Search Results

You are looking at 91 - 100 of 598 items for :

  • "heat stress" x
Clear All

Heat stress is detrimental for cool-season turfgrasses and is characterized symptomatically by a marked decrease in TQ in cool-season turfgrass species as a result of heat-induced leaf senescence. Heat-induced leaf senescence is associated with

Open Access

were used to identify heat tolerance when planted in five environments in field experiments ( Table 1 , Supplemental Fig. 1). These genotypes were selected from preliminary evaluations of 3-week-old lettuce plants. Seedlings were exposed to heat stress

Open Access

avoid water and heat stress under drought conditions ( Álvarez et al. 2009 ). For example, Mee et al. (2003 ) reported that native plants in the arid western United States, such as Artemisia tridentata Nutt. (big sagebrush) and Cercocarpus montanus

Open Access

Influence of irrigation regime on growth of select field-grown tree species in a semiarid climate J. Environ. Hort. 27 134 138 Harlan, S.L. Brazel, A.J. Prashad, L. Stefanov, W.L. Larsen, L. 2006 Neighborhood microclimates and vulnerability to heat stress

Full access

overall turf quality of cool-season grasses during summer months is commonly referred to as summer stress. Summer stress can be broken down into two major components, heat stress and drought stress ( Huang et al., 1998a ; Jiang and Huang, 2000 , 2001b

Free access

than did BD (10.7 nodes). The heat stress treatments did not affect the number of vegetative nodes produced. Discussion Flower dry weight and flower abscission were most affected at the visible bud stage, which corresponds to stress treatments during

Free access

, Steyn WJ . 2014 . Response of Apple ( Malus domestica Borkh.) fruit peel photosystems to heat stress coupled with moderate photosynthetic active radiation at different fruit developmental stages . Scientia Hortic . 178 : 154 – 162 . https

Open Access

Abstract

Positional differences among leaf and fruit surface temperatures and water relations of ‘Ruby’ grapefruit (Citrus paradisi Macf.) were related to fruit load and juice quality. Southern top canopy positions experienced the highest temperatures and lower water potentials and yielded more fruit with more soluble solids than other canopy positions. Canopy depth was also an important determinant of fruit yield and early season juice quality. Based on data from 3 trees during 2 seasons, there were greater fruit loads with higher °Brix and lower acidity in the outside canopy positions than in the inside positions. Upper canopy positions tended to have lower acidity and consequently higher °Brix/acid ratios than the lower positions. Abaxial fruit hemispheres were smaller and had a lower percent juice than their paired adaxial fruit hemispheres. Grapefruit from sunlit canopy positions mature earlier than fruit from shaded positions. Since there were more fruit with higher soluble solids in the most exposed canopy positions, daily heat stress and leaf and fruit water stress were not limiting factors in grapefruit yield and juice quality with respect to different tree canopy positions.

Open Access

Selected tomato (Lycopersicon esculentum Mill) genotypes were evaluated for their fruit-setting ability under high-temperature field conditions. A temperature-controlled greenhouse study was conducted to determine the percent fruit set from the total number of flowers and fruit produced per plant. Ratings for set obtained under high-temperature field conditions were significantly (P = 0.001) correlated with percent fruit set determined under similar greenhouse conditions. Most of the Asian Vegetable Research and Development Center (AVRDC) selections, Beaverlodge lines, `Nagcarlan', and `Red Cherry' could be considered heat-tolerant. Small-fruited, abundantly flowering genotypes were less affected by heat stress than larger-fruited cultivars. Prolonged periods of high temperature caused drastic reductions in pollen fertility in most genotypes, except `Red Cherry' and L. esculentum var. cerasiforme (PI 190256). Stigma browning and stigma exsertion commonly occurred on all lines, except AVRDC CL-5915-553 and PI 190256. Diallel analyses indicated that pollen fertility and fruit set under high field temperatures were primarily under additive gene control.

Free access

Heat stress can limit yield in pepper (Capsicum spp.), generally through flower and fruit abortion. A kaolin-based particle film, originally developed to protect fruit trees from insects, has been found to reduce temperatures in tissues of plants. A kaolin-based particle film was tested to determine if it could be used to improve yields of pepper in Oklahoma and Georgia. In Oklahoma, seedlings of a bell pepper, `Jupiter', and a nonpungent jalapeño, `Pace 103', were transplanted at three progressively warmer planting dates from mid-May to mid-July 2002 and 2003, that would ensure that inflorescences would be subject to high day and night temperatures and treated with the kaolin-based particle film. Applications were begun as the first flowers were set and continued through the settings of the first three flushes of flowers on a three-times a week schedule, or on an as needed basis, to determine if the kaolin-based particle film improved yield. In Georgia, the bell peppers `Camelot' and `Heritage VR' were transplanted on 24 Apr. 2003, and treated with the kaolin-based particle film. In addition to yield, physiological measurements and disease incidences were recorded in Georgia. In both locations treatment with water only served as controls. In Georgia, the kaolin-based particle film had no significant effect on net photosynthesis, stomatal conductance, leaf transpiration or leaf temperature, as measured at midday on clear days. In Oklahoma, planting bell pepper after 15 May is not recommended. Planting the nonpungent jalapeño after mid-June can reduce yields. The kaolin-based particle film did not affect yield at either location and is not recommended for use on peppers.

Free access