Timing of fungicide applications to manage …...Department of Employment, Economic Development and...

Department of Employment, Economic Development and Innovation

Timing of fungicide applications to manage postharvest diseases of mango

Chrys Akem, Gerry MacManus and Paula Boccalatte

2© The State of Queensland, Department of Employment, Economic Development and Innovation, 2011

Current Industry Problem

Shelf-life in mangoes is limited mainlyby two postharvest diseases:

Anthracnose and Stem-end rots


The major disease - Anthracnose


Another Major - Stem End Rots


Control of these diseases is largely based on the use of synthetic fungicides

The routine process

Air blast tower sprayer Fruit exiting tank via rollers onto prochloraz spray


Field - Spray Options

Mancozeb

Copper

Octave

Amistar Aero

Shed - Postharvest options

Sportak (prochloraz)

Spinflo (carbendazin) – Out

Hot Dips – Scholar


Current Concerns with Pesticide use

Overuse – Routine calendar sprays

Increasing costs of new ones - Amistar

Environmental concerns - Cu

Resistance development - Systemics

Export market restrictions

- Dictation of what to use

- MRLs limitation

- Need to use them more sustainably


Study Objectives Compare the efficacy of the 2 “systemic fungicides”

- AmistarR - Azoxystrobin

- AeroR – Metiram & Pyraclostrobin

Determine the best time of single and multiple spray applications on:

- Postharvest disease incidence & severity

. Anthracnose

. Stem end rots

Make recommendations based on findings


Treatments(Spray Timing)

Fruit-Set(E=Early)

Fruit Development(M=Mid)

Near Harvest(L=Late)

Single Sprays1. Amistar (E*) Amistar

2. Aero (E) Aero

3. Amistar (L*) Amistar

4. Aero (L) Aero

Double Sprays5. Amistar (E, L) Amistar Amistar

6. Aero (E, L) Aero Aero

Triple Sprays7. Amistar (E, M*, L) Amistar Amistar Amistar

8. Aero (E, M, L) Aero Aero Aero

Combination Sprays9. Amistar (E) + Aero (L) Amistar Aero

10. Aero (E) + Amistar (L) Aero Amistar

11. UTC (Untreated Control) Water Water Water

Treatments


Process- Trial carried out at Ayr Research Station on a KP block

- Four treatment trees for each treatment

- At end of the season harvested 30 random fruits from

each tree replication

- Selected 25 more uniform fruits from each tree harvest

- Washed with mango wash

- Incubated in cool room at 20-22C

- Assessed for disease development at

- 14 DAI and

- 19 DAI

11© The State of Queensland, Department of Employment, Economic Development and Innovation, 2011 Am(E)& Ae(L) Ae(E)& Am(L)

Ae(L)Ae(E)Am(E) Am(L)

UTC

Am(E,L) Am(E,M,L) Ae(E,M,L)Ae(E,L)


Disease incidence on fruits 14 DAI

Treatment SER Anthracnose Dendritic spot Total RotsSingle Sprays1. Amistar (E) 9 a 23 ab 1 a 26 ab2. Aero (E) 13 ab 24 ab 2 a 28 ab3. Amistar (L) 27 bc 37 b 3 ab 55 c4. Aero (L) 34 c 40 b 8 c 60 cDouble Sprays5. Amistar (E, L) 7 a 9 a 0 a 14 ab6. Aero (E, L) 18 abc 23 ab 1 a 33 bTriple Sprays7. Amistar (E, M, L) 4 a 5 a 0 a 8 a8. Aero (E, M, L) 6 a 5 a 0 a 9 aCombination Sprays9. Amistar (E) + Aero (L) 5 a 5 a 0 a 8 a10. Aero (E) + Amistar (L) 4 a 7 a 0 a 9 a11. UTC 43 c 86 c 7 bc 86 dFpr 0.001 <0.001 0.014 <0.001LSD (P=0.05) 16.68 19.22 4.997 21.79


Disease incidence on fruits 19 DAITreatment SER Anthracnose Dendritic spot Total Rots

Single Sprays1. Amistar (E) 36 ab 46 cd 1 a 55 bc

2. Aero (E) 34 ab 57 de 1 a 60cd

3. Amistar (L) 69 de 77 ef 1 a 84 de

4. Aero (L) 81 e 74 e 9 a 90 e

Double Sprays5. Amistar (E, L) 19 ab 24 ab 4 a 34 ab

6. Aero (E, L) 42 bcd 42 bcd 2 a 54 bc

Triple Sprays7. Amistar (E, M, L) 10 a 12 a 1 a 18 a

8. Aero (E, M, L) 20 ab 12 a 0 a 24 a

Combination Sprays9. Amistar (E) + Aero (L) 18 ab 27 abc 1 a 30 ab

10. Aero (E) + Amistar (L) 31 abc 31 abc 1 a 41 abc

11. UTC 58 cde 97 f 5 a 98 e

Fpr <0.001 <0.001 0.077 <0.001

LSD (P=0.05) 27.78 20.62 NSD* 25.68


0

10

20

30

40

50

60

70

80

90

100

Am (E)

Ae (E)

Am (L)

Ae (L)

Am (E,L)

Ae (E,L)

Am (E,M

,L)Ae (

E,M,L)

Am (E) +

Ae (L)

Ae (E) +

Am (L)

UTC

Systemic fungicides

Dis

ease

inci

denc

e (%

)

14 DAI

19 DAI

Treatment Effects on Total Rots Incidence - 2009


0

20

40

60

80

100

Am(E) Ae(E) Am(L) Ae(L)

Systemic Fungicides

Dise

ase

Inci

denc

e (%

)

SERAnthracnoseAll Rots

2009 Disease Incidence of SER, Anthracnose and All Rots 19 DAI


2010 Evaluations


aa

bc bbcd bcde cde cde de e e

0102030405060708090

100

Am(E,M

,L)Ae(E

,M,L)

Ae(E)+Am(L)Ae(E

, L)

Am(L)Am(E

,L)

Ae(L)

Am(E)+Ae(L

)

Ae(E)

Am(E)

Contro

l

Systemic fungicidies

Dis

ease

inci

denc

e (%

)Treatment effects on total rots incidence - 14 DAI - 2010


Weather Data for 2009 & 2010

0

200

400

600

800

1000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

Rai

nfal

l (m

m)

0

5

10

15

20

25

30

35

Ave

rage

Mon

thly

Tem

p(d

egre

e C

)

09 Rainfall

10 Rainfall

09 Temp

10 Temp


Conclusions Timing is critical for field fungicide applications to

manage postharvest diseases

An early application should be considered over a late

one, if only one spray is to be made (depending on

seasonal conditions) - 2009

In a season with highly favourable conditions, follow

label recommendation of multiple sprays in a program

and rotate accordingly – 2010

Trial will be repeated in another “normal” season to

establish the 2009 trend for recommendations.


Acknowledgement with Thanks

• Tropical Pathology Team:

Chrys Akem, Gerry MacManus, Paula Boccalatte, Kerry Stockdale, Dalvinder Lakhesar and Elio Jovicich

Additional Funding support from


Thank youThank you

Date post:	20-Aug-2020
Category:	Documents
Upload:	others
View:	2 times
Download:	0 times

Timing of fungicide applications to manage …...Department of Employment, Economic Development and...

Documents