Title: Control of pecan scab with duter and benlate
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00076502/00001
 Material Information
Title: Control of pecan scab with duter and benlate
Physical Description: Book
Creator: French, William J.
Publisher: Agricultural Research Center, Agricultural Experiment Station, IFAS, University of Florida
 Record Information
Bibliographic ID: UF00076502
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 144846563

Full Text
/ ,o HUME LIBRARY

1- APR 7 1971

AGRICULTURAL RESEARCH CENTER, MONTICELLO
Monticello, Florida I.F.A.S. Univ. of Florida
Mimeo Report 71-5 6 fR February 8, 1971

CONTROL OF PECAN SCAB WITH DUTER AND BENLATE:
A RATE AND SCHEDULE EVALUATION

William J. French1
An effective scab control program can be one of the most expensive items
in the pecan growers operation. Under the present control recommendations
scab susceptible varieties require from 7-9 applications of fungicide and in-
secticide per season, not to mention occasional unscheduled applications of
insecticides in emergency situations. Obviously, any program which would re-
duce the number of applications required without sacrificing nut quality or
yield would reduce the cost of production. This study was designed to evaluate
the effect of fungicide rates and frequency of applications on scab control
based on scab index, and nut quality as based on % kernel weight.

MATERIALS
The efficacy of Duter 46.5W and Benlate 50 for scab control was compared
at .08 lb. and 0.16 lb. per tree in the standard 3 week schedule and in 4 and
5 week schedules. Sprays were applied to 35 year-old Mahan pecan trees with an
airblast sprayer circling each tree. Approximately 12 gallons were applied
per tree. Treatments were applied to single tree plots replicated 6 times.
All treatments started with the prepollination application April 8. Scab
ratings were made in September and kernel percent at harvest. Rainfall from
April 1 to September 30 was 31.14 inches, and scab pressure was high.

RESULTS
The results of the 1970 rate-schedule evaluations are presented in Table
1. The low rate of Benlate applied at 4-week intervals gave good control and
was comparable to high and low rates of Duter applied at 3-week intervals and
superior to all other 4- and 5-week treatments. Nuts from the high rate 5-week
treatments had higher scab indices than the standard but kernel weights were
not significantly reduced. Nut yields varied greatly within treatments due to
limb breakage which occurred throughout the growing season.



Asst. Ptait Pathologist












Results of 1970 Fungicide Rate-Schedule Evaluation.


lb. per tree
Rate


0.16
0.16
0.08
0.08
0.08

0.16
0.08

0.16
0.16

0.08

0.08


Schedule


Treatment


Benlate2
Duter
Duter
Benlate
Benlate

Duter
Duter

Benlate
Duter

Duter

Benlate


Mean Sb
index


1.969
1,980
2.054
2.083
2.093

2.175
2.305

2.472
2.498

2.638

3.008


4.314


% Nuts in
Class 1 & 2


94
95
96
93
92

86
83

69
69

59

42

0


1Scab index % of shuck area scabbed 1 scab free, 2 = 1 25%, 3 = 26 50%,
4 = 51 75%, 5 = 76-- 100%.

2Benlate is not registered by the U.S.D.A. for use on pecan and cannot be
recommended at this time.


We wish to acknowledge the Monticello Nursery Company, DuPont Chemical Corp-
oration, and the Thompson-Hayward Chemical Company for their cooperation in
this study.


I --~c- r


200 cc 2/8/71


4 wk.
4 wk.

5 wk.
5 wk.

5 wk.

5 wk.


% Kernel
weight


49
50
50
50
49

47
48


check


Table 1.




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs