Influence of System of Rice Influence of System of Rice Intensification (SRI) on the Intensification (SRI) on the Incidence of Insect PestsIncidence of Insect Pests

T. Ratna Sudhakar and P. Narsimha T. Ratna Sudhakar and P. Narsimha ReddyReddy

Principal Scientist (Entom.) and Senior Scientist Principal Scientist (Entom.) and Senior Scientist (Br.)(Br.)

Rice Section, Agricultural Research InstituteRice Section, Agricultural Research Institute

Acharya N.G. Ranga Agricultural Acharya N.G. Ranga Agricultural University University Rajendranagar, Hyderabad-500 030.Rajendranagar, Hyderabad-500 030.

Andhra PradeshAndhra Pradesh

Southern Telangana ZoneSouthern Telangana Zone Districts: 3Districts: 3

Ranga ReddyRanga Reddy

NalgondaNalgonda

MahaboobnagarMahaboobnagar

Irrigation source:Irrigation source:

Wells, bore wells, tanks, and minor irrigation Wells, bore wells, tanks, and minor irrigation projects projects

Cropping situation:

Rice – rice; Rice-fallow; Rice-vegetables Rice – oil seeds; Rice-maizeSoils: black clay soils, red loamy soils, chelka soilsRainfall : 700 mm

Materials and MethodsMaterials and MethodsIrrigation Source: Open wellIrrigation Source: Open well Variety: RNR 23064 during Kharif 2006Variety: RNR 23064 during Kharif 2006

Tellahamsa during Rabi 2005-06Tellahamsa during Rabi 2005-06Spacing: 25 x 25 cm for SRISpacing: 25 x 25 cm for SRI

15 x 15 cm for normal method15 x 15 cm for normal methodInsect pests: Whorl maggot, hispa, Insect pests: Whorl maggot, hispa,

thrips, stem borer, and gall midge thrips, stem borer, and gall midgeReplications: 7 in Kharif and 6 in RabiReplications: 7 in Kharif and 6 in Rabi

Yield attributes: Number of healthy Yield attributes: Number of healthy grains/paniclesgrains/panicles

Number of chaffy grains/paniclesNumber of chaffy grains/panicles Grain yield (t/ha)Grain yield (t/ha)

RESULTSRESULTSOccurrence of insect pests with SRI Occurrence of insect pests with SRI

& normal methods& normal methods

StageStage Normal Normal SRISRI

Nursery Nursery ThripsThrips ThripsThrips

HispaHispa

Stem borerStem borer

Gall midgeGall midge

Whorl maggotWhorl maggot

Total:Total: 55 11Contd…

StageStage NormalNormal SRISRI

Main Main field field

Whorl maggotWhorl maggot Whorl maggotWhorl maggot

HispaHispa HispaHispa

ThripsThrips ThripsThrips

Stem borerStem borer Stem borerStem borer

Gall midgeGall midge Gall midgeGall midge

Leaf folderLeaf folder Leaf folderLeaf folder

Cut wormsCut worms Cut wormsCut worms

Rodents Rodents (veg. (veg. stage)stage)

--

Rodents Rodents (reproductive stage)(reproductive stage)

Rodents Rodents (reproduc-tive (reproduc-tive

stage)stage)

99 88

Total Total 1414 99

Incidence of early-stage insect Incidence of early-stage insect pestspests

Particulars Particulars DATDAT Normal Normal SRISRI

Whorl maggot-damaged Whorl maggot-damaged leaves (%)leaves (%)

2424 2.02.0 4.44.4

Hispa-damaged leaves (%)Hispa-damaged leaves (%) 2424 7.37.3 4.24.2

Thrips-damaged leaves (%)Thrips-damaged leaves (%) 2424 31.631.6 19.19.99

Incidence of stem borerIncidence of stem borerSeasonSeason ParticularsParticulars DADA

TTNormaNorma

l l SRISRI

Kharif – Kharif – 20062006

Dead hearts Dead hearts (%)(%)

3737 2.12.1 0.50.5

- do -- do - 5353 4.94.9 1.91.9

- do -- do - 6868 6.26.2 6.06.0

White ears (%)White ears (%) 135135 11.711.7 3.53.5

Total Total 24.924.9 11.11.99

MeanMean 6.26.2 2.92.9

Rabi 2005-Rabi 2005-0606

Dead hearts Dead hearts (%)(%)

