Development and test of an automatic height-adjusting cotton topper

Chen Zhaoyang, Shi Lei


A fine-tuned height-adjustable cotton topper was developed and evaluated in this study. Cotton is topped at the late flowering stage because spindling reduces cotton production and complicates harvest. The main disadvantage of traditional cotton toppers is that their topping height cannot be adjusted according to the heights of individual cotton plants, resulting in a high percentage of missed tops and overcutting that damages fruit branches. To solve this problem, a mechanical-electronic topping prototype was developed that could be adjusted according to the height of cotton. The prototype includes a shearing machine system that can be tuned vertically and an automatic height control system that can detect cotton heights and actuate the mechanical system. This cotton topper was attached to a tractor by a three-point hitch and tested in the field. In the trial, the prototype was tested at ground speeds of 1.1 km/h, 1.5 km/h and 2.2 km/h and excision lengths (from the peak to the cutting point) of 9 cm and 11 cm. Under all tested conditions, the pass rate (the percentage of buds accurately cut without hurting the fruit branch), which reached 74%, was significantly higher than the ideal pass rates of traditional toppers, which were much lower than 50% or even 40%. The dominate factors affecting topping quality were tested. The pass rate was significantly influenced by the forward speed; the missing rate (rate of missed topping) was significantly influenced by the forward speed and excision length; and the overcut rate was significantly influenced by the excision length. The optimized topping speed and excision length were 1.1 km/h and 11 cm respectively, and the other parameters varied according to different user preferences. A replicate trial was conducted and showed that topping at 1.1 km/h and 9 cm prevented further spindling of 90% of the plants, and topping at 1.5 km/h and 11 cm prevented further spindling of 83% of the plants.
Keywords: cotton topper, height-adjusting, topping quality, field test, automatic control
DOI: 10.3965/j.ijabe.20171002.2492

Citation: Chen Z Y, Shi L. Development and test of an automatic height-adjusting cotton topper. Int J Agric & Biol Eng, 2017; 10(2): 44–55.


cotton topper, height-adjusting, topping quality, field test, automatic control


Barrabé A, Rapidel B, Sissoko F, Traoré B, Wery J. Elaboration and test of a decision rule for the application of mepiquat chloride on cotton in Mali. Eur J Agron, 2007; 27(2-4): 197–204.

He L, Liu X, Zhou Y, Zhao Y, Hu B. Vertical lift type single profiling cotton topping machine. Transactions of CSAE, 2013; 44(3): 62–67. (in Chinese)

Renou A, Téréta I, Togola M. Manual topping decreases

bollworm infestations in cotton cultivation in Mali. Crop Protect, 2011; 30(10): 1370–1375.

Keyes A A. Cotton topper. U.S. Patent No. 3017732. 1962.

Marquis A, Sprott W. Cotton topper and boll weevil catcher. U.S. Patent No.1325406. 1919.

Stroman L E. Mechanical cotton defoliator and topper. U.S. Patent No. 2977741. 1961.

Heard M P. Topper and shredder. U.S. Patent No. 2002000081. 2002.

Judson Price H, Tex C. Rotary cotton topper. U.S. Patent No. 2720740. 1955.

Du X, Li Y, Yan S, Li X, Song Z, Li F D. Mechanics characteristics of cotton stalks. Transactions of the CSAE, 2011; 42(4): 87–91. (in Chinese)

Kerby T, Ford B. Making mepiquat chloride application decisions. The Australian Cottongrower, 2005; 25(7): 1442–5289.

Environmental Protection Agency, EPA. (Washington, USA). Reregistration eligibility decision (RED), Case 2375,

Quintás G, Garrigues S, Pastor A, de la Guardia M. FT-Raman determination of Mepiquat chloride in agrochemical products. Vib Spectrosc, 2004; 36(1): 41–46.

Luo Q, Bange M, Braunack M, Johnston D. Effectiveness of agronomic practices in dealing with climate change impacts in the Australian cotton industry—A simulation study. Agric Syst, 2016; 147: 1–9.

Lu Y, Reddy V R. Economic analysis of pix (Mepiquat chloride) application strategies. Int Agric Eng J, 2002; 11(2-3): 133–143.

Jin F, Hub J, Yang M, Jin X, He W, Han H. Determination of diallyldimethylammonium chloride in drinking water by reversed-phase ion-pair chromatography–electrospray ionization mass spectrometry. J Chromatogr A, 2006; 1101(1-2): 222–225.

NSF (National Sanitation Foundation, International). Drinking water treatment chemicals-health effects; document NSF/ANSI 60-2002, New York. 2002.

Yang X H, Zhang Q, Hu B. Design of automatic height control system for cotton’s top cutter. Journal of Agricultural Mechanization Research, 2009; 7: 129–131, 135.

Zhou H Y, Yin S Z, Zhu L C, Yang X J, Yan H R. Design of 3WDZ-6 self-propelled cotton top cutting. Transactions of the CSAM, 2010; 41(Supp): 86–89.

Jeon H Y, Zhu H. Development of a variable-rate sprayer for nursery liner applications. Transactions of the ASABE, 2012; 55(1): 303–312.

Jeon H Y, Zhu H, Derksen R, Ozkan E, Krause C. Evaluation of ultrasonic sensor for variable-rate spray applications. Comput Electron Agric, 2011; 75(1): 213–221.

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