Use of the SPAD-502 in Estimating Nitrogen Content in Leaves and Grape Yield in Grapevines in Soils with Different Texture

Gustavo Brunetto,Eduardo Girotto,George Wellington De Melo,Alcione Miotto,Carlos Alberto Ceretta,Felipe Lorensini,Glaucia Regina Zaferi Moser,Gustavo Trentin

doi:10.4236/ajps.2012.311187

Abstract

The SPAD reading may be used in estimating total nitrogen content (N) in leaves and even in estimating grape yield in grapevines. The objective of this study was to estimate total N content in leaves and grape yield using the SPAD-502 in grapevines submitted to nitrogen fertilization in soils with clayey and sandy texture. In 2008, two experiments were installed in the Southern region of Brazil. In experiment 1, Cabernet Sauvignon grapevines were planted in a soil with clayey texture and with application of 10, 20, 40 and 80 kg·N·ha-1·year-1. In experiment 2, Cabernet Sauvignon grapevines were planted in a soil with sandy texture and with the application of 0, 10, 15, 20, 40, 80 and 120 kg·N·ha-1·year-1. In the grapevines of the two experiments and during the period from 2008 to 2010, SPAD readings were made on leaves throughout the flowering period and at change in color of the berries using the portable chlorophyll meter Minolta-SPAD-502. The leaves were collected, dried, ground and submitted to analysis of the total N content. In addition, grape yield per hectare was evaluated. The SPAD-502 readings estimated the total N content in flowering and at change in color of the berries in the Cabernet Sauvignon grapevines grown on soils with clayey texture and sandy texture, especially in the first year of evaluation. However, the precision of the SPAD-502 readings is low, with there being no relationship between the SPAD-502 readings and grape yield.

Highlights

Grapevines grown on soils with sandy texture and with low organic matter content are normally submitted to the application of nitrogen (N) due to supposed low capacity of the soil to supply this nutrient
The application of increasing doses of N (0, 10, 20, 40 and 80 kg·N·ha−1) in the form of urea in year 1 (20082009) and in year 2 (2009-2010) did not affect grape yield in the Cabernet Sauvignon grapevines grown in soil with a clayey texture and with 27.0 g·kg−1 of organic matter (Figure 1)
The N applied in year 1 did not affect the SPAD readings performed using the portable chlorophyll meter Minolta-SPAD-502 in the leaves collected at flowering of the grapevines (Figure 3(a)), but increased in a linear manner when they were performed on the leaves during change in color of the berries (Figure 3(b)), with the mathematical adjustment being expressed by the equation SPAD Reading = 37.32 + 0.023 dose N (R2 = 0.98, P < 0.05)

Summary

Introduction

Grapevines grown on soils with sandy texture and with low organic matter content are normally submitted to the application of nitrogen (N) due to supposed low capacity of the soil to supply this nutrient. Tissue analysis is a destructive method, which involves collection of the organ, such as leaves, washing, drying, preparation and laboratory analyses. These analytical procedures are not very quick and the results generated most of the time are interpreted and used for definition of the need and the dose of the nutrient only in the following year. In recent years in some fruit-bearing species like apple trees [6], peach trees [7], pear trees [8,9] and the grapevine [10,11,12], the total N content in the leaves has been estimated through the use of non-destructive methods like those that use portable equipment, among them the SPAD-502 (Soil Plant Analysis Division Value). The SPAD has a flexible shaft and another rigid shaft and the leaves are held in between these two shafts through the pressure of the flexible shaft

Objectives

Methods

Results