Sugarcane Farming Guide

What you will see

The inside of the cane stalk turns red when split lengthwise, with characteristic white patches across the red tissue (described as "red background with white islands"). A sour, alcoholic smell emanates from split canes. Externally, leaves yellow and wilt, and the cane may look healthy until split open.

Conditions that favor it

Warm (25-30°C), humid conditions during the grand growth phase. Enters through borer holes, cut ends of setts, and root injuries. Worst in waterlogged fields. Spread through infected planting material.

What you will see

A long, black, whip-like structure (20-100 cm) emerges from the top of infected canes, initially covered by a silvery membrane that bursts to release clouds of black spores. Infected canes are thin, with grassy, profuse tillering. The whip is unmistakable — no other sugarcane disease produces this structure.

Conditions that favor it

Warm, dry conditions promote spore dispersal. Spores infect young buds through wind dispersal. Ratoon crops show higher infection rates than plant crops because infected stools regrow with systemic infection. Spread primarily through airborne spores and infected setts.

What you will see

No distinctive external symptoms — the plant just grows slower with thinner canes. The only reliable field sign is reduced vigor compared to healthy cane. Internal diagnosis: split the stalk and look for red-orange discoloration of the vascular bundles at the nodes (comma-shaped bacteria block the xylem vessels).

Conditions that favor it

Spread almost exclusively through infected planting material and contaminated cutting tools. The most economically important sugarcane disease worldwide because it reduces yields 5-30% with NO visible symptoms. Hot water treatment of setts (50°C for 2 hours) is the primary control.

What you will see

Yellowing of the midrib on the underside of mature leaves, particularly visible on the third and fourth youngest leaves. Yellowing extends from the midrib outward and downward. Severely infected plants show reduced tillering, stunting, and premature senescence of older leaves.

Conditions that favor it

Transmitted by aphids (Melanaphis sacchari) and through infected setts. Widely distributed in all sugarcane-growing regions. Stress conditions (drought, nutrient deficiency) make symptoms more visible.

What you will see

Affects planted setts — internal tissue turns black and has a distinctive fruity, pineapple-like smell (hence the name). Setts fail to germinate or produce weak, spindly shoots. When split open, the tissue is dark, hollow, and smells of fermenting pineapple.

Conditions that favor it

Cold, wet planting conditions that slow germination. The fungus enters through the cut ends of setts. Most severe when planting is followed by cool, wet weather that delays sprouting. Fungicide treatment of sett ends prevents infection.

Damage

Larvae bore into internodes, creating tunnels that disrupt water and nutrient transport. Borer holes serve as entry points for red rot fungus. Severe boring causes "dead hearts" in young cane and weakens stalks, leading to wind breakage. Yield losses of 5-20% are typical; combined borer + red rot losses can exceed 40%.

How to identify

Cream-colored larvae (20-25mm) with brown head capsules, found inside the stalk. Look for small, round entry holes on the stem with frass pushed out. Adult moths are straw-colored with a wingspan of 20-25mm. Deadhearts in young plants — the top can be pulled out. Split stalks to see internal tunneling.

Damage

Nymphs suck sap from leaf undersides, causing yellowing and reduced photosynthesis. Heavy infestations produce thick honeydew deposits and sooty mold, turning leaves black and dramatically reducing sugar production. Also vectors yellow leaf virus.

How to identify

Tiny (1mm) white-winged adults on leaf undersides. Black, oval nymphs (1-2mm) in neat rows on leaf undersides. Black sooty mold coating on upper surfaces of lower leaves. Most damaging during the grand growth phase when photosynthesis is critical.

Damage

Feeds on lower leaf surfaces, causing yellowing, curling, and premature death of lower leaves. Heavy infestations reduce photosynthesis and sugar accumulation. Honeydew production promotes sooty mold. Transmits sugarcane yellow leaf virus.

How to identify

Small (1.5mm), pale yellow aphids with dark cornicles. Found in colonies on the undersides of lower and middle leaves. Leaves may appear sticky from honeydew. Most problematic during dry, warm conditions.

Damage

Feed on planted setts (destroying germination), on dead cane tissue at the base (reducing stand), and on mature stalks (hollowing them out). Severe termite damage causes entire stools to collapse. Most damaging in rainfed sugarcane in tropical Africa and Asia.

How to identify

Soil-colored termites found inside damaged setts, at the base of cane stools, and inside hollowed-out stalks. Mud tubes on the cane surface. Stools that fall over when pushed. Most active during dry seasons.

Damage

Both adults and nymphs suck sap from leaves, causing yellowing and drying. Heavy infestations produce honeydew and sooty mold. Severe outbreaks can reduce sugar yield by 20-30%. Most damaging in the Indian subcontinent.

How to identify

Adults are wedge-shaped (8-10mm), straw-colored leafhoppers with a distinctive conical head. Nymphs are white, waxy, and fluffy. Found on leaf undersides in large numbers. Heavy white waxy deposits on lower leaves indicate nymph feeding.