Title:	Spatiotemporal variability of apple tree vegetative vigor using proximal sensing.
Authors:	GEBLER, L. RUFATO, A. de R. ABREU, J. T. DE SPERANZA, E. A. SESSI, A. MARCHIORETTO, L. de R.
Affiliation:	LUCIANO GEBLER, CNPUV; ANDREA DE ROSSI, CNPUV; JARDEL TALAMINI DE ABREU, EMBRAPA UVA E VINHO; EDUARDO ANTONIO SPERANZA, CNPTIA; ALESSANDRA SESSI; LUCAS DE ROSS MARCHIORETTO.
Date Issued:	2026
Citation:	In: INTERNATIONAL CONFERENCE ON PRECISION AGRICULTURE, 17., CONGRESSO BRASILEIRO DE AGRICULTURA DE PRECISÃO DIGITAL, 11., 2026, Porto Alegre, RS. Anais...Porto Alegre: AsBraAP; AP&D, de 13 a 16 de julho de 2026.
Description:	Apple production in southern Brazil often suffers from excessive vegetative growth due to the region's subtropical climate. Currently, farmers rely on empirical, subjective monitoring to make crucial management decisions regarding pruning, thinning, and the application of growth regulators. Coupled with increasing labor shortages and costs, this empirical approach often leads to operational inefficiencies and compromised fruit quality. To address this, there is a critical need for quantitative, data-driven methods to monitor vegetative vigor and generate precise spatial maps for targeted orchard management. This study investigates the use of multispectral proximal sensors to measure the Normalized Difference Vegetation Index (NDVI) as an objective indicator of plant biomass, replacing traditional empirical assessments. Linear and non-linear regression models were used to correlate NDVI with bud growth rates in two apple orchards in Vacaria-RS across six growing seasons. The analysis incorporated various time windows (ranging from 5 to 11 days) alongside meteorological variables such as accumulated precipitation, solar radiation, and thermal sum. The results indicate that the optimal periods for data collection to accurately identify vegetative vigor variability are windows of 7 to 11 days, specifically occurring between 55 and 67 days after dormancy break. Identifying these crucial periods enables the generation of accurate temporal vigor maps and the delineation of specific management zones. Ultimately, this methodology allows producers to objectively adjust the intensity of vigor control practices according to specific zones, optimizing resource allocation, reducing labor dependency, and ensuring optimal fruit yield and quality.
Keywords:	NDVI Branch growth rate Management zones
Type of Material:	Artigo em anais e proceedings
Access:	openAccess
Appears in Collections:	Artigo em anais de congresso (CNPUV)