practical and economical way of controlling rice blast.
    Systemic fungicides, such as probenazole, tricyclazole, fthalide, pyroquilon and tricyclazole, are effective against the disease.

Thursday, January 27, 2011

farmer succeeds in commercial rice-fish farming with crri technology


Bael and Tulsi aqueous control blast disease in farmers field 
Severe leaf blast occurred in the rice field of a farmer from village Bhairpur in Cuttack district. The intensity of the disease ranged between 65% and 75% on rice variety Lalat. The environmentally safer technology, developed at CRRI to control rice blast disease, comprising of the aqueous extract of Bael leaf @ 25 g/litre of water and steamed aqueous extract of Tulsi leaf @ 25 g/litre of water was sprayed in the blast infested field. The farmer repeated this spray after 10 days. On the subsequent visit after 15 days, it was observed that the blast disease was successfully and effectively controlled. The rice crop had registered, an 80% to 85% recovery as compared to 45% recovery in ediphenphos (Hinosan) sprayed field.


Enhancing Farm Income and Employment Opportunity through Mushroom Cultivation
Shri Jayant Kumar Rout of Bhatpada village in Cuttack district, with a small landholding of 1.18 ha, started growing paddy straw mushroom during kharif season and dhingri mushroom during rabiseason in a small area (375 sq. ft.) in 1998 under the able guidance of the CRRI scientists. This gave him an additional income of Rs 10,000 to Rs 15,000. Encouraged by the profitability of mushroom cultivation, he expanded it to 3500 sq. ft. area and earned a net profit of Rs 40,000 to Rs 50,000. In 2003 and 2004, he further expanded the area under mushroom farming and earned a net profit of Rs 80,000. He was motivated to undergo a training on "Mushroom spawn production" at Bhubaneswar in 2003. Subsequently in 2004, Shri Rout was able to set up a spawn production unit with financial support from the CRRI under a project funded by theInternational Fund for Agricultural Development (IFAD) and earned a net profit of Rs 10,000. Now, he is not only producing the spawn for his own requirement but also supplying it to the nearby villages and helping in generating rural employment. He has further expanded the mushroom cultivation and is expected to get a net profit of Rs1,20,000, in addition to Rs 60,000 from selling the spawn. The CRRI recognized Shri Jayant Kumar Rout as a progressive mushroom farmer.


Orissa Farmer Succeeds in Commercial Rice-Fish Farming with CRRI Technology
Shri Sunakar Mishra of village Mahisara under Dharmasala block and Jajpur district in Orissa has developed a 35 acres large rice-fish farm following the technology developed at CRRI, Cuttack. He has availed a loan amount of Rs 53 lakh for mainly the land shaping and some amount (Rs 3.70 lakh) for seeds of rice, fish and prawn, out of the total Rs 93.52 lakh sanctioned by State Bank of India, Jajpur Town Branch. The farmer purchased a Pocoline Hitachi Machine (LNT 90) and did entire earth work in the farm. The project includes a subsidy amount of Rs 20 lakh from Agricultural Production and Investment Corporation Limited (APICOL), Orissa to be released after completion of the scheme. Shri Mishra grows CRRI semi-deepwater rice varieties (Varshadhan, Durga) along with around 3 lakhs juveniles of fresh water prawn (Macrobrachium rosenbergii) and 2 lakhs fry of fish (Catla, Catla catla and Rohu, Labeo rohita). Vegetables (Bitter gourd, okra, ridge gourd), tuber crops and pulse (Pigeon pea) are being grown on wide bunds (8 meter) all around. The farmer plans to grow around 10,000 improved Guava and 2,000 tissue cultured Banana, 200 Coconut plants, besides agro-forestry with 2,000 Sisso (Dalbergia sisso) plants. Shri Mishra expects an annual return of Rs 60 lakhs from the farm and is confident of refunding the entire released loan amount in the first year itself. Further, the farmer also visualizes phase by phase utilization of Rs 2.2 crores for farm and other infrastructures development in his total 60 acres area and desires to take up commercial farming of rice including quality rice, fish, prawn, horticultural crops, plantation crops and agro-forestry in the farm with expert advice of CRRI scientists.
The farmer get a net income of Rs 16 lakh from rice-fish-prawn and other crops. In the year 2007-08 the farmer took another Rs 60 lakh of loan and expanded and renovated the area to a total area of 65 acre, these includes 3 farms in which rice-fish farming is done in two farms of 55 acre (35+20 acre) and fresh water prawn is being grown in 10 acre area. He has planted 350 saplings of improved mango variety "Amrapali", besides, coconut and other agro-forestry plants on bunds. He also growing number of vegetable crops on bunds. He has a plan to integrate the poultry component this year and expects much more increase in income.


