US-BASED Monsanto, world's pioneer in genetic modification (GM), is releasing this season its Roundup Ready (RR) corn as the Bureau of Plant Industry (BPI) approved the commercialization of this GM crop that's seen to solve much of farmers' weed problems.

Jan Alfred Samson, Monsanto Philippines Inc. (MPI) technical marketing lead for RR corn, said BPI approved last Feb. 28, 2005 the local propagation of RR corn which becomes the Philippines' second GM crop and which is seen to further establish Monsanto's grip on the local market.

The first Philippine GM crop was the Asiatic corn borer-resistant Bacillus thuringiensis (Bt) corn, also developed by Monsanto and was approved for propagation on Dec. 4, 2002.

Samson said MPI is initially holding this current season a technology demonstration of RR corn on 400 sites nationwide of 5,000 square meters each to teach farmers how to use the new technology that basically enables the corn crop to endure spraying of the herbicide Roundup.

"It was approved last February 8, but we have yet to propagate it for two seasons. For now, we will hold a demo on 400 locations," he said in an interview.

RR corn has been proven to withstand herbicide spraying which enables farmers to gain a substantial 15 to 50 percent of yield that they normally lose to weed that destroys corn's yield potential. Since the gene with herbicide resistance was infused I MPI's Dekalb hybrid variety, yield could range from a high of seven to 11 metric tons per hectare. RR corn substantially cuts farmers' labor cost from manual weeding.

In itself, herbicide Roundup, also developed by Monsanto (which has been in use in the Philippines for the last 10 years) is powerful in killing weeds as it has high concentration of glyphosate which is non-selective, killing most weeds other herbicides cannot control.

Roundup is a post-emergent herbicide that can be applied after weeds have grown and does not need weed moisture to control it unlike preemergent herbicides like atrazine (sprayed only prior to corn planting but which still leaves much weed during corn growth).

Roundup has low level of toxicity compared to other chemicals as it takes 5,000 milligram (MG) per kilo of Roundup for 50 percent of test animals to be poisoned while it only takes 2,000 MG per kilo of Vitamin A or only 53 MG of nicotine for test animals to suffer the same fate.

However, Roundup is only most appropriate to be sprayed on tall tree crops because the spray won't kill the crop itself. For corn plants, Roundup is normally applicable only in a farming system called conservation tillage (CT) or where tilling is very minimal.

CT is an environment-friendly farming system (which does not cause soil erosion especially in hilly areas) that over the long term improves soil condition and controls growing of weeds because minimal tilling does not cause most of the weed seeds underneath the soil to shoot up.

"But 90 percent of farmers go for full tilling. If they have a tractor, planting is easier," said Samson.

Thus, RR corn will be liked by more farmers since this GM variety withstands the herbicide spray, although farmers also have to be taught how to use this technology together with the herbicide.

Over the last two to three years, MPI has tested RR corn on nine locations: Luna, Isabela; Tumauini, Isabela; Sta. Maria, Pangasina; Tigaon, Camarines Sur; Dangcagan, Bukidnon; Manolo Fortich, Bukidnon; Claveria, Misamis Oriental; Tupi, South Cotabato; and Cauayan, Isabela.