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Blackgram :: Seed Production

Land Requirement

Land should be free of volunteer plants. The previous crop should not be the other varieties of the same crop. It can be the same variety if it is certified as per the procedures of certification agency. The most ideal soil is well drained soil. Leveling is needed for uniform distribution of water and nutrient.

Field Standards

General Requirements

Isolation

Blackgram seed production fields shall be isolated from the contaminants by allowing the isolation distance as specified below.

Contaminants	Minimum distance (meters)
Contaminants	Foundation	Certified
Fields of other varieties	10	5
Fields of the same variety not conforming to varietal purity requirements for certification	10	5

Pre-sowing seed management

Soak the blackgram seeds in 1/3 volume of 100 ppm ZnSO4 (1:0.3 volume of Seed Solution ratio) for 3 with intermittent stirring for uniform soaking. Dry back the seeds to original moisture content (8 - 9%) under shade
(OR)
Coat the seeds with TNAU VidhaiAmirtham @ 10 ml/kg of seeds.

(Hyperlink for seed coating methodology)

Pre monsoon sowing
Seed hardening

Dibble the seeds at 3-4 cm depth at 30 x 10cm spacing.
Use of mechanized seed drill also recommended

Fertilizer recommendation

Apply fertilizer as per STCR‐IPNS recommendation
(OR)
Adopt blanket recommendation

Recommended Quantity of Nutrient (kg /ha)					Quantity of fertilizer needed (kg /ha)
Recommended Quantity of Nutrient (kg /ha)					Situation I				Situation II
N	P₂O₅	K₂O	S^*	MN	Urea	SSP	MOP	MN	Urea	DAP	MOP	Gypsum	MN
25	50	25	40	5	56	312	42	5	12	110	42	170	5

Entire quantity of NPKS applied as basal in the last plough
Before sowing broadcast 5 kg of TNAU MN mixture for pulses / ha as enriched in FYM at 1:10 ratio incubated for 30 days at friable moisture.

Foliar spray

Apply TNAU Pulse wonder @ 5 kg/ha as foliar spray during peak flowering stage.
Spray should be given during early morning or late evening using Knapsack sprayer with 500 litres of water for one hectare.

Flowering Stage

Pod Formation

Roguing

Roguing should be done from vegetative to maturity stage, based on plant, leaf, flower, pod and seed characters. In addition to the off types, the pest affected and mosaic infected plants should also be removed.

Specific requirements

Factors	Maximum permitted (%)*
Factors	Foundation	Certified
Off-types	0.10	0.20

^*Maximum permitted at the final inspection

Field Inspection

A minimum of two inspections will be made, the first before flowering and the second at flowering and fruiting stage by Seed Certification Officer.

Harvesting

Harvest the pods at physiological maturity (30 days after the 50 per cent flowering) when the colour of majority of the pods (80%) turns black. At this stage pod moisture content shall be about 17 ‐ 18%.

Threshing

Thresh the pods either with pliable bamboo stick or pulse thresher.

Drying

Dry the seeds to 8 - 9% moisture content.

Grading

Grade the seeds using BSS 7 x 7 (British Standard Sieve) wire mesh sieve

Pre-storage seed treatment

Treat the seeds with halogen mixture (CaOCl2 + CaCO3 + arappu (Albizziaamara) leaf powder mixed in the ratio of 5:4:1 3 g / kg of seed as eco-friendly treatment.

Storage

Store the seeds with a seed moisture content of 8-9 % in gunny or cloth bags for short term storage (8 - 9 months).
Store the seeds with a seed moisture content of 8 - 9% in polylined gunny bag for medium term storage (12 - 15 months).
Store the seeds with a seed moisture content less than 8% in 700 gauge polythene bag for long term storage (more than15 months).

Factors	Standards for each class
Factors	Foundation seed	Certified seed
Pure seed (minimum)	98%	98%
Inert matter (maximum)	2%	2%
Other crop seeds (maximum)	5/kg	10/kg
Weed seeds (maximum)	5/kg	10/kg
Other distinguishable varieties (maximum)	10/kg	20/kg
Germination including hard seeds (minimum)	75%	75%
Moisture (maximum)	9%	9%
For vapour-proof containers (maximum)	8%	8%

Updated on Jun 2023