A phytoplasma was detected in naturally diseased 'Chardonnay' grapevines exhibiting symptoms of Australian grapevine yellows disease. The use of PCR designed to amplify phytoplasma DNA resulted in detection of phytoplasma DNA in all of the diseased plants examined; no phytoplasma DNA was detected in healthy seedling grapevines. The collective restriction fragment length polymorphism (RFLP) patt...

LIST OF OBJECTIVES AND DESCRIPTION OF ACTIVITIES CONDUCTED TO ACCOMPLISH EACH OBJECTIVE Objective 1: Develop an experimental, growth chamber temperature regime that can consistently cure Pierce’s Disease affected grapevines without causing unacceptable plant mortality. The results described in previous reports show that our field plants and cold chamber plants showed lower disease ratings and h...

Heterogeneity in root-zone temperature both vertically and horizontally may contribute to the uneven vegetative and reproductive growth often observed across vineyards. An experiment was designed to assess whether the warmed half of a grapevine root zone could compensate for the cooled half in terms of vegetative growth and reproductive development. We divided the root system of potted Shiraz g...

Tyloses form in xylem vessels in response to various environmental stimuli, but little is known of the kinetics or regulation of their development. Preliminary investigations indicated that wounds seal quickly with tyloses after pruning of grapevine shoots. In this study, tylose development was analyzed qualitatively and quantitatively at different depths and times from pruning cuts along curre...

Nutrition is a relevant issue for winegrowers because it influences grapevine growth, berry composition, as well as must and wine quality. In this research, the following impacts on the nutritional status of cv. Tempranillo grapevines were evaluated: simulated 2100 expected CO2, temperature (T) and relative humidity (RH) conditions (FCC; 700 μmol CO2/mol air, 28/18°C day/night and 33/53% RH, da...