Key Check 7: No significant yield loss due to pests

Insect pests, Diseases, Rats, BirdsGolden apple snails

GOLDEN GOLDEN APPLE APPLE SNAIL SNAIL ManagemeManagementntPart 1: Understanding the PalayCheck

System

Exercise: Counting GAS Eggmass

GAS Eggmass

IMAGINE THIS: Most of the eggs (80%) become destructive snails that can

consume young rice plants overnight!

So, why do you think we need to manage GAS?

GAS are: • prolific• voracious feeders

Meet GAS

• Freshwater gastropod endemic to South America• 3 routes of introduction to Philippines

• From Taiwan to Lemery, Batangas in 1982• Florida, USA to Makati Metro Manila in 1983• Argentina to Asturias, Cebu in 1984

• Introduced as means of livelihood and to enrich the protein source in the human diet

• Invaded 3.6% of the total area planted to rice after 6 years of introduction (Rejesus et. Al., 1988)

Meet GAS

• Size depends on the availability of food• Most destructive stage is when it has grown 10 mm-40

mm or the size of a P5 coin

• Life span: 2-6 years with high fertility

• Shell is light brown; flesh is creamy white to golden pinkish or orange

GAS’s address

• Ponds, swamps, irrigated fields, canals and water-logged areas

• They burry themselves in moist soil during the dry season,

• They can aestivate for 6 months, then become active again when the soil is flooded

Meet GAS: The Egg• Eggs are laid at night on any

vegetation, levees, and objects (ex. Twigs, stakes, etc.) above the

water surface• Egg masses are bright pinkish-red

and turn light pink when about to hatch

• Eggs hatch in 7-14 days

Exercise: Identifying GAS Gender

Meet GAS: The adult

• Female GAS operculum is concave: Males have convex

male female

Meet GAS: The adult• Adults mate for 3-4 hours anytime of the day

among crowded plants where there is continuous water supply throughout the year.

• They reproduce rapidly and can lay 1000-1200 eggs in a month.

Meet GAS: The voracious feeder

• Hatchlings grow and mature fast. Golden apple snails devour at the base of young seedlings.

• They can consume young plants in a whole paddy overnight.

• They prefer young plant parts because it feeds by scraping plant surface with its rough tongue.

Meet GAS: The voracious feeder

• It feeds on a wide range of plants such as algae, azolla, duck weed, water hyacinth, rice seedlings, and other succulent leafy plants.

• They also feed on any decomposing organic matter.

Damage

• Missing hills• Floating cut leaves• 1 GAS/m2 2-3 cm ht = 19%

reduction in yield within 30 DAT

Manong Fred’s dilemmaManong Fred knows that GAS attacked his rice plants the previous season. To prevent that from happening again, he plans to plant many seedlings so that there would still be enough left when GAS have consumed other plants. He also wants to flood the field so that he could kill them by drowning; he will employ a wetbed preparation method.

Is Manong Fred’s decision right?

GAS Management: ABCDEA - Attractants and hand-picking

• Before final harrowing, handpick GAS in the morning and afternoon when they are most active and easy to find.

• Use attractants/alternate feeds such as leaves of gabi, banana, papaya, trumpet flower, kangkong and sweet potato (75% damage reduction to rice seedlings)

• Old news paper attracted GAS like other plant attractants.

• Red ants feed on the eggs• Birds feed on eggs and newly hatched snails• Ducks eat the flesh and young shell• Field rats bite on the shell and eat the flesh• Human beings eat the flesh when it is properly cooked

(soups, stews, curries, stir-fry or barbecued)• Long horned grasshopper predated on GAS eggmasses

in rice fields

GAS Management: ABCDEB – Biological control, Botanical

• During the last harrowing, construct deep strips (at least 25 cm wide and 5 cm deep) in the paddies.

• TECHNIQUE: Pull a sack with a heavy object inside to create a canalet.

GAS Management: ABCDEC - Collection, Canalet, Chemicals as last resort

Place a wire or woven screen on the main irrigation water inlet and outlet to prevent entry of hatchlings and adults.

GAS Management: ABCDEC - Collection, Canalet, Chemicals as last resort

• Put bamboo stakes on waterlogged areas in paddies or near canals for easy collection; bamboos will be rooms for egg laying

• Collect, cook, then eat the GAS or crush and feed them to ducks and pigs.

