Seed :: Oil Seeds :: Groundnut

QUALITY SEED PRODUCTION IN GROUNDNUT

 

 

Quality seed
           
The seeds which are having high genetic purity, physical purity, high germination and vigour and without the infection of pest and disease are called good quality seeds.

Season

Selection of suitable season is important for seed production. To avoid infestation of pest and disease, moisture stress during crop growth, to protect the seed crop from heavy downpour especially at maturity and harvest and to increase the yield, selection of suitable season assumes greater importance.
           
Heavy rain encourages the plant with high vegetative growth and delays the penetration of pegs which resulted in poor yield. There is also chance to reduce the yield by in situ germination of seeds. Hence sowing at correct season will improve the yield. June-July and December-January are the best suited ones.

High yielding varieties
           
We have to select high yielding varieties for production of seeds, because they respond well for high fertilizer application, short duration and resistant to pest and disease. Thus to get higher yield and profit, selection of high yielding variety is important.

Selection of land
           
The land should be fertile, red sandy loam with aeration and good drainage facilities. The selected land should not have deficiency of micro nutrient such as calcium and boron as these micronutrient deficiency will impair the quality of seeds.

Deficiency

Implications

Boron

Reduction in total number of pods in plants; increased number of one seeded pods; more incidence of fungal disease; production of seeds with hollow heart

Calcium

Darkened plumule which affects germination of seeds.

           
Also make sure that in the selected land groundnut varieties should not have been grown in the previous two seasons so as to avoid volunteer plants.

What are volunteer plants?

Volunteers are plants that grow in the field from the seeds found in the soil. These seeds should have been fallen from previous season crop. Since they grow without sowing or they volunteer to grow by themselves, hence the name volunteer.

Seed selection
           
Obtain seed from healthy pods; shrivelled, broken and disfigured seeds have to be discarded. Use seeds retained by 18/64" (7.2 mm dia) round perforated sieve for sowing.

          
Good Seeds                                                       Shrivelled seeds

Seed rate (for an acre)
           
Small seeded varieties (TMV 2 , 7): 50-55 kg
           
Large seeded varieties (JL 24, VRI 2): 55-60 kg

Groundnut varieties

Groundnut varieties

Isolation
           
Groundnut is purely a self pollinated crop; for production of genetically pure seeds, an isolation distance of 3 m is to be allowed from the source of contamination and from other varieties.

Seed management technique
           
To obtain increased yield in any crop  maintenance of required plant population is very much required which is more suitable in groundnut. A new seed management technique has been developed to separate the viable seeds before sowing from the seed lot for the maintenance of plant population is given below.

Optimum growth of radicle

  1. The graded seeds can be hardened by soaking in 0.5 per cent calcium chloride solution (50% of seed volume) for 6 hrs.
  2. After 6 hrs of soaking, spread the seeds over the moist gunny bag and cover with another moist gunny bag for 24 hrs.
  3. After 24 hrs, the kernels with visible expression of radicle emergence (just sprouted to 5 mm length) are separated.
  4. This process has to be repeated for 2-3 times at 2 hrs interval and all the viable seeds which expressed radicle emergence are to be further separated and dried under shade.
  5. Thus the viable and dead seeds are separated by this process which ensured maximum planting value.
  6. The viable seeds thus separated could be used for immediate sowing.

 

Optimum growth of radicle

Advantages

  1. Field  emergence will be about 95%
  2. Separation of dead seeds is easy
  3. Maintenance of required plant population
  4. 10-15 per cent increase in yield

Seed treatment
           
Seed treatment refers to the application of fungicide, insecticide or a combination of both to seeds so as to disinfect and disinfest them from seed borne or soil borne pathogenic organisms to maintain the required plant population in the field. It also refers to subjecting the seeds with treatment of bio-control agents and Rhizobium.

Fungicide treatment
           
Treat one kg of seeds with 2 gm of Thiram before sowing. Keep the fungicide  treated seeds for 24 hrs and use for sowing.

Trichoderma treatment
           
Treat the seeds with biocontrol agents of Trichoderma viridi @ 4g per kg of seeds just before sowing.

Attention
       
If the seeds are treated with biocontrol agent of Trichoderma, such seeds should not be treated with fungicide

Rhizobial treatment
         
It is better to treat the seeds with specific Rhizobium of TNAU 14 and phosphobacteria for groundnut seeds.

