Establishment of an NPK nutrient monitor system in yield-graded cotton petioles under drip irrigation

Table 6 Yield modeling and verification of different methods

Growth period	Methods	Modeling				Validation
Growth period	Methods	Number of samples	R²	RMSE (t/ha)	MAE (t/ha)	Number of samples	R²	RMSE (t/ha²)	MAE (t/ha)
Full bud stage	SSO-BP	80	0.85	0.21	0.16	20	0.96	0.06	0.05
	GWO-BP	80	0.95	0.12	0.10	20	0.95	0.09	0.08
	BP	80	0.82	0.23	0.18	20	0.85	0.45	0.42
Full bloom stage	SSO-BP	80	0.85	0.20	0.17	20	0.95	0.07	0.06
	GWO-BP	80	0.91	0.16	0.13	20	0.91	0.10	0.08
	BP	80	0.83	0.22	0.17	20	0.83	0.12	0.11
Full boll stage	SSO-BP	80	0.93	0.17	0.12	20	0.91	0.09	0.07
	GWO-BP	80	0.96	0.11	0.08	20	0.90	0.10	0.08
	BP	80	0.88	0.19	0.14	20	0.88	0.17	0.15

ISSN: 1746-4811