Vandana—A Pre-cyclone Rice for the Benefit of Coastal Farmers in Orissa
Coastal part of Orissa frequently faces cyclone of different intensities, particularly in the months of September to November resulting in the damage of wet season’s rice and other field crops to varying degrees.  In the end of October 1999, the super cyclone devastated the coastal districts of Orissa, specially Ersama block of Jagatsinghpur district causing total damage of field crops and animals besides, houses and human lives to greater extent. In such unpredictable, adverse situation, the growing of contingent field crops before cyclone will be an appropriate approach for providing food and nutritional security to the farm families. Keeping this in view and also with an aim of restoration of the devastated farming sectors in the super cyclone affected areas of two blocks, Ersama in Jagatsinghpur district and Astaranga in Puri district of Orissa, a project entitled “Management of Coastal agro-ecosystem in super cyclone affected areas in Orissa” was initiated in June 2001.  This project for a period of 3 years with funding from NATP to the extent of Rs 195.62 lakhs, is a multidisciplinary and multi institutional activity with CRRI, Cuttack as lead centre and eight other cooperating centers, involving all the ICAR Institutes/Regional Stations and Orissa University of Agriculture and Technology located at Bhubaneswar.

The concept of pre-cyclone rice was conceived for the first time, in addition to many other programmes, especially with the growing of early rice variety ‘Vandana’ (90 days duration) in upland and medium land situations.  A total of 100 kg quality seed of this variety was distributed to 19 farmers including the seed production farmers (10) in both target areas.  One among these farmers was Mr Seikh Mohammad, about 60 years old, in the village of Chaulia, Ersama block.  He belongs to marginal group of farmers with 3 acres of land.  He cultivated rice ‘Vandana’ in the wet season of 2002, in 252m2 area of medium land. The nursery was raised on June 8, 2002 and the healthy rice seedlings of 20 days old were transplanted on June 28, 2002. This rice crop was raised with a fertilizer schedule of 60 kg N, and 30 kg each of P2O5 and K2O per ha. The nitrogenous fertilizer was given in two splits, 50% at basal and the rest after 30 days.  The major insect pest was gundhibug, at flowering stage of the crop. He controlled the pest of gundhibug by two sprays with the insecticide monocrotophos @ 0.5 kg ai/ha.  The rice crop was harvested in the first of September, after 90 days of seeding.  Mr. Mohammad realized a rice grain yield of 167 kg in 252 m2 area, that was with an estimated yield of 6.6 t/ha. Other farmers in the project areas obtained a grain yield in the range of 4 to 5 t/ha with in a 3 month period.  These farmers were benefited by growing rice ‘Vandana’ and harvesting good quantity of rice within a short period of 90 days.  This strategy would held the farmers to escape the bad effects of a possible cyclone in the months of September to November, which occur frequently in Orissa.

This strategy of the project has created greater awareness among the farmers for growing the early rice variety ‘Vandana’. All the adopted farmers are keeping the seeds of this variety for use of the Wet season of 2003.  Mr. Seikh Mohammad grew this variety, even in the dry season 2003, to produce more quantity of seeds.  About 100 farmers will grow this rice variety ‘Vandana’, by collecting seeds from the adopted farmers. By the end of this project period, it is expected that a large number of farmers will accept this rice variety ‘Vandana’.  The cultivation of ‘Vandana’ and similar varieties with early duration will facilitate in the built up of enough reserve food before cyclone occurs in the months of September-November.

Production Technologies Refined through CRRI led IVLP-TAR Brought Prosperity in the life of Rainfed Farmer
In eastern India, many rainfed rice farmers have small and marginal land holdings with meager resources.  Rice is the staple food crop, grown under different land situations.  These ecologies are depended mostly of rainfall and are therefore subject to both moisture deficit (upland) and excess (lowland to flood-prone) situations.  The productivity of rice on these lands is generally poor and especially, under rainfed condition, it is distressingly low.

Nearly about 70% of the available agricultural production technologies are not adopted by the farmers due to various constraints, from biophysical to socio-economic conditions operating at the farm level.  Most important reasons for low  level of acceptance of the technologies are—that they are not economically viable, not operationally feasible, not stable, not matching with farmer’s needs and not compatible with existing farming systems.

Considering this conjuncture, the evaluation of the on-farm farmers’ participatory traits was conducted during 1999-2002 and refined some of the production technologies related to rainfed rice in respect of varieties and their response to method of stand establishment, weed management and nutrient management through Institute Village Linkage Programme in rainfed areas of Cuttack district, Orissa.

