Peanut Root Response to Drought Stress
- C. A. Meisner and
- K. J. Karnok
Knowledge concerning the response of peanut [Arachis hypogaea (L.)] root growth during stress and to irrigation after stress is limited. This study was conducted to determine the effect of timing of water stress imposition on peanut root growth, reproductive development, and pod yield. Root growth was measured weekly using nondestructive methods in rhizotron chambers containing a 4:1 mixture of sand and fritted (calcified) clay. A portable rain shelter was used to impose 30-d stress treatments beginning at 20, 50, 80, and 110 d after planting (DAP), in addition to a well-watered control. Root growth was significantly reduced in the upper 40-cm depth during stress from 20 to 50 DAP compared to root growth during the same period of the wellwatered control. No other stress periods resulted in significantly altered root growth compared to the control. Root growth was not affected in the lower depths of this treatment by stress because of adequate soil moisture. Upon rewatering, there was a trend for root growth to recover and continue further into the season for the two stress treatments beginning at 20 and 50 DAP. By the end of the season, there were no differences in overall average root growth among treatments. Peanut root growth may be temporarily reduced during early stress but appears to recover once rewatered. Pod yields were reduced, 49 and 37%, compared with the control by stress imposed at 50 and 80 DAP, respectively. Thus, adequate moisture during 50 to 80 and 80 to 110 DAP is critical for obtaining maximum yields.
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