Filipino scientists have determined the best dates for the planting of corn in Isabela and Bukidnon using climate simulation and weather prediction systems.
Next to rice, corn (scientific name--- Zea mays L.) is the country’s most important cereal but it is most sensitive to climatic aberrations, with resulting reduction in yields.
The Philippine Council for Agriculture, Forestry and Natural Resources Research and Development (PCARRD) bankrolled the study of Dr. Felino P. Lansigan of the Institute of Statistics (Instat) of the University of the Philippines at Los Banos (UPLB) in 2008 and 2009 to find out how corn growing in the two provinces could overcome these aberrations and find out when is the best to plant corn.
Lansigan coordinated with UPLB-School of Environmental Science and Management (SESAM) in assessing the risk due to climatic variability in corn production systems in Isabela and Bukidnon.
His team analyzed potential corn production systems strategies that could help corn producers overcome climatic variability and explore the use of advanced seasonal climate information in crop forecasting.
Lansigan’s team used the CERES-Maize model and SIMMETEO to simulate the effects of climate variability on corn grown in the two provinces.
Through CERES, corn yield is simulated on the basis of the combined effects of crop phenotype, soil and weather as well as crop management system.
SIMMETEO simulates weather based on monthly observed data.
The models were used to predict possible yields for IPB 911 corn variety under three planting scenarios in the two provinces.
These scenarios were normal year (average year), dry year (El Niño year) and wet year (La Niña year.)
Climate variability affected crop yield in the two provinces differently, with the climate system in Isabela is different under the wet and dry scenarios, resulting in varying crop yields.
There were no significant variations in corn yields in Bukidnon since El Niño did not affect the province.
Through the mean variance analysis, the researchers determined optimum planting dates for the normal, wet and dry years.
Mean variance analysis assumes that risk is measured by variance, and that the standard should be to minimize the variance given expected return, or to maximize expected return for a given variance. Planting dates then were determined based on dates that will give the highest possible yield with the lowest possible variance.
Corn is planted in Isabela from June to July for the wet season (WS) cropping and from November to December the dry season (DS). For WS, the best planting date during a normal year is July 9, according to the risk analysis, with a mean projected yield of 2.831 tons/ha.
During La Niña year, the most risk-efficient planting date is May 20 as well, with mean yield of 3.5 tons/ha.
For DS cropping under normal and El Niño years, the best planting date is November 12, with a mean projected yield of 2.6 tons/ha and 1.4 tons/ha, respectively. Under a La Niña year, it is best to plant corn on November 22, which would potentially result in a mean yield of 2.8 tons/ha.
For Bukidnon, corn is planted during August to September for the WS cropping and February to March for the DS cropping. During the WS cropping, August 28 is the best planting date under a normal year, with a mean yield of 4.3 tons/ha. Moreover, it is best to plant corn on September 17 under an El Niño year, producing a mean yield of 4.1 tons/ha.
During the DS, it is most risk-efficient to plant on January 23 under a normal year with a mean yield of 4.2 tons/ha. Under an El Niño year, the best planting date is on March 4, with mean yield of 4.8 tons/ha. For a wet year, it is best that the corn be planted on March 14, with mean yield of 4.5 tons/ha.