Influence of Row Width and Population Density on Yield and Fiber Characteristics of Cotton¹

Abstract

A critical need to evaluate methods to reduce production costs of Upland cotton (Gossypium hirsutum L.) to help maintain its. competitive market position, prompted experiments designed to evaluate the influence of row width and plant population on yield and fiber properties. Upland cotton was grown in 25.4‐, 50.8‐, 76.2‐, and 101.6‐cm‐spaced rows with population levels of 128,000 (low) and 256,000 (high) plants/ha at three locations in Georgia. Significant differences in yield due to test location and to row width were found, but differences in plant populations did not affect yield. Seeding with a modified grain drill produced 88% of the plants desired at the low population level and 82% at the high population level, but left much to be desired in uniformity of seed distribution, placement, and coverage. We found no difference in lint percentage and seed size except that due to location. Boll size was affected by plant population and location but not by row width. The only fiber characteristic affected by row width was fiber fineness. Earliness was influenced only by location. Significant interactions of row width × location were found for yield, number of plants, lint percentage, and fineness. The population × location interaction was significant for boll size and number of plants. The second order interaction of population × row width × location was significant for boll size. Results relative to yield were encouraging and indicated that the narrow‐row, high‐population system might provide partial solutions to some production problems.

Yield and Maturity of Ultra‐Narrow Row Cotton in High Input Production Systems

“…Maturity did not differ significantly between row spacings in the combined analysis across the six experiments (Tables 2 and 3). Other studies also report little difference in maturity between row spacings in cotton (Gerik et al, 1998; Hawkins and Peacock, 1973), while some report significantly earlier maturity (Cawley et al, 1998, 1999; Hearn and Hughes, 1975; Young et al, 1980), and others report inconsistent maturity differences between row spacings in different years of their studies (Constable, 1977b; Jost and Cothren, 2001). There was also no interaction of the application of mepiquat chloride and row spacing on maturity (Table 4), suggesting that the effect was consistent across spacing treatments.…”

“…In low input systems differences in yield between row spacings have been variable with no consistent yield benefit with the use of UNR spacings. Some studies have reported higher yields in UNR crops (Atwell, 1996; Bader and Culpepper, 2002; Gerik et al, 1999, 1998, 2000; Gwathmey, 1996, 1998; Gwathmey et al, 1999; Hawkins and Peacock, 1973; Heitholt et al, 1992; Koli and Morrill, 1976; Nichols et al, 2003, 2004; Steglich et al, 2000; Vories et al, 2001), others have reported that differences in yield when comparing UNR and conventionally spaced cotton are not consistent across years (Bader and Culpepper, 2002; Cawley et al, 1998, 1999; Constable, 1977a, 1977b; Jost and Cothren, 2001; Nichols et al, 2004; Vories et al, 2001). There are studies that report no yield benefit in UNR cotton (Baker, 1976; Bednarz et al, 1999; Clawson and Cothren, 2002; Marois et al, 2004; Nichols et al, 2004), or yield was lower (Boquet.…”

Phenotypic Alterations and Crop Maturity Differences in Ultra‐Narrow Row and Conventionally Spaced Cotton

“…Row spacing and plant density treatments did not affect micronaire readings in either year of the study (Table 9) These results are contrasted to those obtained by Vories et al (1999), who showed that in 2 out of 3 yr micronaire readings were reduced in UNRC vs. conventionally‐grown cotton. Results from past row spacing and plant density studies and their effect on micronaire have been varied (Douglas et al, 1970; Hawkins and Peacock, 1973).…”

Espaçamentos ultra-adensado, adensado e convencional com densidade populacional variável em algodoeiro

“…Verificando-se a análise de variância para produção de algodão em caroço na Hawkins & Peacock (1970); Hawkins & Peacock (1973);Lamas (1988);Carmi (1996); Krieg (1996);Gerik et al (1998);Bednarz et al (1999);Gerik et al (1999). Contudo, Atwell et al (1996);Maas (1997);Bednarz et al (1999), obtiveram maior produção utilizando o espaçamento convencional.…”

“…Dentre as características tecnológicas da fibra, Williford (1992); Gwathmey Quanto ao índice micronaire, Hawkins & Peacock (1973) …”