Course Content
Crop Production (Unit 6)
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Dryland Agronomy Unit 4
ASRB NET Agronomy
    1. Introduction

    Sugarcane (Saccharum officinarum) is the most important sugar crop in the tropics and subtropics. It belongs to the Poaceae family and is a long-duration, perennial crop, though generally cultivated as an annual. It is mainly grown for its juicy stem, which contains 10–20% sucrose that is extracted for sugar, jaggery, ethanol, and molasses. Besides being a cash crop, it is a major source of employment, industrial raw material, and bioenergy.

     

    1. Botanical Information
    • Family: Poaceae (Gramineae)
    • Botanical name: Saccharum officinarum
    • Origin: New Guinea (tropical cane origin)
    • Inflorescence: Open panicle called an “arrow”
    • Root types:
      • Sett roots – temporary, arise from the buds of planted setts, support initial growth.
      • Shoot roots – permanent, provide anchorage and uptake of water/nutrients.

     

    1. Major Producing Countries
    • Brazil – World’s largest producer (since 1979).
    • India – Second largest producer, but leading consumer of sugar.
    • Cuba – Historically important producer.
    • China – Major producer in Asia.

     

    1. Climatic and Soil Requirements
    • Temperature:
      • Germination: 32–38 °C
      • Tillering: 25–30 °C
      • Maturity: 15–20 °C
    • Rainfall: 1000–1500 mm annually, well-distributed.
    • Sunlight: Bright sunshine is essential for sucrose accumulation.
    • Soil:
      • Deep, fertile, well-drained loamy soil.
      • Rich in organic matter.
      • Optimum pH: 6.5–7.5.

     

    1. Varieties of Sugarcane
    • Tropical canes (S. officinarum): Thick, juicy, high sugar content, grown mainly in tropical regions.
    • Indian canes (S. barberi, S. sinense): Short, thin stalks, early maturing, grown in subtropical regions like North India.

     

    1. Land Preparation
    • 2–3 deep ploughings followed by harrowing.
    • Field should be well-leveled and weed-free.
    • 10–15 tonnes/ha of FYM or compost is applied before the last ploughing.

     

    1. Planting

    Time of Planting

    • Tropical India: Autumn: October–November. Spring: January–February
    • Subtropical India: Spring: February–March

     

    Methods of Planting

    • Conventional methods: Flat bed planting (North India). Furrow method (Eastern UP, Peninsular India). Trench/Java method (coastal windy areas).
    • Improved techniques:
      • Partha method (Tamil Nadu, waterlogged conditions).
      • Spaced transplanting technique (IISR).
      • Winter nursery system (IISR).
      • Rayungan, Sablang, Tjeblock, Algin methods (regional practices).
    • Sett placement techniques:
      • End-to-end method (low sett rate).
      • Eye-to-eye method.
      • Double row system (thick planting).
      • Single-bud planting (nursery).

    Seed Rate

    • 50–70 q/ha (3-budded setts).
    • Single bud nursery: 18,000 setts/ha.

     

    1. Nutrient Management
    • Nitrogen (N): 150–200 kg/ha (in split doses).
    • Phosphorus (P₂O₅): 60–80 kg/ha.
    • Potassium (K₂O): 60–120 kg/ha.
    • Micronutrients: Zn, Fe as per soil test.

     

    1. Water Management
    • Total water requirement: 1500–2500 mm.
    • Critical stages: Germination, tillering, grand growth, maturity.
    • Irrigation interval:
      • Summer: every 7–10 days.
      • Winter: every 15–20 days.

     

    1. Intercultural Operations
    • Weeding: First 30–60 days.
    • Earthing up: At 60–90 days after planting.
    • Trash mulching: Helps conserve moisture and suppress weeds.

     

    1. Growth Phases
    1. Germination phase: 0–60 DAP (days after planting).
    2. Tillering (formative) phase: 60–130 DAP.
    3. Grand growth phase: 130–250 DAP.
    4. Maturity phase: 250–365 DAP.

     

    1. Harvesting and Ripening

    Indicators of Maturity

    • Yellowing of leaves.
    • Stalks become brittle, produce metallic sound.
    • Arrowing and cessation of growth.
    • Brix % in stalk middle: 16–18%.
    • Glucose content <0.5%.

