Adapting to Climate Change
“For agriculture to adapt, crops must adapt”, says Ren Wang, director of the Consultative Group of International Agricultural Research Center in an interview.
As the effects of climate change loom, the need for anticipatory actions are important. This means that we have to prepare for the changes that may be brought about by climate extremes. Crops that can survive to either hotter or cooler temperatures are needed.
According to the Intergovernmental Panel for Climate Change (IPCC), global temperature increase will rise from 1.1°C - 6.4°C in the next century. Philippine temperatures fall, on the average, between 27°C -38 °C. Rice scientists believe the change in temperature will certainly have an impact on rice production.
SURVIVE THE HEAT
According to Dr. Norvie L. Manigbas, a research fellow from the Philippine Rice Research Institute (PhilRice), rice grows optimally between 20°C-35°C. Any temperature higher than that can cause yield loss due to high sterility of the grains. Hence, temperature increase above optimum (35°C) even just for one hour period can have adverse effects on the rice plant.
This makes breeding for heat tolerance relevant. In the past, Dr. Manigbas said there were only a few studies on heat tolerance as there were more pressing concerns then like pest and disease resistance, yield, other abiotic stresses, and grain quality.
According to him, there are two breeding strategies for heat tolerance for rice. One is adaptation or breeding for heat tolerance per se or the rice plant will show high fertility despite high temperatures. The other one is avoidance or changing the time of flowering from the usual 10:00 AM-12:00 PM to early morning when temperature is lower.
A very good example of gene source for heat tolerance, according to him, is the wild type Oryza glabberima which sheds its pollen during early morning around 6:00 AM-7:00 AM. He added that as coping mechanism, at the moment, farmers
can plant rice during the period by which it will not be subjected to high temperature during flowering.
But what if temperature goes high during the growth period? Breeding rice for heat tolerance will become important as it is now, stressed Dr. Manigbas.
At PhilRice, he said they have screened 157 rice varieties from International Rice Research Institute’s (IRRI) International Network for the Genetic Evaluation of Rice (INGER) and genebank. These varieties came from countries with high temperatures like in the Middle East, South Asia, Latin America, and Africa.
From their initial results, they found 56 varieties that could tolerate heat and could be used for breeding and genetic studies. These varieties had low sterility levels, according to Dr. Manigbas. He added there are genetic variations that could be observed as far as heat tolerance is concerned from among the varieties screened. There are varieties that car, remain fertile even when temperature goes up to 45°C.
The next step being done by the group of Dr. Manigbas is to use these varieties for breeding work, thus combining the heat tolerance trait with good quality local varieties.
“No REGRETS ACTIONS”
Meanwhile, Dr. John de Leon, plant breeder and chief science research specialist at PhilRice, said we should adopt the “no regrets actions” in response to climate change
He simply means that “we should do what is expected of us as private individuals to remain well informed and help build resilience in adapting to climate change concerns.” He emphasized that concerted efforts from all sectors are needed to cope with the effects of climate change.
On the other hand, for research institutions, “investments in plant breeding and other sciences must be continued and strengthened.”
He added that many researchable areas on rice production arise due to climate change. “Pest expansion, weed resilience, effect on dynamics of insect pests and natural enemies, agronomic practices like the schedule of planting, and fertilizer applications are among the many areas that are worth looking at.”
Furthermore, Dr, de Leon said that some studies also suggest a relationship between increase in temperature and the low grain quality. Hence, a detailed study on this aspect is recommended.
On the other hand, he clarifies that climate change is not all negative for agriculture. There will be increased concentration of carbon dioxide in the atmosphere which is essential in the photosynthetic ability of the rice plant. This could result in increased yields. However, weeds may likewise benefit from this.
Although climate change will not happen in a year’s time, Dr. de Leon urges for anticipatory actions especially in plant breeding.
