Light traps to capture caterpillar moths in coconut

Among different caterpillars that feed on coconut leaves, the slug
caterpillar can cause sporadic outbreak under favourable conditions
especially in summer months. Grown up caterpillars eat the entire
laminar portion of the leaf leaving the mid ribs.
Some times, balls of excreta will be seen as a layer on the ground
around the coconut palm basin.
In severe outbreak, the pest invades nuts and even leaf stalks. Drying
of entire foliage, drooping of leaves and bunches, falling of buttons
and nuts are ultimate symptoms of pest attack.

Damage to intercrops
The pest was observed causing damage even to intercrops such as banana/
cocoa and surrounding hedge plants like agave after drying of coconut
crop. In such cases, falling of buttons and nuts, drying of total
foliage leads to severe yield loses and spathe emergence will be
delayed till the palm recovers.
The total life cycle of the pest is completed in about two months.
Caterpillar is yellowish green in colour, a series of tubercles are
present on the dorsal and lateral sides of the caterpillar. After
completion of larval period all the caterpillars congregate together
and pupate in the corners of the leaflets or crown region.

Light trap studies
There is a natural phenomenon of getting attracted to light source to
certain types of lepidopteran insects (moths), which can be exploited
for pest monitoring, mass trapping and destruction.
To test this phenomenon in the caterpillar, studies were conducted at
infested coconut gardens of Sakinetipalli village with electric bulbs,
gas lights and emergency lights.
Observations were recorded throughout the night (5 pm to 5 am). A
large number of moths (about 100 to 1,200 per light) were being
attracted in a night. These attracted moths were trapped and killed by
placing a big pan with water and sticky paper under the bulb.
Major breakthrough
This is a major break through in the slug caterpillar management and
it can be used as tool for monitoring and also for mass trapping and
destruction of the pests.

Dr. A.Sujatha
Dr. N.Emmanuel
&. Dr. B.Gautham
Andhra Pradesh
Horticultural University
Ambajipeta
Andhra Pradesh

Management of leaf folder in rice

Yield loss is from 30-80 per cent
Insect pests damage rice crop at different stages of crop growth.
Among other pests leaf feeding insect pests are of major importance because of their ability to defoliate or to remove the chlorophyll content of the leaves leading to considerable reduction in yield.
Rice leaf folder, Cnaphalocrosis medinalis was considered as pests of minor importance have increased in abundance in late 1980’s and have become major pests in many parts of India including Tamil Nadu.
The yield loss is from 30-80 per cent due to leaf folder epidemic situation.

Symptoms of damage
Longitudinal folding of leaves and scrapping of green tissues. Eventually leaves become white and dry.
During severe infestation the whole field exhibits scorched appearance. Identification of insect pest
Egg is flat, oval in shape and yellowish white in colour. Larva is pale green, transparent and actively moving caterpillar. Adult is orange brown moth with many dark wavy lines in the centre and dark band on the margins of wings.

Management strategie
— Release Trichogramma chilonis thrice at 1,00,000/ha (if moth activity is noticed) and spray Bacillus thuringiensis at 1.0 kg/ha when the leaf folder crosses tolerance level.
— Avoid use of excess nitrogen
— Set up light traps to attract moth
Spray any one of the following: Fenitrothion 50 EC 1000 ml/ha (or) Phosalone 35 EC 1500 ml/ha (or) Quinalphos 25 EC 1000 ml/ha (or) Dichlorvos 76 WSC 250 ml/ha (or) Chlorpyriphos 20 EC 1250 ml/ha Carbaryl 50 WP 1.0 kg/ha (or) Fenthion 100 EC 500 ml/ha Profenophos 50 EC 1000 ml/ha (or) Neem seed kernel extract 5 per cent 25 kg/ha.

L. Allwin V. Radhakrishnan & C. Harisudan Tamil Nadu Agricultural University, Coimbatore

An excellent method to ward off wild animals from crops

An excellent method to ward off wild animals from crops

M.J. PRABU

The eggs’ pungent odour repels herbivorous animals from entering the field

— Photo: M. Balaji

Perennial problem: A wild bison has strayed into a banana field situated near the edge of a forest.