GAS Management: ABCDEC - Collection, Canalet, Chemicals as last resort

GAS is nutritious!!A bite-sized golden apple snail contains the following:

• Food energy 83.0 cal• Protein 12.2 g• Fat 0.4 g• Carbohydrates 6.6 g• Ash 3.2 g• Phosphorous 1.0 mg• Sodium 0.4

mg

Potassium 17.0 mg

Riboflavin 12.0 mgNiacin 1.8 mgOther food values are

Vitamin C, Zinc, Copper, Manganese and Iodine

NEWS!!! Chicharon golden apple snail recipe has been improved.

When other methods don’t work:• Use Chemicals: Molluscisides

GAS Management: ABCDEC - Collection, Canalet, Chemicals as last resort

• Herd ducks in rice paddies immediately after harvest up to the last harrowing for the succeeding crop.

GAS Management: ABCDED - Ducks, Dry land preparation, Draining

GAS Management: ABCDED - Ducks, Dry land preparation, Draining

• Using 900 ducks/ha (Vega 1991) observed 74-84% decrease of GAS in rice fields after rice harvest.

• Duck herding before transplanting was better than herding 14-19 days at one month after transplanting.

GAS Management: ABCDED - Ducks, Dry land preparation, Draining

• Duck control was more effective than mullusicides• Lasted only for 2-3 days• More lethal to non-destructive native snails• Ineffective either because of poor drainage by crawling

out of treated water• Endosulfan (organochloride) could accumulate in GAS

tissues and maybe biomagnified when taken by humans (PCARRD Monitor, 2000)

• Dry land preparation exposes buried GAS which causes them to die.

• Draining (condition: two 25 mm GAS/m2)– 21 DAS - 100% alive plantation– 14 DAS – 90% alive plantation– 10 DAS – 70% alive plantation– 7 DAS – 18% alive plantation

GAS Management: ABCDED- Ducks, Dry land preparation, Draining

For defense, energize or strengthen your field! Follow PalayCheck recommendations

• Follow the standard seeding rate and distance so that the plants will have sturdy stems.

• Varieties least preferred by GAS: PSB Rc36, Rc38, Rc40, and Rc68.

• Transplant older seedlings of early-maturing varieties (especially in low-lying areas).

GAS Management: ABCDEE- Energize your field

For defense, energize or strengthen your field! Follow PalayCheck recommendations

• Management Practices:– Direct seeding – irrigation after 1-2 weeks– Transplanted – shallow water (4.0 leaf stage or older)

• Maintain shallow paddy water level (2-3 cm shallow) starting 3 days after transplanting.

• Drain the field occasionally to limit snail mobility and feeding activity.

GAS Management: ABCDEE- Energize your field

For defense, energize or strengthen your field! Follow PalayCheck recommendations

• Basal application of complete fertilizer and urea incorporated with the soil at recommended rate during the last harrowing reduce GAS population up to 54%.

• Maintain shallow paddy water level (2-3 cm shallow) starting 3 days after transplanting.

• Drain the field occasionally to limit snail mobility and feeding activity.

GAS Management: ABCDEE- Energize your field

A Attractants and hand-picking

B Biological control, BotanicalC Collection, Canalet, Chemicals as last resort

D Ducks, Dryland preparation, Draining

E Energize you field

ABCDE in GAS Management

Yield loss is significant when 10% or more of the area is damaged by GAS (missing hills, etc.)

In 1 ha field, about 1,000 sq m of damage.

Continuous community action is very important

CREDITSInstructional presentation designer: Ms. Ella Lois Bestil

Sources of technical content/reviewers of presentation:Mrs. Annie Antonio, Mr. Mario Dela Cruz, Mr. Rolando San Gabriel

Note:Adapted from a powerpoint presentation developed by: Mr. Glenn Ilar, Mrs. Marissa Reyes

You may use, remix, tweak, For more information, visit:& build upon this presentation non-commercially. However, alwaysuse with acknowledgment.

Unless otherwise stated, the names listed are PhilRice staffers.

Produced in 2011Text: 0920-911-1398