There have been increasing demands for high-quality cotton fibers that meet the textile industry quality standards. Concurrently, there have been efforts to reduce contaminants during harvesting to reduce harvesting costs. The goal of this research was to evaluate the efficiency of the picker platform with Variable-Row-Spacing (VRS) for harvesting cotton in narrow rows, over two harvest seasons in two regions within the state of Mato Grosso, Brazil. In this study, how the presence vs. absence of scraping plates and variations in travel speed was related to quantifiable levels of impurities the harvested fibers was examined. The research was divided into three experiments (Exp. I, II, and III), using cotton varieties FM 975 WS, IMA 5672 B2 RF, and IMA 5675 B2 RF, with row spacing of 0.45 m. The experimental design was randomized blocks, in a 2 × 3 factorial design, using the presence/absence of the plate and three speeds (0.61, 1.0, and 1.42 m·s-¹), with seven repetitions, totaling 42 experimental plots. The plot size was 108 m² (3.6 × 30 m). The data were analyzed using the F test in ANOVA and the post-hoc Tukey test (p < 0.05). The results showed that scraping plates increased the number of stems and cones, and reduced the harvest efficiency of cotton planted in narrow rows in the region of Sorriso-MT during the 2013/2014 harvest. For the 2014/2015 harvest, the highest speed and the presence of the scraping plates increased the number of cones in the cotton samples. In the experiment conducted in Serra da Petrovina, the removal of the scraping plates decreased the amount of cones in the harvested cotton. Key words: Cotton planted in narrow rows. Mechanical harvesting. Harvest efficiency. ResumoA demanda por fibras de algodão de alta qualidade para atender a demanda da indústria têxtil e a busca incessante para reduzir a presença de contaminantes no momento da colheita de forma a contribuir para a redução dos custos. O objetivo da pesquisa foi avaliar a eficiência da plataforma Picker VRS (unidades de espaçamento variável) de colheita do algodão adensado no Estado de Mato Grosso, com e sem placas de raspagem, variando a velocidade de deslocamento, quantificando as impurezas nesse processo e avaliando a qualidade extrínseca e intrínseca da fibra colhida. A pesquisa foi dividida em 3 experimentos (Exp. I, II e III). As variedades de algodão utilizadas foram FM 975 WS, IMA 5672 B2 RF e IMA 5675 B2 RF, com espaçamentos entre linhas de 0,45 m. O delineamento experimental utilizado foi de blocos casualizados, em esquema fatorial 2x3, sendo presença e ausência da placa e três velocidades de trabalho (0,61; 1,0 e 1,42m.s-¹), com sete repetições, totalizando 42 parcelas experimentais. A dimensão das parcelas foi de 108m² (3,6 x 30m). Os resultados obtidos foram submetidos à análise de variância por meio do Teste de F, e quando significativos submetidos ao teste de Tukey, a 5 % de probabilidade. As placas de raspagem aumentaram a quantidade de caule, casquinhas e reduziu a eficiência na colheita do algodão adensad...