HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Prasad, P. V. V. Articles by Tuinstra, M. R. PubMed Articles by Prasad, P. V. V. Articles by Tuinstra, M. R. Agricola Articles by Prasad, P. V. V. Articles by Tuinstra, M. R. Related Collections Crop Growth and Development Crop Physiology & Metabolism Sorghum

CROP PHYSIOLOGY & METABOLISM

Sensitivity of Grain Sorghum to High Temperature Stress during Reproductive Development

Dep. of Agronomy, 2004 Throckmorton Hall, Kansas State University, Manhattan, KS 66506; M.R. Tuinstra, current address: Dep. of Agronomy, 1150 Lilly Hall, Purdue Univ., West Lafayette, IN 47907. Contribution no. 08-213-J from the Kansas Agricultural Experiment Station

^* Corresponding author (vara{at}ksu.edu).

Sorghum (Sorghum bicolor L. Moench) grown in semiarid regions is often exposed to short periods of high-temperature (HT) stress during reproductive development. Objectives of this research were (i) to quantify the effects of short episodes of HT stress during reproductive development on physiological, growth, and yield processes of grain sorghum and (ii) to identify the stage(s) most sensitive during the reproductive development phase to HT stress. Plants of hybrid DK-28 E were grown in growth chambers at daytime maximum/nighttime minimum optimum temperature (OT) of 32/22°C until 29 d after sowing. Thereafter, plants were exposed to OT or HT (40/30°C) or were reciprocally transferred at 10-d intervals (10 d before flowering, 0, 10, 20, and 30 d after flowering [DAF]) from OT to HT and vice versa. Transferred plants remained in the new temperature regime for 10 d before being returned to their original temperature regime. Continuous HT stress delayed panicle emergence and decreased plant height, seed set, seed numbers, seed yield, seed size, and harvest indices but did not influence leaf photosynthesis. Exposure to short (10-d) periods of HT stress at flowering and 10 d before flowering caused maximum decreases in seed set and seed yield, and HT stress during postflowering stages (10, 20, and 30 DAF) decreased seed yield, with a larger reduction at early stages of seed development.

Abbreviations: DAF, days after flowering • DAS, days after sowing • HT, high temperature • OT, optimum temperature