FARMERS IN India and abroad face serious threats from pests, natural calamities, thefts, damages by animals and other types of crop losses, resulting in lower yields.

Most often, none of the steps taken to counter the problems are foolproof.

“More pronounced damage gets caused by wild animals in lands adjacent to forest areas during summer, due to food and water shortage in the forests.

“Farmers and officials plead helplessness in solving this perennial problem, and say they only try to drive the wild animals away manually,” says Dr. Narahari, former Professor and Head, Poultry Science, Tamil Nadu Veterinary and Animal Sciences University, Chennai.

New methods

Though scientists constantly search for new methods of crop management, to reduce losses to farmers, the damage by wild animals such as deer, elephants, and wild boars continue.

“For example, in North America, particularly the U.S., crop damage due to wild deer is a common occurrence. Large herds of these animals frequently cross the roads during nights, causing many accidents and enter into human habitations and damage home gardens and field crops.

Hatchery waste

“Though farmers tried several methods, the problem continued. Interestingly, some workers in chick hatcheries noticed that the deer herds do not come near the places where they dispose their hatchery waste; which contains a lot of unhatched eggs,” says Dr. Narahari.

By observing this, some hatchery workers started spraying the egg contents mixed with water, on their home gardens and noticed that the deer do not come near the plants (sprayed with egg contents), probably due to the pungent odour emitted by the raw egg contents when exposed to the air.

Successful results

After noticing these successful results, agricultural scientists started refining this technique for larger application and succeeded in minimising the attacks of the animals on field crops

“In India we read reports that wild animal such as elephants and bison venturing into the fields, destroying the crops.

“If we adopt this idea, we may be able to protect our crops from damage. It will be worthwhile for our farmers to try this method and give us the feedback. As of now I don’t think any person in India is practising this,” he says.

Several problems

With today’s agriculture facing many problems, a good crop yield with minimal expenditure is the need of the hour, and farmers who want to try this method need not spend much.

Giving details on how to use this technology Dr, Narahari explains:

Use egg contents (both albumen and yolk), preferably from broken, damaged, old, liquefied, unhatched or even ordinary table eggs, (unhatched eggs from hatcheries are not only cheaper, but also emit more pungent smell, disliked by herbivorous animals.)

Fertilizer

Break open the egg shell and pour the contents into a bucket or barrel. Mix yolk and albumen together. Hand-crush the leftover shells and use as fertilizer. For each 100ml (2 eggs contents), add 10 litres of water and mix well. Spray over crops, trees etc. using a hand or mechanical sprayer, similar to one used for spraying pesticides.

Since eggs are safe, the dose can be doubled to 200ml/10litre of water, if animals get accustomed to the smell.

Intense spray

Similarly, use double strength solution or more intense spraying on the edges of the crops for about 10 feet on all the four sides of the field or on the side (forest side) from which animals enter the field, to repel them from a distance.

The pungent odour generated by the eggs, will repel the herbivorous animals from entering into the field.

How long will the smell remain?

“The pungent smell remains for about a month; but during rains, the water will wash away the egg contents over the crop. Even snow will remove the smell quickly in about two weeks.”

Eco-friendly

Hence egg spraying has to be repeated after a rain or when the pungent smell is lost. This egg spray protects the crops from animals; without having any harmful side effects and is eco-friendly.

Moreover, the spill-over of highly nutritious egg liquid on the soil, makes it more fertile.

For more information, contact Dr. D. Narahari, former Professor and Head, Poultry Science, Tamil Nadu Veterinary and Animal sciences University, Chennai, email: narahari.devareddy@gmail.com, mobile: 94448-10639.

Brown Plant hopper in Rice ( text from http://www.ncipm.org.in )

Identification
The adults are brown in colour with brown eyes and measures 3.5- 4.5mm
in length. Their legs are light brown and the tarsal claws are black.
The wings are hyaline with brown markings and dark veins. The nymphs
are brownish- black in colour and have greyish- blue eyes.

