Li 3100c

Data were collected at two harvest points (Table 1) from individual plants. Shoots were cut at the soil surface and partitioned into stems and leaves. Fresh weights of the two organs were taken and subsequently leaf and stem samples were dried in an oven (TU-2, Heraeus Holding GmbH, Hanau, Germany) at 70°C for at least 72 h to determine dry weights. Leaf area was determined with a leaf area meter (LI-3100C, LI-COR Inc., USA) prior to leaf drying. Leaf mass per area (LMA, leaf dry weight divided by leaf area) and stem to leaf ratio (stem-leaf ratio, stem dry weight divided by leaf dry) were calculated. Furthermore, hypocotyl, epicotyl, and internode lengths were measured with a ruler. Plant height was defined as the sum of these lengths.

Plant height, stem diameter, main root length, and leaf area were measured by tape ruler, electronic vernier caliper, rule, and leaf area meter (LI-3100C, Li-Cor, Inc., USA), respectively. Plant height growth, stem diameter height growth, and leaf area index (LAI) were calculated as:
Where 0d and 5d are the value measured at 0d and 5d, respectively.

Two weeks after sowing, all the seedlings were harvested. Five seedlings from each pot were selected randomly to measure leaf area, shoot length, fresh weight, and dry weight of root and shoot. Leaf area was measured by using a portable Area Meter device (LI-3100C, LI. COR. inc. Lincoln, Nebraska, USA). The shoot length was determined by using a ruler. The shoots and roots of plants were weighed and dried in an oven at 70℃ for 72 H to a constant weight for dry weight determination. The roots of the three plants were washed with deionized water. Imagery scan screen (12,000 XL, Seko Epson CO. Ltd, Japan) was used to perform root scanning. Further, WinRHIZO software was used for root image analysis.

Plant growth was examined by height, total leaf number (including attached and fallen senescent leaves), leaf area, and plant dry weight. Plant height was measured from the point of stem emergence to shoot apex. The attached leaves were counted from the first fully expanded leaf to the last photosynthetic leaf showing more than 50% greenness over its entire area, while the remaining leaves were counted as senescent. Total leaf area per plant (leaf lamina only) was measured using a leaf area meter (LI-3100C, Li-Cor Inc., Lincoln, NE, United States). Fresh and dry weights of all separated plant parts were determined. For dry weight measurement, all samples were oven-dried to a constant weight at 60°C. In addition to the destructive analysis, total root development in both cassava varieties was studied by MRI (van Dusschoten et al., 2016 (link)), a non-invasive method.

Six plants per cultivar were destructively measured before planting (on 15 August) to determine their initial total biomass and leaf area. For the plants with standard fruit load six plants of each cultivar (one from each gutter) were harvested on 18, 33, 47, 61, 81, 97 days after planting. For plants with half fruit load six plants (one from each gutter) were harvested on 97 days after planting. Fresh and dry weight of leaves, stems, and fruit trusses were determined. Plant organs were dried for at least 48 h at 105°C in a ventilated oven. Leaf area was measured with a leaf area meter (LI-3100C, LI-COR Inc., Lincoln, NE, USA). SLA was calculated by dividing leaf area by leaf dry weight. The regularly removed leaves and harvested fruits were dried and dry weight was added to obtain the cumulative dry weights per plant; area of the regularly removed leaves was also determined for estimating total LAI at different moments which was needed as model input.
For each cultivar, 97–148 fruits from the plants with one fruit per truss were randomly sampled during the experiment, the samples were taken once per week, and fruit diameter, length, age, fresh, and dry weight were recorded. These observations were used to get two relationships: a relationship between fruit volume and fresh weight; and a relationship between fruit age and fruit dry matter content.

Plant height was measured from the surface of the stone wool block to the height of the apex. Leaves of a minimum size of 1 cm² were counted as true leaves, leaf area was measured with a leaf area meter LI-3100C (LICOR, Lincoln, NE, United States). Leaves and stem were separated and weighed for fresh mass and dry mass. Dry mass was measured after drying for 48 h at 80°C.
Daily light integral (mol_{400–700 nm} m^–2 d^–1) was calculated as:
Daily radiation integral (mol_{400–800 nm} m^–2 d^–1) was calculated as:
Light use efficiency (g mol_{400–700 nm}^–1) was calculated as:
Radiation use efficiency (g mol_{400–800 nm}^–1) was calculated as:
Specific leaf area (SLA) (cm² g^–1) was calculated as:
Dry matter content (%) was calculated as:

The primary root length and lateral roots (LRs) length were determined using an optical microscope system with a computer attachment (MPS 60, Leica, Wetzlar, Germany). Root lengths were measured on digital images using ImageJ 1.40 software (http://rsb.info.nih.gov/ij/), from the analysis of 20 plants. The experiments were performed at least twice, independently. Leaf area was determined using an area meter (model LI-3100C; Li-Cor, Lincoln, NE, USA).