Sri Judhistir Behera from Berena village is having one area each of rainfed upland and lowland areas. With a total of 8 family members (3 working and 5 non-working), he takes up rice in those two acres of land.  In a year, he used to get hardly 5-8 q of rice, which was not sufficient to feed his entire family members.  In order to manage the entire family and gain better livelihood, he and his sons worked as casual labourers in other fields. Then, the core team members of IVLP encouraged him to take up rice cultivation in his 2 acres of land, by adopting the refined technologies.  Of course, in the first year the team provided him technical advice and critical inputs required for various cultural interventions.

In his one acre of upland area, he cultivated Vandana variety, which matures in 90 days, having drought tolerance and weed smothering ability in the early days of growth.  The seeds at the rate of 75 kg/ha were sown in the second week of June in rows (20 cm apart), behind the country plough.  At the time of sowing he applied 2 t/ha FYM and 20 kg each of P2O5 and K2O/ha.  Nitrogen @30 kg/ha was applied in two equal splits-half at 3 weeks after sowing and another half at 6 weeks after sowing. Weeds were managed by adopting integrated weed management package i.e. running finger weeder in between lines after 20 days and one hand weeding at 30 days after germination.

In lowland area, he took up semi-dwarf photosensitive variety Gayatri in kharif and hybrid PHB 71 in rabi, by utilizing spring water flowing by the side of his land.  Better crop establishment was achieved by line transplanting and the application of 40-20-20 kg NPK/ha in rainfed lowlands and, 80-40-40 kg NPK/ha for dalua/summer rice.

Within a period of one year, Shri Behera could produce 40 q of rice (12 q from upland, 18 q from lowland during kharif and 20 q from dalua/summer season) from his two acres of land.  In addition to rice he could also produce vegetables like tomato, poi, cucumber etc. in the upland area, after harvest of rice, which was sufficient for his family and helped him to earn some additional income too.  By adopting this rice based cropping system of cultivation during the last two years, Shri Behera could sustain the same level of production besides generating year round employment opportunities for the entire family members. With better opportunities for livelihood, neither he nor his family members are going to others’ fields to work as casual labourers.  In the Berena village, he is one of the many farmers who got benefited by the IVLP-TAR project, operating in rainfed areas of Cuttack district under NATP.

Control of the Most Destructive Rice Blast Disease by Botanicals
A report of the “Mysterious disease affects paddy cultivation in Ganjam (district of Orissa)” appeared in “The Times of India” on 22 August 2002.  A team of scientists from CRRI visited along with the State Government Agricultural Officials and observed the occurrence of severe epidemic, caused by the fungal pathogen Pyricularia grisea in the Gajapati (Chhatrapur), Ganjam and Perhampur regions of Orissa.  The epidemic caused serious damage to the rice seedlings in nursery as well as the transplanted crops in vast area of the Districts. The high yielding cultivar, Swarna, grown in about 75% of the total nursery sown area (10,000 ha approx) was suffered the most, leading to 70-100% damage of seedlings.  The disease was aggravated by the favourable weather conditions, like scanty rainfall, drought conditions, and the susceptible host coupled with sufficient fungal inoculum load.

The scientists from CRRI demonstrated the effectiveness of botanical extract based technology, developed for the control of rice blast at this Institute.  The botanical extracts were prepared from the locally and commonly available leaves of the plants, Aegle marmelos (Bael) or Ocimum sanctum (Tulsi). The method of extract preparation was also explained to the group of the farmers.  After learning this extract procedure, they prepared the botanical extract and use as per the scientific recommendations to control this disease.  Effective communication was made to appraise the farmers of this technology through the active cooperation by, the state agriculture extension machinery, mass media like TV (ETV), AIR, distribution of pamphlets, leaflets in local language and the group meetings.  As a result of this approach, a large number of farmers used this technology and benefited by this technology to control successfully the most destructive rice disease, the blast.

Both the plants, A. marmelos (Bael) and O. sanctum (Tulasi) considered to be the sacred plants are generally available to the farmers and can be grown easily.  The extracts from these plants can be easily prepared by farmers themselves and utilized at the time of need.  The botanical extract-based technology can thus be deployed as an effective strategy of integrated disease management. These botanical extracts are non-hazardous, environmentally safer, locally available, renewable and easily accessible at the time of need for controlling rice blast disease, as against the synthetic fungicides such as Carbendazim, Ediphenphos etc. which are presently in use.