Material requirement (for an acre)
1. Rhizobium                            : 1 packet (200 gm)
2. Phosphobacteria                   : 1 packet (200 gm)
3. Rice gruel                             : 1 lit
4. Good seeds                          : 55 kg.

Procedure

  • Mix thoroughly the rhizobium and phosphobacteria into the rice gruel with constant stirring
  • Spread the seed kernel on a gunny bag
  • Then the rhizobial mixture as prepared with rice gruel is sprayed over the seeds using a twig.
  • Care must be taken by constant stirring so that all the seeds get treated with rhizobium.
  • Dry the seeds under shade for 1-2 hrs and use for sowing within 24 hrs of treatment.


Root nodules in plants
                           

      

Rhizobial seed treatment

Advantages of Rhizobium inoculation

  • Plants uptake more amount of nitrogen.
  • Increase the root nodules of plant and fix atmospheric nitrogen to make available to the plants.
  • The phosphobacteria converts the non-available form of phosphorus in the soil into available form to the plants.
  • Helps for the better root development.
  • The rhizobial treatment increases the yield.

Attention

     ♣ Enough care must be taken for rhizobial seed treatment that the seed coat should not be removed as it may reduce the seed germination
     ♣ Always use freshly prepared Rhizobium packets
     ♣ Fungicide seed treatment must be done 24 hrs earlier to Rhizobium seed treatment.
     ♣ Do not use Rhizobium packet if the content is dried.

Preparation of land
           
The land selected for seed production of groundnut is to be ploughed 4-5 times and prepared to fine tilth. It is better to have deep plouging rather than wide ploughing. In the last ploughing ten cart load (5 tonnes) of well decomposed FYM is to be applied for an acre. Then the land can be prepared either with beds and channels or ridges and furrows based on the nature of soil and water flow for irrigation.

Spacing
           
Seeds should be sown within 15 cm each in 30 cm spacing between rows. Seeds are to be sown within 4 cm depth in the soil.

 Population maintenance
           
In groundnut field observed some gap in the plant population which leads to poor yield. But it is easy to maintain the required population so as to get increased yield. The following are some useful tips to be followed to maintain plant population in groundnut.

  • Use required quantity of seed kernels for sowing.
  • Obtain seeds from healthy pods. Shrivelled, broken and disfigured seeds have to be rejected.
  • Fully matured graded seed only have to be used.
  • Follow seed treatment before sowing
  • Seed management technique is to be followed to utilize sprouted seeds for sowing.
  • Care must be taken for proper preparation of land
  • Sowing to be done with proper spacing

By following the above tips, wastage of applied nutrients is avoided required plant population is maintained thereby chances of getting higher yield is increased.

Fertilizer management
           
For better growth of plants, root development, increased flowering, for resistance of pest and disease and to increase the yield in groundnut adopting integrated nutrient management is important.

Farm yard manure:  5 tonnes of FYM is to be applied to an acre and incorporated in the field by ploughing 4-5 times.

Inorganic fertilizers

    • By applying macro nutrients the yield could be increased
    • Applying nitrogenous fertilizers help in the better growth of plants.
    • Phosphotic fertilizers improve the development of roots and pods.
    • Potash application develops resistance in the plant for pest and disease and also for drought.
    • Application of micronutrients helps the plant growth without any nutrient deficiency and also in the absorption of other nutrients.

Basal dressing (kg / acre)

Nitrogen

Phosphorous

Potash

16

16

24

Urea 34 kg

Super phosphate 99 kg

Muriate of potash 38 kg

4 kg of Borax and 5 kg of micronutrient mixture are to be applied on the soil after sowing.

Weed Management
           
To get increased yield in any crop, weed management is an important aspect. To avoid wastage of plant nutrients, soil moisture, to facilitate the availability of sun light to crops, to prevent the spread of pest and diseases and to realize increase in yield weed control assumes greater importance. Since the crop-weed competition is more in early stages of crop growth, control of weeds within 45 days of sowing is critical.

Before sowing

1. Summer ploughing may be taken up.
2. Deep ploughing, collection of weeds and destroying them.
3. Crop rotation and keep cleaning the bunds of the field.
4. Monocot grass weeds could be controlled by using herbicides.

