Seed :: Vegetables :: Bhendi

QUALITY SEED PRODUCTION IN BHENDI

 

Selection of land for quality seed production
        
The selection of land is the first and foremost task for a seed producer. The seed production plot must be selected carefully. A fertile and healthy seed plot will certainly produce quality seed. The field selected for seed production must not have been sown with bhendi in the previous season. This is done to avoid volunteer plants that cause admixture.
         
Soil with neutral pH must be selected. Loam or clay loam soils are best suited. Higher organic matter will lead to production of vigorous seed.

What are volunteers?
       
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. As they germinate without sowing or they volunteer to grow by themselves, hence the name volunteer plants.

Isolating the seed crop to avoid genetic contamination
      
T
he quality seed must be genetically and physically pure. Genetic purity can be maintained by preventing cross pollination with other undesirable varieties. This is achieved by isolating the seed crop.
       
Isolation is the act of growing the seed crop away from a contaminant such that cross pollination is prevented. Bhendi seed crop must be grown 100 m (300 feet) away from another variety of bhendi.

Selecting the right season for raising seed crop
        
Seed is very sensitive to weather. Hence selecting the right season is necessary. Though bhendi can grown through – out the year, seed crop should be grown such that the seed matures in cool dry climate. This will facilitate proper ripening of fruits and reduce the pest and disease infection. Seasons are selected with this idea in mind. In Tamil Nadu best seed crop growing seasons are June-July and February-March, which are followed by mild summer climate, thus providing proper drying.

Seed selection
        
Selecting ripe and vigorous seed is the first step of production of robust seedling which will ultimately lead to producing quality seed. Planting robust seedling will impart disease and pest resistance and help in proper uptake of precious fertilizer applied to the main field. Proper care must be taken to avoid the usage of aged seeds those are stored for more than a year.
        
Selection of seeds is the first step in production of quality seed. This involved selection of seeds with the right genetic make-up of the variety chosen to be produced. Seeds must be from an approved source. This is possible if the seed is got from the breeding firm / University research station or from the breeder himself. Verify if the seed you have brought has breeder seed tag (for producing foundation seed); foundation seed tag (for production of certified seed). Further, the seeds must be free from pest and diseases, rotten, dull coloured, black spotted seeds must be removed. Seeds of uniform size and shape alone must be used for sowing.

Seed quality upgradation by water floatation technique
         
Storage potential of the seeds will depend on the season, place of storage and its environment. Stored seeds are normally posses less vigour and hence those less vigour seeds are to be separated to improve the planting value of the seed lot. By water floatation technique we can easily separate the less vigour seed based on the weight.
        
Put the seed slowly into plastic container of 15 litres capacity having 10 litres of water and stir well. The seeds of lesser weight will float and heavier seeds will sink in the water column. Then remove all the floating seeds and collect only the seeds settle at the bottom of container. The collected seeds should be dried properly.

Seed treatment
        
The upgraded seeds should be treated with captan or thiram @ 2 gram per Kg of seed. Treated seeds can be used for sowing.

Preparation of main field and transplantation
         
The selected field is ploughed twice till the soil achieves fine tilth. During the last ploughing, 20 cart loads (10 tonnes) of well decomposed compost is applied and again ploughed. After last ploughing, the land is thrown into ridges and furrows of 60cm (2 feet). Later plots of 2m (6 feet) length and 1.5 m (4.5 feet) width are made and irrigation channels are laid out.
          
Urea at 35 Kg per acre, Super phosphate at 120kg per acre and potash at 26kg per acre are applied as basal. The recommended dose of fertilizer is applied on the base of the ridge on the side of sowing.

Sowing
       
The upgraded seeds are to be sown at distance of 20 cm in the ridges at the rate of two seeds per hill.

Irrigation management
       
After sowing field has to be irrigated by complete soaking of ridges. Again the field should be irrigated third day after sowing. Then field has to be irrigated at weekly intervals. The care must be taken to avoid any water stress to the crop, especially during flowering, pod and seed maturation stages. Because, this will affect the seed yield and quality.