Monday, January 24, 2011

Rhizopus Rot of Jackfruit


THE
 plant genus Artocarpus  comprises roughly 50
species of tropical trees native to the Pacific and
South and Southeast Asia, several of which produce edible fruit. Jackfruit, Artocarpus heterophyllus, is a popular garden species prized for its edible flowers, fruit, and
seeds for fresh consumption or cooking. Jackfruit trees
can reach over 60 ft in height and bear fruit that can be 2
feet or more long and weigh as much as 70 pounds.
Rhizopus rot is a common fungal disease of jackfruit flowers and fruit. Rot is more likely to occur in
high-rainfall areas or during and after stormy periods.
When warm, humid, wet weather coincides with the
flowering and fruiting season, rhizopus rot can cause
total loss of fruit in jackfruit trees.
*
Symptoms
At first, soft, watery, brown spots develop on the flowers and fruit. Subsequently, a powdery, fuzzy-looking
mass of black spores and white fungal mycelia covers
the jackfruit surface. The pathogen engulfs the young
fruit, resulting in the characteristic black, rotten,
shrunken, and sometimes mummified fruit remains. Fruit
symptoms can appear on the tree or can develop on fruit
that are in storage or transit.
Cause
Three species of plant-pathogenic fungi of the genus
Rhizopus can cause this disease in the tropics: Rhizopus
oryzae, Rhizopus artocarpi, and Rhizopus stolonifer. No
Rhizopus Rot of Jackfruit
Scot Nelson
Department of Plant and Environmental Protection Sciences
*According to observations by personnel at the UH-CTAHR Agricultural Diagnostic Service Center.
Left: a healthy, maturing jackfruit; center and right: young jackfruits with rhizopus rot.UH–CTAHR Rhizopus Rot of Jackfruit PD-29 — July 2005
2
jackfruit varieties are reported to have significant resistance to the disease.
Epidemiology
Warm, humid, rainy conditions favor the development
of rhizopus rot. Wind, rain, and insects dislodge and
spread the tiny fungal spores. When deposited on moist
fruit surfaces, the spores germinate and infective mycelia grow into the tissues. The infection produces a layer
of black spores on the fruit surface to start secondary
cycles of infection and disease. Although wounds can
predispose the fruit to infection, unwounded flowers and
young fruit are also susceptible. Rhizopus can survive
on decaying plant litter or in the soil to initiate new infections.
Management
Prune the tree to encourage good ventilation and to reduce relative humidity in the canopy. Remove and destroy diseased fruit from trees and the ground. Clean up
decaying organic debris within and around the tree. Ensure that water does not pond around the tree’s root zone.
Control weeds around young trees. Intercrop jackfruit
with trees that are not susceptible to infection by Rhizopus. Keep ripe fruit from contact with the soil or decaying organic material. Avoid wounding the fruit. Wash
fruit after harvest in clean water and dry thoroughly before packing or transporting. Do not pack fruit with
symptoms—destroy them. Avoid storing fruit after harvest in hot, poorly ventilated containers. Where disease
is severe, protect fruit with periodic sprays of copper
fungicides or other products registered for use on jackfruit in Hawaii.

Diseases
€ Blossom rot, fruit rot or stem rot, all caused by Rhizopus artocarpi, are serious
diseases, which may cause 15 to 32% crop loss.
€ The inflorescence, tips of the flowering shoots or the stalk of the tender fruits are
infected and blackened by fungal structures called sporangia.
€ Flowers and fruits rot and drop.
€ Collect and destroy the fallen leaves and fruits under the tree.
€ On appearance of blossom rot, an application of Folicur or Tilt 250 EC @ 0.5 ml
per litre of water may be sprayed as a further controlling measure.

Saturday, January 22, 2011

Nutrient Management - Transplanted Rice


Nutrient management: Pre planting phase (residue management | organic materials and manure management) | Early vegetative - transplanted | Early vegetative - wet-seeded | Late vegetative | Reproductive phase | Ripening phase

From 2 days before transplanting to 14 days after transplanting (DAT), apply:

  • Only a moderate amount of nitrogen (N) fertilizer, because the rice plant’s need for supplemental N is small during this period of slow initial plant growth.
  • All of the required phosphorus (P) fertilizer, because P is important for early crop growth, especially for root development and tillering.
  • At least half of the required potassium (K) fertilizer, because K contributes to greater canopy photosynthesis and crop growth.
  • All of the required zinc (Zn) and sulfur (S) fertilizer.

