Five decades of productivity gains in the Louisiana sugar industry

This study analyzed trends across five decades of productivity data from the Louisiana Sugar Industry, from 1969 to 2021, for sucrose content, cane yield, and sugar yield. Trends over the five decades were revealed using robust regression models, and the least square means allowed for decade-wise comparisons of trends. Sucrose content increased 45%, from 80.9 +/- 6.4 g kg(-1) in the first (1969-1979) to 116.7 +/- 4.8 g kg(-1) in the fifth (2010-2021) decade, at 0.85 +/- 0.06 g kg(-1) per year. Cane yield increased slower (32.2%), from 57.7 +/- 5.9 Mg ha (-1) in the first to 76.3 +/- 6.3 Mg ha(-1) in the fifth decade, at 0.45 +/- 0.07 Mg ha(-1) per year. Sugar yield increased 93% from the first (4.6 +/- Mg ha(-1)) to the fifth (8.9 +/- 0.76 Mg ha(-1)) decade at 0.1 +/- 0.01 Mg ha(-1) per year. The gains were neither significant nor consistent when comparing successive decades, incremental rather than rapid, and maintained once achieved. Significant (p < 0.05) gains in all traits occurred only in the third decade (1990-1999) with yearly increases of 1.15 +/- 0.30 g kg(-1) for sucrose content, 3.00 +/- 0.27 Mg ha (-1) for cane yield, and 0.35 +/- 0.05 Mg ha(-1) for sugar yield. Comparisons of trait means between successive decades found both significant (p < 0.05) and nonsignificant (p > 0.05) differences; however, comparisons between noncontiguous decades were all significant (p < 0.05). Variety development accounted for 60% of the progress with sucrose content contributing more (10% more) compared with cane yield. The Louisiana sugar industry has experienced substantial productivity gains in the last five decades thanks to a combination of factors with variety development being the most impactful.