Respiration

Respiration breaks down sugars to release usable energy (ATP) for growth, transport, nutrient uptake, and repair. It consumes O₂ and releases CO₂.

Key points

• Runs 24/7 (night respiration is real)
• Net growth depends on photosynthesis (gain) minus respiration (cost)
• Roots must respire — oxygen shortage quickly limits uptake

Why it matters to yield

Carbon balance

Warm nights increase respiration cost and can reduce net growth/fruit fill even if days are bright.

Root oxygen (often the hidden limiter)

Saturated media reduces oxygen supply: - uptake slows - plants can wilt despite wet media (“wet feet”) - root health declines and disease risk rises

Common respiration-linked problems

• Warm nights: sugar drain → softer growth, weaker fruit fill
• Low root oxygen: stalled uptake, root browning, wilting despite wet substrate
• Recovery lag: post-stress repair uses energy → temporary growth stall

Practical levers

• Night climate: avoid unnecessarily high night temperatures where possible
• Root zone: improve aeration/drainage; avoid prolonged saturation
• Irrigation timing: prevent long anaerobic periods in substrate
• Stress prevention: reduce repeated heat/VPD spikes where possible