highly significantp < 0.001
(1) Y = − 1278.9 + 92.39 X 1 + 408 X 2 − 0.7659 X 1 2 − 1115 X 2 2 + 4.98 X 1 X 2 The model was significant ( p < 0.05), with highly significant ( p < 0.001) X 1 , X 2 , and X 1 2 , adjusted R 2 = 0.9962, and predicted R 2 = 0.982 ( Supplementary Fig. 3A ).