Search Results

You are looking at 91 - 100 of 540 items for :

  • "heat stress" x
  • Refine by Access: All x
Clear All
Free access

Fenny Dane, A. Gene Hunter, and Oyette L. Chambliss

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

V.M. Russo and J.C. Díaz-Pérez

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.

Open access

Stephanie Rossi and Bingru Huang

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

Free access

D. Michael Glenn

); however, reducing canopy temperature can reduce heat stress and increase water use resulting in reduced water use efficiency and increased productivity ( Glenn, 2010 ). The reduction of PAR by the film at the leaf level is compensated in varying degrees

Open access

Abbas Lafta, Germán Sandoya, and Beiquan Mou

differences ( P < 0.0001) among the tested cultivars ( Table 2 ), indicating genetic variation for the traits under heat stress. These data confirmed a previous report of genetic variation for heat tolerance–related traits in eight crisphead lettuce cultivars

Free access

Timothy G. Porch, James R. Smith, James S. Beaver, Phillip D. Griffiths, and Craig H. Canaday

significantly higher seed yield than Montcalm in the Juana Diaz (2004) stress trial ( Table 2 ), whereas TARS-HT2 had a significantly higher seed yield than Montcalm in the 2002 heat stress trial in Jackson, TN, and a significantly higher yield than ‘Redhawk’ in

Open access

Gustavo F. Kreutz, Germán V. Sandoya, Gary K. England, and Wendy Mussoline

tipburn, heat stress-induced physiological disorders, and maturity traits in crisphead lettuce Theor. Appl. Genet. 126 12 59 70 doi: 10.1007/s00122-013-2193-7 Jenni, S. Yan, W. 2009 Genotype by environment interactions of heat stress disorder resistance in

Full access

Kamal Aberkani, Xiuming Hao, Damien de Halleux, Martine Dorais, Stephen Vineberg, and André Gosselin

fogging systems have been used to prevent plant heat stress during the day. In fact, shading is one of the conventional and familiar techniques used by growers to decrease solar radiation and reduce air and leaf temperatures ( Sandri et al., 2003 ). Many

Free access

D. Michael Glenn, Nicola Cooley, Rob Walker, Peter Clingeleffer, and Krista Shellie

production regions with high solar radiation ( Tarara et al., 2008 ; Wample, 1996 ). A porous kaolin-particle film on a leaf or fruit surface (PFT) has been shown to reduce heat stress without restricting gas exchange ( Glenn, 2009 ; Glenn et al., 2001

Free access

Suping Zhou, Roger J. Sauvé, Zong Liu, Sasikiran Reddy, Sarabjit Bhatti, Simon D. Hucko, Yang Yong, Tara Fish, and Theodore W. Thannhauser

and functionality of enzymes associated with photosynthetic activity are sensitive to heat stress ( Berry and Björkman, 1980 ; Murakami et al., 2000 ). Significant inhibition of photosynthesis occurs at temperatures only a few degrees above the