Critical petiole nitrate concentration of two processing potato cultivars in Eastern Canada

American Journal of Potato Research, Jul/Aug 2003 by Belanger, G, Walsh, J R, Richards, J E, Milburn, P H, Ziadi, N

Accepted for publication 7 May 2003.

ABSTRACT

Plant-based diagnostic methods of nitrogen (N) nutrition such as petiole nitrate (NO^sub 3^-N) concentration can be used to improve the efficiency of N utilization, and hence decrease the risks of N losses to the environment. Our first objective was to determine the effect of N fertilization and supplemental irrigation on the petiole NO^sub 3^-N concentration during tuber growth of two potato cultivars, Russet Burbank and Shepody, widely grown for processing in Eastern Canada. Our second objective was to establish the critical petiole NO^sub 3^-N concentration using the relationship between petiole NO^sub 3^-N concentration and the N nutrition index (NNI), an index based on the N concentration of shoots and tubers. This on-farm study was conducted at two sites in each of three years, 1995 to 1997. The N fertilization rates ranged from 0 to 250 kg N ha^sup -1^ with three rates in 1995, six rates in 1996, and four rates in 1997. The NO^sub 3^-N concentration of petioles from the most recently mature leaves was measured on three sampling dates in 1995 and four sampling dates in 1996 and 1997. The petiole NO^sub 3^-N concentration generally decreased with time. At all sites and on all sampling dates, the petiole NO^sub 3^-N concentration increased with increasing N fertilization and was significantly greater for Shepody than for Russet Burbank. Irrigation had no consistent effect on petiole NO^sub 3^-N concentration. Petiole NO^sub 3^-N concentration was related to NNI (0.29

ADDITIONAL KEY WORDS: Solanum tuberosum L., nitrogen fertilizer, irrigation.

RESUMEN

Metodos de diagnostico de nutricion nitrogenada (N), como el del concentrado de (NO^sub 3^-N) en peciolos, pueden ser usados para mejorar la eficiencia de utiliazcion del N y reducir los riesgos de perdidas al medio ambiente. Nuestro primer objetivo fue determinar el efecto de la fertilizacion con N e irrigacion suplementaria sobre la concentracion de NO^sub 3^-N en el peciolo, durante el periodo de desarrollo de tuberculos en dos cultivares de papa, Russet Burbank y Shepody,.ampliamente cultivados en el Oriente Canadinese para procesameinto. Nuestro segundo objetivo fue establecer el nievel de concentracion critico del NO^sub 3^-N en el peciolo, usando la relacion entre la concentracuion de NO^sub 3^-N en el peciolo y el indice de nutricion de N (NNI), indice que esta basado en la concentracion de N en los tallos y tubercules. Este estudio fue conducido en finca de agricultores en dos lugares por tres anos consecutivos, 1995-1997. Los niveles de fertilizacion oscilaron entre 0 y 250 kg N ha^sup -1^, con tres niveles en 1995, seis en 1996 y cuatro en 1997. La concentracion de NO^sub 3^-N en los peciolos de las hojas maduras mas recientes fue medida durante tres fechas en 1995 y cuatro fechas en 1996 y 1997. La concentracion de NO^sub 3^-N en el peciolo generalmente disminuyo con el tiempo. En ambos lugares y en todas las fechas en que se tomaron las muestras, la concentracion de NO^sub 3^-N en el peciolo se incremento a medida que se aumento el nivel de fertilizacion de N; siendo significativamente superior el incremento en Shepody que el de Russet Burbank. La irrigacion suplementaria no tuvo un efecto consistente en la concentracion de NO^sub 3^-N en el peciolo. La concentracion de NO^sub 3^-N en el peciolo estuvo relacionada con el NNI (0.29

INTRODUCTION

Plant-based diagnostic methods of nitrogen (N) deficiency can be used to improve the efficiency of N utilization, and hence decrease the risks of N losses to the environment. The use of petiole nitrate (NO^sub 3^-N) concentration as a diagnostic method has been widely studied, and critical values or ranges of petiole NO^sub 3^-N concentrations have been suggested for potatoes in the producing region of Atlantic North East America (MacMurdo et al. 1988; Porter and Sisson 1991), in other regions of North America (Gardner and Jones 1975; Westcott et al. 1991; Waterer 1997), and other regions of the world (Williams and Maier 1990; Singh 1993; Hegney and McPharlin 2000).

Several factors affect petiole NO^sub 3^-N concentration. Nitrogen fertilization increased petiole NO^sub 3^-N concentration in studies conducted in different parts of the world (Doll et al. 1971; Gardner and Jones 1975; Porter and Sisson 1991; Westcott et al. 1991; Huett and White 1992; Singh 1993; Lewis and Love 1994; Maier et al. 1994; Sharma 1996) including Eastern Canada (Sanderson et al. 1999). Excessive irrigation reduced petiole NO^sub 3^-N concentration during substantial portions of the tuber bulking period (Stark et al. 1993) whereas insufficient water for plant growth resulted in the accumulation of NO^sub 3^-N in potato petioles (Meyer and Marcum 1998). Cultivar differences in critical petiole NO^sub 3^-N concentrations were reported (Porter and Sisson 1991; Singh 1993; Lewis and Love 1994). Petiole NO^sub 3^-N concentrations also decreased with time or plant maturity (Doll et al. 1971; Gardner and Jones 1975; Porter and Sisson 1991; Westcott et al. 1991; Singh 1993; Sharma 1996).