Nitrogen (N)

Use the following general guidelines to determine the early application of N before 14 DAT:
  • Typically apply 20–30 kilograms of N per hectare in seasons when yield response to N is between 1 and 3 tons per hectare.
  • Apply 25–30% of the total N in seasons when yield response to N is greater than 3 tons per hectare.
  • Eliminate early application when yield response to N is less than or equal to 1 ton per hectare.
  • Do not use the Leaf Color Chart (LCC) with early N application.
  • Reduce or eliminate early N application when high-quality organic materials and composts are applied or the soil has a high existing N content.
  • Increase N application to 30–50% of the total N when older seedlings (more than 24 days old) and short-duration varieties are used.
  • Increase early N application in areas with low air and water temperature at transplanting, and for low-tillering and large-panicle varieties.

Phosphorus (P)

As a general rule for modern rice varieties with harvest indices of 0.45–0.55, when most of the crop residue is retained in fields after harvest and little or no manure is applied to fields, apply 4 kilograms of P2O5 per hectare per ton of grain harvested to replenish the P2O5 used by the previous season’s crop (for example, 20 kilograms P2O5 per hectare for a grain yield of 5 tons per hectare). When all crop residues are removed from fields after harvest and there is little or no P added from organic fertilizer (such as manure) is negligible, apply about 6 kilograms of P2O5per hectare per ton of grain harvested to replenish the P2O5 used by the previous season’s crop (for example, about 30 kilograms P2O5 per hectare for a grain yield of 5 tons per hectare).
Harvest index. The ratio of grain weight to total aboveground plant dry weight.

Potassium (K)

Apply about 3.5 kilograms of K2O per hectare per ton of grain harvested to match the export of K2O with harvested grain when all crop residues are retained in fields after harvest. For example, apply about 17.5 K2O per hectare for a grain yield of 5 tons per hectare. When all crop residues are removed from fields after harvest, apply about 12 kilograms of K2O per hectare per ton of grain harvested to match the net export of K2O with harvested grain and straw and maintain soil K fertility. For example, apply about 60 K2O per hectare for a grain yield of 5 tons per hectare.
When the total K fertilizer requirement is relatively low (less than or equal to 30 kilograms of K2O per hectare), apply all K fertilizer before 14 DAT. On sandy soils or when larger amounts of K fertilizer are required, apply about 50% of the required K fertilizer before 14 DAT.

Sulfur (S)

If the soil is deficient in S, apply about 2.5–3 kilograms of S per hectare per ton of anticipated crop yield before 14 DAT.

Zinc (Zn)

If the soil is deficient in Zn, apply about 5 kilograms of Zn per hectare as zinc sulfate before 14 DAT. Alternatively, apply zinc sulfate in the nursery seedbed, or dip seedlings in 2–4 % zinc oxide suspension before transplanting.

Sunday, January 2, 2011

: Pulses :: Greengram

  1. AnthracnoseColletotrichum lindemuthianum
  2. Bacterial Leaf BlightXanthomonas phaseoli
  3. Cercospora leaf spotCercospora canescens
  4. Leaf crinkle disease: Leaf Curl Virus
  5. Macrophomina BlightMacrophomina phaseolina
  6. Yellow mosaic : Mungbean yellow mosaic virus
  7. Powdery Mildew: Erysiphe polygoni
  8. Root Rot and Leaf BlightRhizoctonia solani
  9. Rust: Uromyces phaseoli                                                                                                                                 

1. AnthracnoseColletotrichum lindemuthianum

Symptom
  • The fungus attacks all aerial part parts and at any stage of plant growth.
  • Symptoms are circular, black, sunken spots with dark center and bright red orange margins on leaves and pods.
  • In severe infections, the affected parts wither off. Seedlings get blighted due to infection soon after seed germination.

Management

  • Seed treatment with Carbendazim 2g/kg of seed.
  • Spray Mancozeb 2g or Carbendazim 0.5g/lit.
2. Bacterial Leaf Blight: Xanthomonas phaseoli
Symptom
  • It is characterized by many brown, dry and raised spots on the leaf surface.
  • When the disease is severe several such spots coalesce, the leaves become yellow and fall off prematurely.
  • The lower surface of the leaf appears red in colour due to the formation of raised spots.
  • The bacterium is also seed-borne
  • The stem and pods also get infected.
Management
  • Use disease free seed
  • Destruction of debris and stubbles.
  • Soak the seeds in 500 ppm Streptocycline solution for 30 min. before sowing followed by two sprays of Streptocycline combined with 3 g of Copper Oxychloride per litre at an interval of 12 days is recommended.
3. Cercospora leaf spot: Cercospora canescens
Older spots on green gram leaf
Symptom
  • This is an important disease of green gram and is usually occurs in a severe form, causing heavy losses in yield.
  • Spots produced are small, numerous in number with pale brown centre and reddish brown margin. Similar spots also occur on branches and pods.
  • Under favourable environmental conditions, severe leaf spotting and defoliation occurs at the time of flowering and pod formation.