    Chemical Ripeners

    • Balsario: 4.5 kg/ha in 1000 L water.
    • Polaris, Sodium Metasilicate (sprayed 6 weeks before harvest).

     

    1. Yield and Recovery
    • Average cane yield: 60–100 t/ha.
    • Sugar recovery: 10–12%.
    • Jaggery recovery: 9–10%.
    • By-products: Molasses, bagasse, press mud.

     

    1. Importance
    • Provides raw material for sugar, jaggery, ethanol, biofuel, paper, and electricity generation.
    • Bagasse used in paper and board industries.
    • Molasses used in alcohol, vinegar, citric acid production.
    • Press mud used as organic manure.
    • Generates employment and contributes to rural economy.

     

    1. Sugar Extraction and By-Products

    Process

    Output

    Ordinary crusher

    50–65% juice

    Power crusher

    60–70% juice

    Vacuum crusher

    70–75% juice

    Gur recovery

    9–10% (max 15–18%)

    Crystallized sugar

    62.5% from gur

    Sucrose in cane

    13–24%

    Molasses yield

    3.5%

    Rab yield

    18–20% of juice

    By-products utilization:

    • 50% → White sugar
    • 30% → Gur/jaggery
    • 20% → Alcohol (ethanol fuel, gasohol = 80% petrol + 20% ethanol).

     

    1. Sugarcane vs. Sugarbeet

    Aspect

    Sugarcane

    Sugarbeet

    Extraction

    Crushing

    Diffusion

    Sugar %

    6–10%

    Higher

    World share

    60%

    40%

    Grown in

    Tropics

    Temperate zones

     

    1. Important Research Institutes
    • Sugarcane Breeding Institute (SBI), Coimbatore – breeding of high-yielding varieties.
    • Indian Institute of Sugarcane Research (IISR), Lucknow – agronomic research.
    • Indian Sugar Institute (ISI), Kanpur – sugar technology and training.

     

    Major Diseases

    • Red Rot (Colletotrichum falcatum) – Most destructive disease, causes reddening of stalk tissues.
    • Smut (Sporisorium scitamineum) – Black whip-like growth emerges from the stalk tip.
    • Wilt (Fusarium moniliforme) – Yellowing, drying, and wilting of plants.
    • Grassy Shoot Disease (Mycoplasma-like organism) – Excessive tillering, grass-like shoots.
    • Ratoon Stunting Disease (RSD) – Caused by bacteria, stunted growth in ratoon crops.

    Management: Resistant varieties, seed treatment (hot water), crop rotation.

     

    Important Facts on Sugarcane

    • Botanical name Saccharum officinarum
    • Family – Poaceae (Gramineae)
    • Origin – New Guinea
    • Inflorescence – Open panicle (called arrow)
    • Type of crop – Long-duration, perennial (cultivated as annual)
    • World’s largest producer – Brazil
    • India’s top producing states – Uttar Pradesh, Maharashtra, Karnataka, Bihar, Tamil Nadu
    • Optimum pH of soil – 6.5–7.5
    • Water requirement – 1500–2500 mm annually
    • Critical stages for irrigation – Germination, Tillering, Grand growth, Maturity
    • Growth phases – Germination → Tillering → Grand growth → Maturity
    • Seed rate – 50–70 q/ha (3-budded setts)
    • Average yield – 60–100 t/ha
    • Sugar recovery – 10–12% (best variety Co 0238 gives higher recovery)
    • By-products – Bagasse, Molasses, Press mud (all have industrial uses)
    • Disease known as “cancer of sugarcane”Red rot
    • Important high-yielding varieties – Co 86032, Co 0238, CoJ 64
    • Institutions
      • SBI (Coimbatore) – breeding research
      • IISR (Lucknow) – agronomy research
      • ISI (Kanpur) – sugar technology
    • Ethanol blending – Sugarcane molasses is key for India’s 20% ethanol blending target (by 2025).
    • Nickname – Sugarcane is called a “cash-cum-industrial crop” because of its multiple uses.

     

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