Controlling weed
       
It is always essential to control the weeds early during the crop growth period as this saves labour and time. This can be done by applying weedicide Fluchloralin – 800ml or Metachlor 600 ml dissolved in 400 litre of water and sprayed using knapsack sprayer. The weedicide is applied on the third day prior to life irrigation. This will kill all the germinating weed seeds. If it is not possible to spray, then the recommended dose of weedicides is mixed with 30-40kg sand (6-8 iron chatties of sand) and spread uniformly on the third day and the crop is life irrigated.
       
Weedicide will prevent emergence of dicot weeds for 15days after which the late emerging weeds can be controlled by hand weeding on 30-35 days.

Top dressing
       
Seed crop is entirely different from vegetable crop. Hence, fertilizer is applied as two or three split doses. Urea is applied in two split doses as 9kg during flowering and another 9 kg after 10 days of the first top dress. This leads to higher fruit bearing, higher fruit retention and heavier seed.

Maintaining seed quality by rouging
       
One of the most important aspects of seed production is thorough rouging. Rogue is defined as the presence of those plants that deviate from the characters described for the variety. Such rouges if left in the field they tend to reduce the genetic purity of the seed crop and thus reduce purchase value of resultant seed. Roguing is defined as the operation of removing rouges. In practice, all plants that do not obey the characteristics of the particular seed crop are to be removed along with diseased plants particularly yellow vein mosaic disease infested plants, other crop plants, weeds, insect affected plants during rouging operation.

When to do rouging
       
Rouging is more effective if done prior to flowering, since upon flowering there is very high possibility of cross pollination. Rouging is also attempted during vegetative phase, fruit formation stage and prior to harvest.

Rouging during vegetative phase
       
During vegetative phase, i.e. during first 30-35 days, rouging is attempted based on plant characters like height of plant as shown in the photo, leaf shape, size, surface of leaf. Plants showing heavy branching and spreading nature are removed. Plants showing variation in stem or leaf base colour are also removed. Those plants showing symptoms of yellow mosaic are also removed.

cv

Rogue plant

Rouging during fruit formation phase
      
At this phase, the rouges are removed based on fruit characteristics like length of fruit, size, shape and colour.

Rouging during pod harvest phase
       
Rouging is done prior to harvest based on fruit colour and fruit borer infection. While harvesting the workers can be taught to separate infected fruits from good ones and forward only the uninfected fruits for seed extraction.

Caution!
        
All the rouges must be immediately removed from the seed field and destroyed

Foliar application of nutrients
        
In addition to the fertilizer application, seed crop needs nutrients at their different stages for the proper seed development and maturation. Hence, application of nutrients through leaves is important. For bhendi seed crop, foliar application of DAP 0.5 per cent solution thrice at an interval of days starting from flowering stage is essential. This will helpful for the harvest of higher yield of quality seeds.

Harvesting
        
The change of pod colour to brown is the indicator for harvest in bhendi seed crop. At that stage the seed posses higher vigour and viability. Once there is a symptom of hair line cracks on the edges of the pod, it should be harvested without any delay. Is there any delay in harvest it will lead to shattering loss as shown in photo.

Optimum stage of harvest

Damage caused due to delayed harvest

Processing to improve seed quality
       
After the pod harvest and before the seed extraction, only healthy pods of true to type and free from pod borer infestation are to be selected for seed extraction.

Seed extraction method
        
The selected pods as shown in the photo are to be dried for one or two days before seed extraction. Dried pods are to be spread over the gunny bags and beaten using pliable sticks. Then the separated seeds are cleaned and upgraded by water floatation technique to remove all the ill filled and pest affected seeds.

 

Pods selected for seed extraction

Seed drying
       
Seeds extracted by beating using pliable sticks have a moisture content of 12-13% and hence have to be dried before storage. The seeds are hence dried by spreading them over a tarpaulin for 8-10 hrs under partial shade. This is followed by sun drying where the seeds are dried between 8-12 am and 3-5 pm only. Drying during the hot hours of 12-3 pm will lead to seed damage caused by higher temperature and presence of UV radiation in sunlight.

Caution
       
After the upgradation of seeds by water floatation technique the seeds should not be dried directly under the sun light. This will reduce the seed vigour and viability.

