Applying roundup to the base of lemon tree canopies: effects on leaves, flowers, fruitlets, and yield

Persistent Link:
http://hdl.handle.net/10150/222513
Title:
Applying roundup to the base of lemon tree canopies: effects on leaves, flowers, fruitlets, and yield
Author:
McCloskey, William B.; Wright, Glenn C.
Affiliation:
Department of Plant Sciences, University of Arizona, Tucson, Arizona; Dept. Plant Sciences, U. of A., Yuma Mesa Agricultural Center, Yuma, Arizona
Issue Date:
Nov-1999
Publisher:
College of Agriculture, University of Arizona (Tucson, AZ)
Journal:
Citrus and Deciduous Fruit and Nut Research Report
Abstract:
The effect of Roundup on lemon trees (Citrus limon) was evaluated by repeatedly spraying 0.5, 0.75, 1, 1.25, and 1.5 lb. a.i./acre (corresponding to 0.5, 0.75, 1, 1.25, 1.5 quarts of Roundup Ultra/acre) on the bottom 20 to 24 inches of the tree canopies, over a three year period. The Roundup applications caused significant leaf injury in the sprayed area of the canopies and there was also significant defoliation of branches at the higher Roundup rates in all three years of the study. In 1996 after three Roundup applications, increasing rates of Roundup had no effect on flower or fruitlet production in either the sprayed or unsprayed portions of the tree canopies as judged by the counts collected from branches in each canopy zone. Similarly, in 1997 after five Roundup applications, and in 1998 after nine Roundup applications, increasing rates of Roundup had no effect on flower or fruitlet production in the sprayed or unsprayed portions of the tree canopies. Spraying Roundup on the bottom of the tree canopies did not reduce total lemon yield per tree in 1996, 1997 or 1998 at any of the application rates. In all three years of the study, increasing Roundup rates had no effect on the yield of the first or second ring picks or the percentage of the total crop picked on the first harvest date. Increasing Roundup rates also did not affect fruit size at any harvest date in 1996, 1997 or 1998. Similarly, increasing Roundup application rates did not affect fruit quality at any harvest in 1996, 1997 or 1998. Thus, there was no relationship between the rate of Roundup sprayed on the trees and yield, fruit size or quality in all three years of this study. The three years of data collected in this study indicate that accidental drift or inadvertent application of Roundup onto lemon trees when spraying weeds on the orchard floor has no significant effect on lemon tree productivity.
Keywords:
Agriculture -- Arizona; Citrus fruits -- Arizona; Lemon -- Arizona; Lemon -- Weed control
Series/Report no.:
AZ1138; Series P-117
Sponsors:
Arizona Citrus Research Council

Full metadata record

DC FieldValue Language
dc.titleApplying roundup to the base of lemon tree canopies: effects on leaves, flowers, fruitlets, and yielden_US
dc.contributor.authorMcCloskey, William B.en_US
dc.contributor.authorWright, Glenn C.en_US
dc.contributor.departmentDepartment of Plant Sciences, University of Arizona, Tucson, Arizonaen_US
dc.contributor.departmentDept. Plant Sciences, U. of A., Yuma Mesa Agricultural Center, Yuma, Arizonaen_US
dc.date.issued1999-11-
dc.publisherCollege of Agriculture, University of Arizona (Tucson, AZ)en_US
dc.identifier.journalCitrus and Deciduous Fruit and Nut Research Reporten_US
dc.description.abstractThe effect of Roundup on lemon trees (Citrus limon) was evaluated by repeatedly spraying 0.5, 0.75, 1, 1.25, and 1.5 lb. a.i./acre (corresponding to 0.5, 0.75, 1, 1.25, 1.5 quarts of Roundup Ultra/acre) on the bottom 20 to 24 inches of the tree canopies, over a three year period. The Roundup applications caused significant leaf injury in the sprayed area of the canopies and there was also significant defoliation of branches at the higher Roundup rates in all three years of the study. In 1996 after three Roundup applications, increasing rates of Roundup had no effect on flower or fruitlet production in either the sprayed or unsprayed portions of the tree canopies as judged by the counts collected from branches in each canopy zone. Similarly, in 1997 after five Roundup applications, and in 1998 after nine Roundup applications, increasing rates of Roundup had no effect on flower or fruitlet production in the sprayed or unsprayed portions of the tree canopies. Spraying Roundup on the bottom of the tree canopies did not reduce total lemon yield per tree in 1996, 1997 or 1998 at any of the application rates. In all three years of the study, increasing Roundup rates had no effect on the yield of the first or second ring picks or the percentage of the total crop picked on the first harvest date. Increasing Roundup rates also did not affect fruit size at any harvest date in 1996, 1997 or 1998. Similarly, increasing Roundup application rates did not affect fruit quality at any harvest in 1996, 1997 or 1998. Thus, there was no relationship between the rate of Roundup sprayed on the trees and yield, fruit size or quality in all three years of this study. The three years of data collected in this study indicate that accidental drift or inadvertent application of Roundup onto lemon trees when spraying weeds on the orchard floor has no significant effect on lemon tree productivity.en_US
dc.subjectAgriculture -- Arizonaen_US
dc.subjectCitrus fruits -- Arizonaen_US
dc.subjectLemon -- Arizonaen_US
dc.subjectLemon -- Weed controlen_US
dc.identifier.urihttp://hdl.handle.net/10150/222513-
dc.relation.ispartofseriesAZ1138en_US
dc.relation.ispartofseriesSeries P-117en_US
dc.description.sponsorshipArizona Citrus Research Councilen_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.