|
|
 |
Efficacy of Acaricides on Citrus Rust Mite, 2001
Printer Friendly Version
(acaricide.pdf 10kb Requires Acrobat Reader)
P. A. Stansly, and J. Conner
University of Florida/IFAS
Southwest Florida Res. and Ed. Center
2686 State Road 29 North
Immokalee, Florida 34142-9515
Phone: (239) 658-3427
Fax: (239) 658-3470
Email: pas@ifas.ufl.edu
ORANGE: Citrus sinensis (L.) Osbeck ‘Pineapple’
Citrus rust mite (CRM): Phyllocoptruta oleivora (Ashmead)
Citrus rust mite continues to be the major arthropod pest of citrus in Florida, both in terms of economic damage to fresh fruit and control costs. The objective of this trial was to compare the efficacy and persistence of abamectin-like compounds to the industry standard, Agri-Mek against CRM populations. The trial was conducted at the Duda Grove in Henry county, Florida, on 28-year old ‘Pineapple' orange trees planted at 17.5 X 21.4 ft. spacing. A RCB design was used to assign 4 replications of 5 treatments including an untreated check to 10- tree plots, separated by a 10 tree buffers in 2 rows. A mean of 2.44 CRM per standard 10x lens field pre-count was observed in a pre-treatment count on 26 Jul of 4 trees per plot with no significant differences
among plots. Treatments were applied on 27 Jul using a Durand Wayland 3P100-32 air blast speed sprayer with an array of seven # 3 T-Jet stainless steel cone nozzles per side, at a pressure of 400 psi delivering 100 gpa. All treatments were tank mixed with 1 % v/v FC 435-66 horticultural mineral oil. All plots were sprayed with 3 lb Kocide 2000 and 5 gal/A oil 28 Aug, 25 DAT for disease control. Treatments were evaluated for CRM incidence 9 times over a 127 day period starting 3 Aug. Four fruit, 2 per side, were sampled from 8 trees for a total of 32 fruit per plot. All mobile CRM were counted in two, 1.5-cm diameter fields using a 10x Bauch and Lomb® Triplex lens on each partially shaded side of each fruit.
CRM pressure in untreated trees was moderate initially but began to rise in September to a peak of 15.2 per lens field on 17 October, 105 days after treatment (DAT) and were still over 10 per lens field when the trial was terminated on 8 Dec at 128 DAT. Over the first 8 of 9 evaluations, significantly fewer CRM were seen from all treated fruit compared to the control with no differences among treatments. Only on the last date were there not significantly fewer CRM from trees treated with one product (GX644007). Thus, these products provided significant levels of control of CRM for 128 days, through half the summer rainy season and most of the fall.
| Mean number of CRM per lens field on 2 sides of 4 orange fruit. |
|
Treatment/ Rate formulation oz/acre |
CRM per 1.5 cm diameter lens field |
|
7 DATa |
12 DAT |
26 DAT |
43 DAT |
57 DAT |
71 DAT |
85 DAT |
105 DAT |
128 DAT |
|
GX644004a |
10.0 |
0.44b |
0.39b |
0.44b |
0.45b |
0.97b |
0.78b |
3.25b |
4.97b |
3.91b |
|
GX644005 |
10.0 |
0.38b |
0.64b |
0.24b |
0.65b |
0.58b |
1.22b |
1.25b |
4.86b |
3.70b |
|
GX644007 |
10.0 |
0.24b |
0.53b |
0.60b |
0.35b |
1.09b |
0.70b |
2.36b |
7.13b |
6.52ab |
|
Agri-Mek |
10.0 |
0.37b |
0.35b |
0.43b |
0.35b |
0.61b |
3.02b |
2.88b |
6.36b |
4.38b |
|
Untreated |
|
3.23a |
2.16a |
2.59a |
1.85a |
2.77a |
7.44a |
13.17a |
15.23a |
10.86a |
|
Means in columns followed by the same letter(s) are not significantly different (LSD, P < 0.05)
a Days after treatment
|
Back |
