Effects of nitrogen, phosphorus, and potassium on SPAD-502 and atLEAF sensor readings of Salvia. (9th August 2018)

• Record Type: Journal Article
• Authors: Dunn, Bruce L.; Singh, Hardeep; Payton, Mark; Kincheloe, Sean
• Is Part Of: Journal of plant nutrition. Volume 41:Number 13(2018)
• Page Start: 1674
• Page End: 1683
• Publication Date: 2018-08-09
• Subjects: fertilizer -- greenhouse -- lamiaceae -- nutrient management -- optical sensor; Plants -- Nutrition -- Periodicals; Plants -- Effect of minerals on -- Periodicals; Deficiency diseases in plants -- Periodicals; 575.76
• DOI: 10.1080/01904167.2018.1458874
• Languages: English
• ISSNs: 0190-4167

Abstract

ABSTRACT: There are various optical sensors in the market for precision nitrogen (N) management, which estimate leaf N status from chlorophyll content of leaves. However, readings may also be affected by the amounts of other nutrients in the plant leaves like potassium (K) and phosphorus (P), as well as sampling location within a plant or leaf. SPAD-502 and atLEAF optical sensors were used on Salvia 'Vista Red' plants grown with 0N-7.9P-0K, 41N-0P-0K, 0N-0P-31.6K, 0N-7.9P-0K + 41N-0P-0K, 0N-7.9P-0K + 0N-0P-31.6K, 41N-0P-0K + 0N-0P-31.6K, or 0N-7.9P-0K + 41N-0P-0K + 0N-0P-31.6K fertilizer plus a control. Both sensors were correlated with leaf N and each other. However, both sensor readings were affected by the presence or absence of P and K in the leaves, and thus these nutrients should be analyzed and reported along with leaf N values. Sensor readings were found to vary within a leaf and within leaf canopy location, so sampling needs to be consistent.