Testing and treatments of seed paddy

Content Introduction Reason for seed paddy testing Components and procedures in seed paddy testing Seed paddy treatments Summary

Introduction Four types of seed classes - Breeder seed - Foundation seed - Registered seed - Certified Seed Seeds Act is to regulate seed quality during production (seed certification ) and at distribution phases through sample testing.

How can we get certified seeds How can we get certified seeds Get the application Verification of Seed Source and other requirements. field inspections to prescribe standards Seed sampling and testing Grant of certificate and certification tags, tagging and sealing. (345/= /sample –full test)

Seed paddy testing Technologies used to ensures the viability and all the physical factors that regulate the germination and growth of the seed/ seeding tests carried out by seed testing laboratories.

Seed paddy testing laboratories- Srilanka Government laboratories Gannoruwa Mahailluppallama Leading first private Seed Testing Laboratory-CIC. Activities - Receipt & Registration of samples - testing of samples - Reporting

Reason for seed paddy testing To detect other crops seeds inert matter weed seeds To assure the germination To maintain the genetic identity and purity To meet specified standards (final seed lot) To provide quality certified seed

Benefits by testing of seed paddy guarantee the superior quality supplying the best seeds/planting material help to improve the farmer income

Components in seed paddy testing Sampling of seeds Germination Test Seed Purity Test - Other Distinguishable Varieties (ODV) - Troublesome weed seeds - Broken and Damaged seeds - inert Matter - Color, Smell and Appearance (CSA) Moisture Test

Seed sampling Take equal portions from evenly distributed seeds -automatic sampling device (before conditioning) -long probe (after conditioning) considerations-: take from well-distributed points in the bulk Sufficient amounts from the bulk at least 10%of the number of bags in the lot.

Germination Testing purpose of testing to assess seed viability to predict performance of the seed and seedling in the field. to obtain information about the planting value of the seed sample to decide the seed rate to achieve desired field establishment. to Seed certification purposes.

Procedure of germination testing Take random samples(atleast-3) Count 100 seeds from each sample place on absorbent material inside the tray Record the number of germinated seeds(10days)

Calculation number of seeds germinated Germination = *100 (%) number of seeds on tray use seed germinators High germination percentage indicates -high vigor -good for field establishment

Seed lot purity The impurities measured to test the purity of the seed batch - Other Distinguishable Varieties (ODI) - Weed seeds - Inert matter. - Broken and Damaged seeds -Color, Smell and Appearance (CSA)

Procedure Take random a sample of the seed(100gm) Remove all of the weed and other crop seeds and the inert matter weed Damaged seed Inert matter paddy

Weigh each component and calculate %inert matter =Wgt of inert matter *100 Wgt of total sample

Varietal purity test 1-Grain dimensions The grain size and shape (length- width ratio) Comparing the length-width ratio of the sample Significant deviation indicates that the sample is impure

Procedure Take random sample(20 grains) Use a Verniercaliper Measure the length,width Calculate length width ratio SCALE (Length) 1 -Extra long (>7.5mm) 3 -Long ( mm) 5 -Medium ( mm) 7 -Short (<5.5mm )

Con…… Scale Shape Ratio 1 Slender > Medium Bold Round <1.1

grain weight grain weight. Each variety publish this way If the sample departs from this, it may be an indication that the sample contains a mixture of varieties. Procedure  Select a random sample from the seed batch  Count 1,000 whole grains from the sample.  Weigh the 1,000 grains.  This is the 1,000-grain weight.

Moisture content 1) Drying oven method (primary method) Set the oven at 130 o C Weigh 100-gram seed samples (3) Place samples inside the oven (16-24 hrs) Take final weight of each sample MC= initial weight - final weight *100 initial weight take average over three samples

2)Electronic moisture meter Turn the moisture meter on(Ensure it is set for paddy) Fill the bowl of the moisture tester with a sample press the knob until the reading is displayed (Test at least three samples ) (Take the average of the three)

Certified seed paddy quality-Srilanka  Germination - > 85%  Other Distinguishable Varieties (ODV) - > 100/500g  Troublesome Weed Seeds - < 5 seeds/500g  Moisture - 13% Maximum  Color /Smell/Appearance (CSA) – Good  Broken & damaged seeds - 100/500g  Inert matter - < 2%

Certified seed paddy bag Should print: - Association emblem /trademark - variety name -The percentage of germinating seed -net weight -Tags Breeder Seed White Tag Foundation Seed White Tag Registered Seed Light green Tag Certified Seed Light blue Tag

Seed treatment  To prevent Seed born diseases (Riceblast/bacterial wilt)  To remove the empty seeds/half fill seeds Treatments 1)Soaking: up to hours in water. The germination will be facilitated after soaking

Con…. 2)Traditional method Soak the seeds(30 kg) in water for 18 hrs transferred into a gunny bag bottom layered with 1 kg each of `vadhanarayana' (Delonix elata) and `kuppaimeni' (Acalypha indica) place cow dung cakes above the layer filled(3/4 th of sack) with already soaked paddy seeds

cow dung cakes are placed over the seeds. Final layer leaves of `above plants Tie the sack tightly and place stones above bag 24 hours. Take sprouted seeds and sown for raising in paddy nursery Advantages seedlings grow very fast resistant to red spot disease more number of grains after palnting

3)Egg floating treatment -put the egg in 1 liter water and it should hit bottom settle horizontally then remove the egg from the water - add 200 grams of salt to the 1 liter of water. -After salt dissolved put egg it should float

-Let the seeds sit in the solution for 15 minutes -After about 2 min (of 15 min), remove the hollow floating seeds -After the 15 min pour off and separate the hard seeds, And rinse well

4)Disinfection of the seed: fungicide treatment applied before seeding the seed for germination -Thiram75 WDP100g/100kg seed -Captan 75 dust300g/100kg dry dressing 5)Acid treatment soaking the seed in normal nitricacid (HNO3,0.2%) for 24 hrs (after preheating at 50 °C). Reduce dormancy

Summary  Seeds should undergo different tests before the certification  Seed treatments important to over come the vigor less  Pre germination test should done before sowing in nursery/field