Seed cleaning and processing
       
One of the main characteristics of seed quality is the right size. Plumpy seeds are better than ill-filled puny seeds. Iii filled seeds are removed by winnowing as they are lighter. To remove the small seeds from well formed plumpy seeds, grading is done. Grading is one simple method by which we can separate the filled seeds from broken and puny seeds. Grading is done using round holed or wire mesh sieves are easily available in the market. For bhendi seed processing BSS 6 wire mesh sieve is to be used. By sieving, those seeds that are broken, fungal infected, seed coat damaged seeds are removed.

Caution
        
While using wire mesh or round hole sieves, be through in cleaning the sieves. Any remnant of previous crop seed will lead to contamination. Seed generally get struck in the holes and have to be removed before commencing the sieving operation.

Good quality bhendi seeds

Protecting seeds during storage  
         
Producing quality seeds is only half of the job, the other half is protecting the seed during its storage that starts after processing till it is sown by the farmers. The major aspects that impart good storability are optimum seed moisture, seed treatment, mid storage correction and seed storage   container. We will see them one by one.

Seed moisture
         
Seed moisture is the foremost seed physical attribute that contributes for storage life. Lower the seed moisture, longer the shelf life. Short term storage can be achieved by drying the seeds to 8-10% moisture, content while long term storage is possible by reducing the seed moisture even further to 6%. Under such low moisture content, seeds have to be stored in moisture proof bags made of thick polythene (700 guage).

Seed treatment
        
Prior to storage, seeds are treated with fungicide to ward off fungal pathogens. Seeds are mixed with Carbendazim 4 g/ kg.
        
A novel technique called Halogen permeation treatment is also recommended now-a-days. Calcium oxy-chloride, commercially known as bleaching power and powdered calcium carbonate (lime stone) is mixed in equal ratio. Thus mixture is added to seed at 5g/kg and stored.

Seed container
         
Apart from seed and seed treatment, the next most important aspect of seed storage is seed container. Container can be chiefly differentiated as moisture pervious and moisture impervious types. Cloth, paper, gunny bags are moisture pervious as the moisture from outside atmosphere can enter and exit freely. Hence, even if the seed is dried to safe moisture, but stored in a humid climate, then seed gains moisture during storage and looses vigour. So, to safely store seeds in moisture previous bag, then the outside humidity must be low. In Tamil Nadu, most of the months are hot and humid, hence after drying the seed to safe moisture limit, seeds can be safely stored in moisture impervious bag like thick polythene bag of 700 g or in tin / plastic containers that are sealed tightly. In case of short term storage (4-6 months) cloth or gunny will be sufficient.

Seed certification
       
Seed certification will give guarantee for genetic purity and other qualities. It is a legally sanctioned system for quality seed production. The supply of improved varietal seed to the farmers with high genetic purity, physical purity and germinability are being the main objectives of the seed certification.
         
Seed certification acts at different stages from sowing to issue the tags and sealing the bags. They start their function by verifying the seed source before the seeds are sown, then verifying the isolation distance followed for that seed crop, taking field inspections at different stages viz., bagging operations. In addition to these operations, it is their duty to send samples to seed testing laboratory and after receiving the results, they will be issuing the certification tags.
        
The seeds so produced will be issued certification tag only after meeting out the prescribed field and seed standards.Hence, by registering the seed production fields under seed certification we could able to produce genetically as well as physically pure seeds.
          
The private seed producers can also subject their seed production fields under seed certification for quality seed distribution.

For more details contact the seed certification officers nearby area.

Minimum seed certification standard prescribed for certified seed

Field standard

 

Rogues (maximum limit)

0.2%

Objectionable weed plants (maximum limit)

None

Seed standards

Pure seeds (minimum limit)

99.0%

Inert matter (maximum limit)

1.0%

Other crop seeds (maximum limit)

5 Nos/kg

Weed seeds (maximum limit)

None

Objectionable weed seeds (max.)

None

Germination (minimum limit)

65.0%

Moisture content

Moisture proof bag

8.0%

Moisture pervious bag

10.0%

 

 
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