• Cotton Seed Treatment, Greenlee County, 1986

      Clark, Lee J.; DeRosa, Edith (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Six different seed treatments and one in furrow granular treatment were used in a field with a history of black root rot, caused by Thielaviopsis basicola. The treatment was a follow-up on the study done the previous year (1). Stand counts, root lengths and seed cotton yields were taken to see if any of the treatments increased stand counts or stimulated root growth. Thielaviopsis was not isolated in the plants this year, so the effect of the fungicides on this pathogen were not evaluated. Stand counts were, however, significantly influenced by the seed treatments.
    • Fermentation as an Estimator of Cotton (Gossypium hirsutum) Seed Vigor

      Lehle, Fredric R. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Anoxic -induced fermentation was evaluated as a potential cotton seed vigor test. Seed samples from a single seed lot were subjected to accelerated aging for different durations to create five classes of seeds on the basis of vigor. The ethanol and acetaldehyde excreted from seeds from each class during brief periods of anoxia was quantified by gas-liquid-chromatography. Ethanol and acetaldehyde production during anoxia was negatively correlated with standard germination test results of all seed samples receiving accelerated aging. The fermentation capacity of hydrated cotton seeds remained intact at imbibition temperatures, which significantly reduced radicle growth.
    • Fermentation in Cotton (Gossypium hirsutum) Seeds

      Lehle, Fredric R.; Ahmed, Omer K. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Ethanol and acetaldehyde production by cotton seeds subjected to anoxic stress imposed by CO₂ or N₂ gas was quantified during the imbibition phase. Fermentation capacity was low in dry seeds and quickly increased during the first few hours of imbibition. In hydrated seeds, ethanol and acetaldehyde excretion following anoxic stress followed a linear trend in time. Ethanol excretion exceeded that of acetaldehyde by an order of magnitude. Similar rates of production were observed whether anoxic was imposed by either CO₂ or N₂ gas. Excreted ethanol and acetaldehyde were rapidly metabolized following alleviation of anoxic stress.
    • Leakage of Reducing Sugards and Amino Acids During Cotton (Gossypium hirsutum) Seed Imbibation

      Lehle, Fredric R. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Leakage of reducing sugars and amino acids during cotton seed imbibition was evaluated as a possible vigor test. Seed samples from a single cotton seed lot were subjected to accelerated aging at 46°C and 100% R.H. for up to 216 hours. Aged seeds were imbibed at optimal and suboptimal temperatures, and the leakage of total reducing sugars and amino acids into the imbibition solution was quantified spectrophotometrically. Leakage of seed reserves was positively correlated with the duration of accelerated aging, in terms of subsequent germination performance at 30°C and of similar quantity at both imbibition temperatures.