No description available.

Plant growth products manufactured by BioHumaNetics, Inc. were evaluated in 1986 for a second consecutive year in the same field at the Maricopa Agricultural Center. Treatments included: 1) no fertilizers added, 2) standard fertilization recommended for the farm, and 3) a treatment schedule prescribed by BioHumaNetics. The non fertilized treatment had a significantly lower total yield than the two fertilized treatments.

PIX was applied to cotton in 10 and 20 gallons of water to evaluate the effect of dilution rate on plant growth regulation. No statistical differences were seen at the one pint rate, but the trends looked like the higher rate of water increased the plant growth regulation (i.e., decreased plant height and increased yield). Increasing the rate of PIX to 2 pints in 20 gallons of water, to maintain the same concentration as 1 pint in 10 gallons of water, was detrimental to the yields.

No description available.

The third year was completed of a study designed to evaluate the effects of Burst Yield Booster, a cytokinin based plant growth regulator, on upland cotton. Five treatments were included in the 1986 experiment, which varied application timing, rate, and frequency. Consistent with our studies of the past two seasons, no significant differences in yield were observed.

The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers. / When DPL-90 was exposed to average daily temperatures above 78 °F, the plants were delayed in the location of the first fruiting branch and produced squares which had 4-bracts. At temperatures below 78 °F, there were very few 4-bract squares produced.

The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers. / Seed cotton yields were increased an average 80% by a near doubling of the carbon dioxide concentration (approximately 650 ppm) in 3 years of experiments using CO₂-enriched, open-top chambers on field-grown cotton. Water use was not changed much or in a consistent direction, so water use efficiency increased in step with the dramatic yield increase.

The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers. / PIX application on June 24 to high flowering rate cotton suppressed growth to an average .3 inch per day compared to .85 inch for untreated cotton during the period from July 2 to July 15. Treatment of DPL 90 cotton with a flowering rate of 5 flowers per 25 feet of row held growth to .38 inch per day versus 25 flowers per 25 feet of row also increased small boll numbers by July 15, or 21 days after treatment, over untreated cotton. Treatment of cotton with flowering rate of 5 flowers per 25 feet of row increased small boll numbers by July 29 or 35 days after treatment.

The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers. / An experiment was conducted to test the hypothesis that a nutritional stress (shortage of photosynthate) affects the hormonal balance in bolls and their abscission zones. It did. The concentration of indoleacetic acid (IAA) in abscission zones of young bolls decreased and boll shedding increased as competition for photosynthate increased. Water deficit also decreased the IAA content of young bolls and their abscission zones, but greatly increased the concentration of abscisic acid (ABA) a hormone that may increase boll shedding.

The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers. / PIX was applied on 6 varieties of cotton in 1984 and on 4 varieties in 1985. Application rates of 1/2 pt/ac, a split application of 1/2 pt + 1/2 pt and a single application of 1 pt/ac were evaluated. Different varieties were affected differently, but yield was depressed on all varieties by the split rate in 1984 and increased on all varieties by the single application of 1 pt/ac in 1985. Plant heights were reduced by all applications.