Nitrogen Partitioning and Redistribution in Nonnodulating Peanut Related to Nitrogen Stress1
- A. Selamat and
- F. P. Gardner2
Nitrogen is essential for vegetative and reproductive growth of peanut (Arachis hypogaea L.), and hypothetically plants may become stressed for N especially during fruiting despite effective N2 fixation. The objectives of this study were to determine the effects of N stress during specific fruiting phenophases on N partitioning and fruit growth. Reproductive growth was competitive with vegetative parts in peanut during periods of N stress. In a glasshouse study in 1982, N was completely withdrawn from nonnodulating (M4-2) plants in pots containing silica sand supplied with nutrient solution. The duration of N removal from the medium was more critical than the specific fruiting phenophase in affecting root growth, pod yield, and N redistribution. Nitrogen was redistributed from vegetative parts to pods in the long N stress periods (> 81 days), whereas there was no detectable N redistribution in the control plants or those subjected to short N stress periods. The calculated N distribution index (NDI) showed that pods competed with vegetative parts for N, if the N stress period was long, but competition was not evident during shortstress periods (<30 days). The magnitude of redistribution (NDI) to seeds relative to source was leaves > stems > roots (in that order), the latter resisting redistribution except in stress periods of long durationPlease view the pdf by using the Full Text (PDF) link under 'View' to the left.
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