About Us | Help Videos | Contact Us | Subscriptions
 

Agronomy Journal Abstract - Biometry, Modeling & Statistics

Quantifying Corn Growth and Physiological Responses to Ultraviolet-B Radiation for Modeling

 

This article in AJ

  1. Vol. 105 No. 5, p. 1367-1377
     
    Received: Mar 5, 2013
    Published: July 8, 2013


    * Corresponding author(s): krreddy@pss.msstate.edu
 View
 Download
 Alerts
 Permissions
Request Permissions
 Share

doi:10.2134/agronj2013.0113
  1. K. Raja Reddy *a,
  2. Shardendu K. Singhb,
  3. Sailaja Kotic,
  4. V. G. Kakanid,
  5. Duli Zhaoe,
  6. Wei Gaof and
  7. V. R. Reddy
  1. a Dep. of Plant and Soil Sciences, 117 Dorman Hall, Box 9555, Mississippi State Univ., Mississippi State, MS 39762
    b Crop Systems and Global Change Lab., USDA-ARS, Beltsville, MD 20705
    c RiceTec, Inc., P.O. Box 1305, Alvin, TX 77512
    d Dep. of Plant and Soil Sciences, Oklahoma State Univ., Stillwater, OK 74078
    e USDA-ARS, Sugarcane Field Station, 12990 U.S. HWY 441, Canal Point, FL 33438
    f USDA-UV-B Monitoring Network, Natural Resource Ecology Lab., Colorado State Univ., Fort Collins, CO 80523

Abstract

To understand the consequences of rising levels of ultraviolet-B (UV-B) radiation on corn (Zea mays L.), two experiments were conducted using sunlit growth chambers at a wide range of UV-B radiation levels. Corn hybrids, Terral-2100 and DKC 65-44, were grown in 2003 and 2008, respectively, at four UV-B levels (0, 5, 10, and 15 kJ m–2 d–1) at 30/22°C, from 4 d after emergence to 43 d under optimum nutrient and water conditions. Plant growth, development, and photosynthetic rates were measured regularly. An inverse relationship between many growth process and dosage of UV-B radiation was recorded. Shorter plants were due to shorter internodal lengths rather than fewer internodes and the total leaf area was less due to smaller leaves. Lower biomass under enhanced UV-B was closely related to smaller leaf area and lower photosynthesis. Critical UV-B limits, defined as 90% of optimum or control, were estimated from the UV-B response indices. The critical limits for stem extension and leaf area expansion were lower in both hybrids (1.7–3.5 kJ m–2 d–1) than the critical limit for leaf number (>15 kJ m–2 d–1) and photosynthetic processes, indicating that expansion or extension rates of organs were the more sensitive to UV-B radiation. Hybrid Terral-2100 exhibited greater sensitivity to UV-B radiation than DKC 65-44 for studied parameters. Thus, both current and projected UV-B radiation can adversely affect corn growth. The functional algorithms developed in this study could be useful to enhance the corn models to predict accurately field performance.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2013. Copyright © 2013 by the American Society of Agronomy, Inc.