Management

  • Intercrop with tall growing cereals and millets.
  • Follow clean cultivation.
  • Use disease free seed.
  • Maintain low crop population density and wide row planting.
  • Mulching reduces the disease incidence resulting in increase yield.
  • Cercospora leaf spot can be controlled with Carbendazim 0.5g/lit.or Mancozeb 2.0g/lit.
4. Leaf crinkle disease: Leaf Curl Virus
Symptom
  • The earliest symptoms appear on youngest leaves as chlorosis around some lateral veins and its branches near the margin.
  • The leaves show curling of margin downwards.
  • Some of the leaves show twisting.
  • The veins show reddish brown discolouration on the under surface which also extends to the petiole.
  • Plants showing symptoms within 5 weeks after sowing invariably remain stunted and majority of  these die due to top necrosis within a week or two.
  • Plants infected in late stages of growth do not show severe curling and twisting of the leaves but show conspicuous venial chlorosis any where on the leaf lamina.  
  • The disease develops in the fields mainly through seed or rubbing of diseased leaves with the healthy ones
Management
  • Periodical removal of infected plants upto 45 days.
  • Spray Acephate 1g/lit or Dimethoate 2 ml/lit to control vector.
5. Macrophomina Blight: Macrophomina phaseolina
Symptom                                                                               
  • In rice fallows, symptoms appear on 4 weeks  old crop as raised white cankers at the base of the stem.
  • These enlarge gradually and turn as raised brown streaks spreading upwards.
  • Plants are stunted and leaves are dark green, mottled and reduced in size.
  • Normal leaves on the affected plants drop suddenly and dry.
  • Flowering and podding are greatly reduced.
  • When the affected plants are split/open vertically from the collar downwards, reddish discolouration of the internal tissues is clearly visible while the internal root tissues appear white.
  • The pathogen can survive through seed, soil, diseased plant parts and host plants.
  • The severity of the disease increases with the increase in temperatures.
  • Fungus survives in upper layers of the soil and enters plant through stem.

Management

  • Deep ploughing in summer.
  • Follow crop rotation
  • Soil amendment with farm yard manure @ 12.5 tonnes/ha is helpful in reducing the incidence of the disease
  • Destroy the diseased plant debris by burning of burying in the soil.
  • Seed treatment with T. viride @4g/kg or P. fluorescens @ 10g/ kg of seed or Carbendazim or Thiram 2g/kg of seed.
  • Spot drenching with Carbendazim 1g/lit or P. fluorescens / T. viride 2.5 kg/ha with 50 kg FYM.
6.  Yellow mosaic -Mungbean yellow mosaic virus
Symptom
  • Initially mild scattered yellow spots appear on young leaves. Spots gradually increase in size and ultimately some leaves turn completely yellow.
  • Infected leaves also show necrotic symptoms.
  • Diseased plants are stunted, mature late and produce very few flowers and pods.
  • Pods of infected plants are reduced in size and turn yellow in colour.
  • The disease is transmitted by the whitefly, Bemisia tabaci.
Management
  • Grow resistant varieties to yellow mosaic.
  • Grow seven rows of sorghum as border crop
  • Treat seeds with Imidacloprid 70 WS @ 5ml/kg to control vector.
  • Rogue out MYMV infected plants early in the season to eliminate the source of inoculum.
  • Give one foliar spray of systemic insecticide (Dimethoate @ 750 ml/ha) on 30 days after sowing.
7. Powdery Mildew:  Erysiphe polygoni
Green gram leaf fully covered by white powdery growth
Symptoms
  • Powdery mildew is one of the widespread diseases of several legumes in green gram.
  • White powdery patches appear on leaves and other green parts which later become dull coloured. These patches gradually increase in size and become circular covering the lower surface also.
  • When the infection is severe, both the surfaces of the leaves are completely covered by whitish powdery growth. Severely affected parts get shriveled and distorted.
  • In severe infections, foliage becomes yellow causing premature defoliation. The disease also creates forced maturity of the infected plants which results in heavy yield losses.  
Management
  • The seeds must be sown early in the month of June to avoid early incidence of the disease on the crop.
  • Powdery mildew could be controlled by spraying Carbendazim 1g/lit or Tridemorph 1 ml /lit.
8. Root Rot and Leaf Blight: Rhizoctonia solani
Symptom
  • The pathogens cause seed decay, root rot, damping-off, seedling blight, stem canker and leaf blight.
  • The disease occurs commonly at podding stage.
  • In the initial stages, the fungus causes seed rot, seedling blight and root rot symptoms.
  • The affected leaves turn yellow in colour and brown irregular lesions appear on leaves.
  • On coalescence of such lesions, big blotches are formed and the affected leaves start drying prematurely.
  • Roots and basal portion of the stem become black in colour and the bark peels off easily.
  • The affected plants dry up gradually.
  • When the tap root of the affected plant is split open, reddening of internal tissues is visible.
  • The pathogen is soil-borne.
Management
  • Avoid moisture stress in the soil especially at podding stage.
  • Seed treatment with T. viride @ 4g/kg or P. fluorescens @ 10g/ kg of seed or Carbendazim or Thiram 2g/kg of seed.
  • Spot drenching with Carbendazim 1g/lit or P. fluorescens / T. viride 2.5 kg/ha with 50 kg FYM.
9. Rust :Uromyces phaseoli
Symptom                                                                             
  • The disease appears as circular reddish brown pustules which appear more commonly on the underside of the leaves, less abundant on pods and sparingly on stems.
  • When leaves are severely infected, both the surfaces are fully covered by rust pustules.
  • Shriveling followed by defoliation resulting in yield losses.

