Varietal screening of rice for location-specific adaptability in Caraga Region [Philippines]

In areas with harsh environments, the use of appropriate rice varieties could significantly increase rice yields and reduce production cost for the benefit of farmers. Recent efforts at PhilRice Agusan have been focused on the selection of locally adapted rice cultivars which tolerate adverse biotic and abiotic conditions (e.g. low solar radiation, high rainfall, potassium deficiency, bacterial leaf blight, and white stemborer) in Caraga Region. Four PSB varieties, 3 PJ lines and 1 NSIC variety consistently perform well in terms of yield and resistance to insect pests and diseases across seasons. These include PJ7, PSB Rc14, PSB Rc80, PJ21, PSB Rc28, NSIC Rc22, PSB Rc18, and PJ22. In addition, IR75207 H, IR78386 H, Bio 407, and SI-8H were selected among the hybrid rice selection. These selections obtained about 9% yield advantage over the highest yielding hybrid check. In the field performance tests of advanced breeding lines, the early-maturing entries, namely: IR75282- 10-3-3-2, PR31562- AR32 _7-129 and PR29253- 13-3-1-1-2 were selected while PR 30893- 35-1-1, IR 74286- 55-2-3-2-3, IR75288- 144-1-3, IR74654-6-1-2-2 and IR 72903-121-2-1-2 notably excelled among the medium- maturing group for the transplanted trial. On the other hand, IR77479-8-3-2-1 was favorable in the direct-seeded culture. Moreover, as one of the Multi-location Adaptation Trial (MAT) sites, the following lines stand out: PR26703- 3B-PJ25, PR31563- AR32-19-3-3, and C6053-B-1-2-1-2 transplanted; PR31563-AR32-19-3-3 and PR26841-B-5 (direct seeded). PR31563-AR32-19-3-3 performed well in both crop establishment methods. Of the 115 test entries included in the First Observational Nursery (PhilRice- JICA project), seven entries with relatively higher yields and desirable characteristics were selected, namely; PNIL-57-341IR63311-B-3R-B-29-3, PNIL-57-343, IR64196-3B-13-1, PNIL-54-344, PNIL-57-342, IR52713-2B-8-2B-1-2. The results not only demonstrated and verified the performance of locally-claimed popular rice varieties but also provided vital information of news and promising lines which may become future location- specific rice varieties in the region.