H urII ILL S JULY 1980 JULY 1981

r A. R. Chase and L. S. Osborne
IFAS, University of Florida
,r Agr cultural Research Center Apopka
.F.A.S.-UniV. of FioL RC-A Research Report RH-81-14


The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was

amended by the Pesticide Law of 1978. This new law allows a wider use of

registered pesticides providing the plant or site is on the label. These

changes are reviewed in Foliage Digest II(2):3-5, 1979. The pesticide

registration program at ARC-Apopka is continuing to develop needed data in

support of registrations and label expansions with special interest toward

24-C or special local need registrations allowing Florida use specifically.

If these needed chemicals become unavailable, quality production of orna-

S mental foliage will suffer with reductions in plant quality and yield. ARC-

Apopka is committed to helping the foliage industry obtain and maintain these

registrations; this report concerns pesticide evaluations carried out from

July 1980 to July 1981. Much of the data appearing in this report was de-

veloped through efforts supported by Florida's Tropical Foliage Plant

Industry.

Fungicide Evaluation

Introduction

The fungicide evaluations conducted during 1980-81 concentrated on

obtaining data to expand labels of presently-employed compounds, and

establishing labels on new compounds with promise for future use in the

tropical foliage plant industry. This work has been concerned with both

phytotoxicity and efficacy. Compounds, whether old or new, were selected
for test only if sufficient evidence indicated they could fulfill a need






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Lnar presently is nut uemny ict..

I. Studies with Established Compounds

A. Banrot 40 WP

1. Objective Expand the label to include more plants and areas

of use, such as interior plantscape.

2. Need The need to expand the label for this widely used compound

was clear since it only included a limited number of foliage plant

susceptible to root rots. The interior testing was performed to

supply information on an effective compound in that environment

since none are currently labeled.

3. Results -

a. Phytotoxicity testing of the following plants atlx, 2x, and 4x

rates(1x=labeled rate) were found to be safe, when applied there

times at 60 day intervals: Araucaria heterophylla; Brassaia

actinophylla; Ficus benjamin; Fittonia spp.; Hedera helix;

Maranta leuconeura; and Nephrolepis exaltata. Chrysalidocarpus

lutescens was treated also but the occurrence of tipburn on

many plants indicated that use of Banrot 40 WP may be unsafe.

b. Phytotoxicity testing under an interior environment was per-

formed on several plants at the rates listed above. Chamaedore

elegans, Ficus benjamin, Sansevieria trifasciata and

Spathiphyllum 'Mauna Loa' were each safely treated with the

Banrot 40 WP formulation with no visible symptoms of phytotoxic

c. Efficacy testing for control of soilborne pathogens in the

interior environment employed the following host-pathogen

combinations: Aglaonema simplex Pythium sp.; Brassaia

actinophylla Rhizoctonia sp.; Epipremnum aureum Pythium sp.










and Philodendron scandens oxycardium Rhizoctonia sp. Banrot

40 WP was applied at 1/2x, Ix, and 2x rates and was successful

in controlling root rots when used at the x and 2x rates, and

reduced root rot at the 1/2x rate.

. Disposition of the Study This study has been completed and has

resulted in addition of many foliage plant species to the label.

ovral 50 WP

. Objective Determine whether or not Rovral 50 WP will control

Fusarium leafspot of dracaenas and pleomeles.

. Need Fusarium leafspot is a widespread problem for many dracaena

growers and although there are compounds currently labeled for this

use, identification of a more efficaceous compound is desirable.

. Results Plants were artificially inoculated with the pathogen

(Fusarium moniliforme) and then treated on ten day intervals with

Rovral at 1/2 lb or 1 lb (ai)/100 gal or benomyl at 1/2 lb (ai)/

100 gal. The following plant species were included: Cordyline

terminalis; Dracaena deremensis; D. marginata; D. reflexa (Pleomele

reflexa); and Sansevieria trifasciata. In all cases the benomyl






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granular formulation of this compound to try and eliminate some

the residue left on treated plants.

2. Need Reduction in residues left from pesticide applications w

greatly diminish the cost of labor in removing residue from plan

3. Results Three formulations of Daconil were evaluated for phyto

toxicity, residue and efficacy on Dracaena marginata artificial,

infected with Fusarium moniliforme. The treatments included the

4.17 F, the 75 WP, and the 90 WDG formulations each used at the

1x(labeled rate), and 4x rate. Fusarium leafspot was controlled

equally by each of the formulations at the lx rate and no symptom

of phytotoxicity resulted. However, the residue rating was high

for the 90 WDG formulation than for the 4.17 F. The 75 WP form-

ulation gave an intermediate degree of residue on treated plants

4. Disposition of the Study Since this formulation did not succee

in reducing the amount of residue on treated plants it was not

pursued by the chemical company.

Insecticide, Miticide, and Nematicide Evaluations

Introduction

The pesticide tests carried out during this 1980-81 period concen-

trated on obtaining data for label expansion of presently employed chemicals

as well as to establish labels on new chemicals. The major portion of these

evaluations were in the area of phytotoxicity but with efficacy testing

against major pests for which control data was lacking.

Chemicals were selected for evaluations only if judged by this labora-

tory to fulfill a need that is presently not being met and also, only if the

chemical producer is serious in efforts for registration in the ornamental






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tropical foliage plant industry.

I. Studies with Established Compounds

A. Bendiocarb 76 WP

1. Objective Label expansion to include additional foliage species.

2. Need Phytotoxicity evaluations to determine plant safety of

foliar sprays.

3. Results No damage was noted on Brassaia actinophylla, Chamaedorea

elegans, Dieffenbachia maculata, Dracaena marginata, and Nephrolepis

exaltata when applied at Ix (5.97 g/gal), 2x (11.94 g/gal), and

4x (23.87 g/gal).

When this material was applied at weekly intervals some plants were

covered with a white chemical residue. At the Ix and 2x rates

however, all of the plants were determined to be salable. At the

4x rate some of the Brassaia actinophylla were judged unsalable

because of the residue.

4. Disposition of Study Data have been supplied to IR-4 project for

minor use pesticide registrations and they will be forwarded to

the manufacturer.

II. Studies to Establish Chemical Controls against Diaprepes abbreviatus,

the Sugarcane Rootstalk Borer Weevil

A. Preventative Applications

1. Objective To determine if chemical drenches at 3-month intervals

and soil incorporation of granular insecticides would prevent soil

and root infestation by Diaprepes abbreviatus larvae.

2. Need An alternative chemical to heptachlor is needed by October

1981 at which time the EPA permit to use this material will be

cancelled. In order to meet the current USDA certification









requirements a material is needed which will be 100% effective I

at preventing infestation by this insect with one application

for a 2 year period.

3. Results

a. Drench treatments Two drench applications 3 months apart

were made at two rates each with Bendiocarb 76WP (0.127#

ai/acre and 0.253# ai/acre) and Acephate 75S (0.125# ai/acre

and 0.25# ai/acre). No larvae were found in any of the treat-

ments when they were evaluated after the 2nd treatment.

b. Granular treatments Plants were potted in soil which had

insecticide incorporated into it. Two rates (5# ai/acre and

10# ai/acre) were used for both materials we evaluated. The

first material was a 5% granular formulation of Bendiocarb and

the second was a 5% granular Acephate formulation. After 1,

2 and 3 months post-incorporation, weevil larvae were intro-

duced into the pots to test the efficacy of the residual. The
high rate of Bendiocarb (10# ai/acre)was the only treatment

which was 100% effective at preventing infestation of the

pots for 3 months.