Classification

A) Based on seed size, seed coat color and oil content:

Oil type:

• small black seeded varieties (8-14 mm long, 1000- seed wt: 35-75g) with high oil content (53-63%).

Chewing type:

• large white seeded varieties (15-28 mm long, 1000- seed wt: 100-170g) with low oil content (20-35%).

Intermediate type:

• intermediate seed size and oil content.

B) Based on habit of growth

Group I:

• having tall, unbranched single headed type with well-developed achenes.

Group II:

• having comparatively shorter, branched growth and with many heads.

Climate

• Highly adaptable to both cold and high temperature condition.
• Tolerable temperature: 8-34 ⁰
• Optimum temperature: 27-28 ⁰
• Minimum temperature for germination: 8-10 ⁰
• Emergence is faster at 15 ⁰
• Night temperature of 18-20 ⁰C and day temperature of 24-26 ⁰C result in more seed per plant, heavier seed, high oil quantity and quality.
• Temperature above 25 ⁰C at flowering reduces seed yield and oil yield.
• <16 ⁰C reduce seed set and oil content.
• For fruit set, 21-24 ⁰C is desired.
• Frost will damage all stages of plant while mature one are more resistant to low temperature.
• Plant is day neutral (day length of 12-14 hrs is desirable).
• Drought resistant however stress condition reduce oil content.

Soil

• Sandy soil is preferred to clay soil.
• Grown in alfisols (red soil), entisols (alluvial soils) and vertisols.
• pH: 6.5-8
• Salinity effects plant growth, development, oil content and also influences nutrient uptake.

Land Preparation

• Requires well pulverized and weed free land with adequate moisture.
• One deep tillage by MB plough followed by harrowing and planking ensures fine seed bed.
• Should have sufficient moisture to ensure proper germination.

Seed selection and treatment

• Select true to type, bold seeds free from inert matter with optimum viability, vigor and moisture.
• Seed treated with broad spectrum fungicides (Captan, Thiram, Carboxin) @ 2g/kg seed.
• Exogenous application of ethrel, benzyl adenine and GA3 for proper germination.
• 12 hr soaking in water and shade drying gives better results.
• Treat with Azospirillium @100g/kg seed that help in N fixation.

Sowing time

• Rainy season: Mid-June-Mid-July
• Winter season (as rainfed crop): September- Mid October
• Winter season (as irrigated crop): November
• Summer season: Mid-January-first week of February

Sowing method

• Dibbling, Drilling, Line sowing.

Spacing

A) According to crop genotype;

• For long duration hybrids: 60x30cm
• For short duration cultivars: 45x30cm

B) According to soil type;

• For light soil: 45x20cm
• For medium soil: 45x30cm
• For heavy soil: 60x30cm

Sowing depth

• 3-5cm or even 8 cm.

Seed rate

• 8-15 kg/ha depending on seed size.
• 8-10 kg/ha is sufficient to ensure good crop stand.
• Under dryland farming, Plant population should be 12,000-15,000 plants/ha.