Relationships Between Plant Architecture Traits and Cotton Yield Within the Plant Height Range of 80–120 CM Desired for Mechanical Harvesting in the Yellow River Valley of China

Yan Yan,Zhao Zhao,Xue Xue,Eneji Eneji,Xu Xu,Huang Huang,Yang Yang,Li Li,Wang Wang,Meng Meng,Tian Tian,Qi Qi,Du Du

doi:10.3390/agronomy9100587

Abstract

Mechanical harvesting has become inevitable for cotton production in China due to the rising labor cost in the country. It usually requires a moderate plant height and compact plant architecture. Correlation and stepwise regression were employed to analyze databases of our 24 field experiments between 2010 and 2017 in Hebei Province. The purpose is to identify the relationships between plant architecture traits and seed cotton yield within natural plant height range (58.6–163.2 cm) or preferred plant height range (80–120 cm) for mechanical harvesting in the Yellow River Valley of China, and define some important factors affecting seed cotton yield. Under natural plant height range across all experiments, there was a significantly negative correlation (r= −0.452) between plant height and yield. On limited plant height range desired for mechanical harvesting, the degree of this negative correlation decreased to r= −0.366. The correlation of plant height with seed cotton yield varied greatly with year, cultivar, plant density and mepiquat chloride (MC) application. Moreover, stepwise regression analysis picked internode length of the 1st (generally including 1st–7th mainstem node from bottom), 2nd (8th–12th node) and 4th (above 17th node) mainstem section and the length of lower fruiting branch (LFB) as significant factors influencing seed cotton yield under plant height range of 80–120 cm. The results have implications for precise control of cotton plant architecture preferred for mechanized harvesting in China.

Highlights

Plant architecture, defined as the three-dimensional organization of the above-ground plant part, significantly affects the light interception and radiation use efficiency in the crop canopy, Agronomy 2019, 9, 587; doi:10.3390/agronomy9100587 www.mdpi.com/journal/agronomyAgronomy 2019, 9, 587 and determines plant growth, biomass production and partitioning, and yield potential [1].plant architecture greatly influences ease of agronomic management, including harvest [2,3].In terms of the suitable plant type for cotton, the shorter plants are better choices for mechanical harvesting since taller plants are often associated with excessive vegetative growth and later maturity, which can cause harvesting difficulties [4]
When we limited the height range to 80–120 cm which is preferred for mechanical harvesting [5,6], the mean plant height reduced to 104.6 cm and the negative correlation decreased (r = −0.366) (Figure 1B), suggesting that shorter plants and narrower range of height may produce more stable yields
The correlation of plant height with seed cotton yield was affected by year, cultivar, plant density and mepiquat chloride (MC) application

Summary

Introduction

Plant architecture, defined as the three-dimensional organization of the above-ground plant part, significantly affects the light interception and radiation use efficiency in the crop canopy, Agronomy 2019, 9, 587; doi:10.3390/agronomy9100587 www.mdpi.com/journal/agronomyAgronomy 2019, 9, 587 and determines plant growth, biomass production and partitioning, and yield potential [1].plant architecture greatly influences ease of agronomic management, including harvest [2,3].In terms of the suitable plant type for cotton, the shorter plants are better choices for mechanical harvesting since taller plants are often associated with excessive vegetative growth and later maturity, which can cause harvesting difficulties [4]. Agronomy 2019, 9, 587 and determines plant growth, biomass production and partitioning, and yield potential [1]. Data from the Northwest Inland Cotton region of China showed that the height of the first sympodial branch should exceed 20 cm to reduce the intake of residual plastic mulch which is widely used for cotton production in China. Other cotton plant architecture attributes such as height to node ratio (i.e., the internode length), and length of sympodial branches have direct and/or indirect effect on cotton yield and harvest efficiency [7,8,9,10,11]. There is little information on the effects of more detailed plant architectural attributes such as the length of all mainstem internodes and all fruiting branches on yield. It’s unclear how these effects are when plant height is regulated to fit the range of 80–120 cm

Methods

Results

Discussion

Conclusion