5555 28.128.1 22.22.88

White ears (%)White ears (%) 8686 33.633.6 10.10.44

TotalTotal 61.761.7 33.33.22

MeanMean 30.830.8 16.16.66

Incidence of gall midge (%)Incidence of gall midge (%)

SeasonSeason ParticularsParticulars TimTimee

NormaNormal l

SRISRI

Kharif – Kharif – 20062006

Silver Silver shootsshoots

5353 0.30.3 0.40.4

- do -- do - - do -- do - 6868 0.50.5 1.31.3Total Total 0.80.8 1.71.7

MeanMean 0.40.4 0.80.8

Grain yield (t/ha)Grain yield (t/ha)

SeasonSeason NormalNormal SRISRI

Kharif 2006Kharif 2006 * 0.21* 0.21 4.164.16

Rabi 2005-06Rabi 2005-06 2.252.25 3.473.47

* Low yield due to cold injury

Meteorological data & sowing time Meteorological data & sowing time particulars.particulars.Particulars Particulars Normal Normal SRISRI

Date of sowingDate of sowing 11-8-200611-8-2006 11-8-200611-8-2006

Date of plantingDate of planting 11-9-200611-9-2006 25-8-200625-8-2006

Date of harvestingDate of harvesting 8-1-20078-1-2007 8-1-20078-1-2007

Meteorological dataPeriod Period Mean max. Mean max.

00CCMean min. Mean min.

00C C No. of No. of

sunshine sunshine hourshours

11stst – 15 – 15thth Nov- Nov-0606

27.727.7 19.219.2 4.94.9

1616thth– 30– 30ththNov-Nov-0606

29.629.6 17.917.9 7.57.5

11stst – 15 – 15thth Dec- Dec-0606

29.129.1 14.614.6 8.68.6

1616thth – 31 – 31stst Dec- Dec-0606

28.128.1 12.2 12.2 ++ 8.68.6+ Sudden drop in min. temp. between 16th – 21st Dec.-06 (9.2 to 9.80 C for 5 days)

ConclusionsConclusions Less number of insect pests were associated from Less number of insect pests were associated from

seed to seed with SRI than with normal methods seed to seed with SRI than with normal methods Damage of whorl maggot was high in SRI. Hispa Damage of whorl maggot was high in SRI. Hispa

and thrips incidence was less and thrips incidence was less Stem borer and gall midge incidence was more Stem borer and gall midge incidence was more

with SRI at vegetative phase while occurrence of with SRI at vegetative phase while occurrence of white ears was lowwhite ears was low

Grain yield was more in SRIGrain yield was more in SRI SRI escaped partially from cold snap and is the SRI escaped partially from cold snap and is the

best alternative for at-risk locations to escape best alternative for at-risk locations to escape cold (during November – December) under late-cold (during November – December) under late-planted conditions, e.g., August, for medium-planted conditions, e.g., August, for medium-duration varieties.duration varieties.

Future research requirements to Future research requirements to generate crop-protection technologies generate crop-protection technologies for SRIfor SRI

► Nursery protection technologies to protect Nursery protection technologies to protect crop until 25-30 days in main field from crop until 25-30 days in main field from early-stage insectsearly-stage insects

► Need-based protection against stem borer Need-based protection against stem borer and gall midge during 35-70 days after and gall midge during 35-70 days after transplanting and at reproductive phasetransplanting and at reproductive phase

► Schedule for release of Schedule for release of Trichogramma Sp.Trichogramma Sp. to to manage stem borer at vegetative phasemanage stem borer at vegetative phase

► Develop non-pesticide methods for the Develop non-pesticide methods for the management of insect pests under SRImanagement of insect pests under SRI

► Provide low-cost & safe IPM package for SRI Provide low-cost & safe IPM package for SRI

Acknowledgements Acknowledgements

►ANGRAU university officersANGRAU university officers ►Rice Section staffRice Section staff►WWF - for financial supportWWF - for financial support►Farmers – for SRI adoption/promotionFarmers – for SRI adoption/promotion

Thank youThank you