Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 30, 2009
Publication Date: November 5, 2009
Citation: Zhao, D., Glaz, B.S., Comstock, J.C. 2009. Sugarcane growth and physiological responses to water deficit stress on organic and sand soils. American Society of Agronomy Abstracts. Paper 55576 Technical Abstract: Sugarcane (Saccharum spp.) genotype selection has been more successful for organic (muck) than sand soils in Florida, perhaps due to differences in water availability. A greenhouse study was conducted at Canal Point, Florida to compare sugarcane physiological responses to water deficit stress during early growth on each soil type. Sugarcane cultivar CP80-1743 was planted in pots which were fertilized with N, P, and K based on soil analyses. Treatments included two soils (muck and sand) and two water regimes [well watered (WW) and water deficit stress (WS)] planted in a randomized complete block design with seven replications. All pots were well watered before WS was initiated. Starting at 58 d after planting, water was withheld from the WS pots. During the stress period, plant growth, leaf relative water content (LRWC), leaf proline content, stomatal conductance, and photosynthesis were measured every 3 or 4 d. Soil type significantly affected plant response to water stress. Neither leaf proline nor LRWC was a sensitive indicator of sugarcane water stress. Water stress reduced the number of large tillers, green leaf area (GLA), stomatal conductance, and photosynthesis, resulting in reduced shoot biomass. At 24 d after the stress treatment, the number of large tillers, GLA, stomatal conductance, and photosynthesis of the WS plants were reduced 33, 50, 51, and 48%, respectively, on muck soil and 83, 82, 72, and 84%, respectively, on sand soil compared with the WW treatments. There was a greater physiological impact of WS on sugarcane on sand than on muck soils.