บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Effect of nitrogen fertilizer timing and rate on inorganic nitrogen status, fruit composition, and yield of grapevines.

Christensen, L. P.; Bianchi, M. L.; Peacock, W. L.; Hirschfelt, D. J.;

American Journal of Enology and Viticulture Year: 1994 Vol: 45 Issue: 4 Pages: 377-387 Ref: 27 ref.

1994

บทคัดย่อ

Effect of nitrogen fertilizer timing and rate on inorganic nitrogen status, fruit composition, and yield of grapevines.

ABSTRACT :

 

A 4-year (1987-90) trial was conducted to study the effects of timing and rate of N fertilizer application on furrow-irrigated Barbera, Grenache, French Colombard and Chenin Blanc grapevines. There were 6 treatments: 56 kg N/ha applied at budbreak (BB), fruit set (FS), veraison (V) or postharvest (PH), 112 kg N/ha applied at BB and the control. Petiole NO3--N, NH4+-N and total inorganic N (TN) contents were determined at flowering and veraison. Yield and fruit composition parameters were also recorded. Cultivar responses varied widely; Grenache and Barbera were the high and low extremes, respectively, in terms of TN status and responsiveness to N treatment; French Colombard and Chenin Blanc were intermediate. Generally, TN status increased with increasing N application rate. The more recent N applications often resulted in a higher TN status at the next petiole sampling. Postharvest application was particularly effective in increasing petiole TN in the spring. Petiole NO3-N contents were more se

nsitive than NH4+-N contents to fertilizer treatment. The greater contribution of NO3--N than NH4+-N to TN suggested that the usefulness of the latter as an additional measurement of N status is limited. Fruit TSS content was the most responsive fruit parameter to N treatment. Generally, N fertilizer decreased TSS compared with controls, irrespective of application date, and with the highest rate (112 kg N/ha) resulting in the largest decrease. Fruit yields were only affected in Grenache, in which all N treatments except treatment V increased yields compared with controls. This result, plus other negative effects of treatment V, suggest that veraison is the least desirable N fertilizer application date. Otherwise, application date effects on fruit parameters were minor.