Abstract
The ability of peanut plants to adjust to wide plant-to-plant spacing and the use of more precise mechanical planters have not been thoroughly exploited to reduce seeding rates. The magnitude of plant growth adjustment of two runner peanut cultivars to reduced seeding rate was studied in 1992 and 1993. A precision vacuum planter was used to plant the cultivars GK-7 and Southern Runner (SR) in single rows per bed at 8, 12, and 22 seed/m2. Total plant dry matter weight (TDM), leaf area (LA), and main stem height, nodes, and branches were measured six times during each season. Vegetative growth adjustment to reduced seeding rate was detected as early as 52 d after planting (DAP) in 1992 and 42 DAP in 1993. Plants fully adjusted to reduced seeding rate when they began forming pods at 70 DAP in 1992 and 75 DAP in 1993. By this stage, individual plants in the 8 seed/m2 treatment accumulated 2 to 2.7 times as much total dry matter (TDM) as plants in the 22 seed/m2, and all seeding treatments within each cultivar accumulated equivalent amounts of TDM on a unit ground area basis. The 8 seed/m2 treatment produced significantly greater TDM/m2 and leaf area index (LAI) than the 22 seed/m2 treatment by the end of both seasons (132 DAP in 1992 and 152 DAP in 1993). The partitioning of dry weight to pods and leaves was also greatest for the 8 seed/m2 seeding treatment. By the end of the season, the 8 seed/ m2 seeding treatment produced as much as 30% more pod dry weight (PDW) per m2 than the 22 seed/m2 treatment. Plants in the 8 seed/m2 seeding were significantly shorter but produced more main stem nodes and branches than the 22 seed/m2 seeding. Under the conditions of this study, plants of these runner cultivars showed the capacity to grow larger and compensate fully for reduced seeding rate before any measurable pod production began. Pod production, therefore, was not reduced and in some situations increased by reducing the seeding rate to as low as 8 seed/m2.
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Keywords: Arachis hypogaea, leaf area index, partitioning, plant density, yield
How to Cite:
Tewolde, H. & Black, M. & Fernandez, C. & Schubert, A., (2002) “Plant Growth Response of Two Runner Peanut Cultivars to Reduced Seeding Rate¹”, Peanut Science 29(1), p.8-12. doi: https://doi.org/10.3146/pnut.29.1.0002