After sowing

Herbicide application:

Pre-emergence application of fluchlorin @ 2 lit/ha through flat fan nozzle with 900 ml of water may be given followed by irrigation. Herbicide can also be applied by mixing with sand. Herbicide has to be applied within 3 days of sowing. After 35-40 days one hand weeding may be given.

Attention

  • Herbicide is to be applied when there is enough moisture in the soil.
  • It is better to apply during evening hours.
  • To be irrigated within three days.
  • Herbicide is to be sprayed by walking behind in the field.

Advantages

  • Requires less labourers for manual weeding
  • Avoids wastage of plant nutrients and reduces cost of production.
  • Increases seed yield by better crop growth.
  • Shortage of agricultural labourer is managed.

Important after cultivation

Seed production field

Earthing up
           
It is an important operation in groundnut. Earthing up is to be done within 40-45 days after sowing as it helps for the penetration of pegs in the soil and also facilitates for increased pod development.

Gypsum application
           
Application of gypsum is very important. It contains calcium and sulphur. Calcium helps for the development of bold pods with increased weight. Sulphur improves the oil content in the kernel. For an acre 160 kg of gypsum is to be applied on 40-45th day after sowing and earthing up is to be done.

Irrigation Management
           
In order to prevent the spread of weed growth, to control the spread of pest and diseases and for better formation of pods, better water management is important for seed crops.
           
Irrigation is to be regulated based on physiological growth phases. Pegging, flowering and pod development phases are critical for irrigation during which period adequate soil moisture is essential. The important stages are:

  • Sowing (or) pre-sowing
  • Life irrigation, 4-5 days after sowing.
  • 20-22 days after sowing.
  • Pegging stage
  • Pod formation and development stage.

Plant protection
           
Plant protection measures are important to control pest and disease and to get increased yield. Integrated plant protection measures are necessary for the production of quality seeds.

Pest management

Generally, the pest attacking the groundnut crop can be classified into three categories.

  • Sucking pests
  • Leaf eating pests
  • Pod and root borers

Sucking pests

1. Thrips

Symptoms

  • A white crust on the upper side of the leaves may be seen. The lower side will be changed to purple colour.
  • Cup shape leaves facing upward.
  • Dried margin of leaves
  • Shrunken leaves without development

2. Green Jassides

Symptoms :          

  • Galls on the leaves
  • Yellow leaf margin
  • Plants turn yellow in colour with stunted growth

Control Measures: By spraying any one of the following insecticides the sucking insects may be controlled: Monocrotophos 300 ml / chlorpyriphos 300 ml / Dichlorvos 250 ml/acre.

Leaf eating insects

Leaf miner: Lives on feeding the chlorophyll of the leaves. The plants will dry. At the initial stage it enters through the mid-rib and at later stages it rolls the leaves and feed.

Control measures: This insect can be controlled by applying either 10 kg phosalone 4% dust (or) Chlorpyriphos 500 ml per acre.

Infested plants

Prodinia and Heliathis
           
Prodinia also is an important pest in groundnut crop. It will feed totally on leaves. Greenish Heliathis larvae feed on young developing leaves and cause damage to the crop.

Control Measures

  1. Light traps can be set up to attract the moths
  2. Pheromone traps can also be used to attract the moths
  3. For an acre Dichlorvos 300 m (or). To control fully developed larvae 400 ml Chlorpyriphos can be sprayed.

Red hairy caterpillar
           
These caterpillars in mass cause heavy damage to the crop. The affected field seems to have been grazed by sheep or goat. This can be controlled by setting up light traps.  Also by collection, the gregarious early instar larvae can be destroyed. By spraying Dichlorvos 300 ml (or) Chlorphyriphos 500 ml (or) Fenitrothion 300 ml for an acre this pest can be controlled.

Root and pod borer

1. White grubs
           
The roots of the plants are damaged. To control this pest, summer ploughing can be done. At the time of the last ploughing 10% Phorate granules @ 10 kg/acre can be applied an incorporated thoroughly into the soil.

Pod Borer
           
Pod borer can be controlled by applying Malathion 5% dust 25 kg/ha dust 25 kg/hg to the soil prior to sowing in area where the earwig is endemic. Soil application of any one of the above dust formulations on 40th day of sowing and incorporated in the soil during earthing up can also be done.

