In this study, the equation of longan yields is applied as equation 2.
YieldPerM2 = 0 + 1 (Canopy) + 2 (FruitArea) + 3 (No_treePerM2)
+ 4 (No_CultivarTreePerM2) + 5 (Age) + 6 (DayLength)
+ 7 (WaterSystem) + 8 (SoilType) + 9 (Manage) + 10 (No_Land) + 11 (Cost)
............................................................................................................................(2)
Where YieldPerM2 is a longan yield (kg/m2) as in equation 3,
Canopy is bush area (cm2),
FruitArea is the area of fruit per tree (m2) as equation 4,
No_TreePerM2 is the number of trees in orchard area (trees/m2) as equation 5,
DayLength is duration date from taken photo to harvest (days),
No_CultivarTreePerM2 is the number of the harvested tree per orchard area (trees/m2)
as equation 6,
Age is the age of tree (years),
WaterSystem is the water use system type (irrigation system, surface water, and
rainfed)
SoilType is a suitability level of cultivation soil (high suitability, medium suitability,
and low suitability)
Manage is the level of management (high, moderate, and low)
No_Land is amount of land holdings (land), and
Cost is the cost using to production (Baht)
And the equations as:
Longan yield (kg/m2) = (yield (kg)) / (spac X (m) space Y (m))..................................(3)
Proportion fruit in bush = (fruit part area (m2) x area of bush (m2)) / 6...................(4)
Number of trees per square meter (tree/m2) = (number of trees) / (planted area (m2))
.............................................................................................................(5)
Harvested trees per square meter (tree/m2) = (Harvested trees) / (planted area (m2))
.............................................................................................................(6)