Title:	Zonal application of plant growth regulator in cotton to reduce variability and increase yield in a highly variable field.
Authors:	VAZ, C. M. P. FRANCHINI, J. C. SPERANZA, E. A. INAMASU, R. Y. JORGE, L. A. de C. RABELLO, L. M. LOPES, I. de O. N. CHAGAS, S. das SOUZA, J. L. R. de SOUZA, M. de PIRES, A. SCHEPERS, J.
Affiliation:	CARLOS MANOEL PEDRO VAZ, CNPDIA; JULIO CEZAR FRANCHINI DOS SANTOS, CNPSO; EDUARDO ANTONIO SPERANZA, CNPTIA; RICARDO YASSUSHI INAMASU, CNPDIA; LUCIO ANDRE DE CASTRO JORGE, CNPDIA; LADISLAU MARCELINO RABELLO, CNPDIA; IVANI DE OLIVEIRA NEGRAO LOPES, CNPSO; SÉRGIO DAS CHAGAS, GRUPO AMAGGI; JEFFERSON L. R. DE SOUZA, GRUPO AMAGGI; MÁRCIO DE SOUZA, INSTITUTO MATO-GROSSENSE DO ALGODÃO; AMANDIO PIRES, INSTITUTO MATO-GROSSENSE DO ALGODÃO; JAMES SCHEPERS, UNIVERSITY OF NEBRASKA.
Date Issued:	2023
Citation:	Journal of Cotton Science, v. 27, n. 2, p. 60-73, 2023.
Pages:	60-73
Description:	Variable-rate application has great potential to reduce variability and increase yield by spatially optimizing agricultural inputs. In cotton, plant growth regulators (PGRs) control excessive growth and provide suitable plant height for harvest operations. This study evaluates the effectof variable-rate PGR application compared toconstant-rate application to reduce yield spatialvariability and increase yield. The variable-rate approach was carried out in 2020 based on zonalapplications defined by clustering analysis using soil electrical conductivity, vegetation indexes,and yield maps. Application doses and timingswere determined by integrating plant heightmeasurements for the whole field in 2019 and byzone in 2020. To compare the two procedures, cultivar and plant populations were kept constant;fertilization and accumulated rain were similarin both seasons. A reduction in yield spatial variability due to the zonal application was observed,with yield coefficient of variation (CV) decreasing from 18% in 2019 to 12% in 2020. Spatial andtemporal analysis of Normalized Difference Veg-etation Index satellite images showed higher CVvalues in 2019 (constant-rate) reaching 30% at theend of the season, whereas in 2020 (variable-rate)CV was constant (approximately 10%). Cotton
Thesagro:	Algodão Agricultura
NAL Thesaurus:	Agriculture Cotton Plant growth Plant growth control Yields Variable rate application Variability Normalized difference vegetation index
Keywords:	Crescimento de planta Reguladores de crescimento de planta Variabilidade espacial Imagem de satélite Séries temporais de NDVI Plant growth regulator Spatial variability Satellite images NDVI Temporal Series
DOI:	10.56454/MIUC6583
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CNPDIA)