Thursday, January 30, 2014

UST GS: Jatropha controls snail vector of Schistosomiasis

Dr Abe V Rotor 
Living with Nature - School on Blog 
Paaralang Bayan sa Himpapawid with Ms Melly C Tenorio 
 738 KHz DZRB AM Band, 8-9 evening class, Monday to Friday

Scientists Dr Domindo Tapiador of UN-FAO (left) and Dr AV Rotor
examine Jatropa tree at the St Paul University Botanical Garden, QC.
With them is Mr Dell H Grecia (center), veteran journalist and
columnist of Women Journal and Ating Alamin Gazette.
Details of Jatropha pods and seeds 

The leaf extract of tubang bakod (Jatropha curcas) found growing wild on wastelands is effective in controlling golden or apple snail, Pomacea caniculata.

Ingestion of the bait prepared with one part of the crude extract with 10 parts rice bran (darak) resulted in sure death of the pest in both its immature and adult stages, thus preventing the pest from further destroying standing rice crop or spreading to nearby fields.

It will be recalled that the golden snail was introduced into the country in the seventies as supplemental food, but later turned maverick, and is now in the rank of pest, which includes stemborers and leafhoppers that attack rice and other crops.

The finding is traced to a thesis defended by Marie Shiela Alberto for a BS Biology degree at then St Paul College QC. Dr Anselmo S Cabigan, a well known biologist, and former director for research of the National Food Authority was the adviser.

Dr Cabigan emphasized the safe nature of botanical pesticides which are readily biodegradable, besides being practical in field application. Today some 2 million hectares of ricefields which harbor this pest stand to benefit from the result of this study.

Schistisomiasis Control

Jatropha curcas was also found effective in controlling the snail vector (Oncomelana quadrasi) of Schistozomiasis, a dreaded parasite that affects humans in tropical countries, the Philippines among the most affected. I had a chance to work in a project to drain and farm the fringes of the huge Sab-A Basin in Leyte. Various methods of controlling Schistozomiasis was conducted in consultation with the local Schistozomiasis Control Center headed by Dr B.I. Blas. The vastness of the swamp needed a more extensive study to eradicate the snail and consequently the disease.

Direct Control Method 

Here is a practical method I learned from farmers. Plant Jatropha on the high levees where it can grow into a small tree. Prune periodically the growing rice crop. Chopped and spread on the flooded field. Apply once or twice, on the early and late growing period of the crop. The biomass when decomposed will also serve as organic fertilizer.

NOTE: The plan to produce biofuel from Jatropha opens a potential source of natural pesticide. The active principle, although biodagradable, may be poisonous to other organisms, including fish, amphibians, beneficial insects, and the like. Toxicology studies should emphasize safety to humans and the environment as well.~ 

Schistosomiasis, or snail fever, is one of the more severe disease problems in the Philippines. Primarily rural, schistosomiasis has socioeconomic ramifications because it affects mostly farmers and their families, and thus hampers agricultural productivity.

There are about half-a-million endemic cases of Schistosoma japonicum distributed in 24 endemic provinces including: Oriental, Mindoro; Sorsogon, Luzon; the 3 provinces in Samar; Leyte and Bohol in the Visayas; and all the provinces of Mindanao except Misamis Oriental and Sulu (Figure 1). In these provinces, the human population at risk is 5.1 million and there are 2,987 known snail colonies with an approximate area of 28,731 hectares. The exposed human population in the 1,160 barangays (villages) is about 1.5 million (BI Blas et al)

Acknowledgement: Wikipedia, Internet, Dt BI Blas, Schistozomiasis Control Center 

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