Regional Soybean Mutants Multi-Location Trials

Abstract

 The experiment was conducted at Chiang Mai Field Crops Research Centre (FCRC) (18" 14'.N latitude, 93  3'.  E longitude, 316 m altitude) in rainy season in 2003 - 2005 and Sukhothai Plant Production Technical Service Centre (PPTSC) (17   10'.  , N latitude, 99 52' , E longitude, 54 m altitude) in rainy and dry seasons in 2005, to compare the adaptability of exotic soybean mutants and their parents under northern Thailand conditions.  RCB design was used with 3 replicates and 14 treatments namely, two mutants from Indonesia (GH-7, M-220), one parent and two mutants from Korea (Kumkangdaerip KEX-2, bangsakong), two mutants from Vietnam (M 103, DT 84), two parents and two mutants from China (HC 18, HC 18M, AJMD, AJMDM) and an original parent (Chiang Mai 60), a mutant (CM 60-10KR-71-PS-21) and a local check (Sukhothai 2) from Thailand.  Plot size area was a 3.0 x 5.0 m with harvested area of 2 x 4 m.  Plant population density was about 30-40 plants/m with 50 cm between rows., 20 cm between hills and 3 to 4 plants/hill.  Seed was inoculated with Bradyrhizobium at chiang Mai FCRC.  Fertilizer grade of 12-24-12 (N-P2O5 -K2O) at rate of 156.25 kg/ha was applied at 15 days after sowing (DAS).  Pre-emergence herbicide was sprayed plus hand weeding prior to flowering for control weeds.  Insecticides were sprayed to control key insect pests namely beanfly, whitefly, pod borers and bugs.  Soybean was planted in both rainy and dry seasons, The amounts of rainfall during the crop duration inrainy season at Chiang Mai FCRC wee 488, 649 and 1,007 mm in 2003, 2004 and 2005 and at Sukhothai PPTSC were 546 and 672 mm in the year of 2004 and 2005 respectively.  In dry season, the plots were irrigated by flood-furrow system five times with a total amount of about 300 mm of wter.  Plants were harvested at 95% of pods reach their maturity.  Result at Chiang Mai FCRC was found that DT 84 produced similar grain yield with Chiang Mai 60 and it matured 77 days after emergence (DAE), 19 days earlier than Chiang Mai 60.  At Sukhothai PPTSC, it matured 12 days earlier than Sukhothai 2.  then DT 84 and Bangsakong are suitable to be grown in the rice based cropping systems.  Both soybeen mutants will be further tested in farmers' fieds to support the release.