Silicon Fertilizer Effects on Electrolyte Leakage from Sugarcane Leaf Cells after Exposure to Freezing Temperatures

Authors: Morris, Dolen; TAI, P.Y.P. - USDA, ARS, RETIRED

Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 4/26/2006
Publication Date: 6/14/2006
Citation: Morris, D.R., Tai, P. 2006. Silicon Fertilizer Effects on Electrolyte Leakage from Sugarcane Leaf Cells after Exposure to Freezing Temperatures. American Society of Sugar Cane Technologists 26:53

Interpretive Summary: Sugarcane grown in subtropical regions often sustains damage from freezing temperatures. Some sugarcane growers have reported that commercial fields fertilized with silicon had less freeze damage than non-silicon fertilized fields. The purpose of this study was to determine if fertilizer silicon reduces freeze damage to sugarcane leaf cells. A factorial experiment with seven sugarcane genotypes (CP 78-1628, CP 80-1743, CP 88-1752, CP 89-2143, CP 57-603, Green German, and Muntok Java), two silicon (with and without silicon fertilizer), and two soil (muck and sand) treatments, and four replications was conducted in a greenhouse for 13 months. Cell damage was determined after 6 (sample 1) and 13 (sample 2) months of growth by the electrolyte leakage method using plant-top leaf pieces after exposure to freezing temperatures. Higher electrolyte leakage percentages are an indicator of increasing cell damage. At sample 2, freezing temperatures caused greater electrolyte leakage from leaf cells in non-silicon fertilized leaves (79%) compared to silicon fertilized leaves (74%). There was a tendency for the same response at sample 1 (77 vs 76%, respectively) as well as a high correlation (r=0.94**) between electrolyte leakage at sample 2 vs. sample 1. At harvest, silicon fertilized treatments had higher shoot dry yields (763 g/pot) and percentage silicon contents (0.18%) than non-silicon fertilized treatments (601 g/pot and 0.15%, respectively). There were significant differences in electrolyte leakage due to freezing among genotypes with Muntok Java and CP 78-1628 having the highest (84%) and lowest electrolyte leakage (70%), respectively, averaged across both sample dates. Freezing temperatures caused greater electrolyte leakage in plants growing in muck soil (average 84%) compared with the sandy soil (average 78%). However, there were no significant differences in electrolyte leakage after freezing among genotypes growing in the muck soil for samples 1 and 2 (average 83 and 84%, respectively). In the sandy soil, there were significant differences in electrolyte leakage among genotypes. Electrolyte leakage ranged between 57 and 84% and 54 and 85% for samples 1 and 2, respectively. Our data indicate that silicon fertilization reduces cellular damage in sugarcane leaves when exposed to freezing temperatures. The trait for freeze injury to sugarcane cells based on electrolyte leakage is best expressed in a sandy soil compared with a muck soil.

Technical Abstract: Sugarcane grown in subtropical regions often sustains damage from freezing temperatures. Some sugarcane growers have reported that commercial fields fertilized with silicon had less freeze damage than non-silicon fertilized fields. The purpose of this study was to determine if fertilizer silicon reduces freeze damage to sugarcane leaf cells. A factorial experiment with seven sugarcane genotypes (CP 78-1628, CP 80-1743, CP 88-1752, CP 89-2143, CP 57-603, Green German, and Muntok Java), two silicon (with and without silicon fertilizer), and two soil (muck and sand) treatments, and four replications was conducted in a greenhouse for 13 months. Cell damage was determined after 6 (sample 1) and 13 (sample 2) months of growth by the electrolyte leakage method using plant-top leaf pieces after exposure to freezing temperatures. Higher electrolyte leakage percentages are an indicator of increasing cell damage. At sample 2, freezing temperatures caused greater electrolyte leakage from leaf cells in non-silicon fertilized leaves (79%) compared to silicon fertilized leaves (74%). There was a tendency for the same response at sample 1 (77 vs 76%, respectively) as well as a high correlation (r=0.94**) between electrolyte leakage at sample 2 vs. sample 1. At harvest, silicon fertilized treatments had higher shoot dry yields (763 g/pot) and percentage silicon contents (0.18%) than non-silicon fertilized treatments (601 g/pot and 0.15%, respectively). There were significant differences in electrolyte leakage due to freezing among genotypes with Muntok Java and CP 78-1628 having the highest (84%) and lowest electrolyte leakage (70%), respectively, averaged across both sample dates. Freezing temperatures caused greater electrolyte leakage in plants growing in muck soil (average 84%) compared with the sandy soil (average 78%). However, there were no significant differences in electrolyte leakage after freezing among genotypes growing in the muck soil for samples 1 and 2 (average 83 and 84%, respectively). In the sandy soil, there were significant differences in electrolyte leakage among genotypes. Electrolyte leakage ranged between 57 and 84% and 54 and 85% for samples 1 and 2, respectively. Our data indicate that silicon fertilization reduces cellular damage in sugarcane leaves when exposed to freezing temperatures. The trait for freeze injury to sugarcane cells based on electrolyte leakage is best expressed in a sandy soil compared with a muck soil.