PT  - JOURNAL ARTICLE
AU  - S. E. Spayd
AU  - R. L. Wample
AU  - R. G. Stevens
AU  - R. G. Evans
AU  - A. K. Kawakami
TI  - Nitrogen Fertilization of White Riesling in Washington: Effects on Petiole Nutrient Concentration, Yield, Yield Components, and Vegetative Growth
AID  - 10.5344/ajev.1993.44.4.378
DP  - 1993 Jan 01
TA  - American Journal of Enology and Viticulture
PG  - 378--386
VI  - 44
IP  - 4
4099  - http://www.ajevonline.org/content/44/4/378.short
4100  - http://www.ajevonline.org/content/44/4/378.full
SO  - Am J Enol Vitic.1993 Jan 01; 44
AB  - Nitrogen fertilizer was applied through the drip irrigation system to White Riesling (Vitis vinifera L.) grapevines at rates of either 0, 56, 112 or 224 kg N/ha per year for three years. Pruning weight increased up to 112 kg N/ ha and shoot weight tended to increase with increasing rate of N fertilization. The first year, fruit yield increased when N fertilizer was applied, but did not differ between 56 and 224 kg N/ha fertilized vines. Vines were pruned to equal node numbers the preceding winter. Vines were balance pruned the last two years. Fruit yield peaked at 56 kg N/ha in 1987 and 112 kg N/ha in 1988. When data were pooled over the three years, yield tended to increase with increasing bloomtime petiole NO3-N concentration to about 1500 mg/kg. Above 1500 mg/kg, yield was not correlated with bloomtime petiole NO3-N concentration. Based on yield and pruning weight, application of no more than 56 kg N/ha is recommended to White Riesling grapevines growing in soils low in N and under well-managed trickle irrigation.