USM experts develop 6 new HYV corn varieties

MANILA, Philippines -Researchers from the University of Southern Mindanao have developed six new high yielding white corn varieties resistant to stalk rot and ear rot diseases.

The varieties were bred by Fabiola Alejandro, Efren Magulama, Milagros Malinao, and Dr. Naomi Tangonan.

Of the new maize (corn) culti-vars, three are composite (USM var 16, 18 and 28), two are synthetic (USM Var 24 and 26), and one is a hybrid.

The Phil-ippine Coun-cil for Agri-culture, Fo-restry and Natural Resources Research and Development said the develop-ment of the new varieties is ex-pected to provide farmers with va-rietal options in combating bacterial stalk rot (BSR) and Fusarium ear rot (FER), two important diseases of corn in the Philippines.

It is also expected to provide them with more reliable, effective, economical, and environment-friendly disease control measures for the said diseases and address the problem on the very low yield of white maize in the country due to the use of traditional varieties, PCARRD said.

Reports said that of the 1.47 million hectares planted to white corn in 2006, about 74 percent was planted to traditional varieties. The yield of white maize was estimated at 1.60 tons per hectare only, compared to 3.39 tons per hectare yield of yellow corn, the agency said.

“The problem on low yield of white maize was aggravated by the number of important diseases in corn, the most serious and wide-spread of which are stalk rot and ear rot. Studies showed that there is no effective control method against BSR and FER, thus the need for breeding host-resistant germ-plasm,” PCARRD said.

Stalk rots, which are often caused by a number of fungi, nema-todes, and sometimes bacteria, are the most serious and widespread group of diseases in maize. It may result to premature plant death, plant lodge, and infection of the soil as a result of the ear on lodged plant coming in contact with the soil. 

PCARRD, an attached agency of the Department of Science and Technology, said stalk rot may reduce yields by 47 to 55 percent on a particular hybrid, while ear rot may reduce yields by an average of 33 percent as shown in three field trials conducted in Bukidnon.   

The researchers said they screened thousands of germ-plasm materials to determine BSR-and FER-resistant varieties. The identified resistant germ-plasm were used in the formation of the new maize cultivars.

The researchers explained that combining plant genetic resistance and high yielding trait in breeding strategies could help achieve long-term control of these major diseases, ensure stable food production, and protect the environment. 

The study titled “High yielding white maize varieties resistant to Bacterial stalk rot and Fusarium ear rot” was the official entry of the Southern Mindanao Agricultural Resources Research and Development Consortium in the recent National Symposium on Agricultural Resources Research and Development (NSARRD).