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. 2019 Jul 18;10:809. doi: 10.3389/fpls.2019.00809

TABLE 1.

A detailed summary of the input variables for early-/mid-season SGB models.

Data source Raw data Model input variables Variable name Pearson correlation
Grower data
Yield records from 8 major almond growers in the Central Valley of California. Planting year
Historical yield
Cultivar variety and composition
Age
Previous two years’ yield
Cultivar percentage
Age
Pre 2Y Yld, Pre 1Y Yld
CulP 1, …., CulP 20
−0.16*
0.53*, 0.53*
−0.27∼0.25
Weather data
CA-BCM data with 270 m spatial resolution for years 1990–20161; Monthly mean daily maximum temperature (Tmax);
Monthly mean daily minimum temperature (Tmin);
Monthly accumulative precipitation (PPT)
Current year monthly Tmax and Tmin from January to June2, and PPT from January to March Tmin, Tmax, PPT January
Tmin, Tmax, PPT February
Tmin, Tmax, PPT March
Tmin, Tmax April
Tmin, Tmax May
Tmin, Tmax June
−0.06*, −0.06, −0.22*
−0.17*, 0.17*, −0.27*
0.05*, 0.21*, −0.30*
0.25*, 0.30*
0.17*, 0.12*
0.17*, 0.21*
Previous year summer mean temperature averaged over July and August Pre Tmean July–August 0.36*
Long-term mean seasonal Tmax, Tmin, PPT (averaged over 1990–2009 for each season3). LT Tmin, Tmax, PPT January–March
LT Tmin, Tmax, PPT April–June
LT Tmin, Tmax, PPT July–September
LT Tmin, Tmax, PPT October–December
0.26*, 0.50*, −0.58*
0.43*, 0.60*, −0.61*
0.38*, 0.49*, −0.57*
−0.31*, 0.51*, −0.58*
CIMIS station data for years 2009–2017 Hourly temperature Winter chilling portions calculated by the Dynamic Model ChillP −0.14*
Remote sensing imagery
NAIP aerial imagery from 2016 with 0.6m resolution NAIP RGB imagery acquired in 2016 2016 canopy cover percentage CCP 0.20*
Landsat satellite imagery with 30 m resolution years 2009–2017 Landsat multispectral imagery every 16 days Previous year annual maximum NDVI and EVI;
Current year June average EVI
Pre Max NDVI
Pre Max EVI
June Mean EVI
0.13*
0.31*
0.35*

12017 Tmax, Tmin and PPT were collected from the original PRISM data archive. 2Variables used only for mid-season prediction models were shown in Italic. 3The four seasons are separated as (1) January–March, (2) April–June, (3) July–September, (4) October–December. *Represents for p < 0.05.