Critical Nutrient Ranges for Petiole Phosphorus Levels of Sprinkler-Irrigated Russet Burbank Potatoes1
- S. Roberts and
- A. I. Dow2
Two field experiments were conducted for the purpose of establishing critical nutrient range (CNR) values for P in petioles of Russet Burhank potatoes (Solanum tuberosum L.) for use as standards in assessing plant nutrient status. The CNR is defined as the range of nutrient concentrations in plant tissue at a selected growth stage, above which the crop has an ample nutrient supply and below which the crop is nutrient-deficient. The experiments were conducted under center-pivot irrigation on soils classified as Quincy and Winchester loamy sands (mixed, mesic, Xeric Torripsamments). Five treatment levels from 0 to 269 kg P/ha were applied broadcast and incorporated before planting in April. Petioles were analyzed for P six times through the season, and potato yield was determined at harvest in late September. Adequate P fertilization produced maximum yields of 64 metric tons/ha on Quincy soil and 73 metric tons/ha on Winchester soil as compared with yields of only 79 to 86% of maximum without P fertilization. It was concluded that for 95 to 100% of maximum yield the estimated CNR was 0.38 to 0.45% P at the 2-cm tuber stage in June and generally decreased with time to give a CNR of 0.14 to 0.17% P toward the end of the season 10 weeks later.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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