Dry Matter Production in Tops and Roots of Winter Wheat as Affected by Phosphorus Availability During Various Growth Stages

Sutton, P. J.; Peterseon, G. A.; Sander, D. H.

Dry Matter Production in Tops and Roots of Winter Wheat as Affected by Phosphorus Availability During Various Growth Stages

1983

Sutton, P. J. | Peterseon, G. A. | Sander, D. H.

The timeliness of P availability to a plant is important for maximum plant growth. There is little information pinpointing the critical time(s) in the life cycle of winter wheat (Triticum aestivum L.) at which P uptake is the most important for maximum growth response. The objectives of this research were: i) to determine the effects of removing P from the growing medium during progressive stages of growth on dry matter production and P uptake of winter wheat; and ii) to compare the P demand pattern of winter wheat with that known for spring wheat. ‘Centurk’ winter wheat was grown using a modified Hoagland's nutrient solution in a greenhouse environment. Treatments consisted of evaluating the plant response to the time grown with and without available P in the nutrient solution. This was accomplished by replacing the complete nutrient solution with a nutrient solution devoid of P and allowing plants to continue growth to physiological maturity. Winter wheat had taken up sufficient P by the first node stage to ensure maximum dry matter production of the mature roots and tops. Phosphorus availability in later growth stages did not significantly increase mature root and top dry matter production. Maximum grain yield at maturity, however, was only realized when P was available through the mealy-ripe stage (Feekes' Scale 11.2) of grain development. It appears that after noding stage only a small amount of P may be needed to allow carbohydrate translocation mechanisms to function. Spring wheat differs from winter wheat in that it only requires adequate P up to heading to produce maximum grain yields.

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