Meeting Notes – Predawn & Daytime Measurement Protocols, Rack Evaluation

Project Landscape

• Two main experimental streams discussed:
• Cotton Project – team: Romy (lead), Ben, Cliff; extending genotypic/phenotyping work into late-August cohort.
• Baby-kale Vertical-Farm Rack (“RAIN system”) validation study – team: Ben & Cliff (Nathan, Violetta now gone).

Hardware & Software Status

• Thermal camera already functional on Windows, but API/library incompatible with in-house code.
• Worst-case: write custom driver/library.
• Two Multispec (multispectral fluorometer) units + two laptops; charging rule: plug in only if battery < 30 %.
• Depth-camera yet to be installed; once operational, plant height data will be automated (manual height no longer required).
• Vertical rack plumbing is rigid – shelf height can’t be adjusted without cutting PVC; causes uneven PPFD.

Predawn Fluorescence Measurements

• Goal: capture physiological “reset” state before artificial lights engage.
• Room lights ON at 06{:}00; all predawn readings must finish beforehand.
• Corridor and stairwell lighting protocol:
• Switch off corridor lights; stairwell lights are fixed.
• Use only tablet screen or green headlamp (night-vision safe) at plants.
• Tablet supplies sufficient illumination for cutting leaves.
• Dawn defined by ARTIFICIAL lights, not natural sunrise.

Leaf Selection & Probe Orientation (Multispec)

• Measure the three highest, fully expanded TRUE leaves per pot.
• Skip cotyledons & incompletely expanded/axillary leaves.
• If 3rd leaf is shaded/stacked, still valid if fully developed.
• Clamp rule: keep Multispec PAR sensor parallel to leaf blade.
• Follow leaf angle; do NOT twist.
• PAR sensor must face the adaxial (upper) surface and operator.

Measurement Schedule (Cliff)

• Frequency: every other day (EOD).
• Times per EOD cycle:
• 03{:}00 – Predawn
• 09{:}00 – Morning (avoid 09-12 if possible; earlier better)
• 16{:}00 (4 PM) – Afternoon (avoid solar noon, maximize stomatal openness)
• Camera imaging (separate team): 08{:}00, 12{:}00, 16{:}00, 20{:}00 (every 4 h, 08-20).
• No conflict—temporal separation OK.

Soil-Moisture Protocol

• Also EOD; paired with fluorescence days if possible.
• Well-watered regime; missing a single reading is acceptable—skip moisture rather than Multispec if time-constrained.
• Historical readings: Cliff will back-fill timestamps while memory is fresh.

Data Nomenclature & Storage

• Pot ID = alphanumeric (e.g.
• 1A, 2A …) – do NOT prefix with “pot”.
• Multispec files auto-upload to PhotosynQ platform; accessible via web.
• Required metadata for every record:
• Pot ID
• Exact Date-Time stamp (ISO format preferred)
• Treatment & bench (for rack study)
• Image/soil-moisture datasets will be joined using nearest-neighbor timestamp matching.

Environmental & Instrument Variables Recorded

• Multispec outputs ≈20 parameters per scan:
• Steady-state fluorescence (Fs) • Maximum fluorescence (Fm) after saturating pulse
• Quantum yield \Phi_{PSII}, NPQ, leaf thickness, PAR, etc.
• Rack monitoring: electrical conductivity (EC), pH, reservoir temperature (stable), airflow (qualitative), PPFD maps.
• Light map findings:
• Top shelf: 260{-}300\,\mu mol\,m^{-2}\,s^{-1}
• Mid/low shelves: <240\,\mu mol\,m^{-2}\,s^{-1}
• Photoperiod set to 18\,h constant intensity; no diurnal ramp.

Harvest & Biomass Plans

• Manufacturer suggests 4-week cycle – reached today, but plants undersized due to low light & media issues (rock-wool overly saturated).
• Extended growth; harvest slated for 04 Aug (Ben departs 05 Aug).
• Biomass (fresh & dry) + Multispec final scan will close study.

Critical Feedback on RAIN Rack (to be compiled into 1–2 pp report)

• Design not intuitive; significant engineering flaws:
• Static plumbing = fixed shelf height.
• Uneven PPFD across levels.
• Narrow spacing makes fan adjustment difficult.
• Media compatibility: rock-wool + constant drip kept seed zone too wet → poor germination & variable emergence.
• Recommendation: redesign or adjust plumbing, lighting array, and media guidelines.

Coordination & Access

• Cliff lacks keycard for baby-kale room – temporary escort required.
• Multispec units stored second shelf in Tina & Romy’s office.
• Daily equipment plug-in check by Cliff (charge if <30 %).
• Slack updates: Cliff will announce final predawn on 01 Aug before flight.

Action Items Checklist

• Cliff – begin 03-09-16 EOD Multispec regimen tomorrow; back-fill soil-moisture timestamps.
• Ben – designate filesystem path for new data; schedule joint light-map graphing.
• Romy/Tina – escort Cliff for access; show data download on PhotosynQ.
• Software team – investigate or build custom thermal-camera library.
• All – enter pot ID & exact time for every measurement; double-check labels to avoid mis-pairing.
• Draft two-page feedback report with: EC/pH/PPFD graphs, biomass table, design critique.