Ppt on Seed Rate, Sowing Methods, Germination, And Crop Stand Establishment

• Plant propagation occurs via sexual (seeds) and asexual (vegetative) methods.
• A seed is a mature, fertilized ovule and the reproductive unit of flowering plants.
• Seeds are essential for crop establishment and genetic diversity.

• Seed rate: Quantity of seed required per unit area for desired plant population.
• Depends on spacing, test weight, and germination percentage.

Seed Rate Formula:

• Seed rate (kg/ha) = [Plant population/ha × Seeds/hill × Test weight (g) × 100] / [1000 × 1000 × Germination %]

• Common sowing methods: Broadcasting, Dibbling, Sowing behind plough, Drill sowing, Transplanting.
• Choice of method depends on crop type, seed size, and field conditions.

• Randomly scattering seeds over the soil surface.

Features:

• Suitable for small to medium seeds (e.g., sesame, sorghum).
• Easy, quick, and labor-saving; commonly used in India.
• Criss-cross sowing improves uniformity.

Disadvantages:

• Uneven seed distribution and depth.
• Higher seed rate required.
• Lower germination and risk of lodging.

• Placing seeds in holes at specific depth and spacing.

Features:

• Used for medium to large seeds (e.g., maize, cotton, sunflower).
• Practiced on ridges, furrows, or beds.
• Facilitates uniform population and better germination.

Advantages:

• Reduced seed rate.
• Enables mechanization (weeding, harvesting).

Disadvantages:

• Costlier and more time-consuming than broadcasting.

• Seeds dropped in furrows opened by plough, then covered by soil.

Features:

• Manual or mechanical methods available.
• Ensures uniform depth and spacing.
• Suitable for crops like groundnut, redgram, cowpea.

• Dropping seeds at definite depth using sowing implements (seed drills).

Features:

• Maintains uniform depth and population.
• Fertilizer application possible during sowing.
• Suitable for intercropping.

Disadvantages:

• Requires more time, energy, and cost.

• Raising seedlings in nursery, then transplanting to main field.

Features:

• Ensures optimum plant population and crop intensification.
• Nursery area is about 1/10th of total field area.

Disadvantages:

• Labor-intensive and expensive.
• Transplanting shock may occur (5–7 days of slow growth).

• Process where radicle emerges from seed, initiating seedling growth.

Key Factors Affecting Germination:

• Soil type, texture, structure, and microorganisms.
• Moisture availability and excess can cause rotting.
• Temperature: Optimum range required for each crop.
• Light: Red light (662 nm) promotes, far-red (730 nm) inhibits germination.
• Soil tilth and sowing depth (3–5 cm for most crops).

• Good crop establishment ensures optimum plant population and yield.
• Plant population: Number of plants per unit area in the field.
• Optimum population maximizes yield per area; excess or deficit reduces yield.

• Plant size: Larger plants need wider spacing (e.g., cotton vs. rice).
• Elasticity: Indeterminate plants tolerate wider population range.
• Foraging area: Early soil cover maximizes sunlight interception.
• Dry matter partitioning: Higher density increases canopy and dry matter.
• Crop and variety: Population varies by crop and variety (e.g., rice, maize, cotton).

• Time of sowing: Weather, day length, and temperature affect population needs.
• Rainfall/irrigation: Lower population under rainfed, higher under irrigated conditions.
• Fertilizer application: High population utilizes nutrients better; low fertility limits yield at high density.
• Seed rate: Higher in broadcasting, lower in line sowing/transplanting.

• Arrangement of plants in rows and columns to optimize resource use.

Types:

• Random: Unequal spacing, common in broadcasting.
• Square: Equal spacing in both directions (e.g., coconut, banana).
• Rectangular: Rows wider than plant spacing; includes solid row, paired row, skip row.
• Triangular: Used for wide-spaced crops (e.g., coconut, mango).

Importance:

• Ensures efficient use of light, water, nutrients, and space.

• Selection of appropriate seed rate and sowing method is crucial for crop establishment.
• Optimum plant population and geometry maximize yield and resource efficiency.
• Understanding genetic and environmental factors aids in effective crop management.