Management

Closer spacing of 15x10cm creates favourable microclimate in
field for rapid development of hopper population. Hence, a spacing of
20x15cm should be followed.

Alternate drying and wetting the field during peak infestation
and draining out the standing water from the field 2-3 times checks
the population of the hopper to a large extent.

Alley 30cm wide after every 3 meters of rice planting provides
proper aeration to the crop, which ultimately restricts the
multiplication of the pest. Making of alleys also helps in
insecticidal spraying as applicator can move freely in the field.

Spray at ETL of 5-10 insects/ hill. 625g of carbaryl 50WP or
625ml of fenthion 1000EC or 2.0 litres of quinalphos 25EC or 1 litre
of chlorpyriphos 20EC in 250 litres of water per ha. Repeat
application if hopper population persists beyond a week after
application. While spraying nozzle should be directed at the basal
portion of the plants.

Tobacco leaf-eating caterpillar ( text from http://www.indiaagronet.com)

Tobacco leaf-eating caterpillar

Spodoptera litura F.
Family:- Noctuide
Order:- Lepidoptera

Marks of identification: - The moths are medium sized and stout bodied, with front wings pale Grey to dark brown in colour having wavy marking and whitish hind wings. The caterpillars are pale greenish-brown and smooth, with dark markings and a prothoracic plate and are about 37.5mm long when full-grown.

Nature of damage; - The caterpillars, when young, feed gregarously on tender leaves and juicy stems at become isolated at the later stages of growth.

Host plants: - Tobacco, peas, brinjal, castor, banana, agathi are the main hosts.

Life history; - Numerous eggs are laid in masses covered with brown hairs on tender leaves and they hatch in a period of four to five days. The caterpillars, which are darkish in appearance, on hatching start feeding on the soft green layers of leaves gregariously during the night, both in seedbeds and planted fields. They become pupate in rough earthen cocoons. Their pupal period lasts from nine to fourteen days and the total period of their lifecycle is 30 to 40 days.

Control measures; - Preventive measures such as collection and destruction of eggs masses and caterpillars and thorough ploughing after the harvest of the crop to expose pupae may be launched with a fair degree of effectiveness. At the early stage of infestation dusting with 10% carbayl at 20-25 kg/ha controls the pest satisfactory. When the caterpillars are about to pupate it is better to collect and destroy them on large scale.

Leaf spot in Turmeric - Text from http://www.spices.res.in

Leaf spot
The disease is caused by Colletotrichum capsici.

Symptoms
* It appears as brown spots of various sizes on the upper surface
of the young leaves.The spots are irregular in shape, whitish or
grayish in the centre.
* Later two or more spots may coalesce and form an irregular patch
covering almost the whole leaf.
* The affected leaves eventually dry up.
* The rhizomes do not develop well.

Management
* The disease can be controlled by spraying the plants with zineb
0.3% or Bordeaux mixture 1%.

Rhizome Rot ( Phytium graminicolum) in Turmeric - Text from http://www.spices.res.in

From these photographs, you can see various stages of Rhizome rot in Turmeric and ultimate damage too.

Symptoms

• Starting from the margins the leaves get dried up, collar region of pseudostem becomes soft and water-soaked and plants collapse.
• The rhizomes decay as a result of the attack of the fungus.

Control

• Seed Material should be selected from disease free areas.
• Avoid water Stagnation in the field. Light soil may be preferred and drainage facility to be ensured.
• Grow tolerant varieties like Suguna and Sudarshan.
• Crop rotation to be followed.
• Deep ploughing to be given in Summer. Planting to be done in Ridge and furrow method.
• Remove diseased plants and the soil around plants to be drenced with Mancozeb (3gm/lit) or 3gm Ridomil M.Z.
• Spray on the crop Mancozeb (2.5g/lit) or Carbendazim (1g/lit) +1ml Sandovit.
• Seed treatment is a must. Keep Rhizomes in 3gm Mancozeb or 1gm Carbendazim or 3gm Ridomil M.Z or 2.5 gm Metalaxyl mixed in one litre of water solution for one hour and shade dry before planting.