Management

  • Spray Mancozeb 2.5g /lit

Pulses :: Blackgram

 

  1. Anthracnose-Colletotrichum lindemuthianum
  2. Bacterial Leaf BlightXanthomonas phaseoli
  3. Cercospora leaf spot-Cercospora canescens
  4. Powdery Mildew-Erysiphe polygoni
  5. Root Rot and Leaf Blight- Rhizoctonia solani
  6. Rust-Uromyces phaseoli
  7. Stem canker-Macrophomina phaseolina
  8. Yellow Mosaic – Mungbean Yellow Mosaic Virus
  9. Leaf Crinkle-Leaf Crinkle Virus

1. Anthracnose: Colletotrichum lindemuthianum

Symptoms
  • The fungus attacks all aerial part parts and at any stage of plant growth.
  • Symptoms are circular, black, sunken spots with dark center and bright red orange margins on leaves and pods.
  • In severe infections, the affected parts wither off.
  • Seedlings get blighted due to infection soon after seed germination.   
  • The pathogen survives on seed and plant debris
  • Disease spreads in the field through air-borne conidia.
  • The disease is more sever in cool and wet seasons.  
Management
  • Seed treatment with Carbendazim 2g/kg
  • Remove and destruct plant debris
  • Spray Mancozeb 2g/lit or Carbendazim 0.5g/lit.
    2. Bacterial Leaf Blight- Xanthomonas phaseoli
    Symptoms
    • Many brown, dry and raised spots on the leaf surface.
    • When the disease is severe several such spots coalesce, the leaves become yellow and fall off prematurely.
    • The lower surface of the leaf appears red in colour due to the formation of raised spots.
    • The stem and pods also get infected.
    • The bacterium is seed-borne
    • Rain splashes play an important role in the development and spreading of the disease.
                      
    Management
    • Use disease free seed
    • Destruction of debris and stubbles.
    • Soak the seeds in 500 ppm Streptocycline solution for 30 min. before sowing followed by two sprays of Streptocycline combined with 3 g of Copper Oxychloride per litre at an interval of 12 days is recommended.
    3. Cercospora leaf spot-Cercospora canescens
    Symptoms
    • Spots produced are small, numerous in number with pale brown centre and reddish brown margin. Similar spots also occur on branches and pods.
    • Under favourable environmental conditions, severe leaf spotting and defoliation occurs at the time of flowering and pod formation.  
    • The fungus is seed-borne and also survives on plant debris in the soil.
    • High humidity favours disease development.        
    Management
    • Intercrop with tall growing cereals and millets.
    • Follow clean cultivation.
    • Use disease free seed.
    • Maintain low crop population density and wide row planting.
    • Mulching reduces the disease incidence resulting in increase yield.
    • Spray with Carbendazim 0.5g/lit or Mancozeb 2.0g/lit at 30 days after sowing.
                                                                                                       
