Economic advantage of Bt corn over hybrid varieties

With the support of the government, Bt corn was introduced to increase production and productivity among corn farms in the country. The first commercial release of Bt corn was approved by DA [Department of Agriculture] in 2002. Earlier assessment study showed 30 percent yield advantage of Bt corn over the non-Bt (hybrid and inbred) varieties and their resistance to the common corn pest, the Asian corn borer. One methodological issue in previous studies ws the wide use of non-Bt corn, including hybrid and inbred varieties, which served as basis in estimating the economic advantage of Bt corn. It is a fact that the yield potential of various inbred and hybrid corn varieties differ from each other. Since these varieties were grouped as non-Bt corn, there is a possibility of positively or negative bias in the yield potential of non-Bt corn. Thus another study was conducted by Domingo et al. (ISU) to evaluate the economic impact of Bt corn in Isabela corn farms. Specifically, the study estimated the production and yield per hectare of Bt corn and determine its economic advantage over hybrid varieties. The data were gathered through survey of 66 Bt corn farmers and 101 hybrid corn farmers in ten corn-producing municipalities of Isabela. The samples were specifically corn farmers who planted DK818YG and 30Y80 to represent Bt corn, and farmers who planted DK818 and 30B80 to represent hybrid corn. This was done primarily to reduce variances due to varying yield potentials of different varieties. Data were base on the wet and dry cropping seasons of 2004-2005. The study showed that Bt corn has a yield advantage of 33 percent (1,710 kg/ha) over hybrid corn during the WS and 26 percent (1,210 kg/ha) during the DS. Bt corn farmers have lower cost of chemical inputs, although this was offset by higher cost of Bt corn seeds over hybrid. While there was higher cost per hectare for Bt corn, an additional net income of P6,000 to P8,000 can be realized if Bt corn is planted rather than hybrid variety. Bt corn required higher labor use particularly in shelling primarily due to the higher yield of the variety. Bt corn farmers used lesser chemicals during the wet season but this was offset by the higher cost of seeds and fertilizers they applied. There was thus higher value of material inputs used by Bt corn farmers. Both Bt and hybrid corn farmers did not apply chemicals during the dry season. The shift from hybrid to Bt corn using the partial budgeting technique showed positive net change in income. An incremental benefit of P7,158 out of added income of P10,594 versus added cost of P3,436 was realized by shifting from hybrid to Bt corn. The positive change in income was higher during the wet season. Continuous monitoring and evaluation of the performance and impact of Bt corn vis-a-vis hybrids should be done not only in Isabela but also in other provinces and municipalities where Bt varieties are already being planted.