Kakawate leaves as pesticide, bio-organic fertilizer

May 25, 2010 8:22 pm 

By Danny O. Calleja

PILI, Camarines Sur, May 25 -– Other than as pig dewormer, termite and bed bug neutralizer, anti-fungus and bio-organic fertilizer among others, researchers have discovered leaves of Mexican Lilac (Glinicidia sepium) that is locally known as kakawate or madre de cacao an effective pesticide, according to the Department of Agriculture (DA).

Marilyn Sta. Catalina, the regional executive director of the DA Regional Field Unit (RFU) for Bicol based here on Tuesday said the discovery was recently confirmed by Dr. Alfredo Rabena, head of the Research and Development Office of the University of Northern Philippines (UNP) who found out that kakawate leaves contain coumarins, an effective botanopesticide.

Field demonstrations conducted in several parts of the Ilocos region, Sta. Catalina said proved Rabena’s discovery that the kakawate leaves’ botanopesticide effectively eliminated rice weevils, rice bugs and worms in ricefields.

The botanopesticide solution is prepared by way of chopping the kakawate leaves and soaked in water overnight to extract coumarins and using a strainer, the leaves are separated from the solution.

The resulting solution is sprayed to the ricefield and the best time to do it is from eight o’clock to nine o’clock in the morning and from five o’clock to six o’clock in the afternoon. These times, worms and pests are coming out from the leaves making the solution more effective.

If applied earlier or later, its effectiveness would not be maximized as pests are still hibernating. Applying the solution under extreme sunlight will also reduce its effectiveness as the pests hide from the heat of the sun.

Since kakawate is a legume, Sta. Catalina quoted Rabena as saying, “its leaves are rich in nitrogen, an important soil nutrient. Hence, the discarded leaves can be applied to the field as an organic fertilizer.”

It is also recommended that farmers put several leafy branches of kakawate tree in between rice plants two days after planting to prevent pests from attacking the crop, she said.

Coumarins in kakawate leaves are also effective termites and bed bugs neutralizer and Rabena presented this finding through his paper “The Isolation, Characterization and Identification of Active Botano Chemicals of Kakawate Leaves Against Termites” that he presented during the 5th International Congress of Plant Molecular Biology in Singapore in 1997.

His study was also included in the book “The International Society for Plant Molecular Biology” published by the National University of Singapore and Institute of Molecular Agrobiology.

Kakawate leaves are also effective anti-fungus. It can cure Trichophyton Metagrophytes that causes skin diseases like eczema. Crumple several leaves and apply to affected area of the skin for a salicylic acid-like effect.

Rabena, along with Dr. Nelia Aman and Engr. Franklin Amistad also both of UNP, Sta. Catalina said have also discovered lately that the ash of kakawate can be a good concrete mixture for ceramics. Its charcoal is a good moisture and odor absorbent, too.

Kakawate leaves can be used also to deworm pigs. Just have the swine eat ample leaves and the parasites would not live long.

When these uses are not enough, the Bicol DA chief said it should be remembered that kakawate’s flowers can be made into salad or into dinengdeng, a delicious Ilokano veggie dish.

She encouraged farmers to plant more kakawate trees as its adaptability to any type of soil makes it an ideal tree for those who want to cultivate a plantation of it.

It’s perhaps one of the easiest growing plants one could find. It is a leguminous tropical tree that grows mostly in forests and could grow from five to 10 meters tall. Kakawate defoliates during dry season and flowers at the same time making it odd-looking but beautiful leafless trees with nothing but branches and flowers.

The flowers are pea-like with petals that are usually lavender, pink or white. It also bears fruits that look like a leathery pod and seeded.

Kakawate is very easy to propagate and inexpensive. The tree could re-sprout very quickly after pruning. Many farmers plant them mainly to shade other perennial crops like cacao, coffee and tea.

Aside from this, kakawate could provide a lot of uses to the farmers from its roots to its leaves. Its multipurpose use makes it a good plant crop in agroforestry.

Since kakawate is a legume, it is useful for fixing nitrogen in the soil, thus improving soil quality and increasing crop yields.

Kakawate has strong roots. It stabilizes sloping lands and reduces soil erosion. Its wood could be used as firewood, hedges, and fencing field. The leaves are rich in nitrogen and other nutrients suitable for green manure and fodder to farm animals.

This legume is also popular to the rural folks as a ripening agent for their harvested banana. Most farmers are not aware that this plant can be utilized as fertilizer to lessen their farm inputs.

Application of organic materials is a good agricultural practice to maintain soil nutrient level and ameliorate the properties of soil to sustain crop production. Many organic materials contain secondary nutrients and micronutrients in addition to organic matter, nitrogen, phosphorus, and potassium.

Nonilon Badayos of the Department of Soil Science and Dr. Gina Pangga of Farming Systems and Soil Resources Institute, both of the University of the Philippines-Los Baños tested the potential of kakawate as bio-organic fertilizer in an earlier study for eggplant production in Laguna.

The experiment sought to evaluate the effect of kakawate on the growth performance and yield of eggplants and on the soils physical and chemical properties.

Observations revealed that the eggplants fertilized with 50 percent inorganic fertilizer plus 50 percent kakawate were the most vigorous – growth rate was faster and the fruits were heavier than the other treatments.

Sta. Catalina said more scientific results on kakawate’s effect on the crops performance and yield as well as its beneficial effect on the soil physical and chemical properties should be studied further.

Similarly, she added, the economic benefits of applying organic materials as soil amendment and its potential as an alternative to inorganic fertilizers should also be evaluated so that its benefits to the agriculture sector are emphasized. (PNA) LOR/LQ/DOC/mdr


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