(The Philippine Star)
MANILA, Philippines – The Philippine Rice Research Institute (Philrice) has identified rice breeding lines that promises to be heat tolerant and produce higher yields.
The rice research arm of the Department of Agriculture (DA) said screening promising breeding lines would pave the way for the development of new varieties that can withstand very hot weather.
Thelma Padolina, lead researcher for the study titled “Screening of rice-induced mutants for heat and drought tolerance” said that although rice normally grows at temperatures of between 20 degrees Celsius to 35 degrees Celsius, it is most vulnerable during the booting stage and flowering stage.
“Hence, even short-duration chronic dry spells occurring during these stages will result in substantial yield loss,” she said.
Padolina and her team started the series of screening in 2012 where 817 mutant lines were initially screened for drought stress and leaf blast, and later with emphasis to heat stress.
In the study, the team identified promising breeding lines from traditional rice varieties Ballatinaw and Azucena and from modern varieties PSB Rc72H, PSB Rc4, and IR58,
These breeding lines were exposed to temperatures ranging from 21.1 degrees Celsius to 34.4 degrees Celsius at field trials, and 34 degrees Celsius to 38 degrees Celsius at screenhouse trials for three consecutive seasons to test and validate their grain fertility and pollen viability.
During the tests, the Ballatinaw lines yielded six to 6.7 tons per hectare; PSB Rc72H yielded six to 6.2 tons per hectare, and the Azucena lines yielded 2.7 to 4.3 tons per hectare.
The prevailing dry spell is expected to affect domestic palay production as plantings have been delayed.
As such, the DA has revised this year’s palay (unhusked rice) production target to 19.02 million MT from the original target of 20 million MT.
As per advisory from the weather bureau, PhilRice expects the prevailing dry spell to last until mid-2015 with chances of strengthening toward the end of the year.
Affected by the dry spell so far are 29, 714 hectares of rice, 14, 298 hectares of which may not recover. The value of damage has been placed at P1.21 billion with 25, 086 farmers affected.
Rice production areas affected by the dry spell are situated in Ilocos Norte, Cagayan, Oriental Mindoro, Palawan, Camarines Sur, Masbate, Zamboanga, Bukidnon, Lanao del Norte, Misamis Oriental, Davao City, Davao Sur, Campostella Valley, Davao del Norte, North Cotabato, Sarangani, South Cotabato, Sultan Kudarat and Agusan del Norte.