    4. Powdery Mildew-Erysiphe polygoni
    Green gram leaf fully covered by white powdery growth
    Symptoms
    • White powdery patches appear on leaves and other green parts which later become dull coloured. These patches gradually increase in size and become circular covering the lower
      surface also.
    • When the infection is severe, both the surfaces of the leaves are completely covered by whitish powdery growth. Severely affected parts get shriveled and distorted.
    • In severe infections, foliage becomes yellow causing premature defoliation. The disease also creates forced maturity of the infected plants which results in heavy yield losses.
    • The pathogen has a wide host range and survives in oidial form on various hosts in off-season.
    • Secondary spread is through air-borne oidia produced in the season.
    Management
    • The seeds must be sown early in the month of June to avoid early incidence of the disease on the crop.
    • Powdery mildew could be controlled by spraying Carbendazim 1g/lit or Tridemorph 1 ml /lit.
    5. Root Rot and Leaf Blight-Rhizoctonia solani
    Symptoms
    • The pathogens cause seed decay, root rot, damping-off, seedling blight, stem canker and leaf blight in green gram.
    • The disease occurs commonly at podding stage.
    • In the initial stages, the fungus causes seed rot, seedling blight and root rot symptoms.
    • The affected leaves turn yellow in colour and brown irregular lesions appear on leaves.
    • On coalescence of such lesions, big blotches are formed and the affected leaves start drying prematurely.
    • Roots and basal portion of the stem become black in colour and the bark peels off easily.
    • The affected plants dry up gradually. When the tap root of the affected plant is split open, reddening of internal tissues is visible. The pathogen is soil-borne.
    Management
    • Seed treatment with 4g Trichoderma viride formulation
    6. Rust: Uromyces phaseoli

    Symptoms

    • The disease appears as circular reddish brown pustules which appear more commonly on the underside of the leaves, less abundant on pods and sparingly on stems.
    • When leaves are severely infected, both the surfaces are fully covered by rust pustules.
    • Shriveling followed by defoliation resulting in yield losses.

    Management

    • Spray Mancozeb 2.5g/lit to control of the disease.
    7. Stem canker-Macrophomina phaseolina
    Symptoms on stem and internal stem tissue
    Symptoms
    • In rice fallows, symptoms appear on 4 weeks old black gram crop as raised white cankers at the base of the stem.
    • These enlarge gradually and turn as raised brown streaks spreading upwards.
    • Plants are stunted and leaves dark green, mottled and reduced in size.
    • Normal leaves on the affected plants drop suddenly and dry.
    • Flowering and podding is greatly reduced.
    Management
    • Deep ploughing in summer.
    • Follow crop rotation
    • Soil amendment with farm yard manure @ 12.5 tonnes/ha is helpful in reducing the incidence of the disease
    • Destroy the diseased plant debris by burning of burying in the soil.
    • Seed treatment with T. viride @4g/kg or P. fluorescens @ 10g/ kg of seed or Carbendazim or Thiram 2g/kg of seed.
    • Spot drenching with Carbendazim 1g/lit or P. fluorescens / T. viride 2.5 kg/ha with 50 kg FYM.
    8. Yellow Mosaic – Mungbean Yellow Mosaic Virus

    Symptoms

    • The disease is more prevalent on black gram than green gram
    • Initially mild scattered yellow spots appear on young leaves.
    • The next trifoliate leaves emerging from the growing apex show irregular yellow and green patches alternating with each other.
    • Spots gradually increase in size and ultimately some leaves turn completely yellow.
    • Infected leaves also show necrotic symptoms.
    • Diseased plants are stunted, mature late and produce very few flowers and pods.
    • Pods of infected plants are reduced in size and turn yellow in colour.

    Management

    • Grow resistant/ tolerant varieties viz.,Vamban 4, Vamban 5
    • Grow seven rows of sorghum as border crop
    • Treat seeds with Imidacloprid 70 WS @ 5ml/kg to control vector.
    • Rogue out MYMV infected plants early in the season to eliminate the source of inoculum.
    • Give one foliar spray of systemic insecticide (Dimethoate @ 750 ml/ha) on 30 days after sowing.
    9. Leaf Crinkle-Leaf Crinkle Virus
    Symptoms
    • The earliest symptoms appear on youngest leaves as chlorosis around some lateral veins and its branches near the margin.
    • The leaves show curling of margin downwards.
    • Some of the leaves show twisting.
    • The veins show reddish brown discolouration on the under surface which also extends to the petiole.
    • Plants showing symptoms within 5 weeks after sowing invariably remain stunted and majority of  these die due to top necrosis within a week or two.
    • Plants infected in late stages of growth do not show severe curling and twisting of the leaves but show conspicuous venial chlorosis any where on the leaf lamina.  
    • The disease develops in the fields mainly through seed or rubbing of diseased leaves with the healthy ones.
    Management
    • Periodical removal of infected plants upto 45 days.
    • Spray Acephate 1g/lit or Dimethoate 2 ml/lit to control vector.