Search Results

You are looking at 1 - 10 of 120 items for :

  • cardinal temperatures x
Clear All

as observed in several Australian species ( Bell et al., 1993 ; Bellairs and Bell, 1990 ). Germination rate indices are typically used to quantify cardinal temperatures for seed germination and include reciprocal time to median germination and

Free access

improvement proposed by Boote et al. (2002) was followed and can be summarized in three steps. First, an update of the cardinal temperature parameters was performed, replacing the values used by Scholberg et al. (1997) with values reported in recent

Free access

). Because pollen is short-lived after release and acts as an independent functional unit, in vitro responses of pollen germination and tube length response characteristics such as maximum pollen germination and pollen tube length and cardinal temperatures

Free access

( Rojas-Martinez et al., 1999 ) was used to calculate GDH based on linear and curvilinear heat unit models using a range of cardinal temperatures. The curvilinear models included ASYMCUR ( Anderson et al., 1986 ) and a modified ASYMCUR (Roundy and Frisby

Free access

the interaction between thermoinductive temperatures and durations of exposure. Thermoinductive temperatures can vary by species ( Lang, 1965 ) and have been described as cardinal temperatures for vernalization with minimum (T min ), optimum (T opt

Free access

resistance. The main objectives of this study were 1) to determine appropriate temperatures to be used in screening for resistance to Fusarium tuber rot, 2) to assess the effect of isolate aggressiveness when screening for resistance, and 3) to determine

Free access

self-sowing and acceptable percentage of emergence ( Benvenuti, 2014 ; Casalini, et al., 2017 ; Nagase et al., 2013 ). However, there is no published information on C. nepeta optimal and cardinal temperatures for germination, or possible seed

Free access
Author:

Abstract

The effects of high (86°F) and low (68°F) day temperature, and of high (2,500 to 5,000 ft-c) and low (500 to 1,200 ft-c) light intensity, on the coloration of ‘Cardinal’ and ‘Pinot noir’ grapes grown in sunlit, temperature-controlled rooms during the ripening period were investigated. Night temperature (7 PM to 7 AM) was 59°F in all treatments.

Low day temperature significantly increased the level of anthocyanin pigments in the skins of both cultivars at both high and low light intensity. Anthocyanin synthesis was almost completely inhibited in the skins of ‘Cardinal’ berries that had average daytime temperatures between 91 and 95°F.

Low light intensity greatly reduced coloration of ‘Pinot noir’ grapes at both low and high day temperatures but decreased the level of pigments in grapes grown at 86°F. It either increased or had little effect on fruit coloration of ‘Cardinal’ grapes grown at 68°F.

Open Access

A temperature experiment with two cultivars of muskmelon (`Gold Rush' and `Mission') was conducted in growth chambers to determine how main vine leaf appearance rates responded to temperature. We identified three cardinal temperatures for leaf appearance rate: the base temperature (10 °C) at which leaf appearance rate was zero, an optimum temperature where leaf appearance rate was at a maximum (34 °C) and an upper threshold temperature (45 °C) where leaf appearance rate returned to zero. Using these three cardinal temperatures, we constructed a simplified thermal unit accumulator for hourly measurements of air temperature. Main vine plastochron interval (PI), thermal time to harvest and final yield was determined for three cultivars of muskmelon (`Explorer', `Goldrush', and `Mission') grown in the field over six transplanting dates. The PI was calculated for each cultivar-transplanting date combination as the reciprocal of the slope of main vine node number vs. accumulated hourly thermal units (Tu). The PI was significantly affected by both cultivar and transplanting date. Final yield was sharply reduced in the last two planting dates, presumably due to high temperature stresses impacting reproductive development. As air temperatures warmed during the field experiment, the time interval from transplanting to 10% final harvest were reduced by between 21 to 28 days among the three cultivars and the first four transplanting dates. Our goal was to construct a simple muskmelon phenology model that could be run with easily obtainable weather station data and used by growers to quantify phenological development and aid in projecting harvest dates. We also wanted to test whether main vine node number was a useful description of vegetative development for muskmelon.

Free access
Authors: and

Abstract

Three-year-old ‘Cardinal’ and ‘Pinot noir’ vines were grown from véraison to fruit maturity in a stationary and rotating phytotron at high (30°C) and low (20°C) day temperatures in combination with both high (>2,500 ft-c) and low (< 1,200 ft-c) average light intensities. Night temperature (6 PM to 6 AM) was 15°C in all treatments. Berries were collected at weekly intervals and analyzed for various constituents.

Low temperature usually resulted in increased berry weight, total acidity, and malate, and in decreased pH, arginine, proline, and total N in the berry juices, as compared to fruits grown at high temperature. The concentrations of total soluble solids and tartrate in the fruits generally did not significantly differ with temperature. Low light intensity at both high and low temperatures generally resulted in reduced berry weight, total soluble solids, pH, and proline, and in increased levels of total acidity, malate, arginine, and total N in the berry juices compared to grapes grown at high light intensity at the same room temperature. The concentration of arginine was highly correlated with the level of total N in the fruits of both cultivars.

Open Access