Infested pods


Disease management

Leaf spot
           
This disease may appear in all stages of crop growth. Black spots on the leaves can be seen conspicuously and leaves will dry. When the disease intensity is crossed grade 3, Carbendazim 500 g / ha (or) Mancozeb 1 kg/ha can be applied, 15 days later second round can be given, if necessary.

Rust
           
This disease also appears in all stages of crop growth. Yellow boils on lower surface of the leaves can be seen. When the intensity of disease is increased the damage will be heavy as all the leaves are dried. To control this disease any one of the following fungicides can be sprayed when the disease intensity crosses grade 3. Mancozeb 1 kg/ha (or) Chlorothalonil 1 kg / ha (or) Tridemorph 500 ml. If necessary 15 days after another round can be given.

Root rot
           
A white fungal mass on the portion of the plants indicates the presence of this disease. If the plants are pulled, only foliage will be coming up leaving the root portion in the soil. To control this disease seed treatment can be given with Carbendazim @ 2 gm per kg of seeds. Drenching Carbendazim @ 1 g/lit can also be given.

Harvesting and storage
           
To obtain good quality seed harvesting at optimum / correct maturity stage is very important. Proper planning of harvesting will help to avoid wastage during harvest. Harvesting of pods at premature stage results in small and shrivelled seeds with poor germination.

Fully matured pod
           
The fungus infestation will be more if harvest is delayed; in situ germination may also be a problem. Hence the importance of harvesting the pods at correct stage is an important operation in quality seed production.

Optimum stages of harvest and Harvest techniques

  • Tip of the leaves turns yellow
  • Drying and falling down of lower leaves
  • Colour of the inner side of the pod shell turns black
  • The field may be irrigated prior to harvest, if the soil is dry as this will facilitate for easy harvesting.
  • The pulled out plants should not be heaped before stripping of pods.
  • Strip off the pod from the plants by engaging manual labourers or groundnut stripper may be used.

Drying
           
For maintenance of seed quality proper drying is necessary. The Pod moisture at harvest will be around 35-40%. The pods are to be dried under sun for 2-3 days to bring down the moisture content to 10-12%. The pods are to be stirred regularly.The rattling sound will indicate proper drying. The easy removal of testa when the kernel is pressed between two fingers will indicate the proper drying of the pods. The mechanically injured and discoloured pods are to be removed. After drying the pods may be processed using processing machine.

Seed storage
           
After processing, the processed pods are to be collected in gunny bags are stored. Before storage, the pods can be treated with Thiram @ 4 gm per kg of pods. The gunny bags are to be stacked on wooden pallets. The bags should not be stacked on cement floor and they should not touch the walls of storage godown. Aeration in the storage godown is also necessary.

Seed certification
           
Seed certification guarantees the quality of seed as it ensures that the certified seed has the genetical, physical, physiological and seed health qualities. By genetical quality we mean that the seed has all the characteristics as desired by the breeder who had developed the variety, like short duration, higher yield, high protein etc. The physical quality entitles the seed to be free of stones, broken seeds, straw bits, leaf bits and has low seed moisture for better storage life. Physiological quality is measured by germination and seed health envisages freedom from pest and diseases. Only those seeds that possess the aforementioned qualities are certified by the certification agency.
           
The certification officials visit the seed field for quality inspection and only those seed fields that are maintained properly are alone accepted for certification. The accepted fields are then harvested and processed under the supervision of the certification agency and tested for germination and other seed qualities in the laboratory.
           
Only those seeds that possess the required quality are given certificate known as tag. The tag is blue for certified seeds. So, next time when you buy a seed see whether it has the blue tag.

Seed Certification standard

 

 

Field Standard

Foundation

Certified

Offtypes

0.10

0.20

Infected plants by seed borne disease (Alternaria leaf spot)

0.50

1.00

Seed standard

 

 

 

Foundation

Certified

Pure seed (minimum)

97%

97%

Inert matter (max)

3%

3%

Other crop seed  (max)

10/kg

20/kg

Weed seed (max)

10/kg

20/kg

Other varieties (max)

10/kg

20/kg

Germination (mini)

80%

80%

Moisture content (max)

 

 

Moisture pervious container

9%

9%

Vapour proof container

5%

5%

 
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