Li 3100c area meter

Immediately after photosynthetic measurements were recorded, the measured leaf lamina was excised and used for specific leaf area (SLA; gDM m²) and leaf N content estimations. In 2015 and 2016, SLA for each plot was estimated based on a composite sample of 40 1.6 cm² leaf punches taken from all measured leaves within the plot and dried at 60 °C until constant weight. In 2017, excised lamina were kept at ~5 °C and leaf area was measured in the lab with a flatbed leaf scanner (LI-3100C Area Meter; Licor®) and then dried at 60 °C to constant weight. SLA was then estimated as the ratio of average leaf mass to leaf area of all subsamples. All dried samples were then ground to a powder (<1 mm) and a 3–5 mg subsample was mixed with tungsten trioxide and combusted in an elemental analyzer (Elementar, Ronkonkoma, NY, USA) to determine the concentration of N (N_m; gN g⁻¹). Acetanilide was used as a standard N reference. Leaf N content on an area basis (N_a; gN m⁻²) was estimated as the product of N_m×SLA.

To help understand the leaf and shoot development of grapevines under DRZ, preliminary experiments were conducted at harvest in 2018 for investigating the influences of the DRZ on leaf size and carbon and nitrogen contents in leaves and shoots. Two mature leaves (one from the east side and another from the west side) on each grapevine were randomly selected for specific leaf area (SLA) measurement. Leaves were sampled by severing the petiole with a razor blade, then leaves from the same grapevine were put into a sampling bag and stored on ice. All samples were brought back to lab immediately for measuring leaf size by using the LI-3100C Area Meter (LI-COR Biosciences, NE, USA). After leaf size measurement, all leaf samples were put into an air-dryer at 60°C for at least 48 h. Dry samples were weighed for leaf biomass. SLA for each grapevine was calculated as:
Meanwhile, other sets of leaves and shoots were sampled for total carbon (C) and nitrogen (N) content analyses. Twelve leaves and twelve shoots from three central vines in the same subplot, with four leaves and four shoots collected per vine, were mixed and put into an air-dryer at 60°C for at least 48 h. All dried samples were milled into powder, and around 0.2 g powder per dry sample was sent for total carbon and nitrogen content analyses by using the TruSpec Micro analyzer (LECO Corp., MI, USA).

Early stage agronomic measurements were carried out on 19 November 2014, immediately following the first rainfall event to avoid potential loss of irrigation treatment effects. Therefore, the early stage represents the dry growth period before start of the wet season. The number of stalks at early stage in the second and third rows of each plot was counted manually and expressed as stalk number per metre (ESN). Early stage TDM (ETDM) was measured in all plots by randomly sub‐sampling eight stalks per plot, four each from the second and third rows. Leaf and stem portions were separated and dried in an oven at 60°C until constant weight. Finally, ETDM was calculated as the product of total leaf and stem dry weights and ESN. Early stage leaf area (ELA) of all leaves in a sub‐sample of three stalks was measured using a leaf area metre (LI‐3100C Area Meter, LI‐COR Biosciences).

Steers were fasted for 24 h, weighed and slaughtered at a commercial abattoir. After slaughtering, carcasses were weighed and chilled at 4°C for 7 days. Then, carcasses on the right side were cut between the 12th and 13th rib and subjected to measurement of back fat thickness [13 (link)] and loin eye area according to Cacere et al [14 (link)]. The carcass pH was determined in longissimus dorsi muscles at 1, 48, and 168 h after slaughtering using a portable pH meter with a penetrating electrode probe (LE427, Mettler Toledo, Greifensee, Switzerland). The loin eye area was measured by tracing the outline onto tracing paper using an LI-3100 CArea Meter (LI-3100; Li-COR Biosciences, Lincoln, NE, USA). Then, three 2.5 cm thick steaks were removed from each rib section and trimmed of all external fat for measurement of drip loss [15 (link)], cooking loss [16 (link)], shear force with a Material Testing Machine (LR5K; Lloyd Instruments, West Sussex, UK), and marbling score by Thai Agricultural Commodity and Food Standard [17 ]. Meat color was measured using a color meter (HunterLab Mini Scan EZ, Reston, VA, USA) according to the L*, a*, b* system [18 ].

Diploid and tetraploid leaves were collected from mature field trees. The leaf area was measured using an LI-3100C area meter (LICOR, Lincoln, NE, USA) calibrated to 0.01 cm². For stomatal trait analysis, leaf samples were washed using deionized (DI) water and fixed in a 4% paraformaldehyde solution buffered with 1x phosphate-buffered saline (PBS). Samples were dehydrated in an ethanol series (30%, 50%, 70%, 85%, 95%, and 100%). The tissue was incubated in 100% ethanol overnight at 4°C. The tissue was then dried using a Ladd 28000 critical point dryer (Ladd Research Industries, Williston, VT, USA) and mounted on double-sided 12 mm carbon stickers (Electron Microscopy Sciences, Hatfield, PA, USA) on scanning electron microscope (SEM) stubs. Leaf samples were sputter-coated using a Ladd 30800 sputter coater (Ladd Research Industries) with a gold/palladium target. Images of stomata were captured using a Hitachi S4000 SEM (Hitachi, Tokyo, Japan). Twenty randomly captured images were analyzed for the average number of stomata in each group. Stomata from each group were also selected at random for area analysis using ImageJ software at 600X magnification.

Leaf lobe length (of the central leaf lobe), leaf lobe width (the widest point of the central leaf lobe), leaf width, petiole length of the fifth fully-expanded leaf were measured using a meter rule (cm). Plant height was measured using a tape measure (cm) while stem girth was measured using vernier calipers (cm). Leaf lobe number was the number of lobes of the fifth fully-expanded leaf. In 2017, leaf area (cm²) was measured using an LI-3100C Area Meter (LI-COR Inc., Lincoln, NE, USA) and leaf area index (LAI) measured using an AccuPAR Linear PAR/LAI Ceptometer (Decagon Devices Inc., Pullman, WA, USA) in the field. In 2016, the leaf area meter and the ceptometer were unavailable, so leaf area was calculated as a product of leaf length and leaf width, and LAI was calculated using the mathematical formula for calculating the area of a circle (πr²) for overall plant canopy ground area.

Leaf area was measured with LI-3100C Area Meter, LI-COR, (Lincoln, NE, USA), and expressed in mm². For each treatment, 10 plants per pot from three pots were measured.