FLOODING, DEEP PLOUGHING & SOLARISATION

AS A

TECHNIQUE TO MANAGE THE PEST

BY : JAYANT YADAV, CCSHAU, HISAR, HARYANA

FLOODING

It is also the ancient method of using pest of field crops.

The process of keeping the land submerged in water which decrease

the oxygen content of soil and kills the pest by asphyxiation is called

flooding.

Flooding can be used in crop protection since it reduces number as

well as number of pest and nematode in the soil.

Flooding in field

Pest management using flooding

Insect Pest

Flooding of potato fields for 7-10 days , reduce the population of white grub.

Alternate wetting and drying at 10 days interval starting from 35 days after

transplanting drastically reduced brown plant hopper and white backed plant

hopper incidence in continuous standing water.

Flooding of fields also kills root grubs ,termites and soil born plant pathogen.

Flooding followed by tillage, is more effective for suppressing stem borer

population.

Flooding at the time of pupation reduces the survival of H. armigera.

Flooding has strong effect on most soil pest including white grub, mole

cricket, termites and ants.

The cotton bollworm can be shaken off by dragging a rope over the plants and

throwing them into standing water, where it gets killed.

Cont……..

Continuous flooding also reduces the incidence of gall

midge .

Flooding is also effective if used in combination with

crop rotation.

Flooding also eliminates the sclerotia of Sclerotinia

sclerotiorum.

Cont……..

Deep Ploughing

Deep ploughing is defined as the ploughing of field across the slop during hot summer

with the help of specialized tools with primary objective of opening of soil crust and

simultaneously overturning of soil underneath to disinfect it with the help of sun rays.

Ploughing or hoeing helps to expose stages of soil inhabiting pest to such sun heat or to

predatory bird.

Two or three deep ploughings with soil turning device, in hot summer months expose

the pest in soil and infected tissue to solar heat and dehydration.

Efficacy of ploughing can be increased by polythene mulching to trap and retain more

heat than exposed soil.

Deep Ploughing

Insect Control - Deep Ploughing

Deep ploughing has been recommended as a strategy to kill

insect pest that live in top 20 cm of soil.

Deep ploughing immediately after harvest of wheat crop in

April –May is helpful in exposing the resting grubs of rice

root weevil to their natural enemies like birds and to action of

sun.

Raking up and hoeing of soil around melon plant, mango and

other fruit trees serve to destroy pupae of fruit flies.

Light earthing at early stage of sugarcane crop during May-June is

helpful in checking the shoot borer.

Fall ploughing is often helpful in reducing the overwintering

population of H.armigera.

It is also helpful in minimizing the infestation of armyworm in

cereal crops, white grubs attacking groundnut and chilli, pupae of

hairy caterpillar attacking groundnut and green gram.

Other Benefits of Deep Ploughing

Deep ploughing improve soil structure due to alternate

drying and wetting.

A lot of harmful bacteria spores and fungal microbes die

due to exposition to heat of summer.

Deep ploughing and overturning uproot the weeds .So the

competition between crop and weed also reduced for same

nutrient and productivity increased.

Soil Solarisation

Soil solarisation is an environmentally friendly method of using solar

power for controlling pest such as soil born plant pathogen including

fungi bacteria nematode and insect along with weed seeds and

seedling in soil by mulching the soil and covering it with trap usually

with transparent polythene cover, to trap soil energy .

Soil solarisation is a simple, safe, and effective alternative to the

toxic, costly soil pesticides and the lengthy crop rotations now needed

to control many damaging soil pests.

Involves covering the soil with transparent plastic

sheeting during an appropriate summer fallow period.

It captures solar energy and raises the temperatures in

the soil to levels lethal to many soill borne pests.

It’s a pre-plant method for disinfecting soil for control

of soil borne insect, pathogen and weeds.

The major commercial use of solarization has been in

regions with high solar radiation and high temperatures

Soil Solarisation

Procedure of soil solarisation

The soil to be solarised must be worked up to seed-bed condition—that

is, cultivated until it's loose and friable with no large clods or other

debris on the soil surface..

Make sure moisture levels are adequate for working the soil before

laying the plastic tarp.

If the soil is dry, water the areas to be solarized before laying the tarp,

because most soil pests are more sensitive to high temperatures in wet

soil than in dry soil.

There are four factors that need to be remembered while

applying soil solarization

1. Transparent, not black, polyethylene plastic should be used, as

this transmits most of the solar radiation.

2. Solarisation should be carried out during periods of high

temperature and intense solar radiation.

3. The thinnest plastic possible should be used, as it is both

cheaper and somewhat more effective in heating.

4. The plastic sheeting should be kept in place for as long as

possible

Use a clear, UV-stabilized plastic (polyethylene or polyvinyl chloride)

trap or sheeting 0.5 to 4 mils thick.

The edges of the sheets must be buried to a depth of 5 or 6 inches in the

soil to prevent blowing or tearing of the tarp by the wind.

White or black plastic usually does not transmit enough solar radiation

to raise soil temperatures to lethal levels for many soil pests.

Temperature inside the plastic covering rise to 130C higher than outside

temperature which is very lethal to insect-pest and weeds.

Cont……..

Long, hot and sunny days are needed to reach the soil

temperatures required to kill soil borne pests and weed seed.

The longer the soil is heated, the better and deeper the control of

all soil pests and weeds will be.

For effective soil solarisation, a 6 to 8 week traping period may be

needed to ensure good pest control.

However depending upon the geographic location, solarisation

may also be effective in May, August and September.

Cont……..

Pest and disease control using soil solarization

Soil solarisation is one of the effective way of suppressing the

larvae of white grub, cutworm, hairycaterpillar as they gets killed

inside the soil due to high temperature.

Soil solarisation helps in reducing root knot disease by

suppressing the nematode population by 66% in nursery with in

15days.

Other benefits:

Plants grown in solarised potting mix soon after

treatment have often benefited from improved seed

germination, better stand establishment, improved

plant height, early crop maturity and increased yield

(both fresh and dry weights).

Cont……..