The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.

Low quality Stoneville 825 seed produced reduced stands and, in most cases, reduced lint yields when planted at 3 dates and 3 planting dates at 3 locations in Arizona. Reduced lint yields were explained by reduced stands. Highest lint yield was obtained from the second plantings, 24 and 21 April at Marana and Safford, respectively.

The effect of various concentrations of calcium nitrate and calcium chloride on the primary root (radicle) growth of cotton seed at a suboptimal temperature was evaluated 14 days after imbibition onset under laboratory conditions. Both forms of calcium at concentrations up to 10 mM enhanced cotton seed radicle growth at 15 C.

The effect of calcium sulfate on cotton seed radicle growth at a low temperature was evaluated under laboratory conditions. Direct imbibition of solutions of calcium sulfate was stimulatory to radicle growth at 15 C at concentrations up to 10 mM. Anomalous stimulation of radicle growth at 15 C occurred when seed rolls moistened with water were placed adjacent to dilute open solutions of calcium and magnesium sulfate inside sealed chambers. The stimulation appeared due to an indirect influence of sulfate by an unknown mechanism.

In a preliminary, unreplicated test, cotton was planted in 40 inch and 27 inch rows on April 10 and again on May 1. Narrow rows outyielded 40 inch rows at both planting dates. The yield difference between the row spacing treatments was greatest in the May 1 planting. Both row spacings had higher yields when planted on the later date, as did both the DPL 90 and ST506 varieties used in the test.

A breeding program aimed at increasing the ability of long and short staple cotton strains to emerge in saline soils under cool springtime soil conditions has now completed the second cycle of selection. Cycle II emergence results show evidence of progress.

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.

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 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.

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.