Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: Richard Hamman x
Clear All Modify Search

The response of grapevines to methanol was investigated at the Orchard Mesa Research Center in Grand Junction, CO. Optimum sublethal methanol dose levels, based on visual assessments, were 90% for leaves and 100% for trunks for 10 cultivars. Total soluble sugars (TSS) of the berries, monitored every week until harvest, showed significant differences with Muscat Blanc during veraison. Berries from the methanol-treated vines had higher TSS (16.4 °Brix) than controls (15 °Brix). However, no significant differences were observed later in the season when approaching fruit maturity. At harvest, data on yields as estimated by cluster weight, berry weight and berry size showed no differences between the two treatments. Methanol did not enhance cold hardiness of bud tissues. measured by differential thermal analysis. It was concluded that, although methanol has been reported to improve several physiological features of C3 crops, our study suggested that it has little or no practical effect on grapes. More data on the determination of sugars in berries by HPLC will be discussed.

Free access

Field studies were conducted to determine the effect of three drip irrigation regimes on grapevine growth, juice and wine quality, soil moisture, cold hardiness of bud and cane tissues and soluble sugar content of cortical cane tissues of Vitis vinifera, Linnaeus `Cabernet Sauvignon'. This study was developed to help provide some irrigation management strategies that would improve fruit quality and reduce excessive vigor. Irrigation treatments of 192, 96, and 48 L (51, 25, and 13 gal) per vine per week were initiated at bud break until veraison (initiation of berry color) and then reduced by 25% through harvest. Significant differences of fruit weight per vine, crop load, soil moisture, average berry and cluster weight, shoot length and pruning weight per meter of canopy row were observed among treatments. Juice and wine compositions and wine color were also significantly different; however, cold hardiness and soluble sugar contents did not differ between treatments.

Full access