Screening for drought tolerance of different local and CIMMYT [Centro Internacional de Mejoramiento de Maiz y Trigo, Mexico] maize populations and hybrids

Drought stress is an important abiotic factor affecting corn productivity especially in developing countries. Identification of populations and hybrids with confirmed drought tolerance coupled with high yield is needed to increase productivity. Evaluation of materials in drought and irrigated conditions were conducted during 2006 DS. Populations and hybrids from local breeding institutions and CIMMYT were tested in Pangasinan, USM and CMU. High estimates of GCV for grain yield, number of ears harvested, anthesis-silking interval, leaf senescence and leaf rolling were observed. In Pangasinan, grain yield have a highly significant positive correlation with ear height, plant height and number of ears harvested. Same is true in USM and CMU for number of ears harvested. Meanwhile, days to anthesis and days to silking have significant negative correlation with grain yield in Pangasinan. Comparing the results of 63 common entries in three location, drop in yield in USM due to drought was not much compared to irrigated i.e. 4.6 vs 5.4 t/ha, which accounts for 14.8% yield decrease. This is in contrast to Pangasinan of 2.4 vs 4.4 t/ha (45.5%) and CMU, 2.9 vs 9.8 t/ha (70.4%). The best 5 performing populations were (1) Phil 2-19 (PHBc syn7 (LMQ), F1-No.-No.), (2) Phil 1-117 (SW S003-3-No.-No.), (3) Phil 1-107 (S98D24-No.-No.), (4) Phil 1-101 (PHAm syn 3 (MM-No.-No.) and (5) Phil 2-18 (syn 4 (LS) F1-No.-No.). In 2008 DS, adaptability trials of these materials were conducted in UPLB and CMU. Results shows that Phil 1-116 (SW S003Y-S-No.No.) (4.7 t/ha) and Phil 1-102 (PHAm syn 4(EM)-No.-No.)(4.53 t/ha) were the highest yielding populations. Phil 1-107 (S98 D24-No.-No.) and Phil 2-18 (PHBc Sy4 (LS) F1-No.-No.) ranks third (4.32 t/ha). Identified good performing populations will be subjected to recurrent selection to come up with drought tolerant OPVs that can be available to farmers especially in drought prone areas of the country.