| It is vital to increase quality of cotton picking and reduce the cost of cotton planting. Three machine cotton modes in the current field conditions were explored to assess their effects on plant morphology of cotton varieties Xinluzhong No. 54 and Xinluzhong No. 75. The morphological characteristics of nine main cotton varieties were measured respectively in the boll setting stages and in the boll opening stage to evaluate effects of mechanical sampling pattern on the morphological characteristics of cotton varieties and their morphological indexes. The results showed that different planting patterns had a significant effect on the main seven morphological characteristics of cotton varieties. Agronomic traits, such as first fruit node height, first fruit node and fruit length among different varieties varied significantly.The reproductive process in the four-line model was 4 to 6 days earlier, the pre-frost rate increased by 2% to 4%, and the number of the Boll per plant improved 1 to 2 by multiple comparison. It would be more suitable for the machine piking as the average spacing increased and the density decreased. In addition, Xinluzhong No. 75 was more suitable for machine piking. The correlation analysis showed that the cotton height was significantly correlated to fruit height, fruit number and leaf index.The correlated coefficients were 0.834, 0.730 and 0.560 respectively. There was a significant positive correlation between stem diameter and boll number and the correlation coefficient was 0.735. It would be benefit to Nanjiang machine picking cotton by increasing height to meet machine picking requirements,thickening stem to improve boll numbers per plant, decreasing lodging and machine picking loss. It was difficult for the short and high density plants to adapt to the machine picking. The traditional “low-dense-early” cultivation pattern was out of date. |