The impact, on fibre quality, of changing from conventional cotton to genetically modified cotton

This study was aimed at investigating the impact, on cotton fibre quality, of changing from conventional (non-GM) to genetically modified (GM) cotton, in both South Africa and the United States of America (USA). The cotton quality data, pre- and post-GM, generated by Cotton SA and the USDA, respectively, using the HVI systems, were accessed for 25 years in South Africa, and 27 years in the U.S. The key cotton quality parameters evaluated were staple length, micronaire and strength. These quality parameters had been measured on the Uster® HVI system by the various classing facilities in South Africa and the USA, on each bale of cotton produced within the specific country. The data for South Africa covered the period from 1992 (six years before the introduction of GM cotton) to 2016, composing at least 90% GM cotton since 2007. Data for the USA covered the period from 1990 (five years before the introduction of GM cotton) to 2016, composing at least 90% GM cotton since 2010. The data accessed and compiled, from the respective databases of two different countries, had to be electronically captured, regrouped (according to standards provided by the USDA) and thereafter analysed. It was found that the introduction and phasing in of GM cotton in both South Africa and the USA had a beneficial impact on the overall quality (FQI) of cotton produced in these countries. These positive trends in FQI were mainly caused by an increase in staple length for both countries, due to the beneficial impact that the introduction and phasing in of GM cotton had on staple length. Certain of the fibre parameters, notably micronaire, tended to fluctuate from year to year, quite unrelated to the introduction and phasing in of GM cotton, this being ascribed to fluctuating climatic conditions, and the parameter’s extreme sensitivity to such conditions. Over the period covered, cotton fibre, strength, showed a different trend for each country, remaining largely constant in South Africa, while increasing in the USA, this being unrelated to the introduction of GM cotton per se.