Proceedings of the Fifth Asian Regional Maize Workshop - Search ...

Table 1. Maize area harvested, proWction, and yield in Indonesia.
Year
Area harvested Production Yield
(ha) (t) t/ha
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
Source:
2,061,299 3,234,825 1.57
2,832,443 4,860,127 1.72
2,924,981 5,071,546 1. 73
2,306,717 4,148,888 1.80
3,092,187 5,866,161 1.90
2,626,033 5,155,680 1.96
3,405,751 6,651,917 1.95
2,944,199 6,192,512 2.10
3,158,092 6,734,028 2.13
2,909,100 6,255,906 2.15
Central Bureau of Statistics, Jakarta.
Hybrid maize breeding.
In Indonesia, maize breeding has been done since 1950 (Sjofjan, 1956). During those days,
the best single crosses yielded more than 200% of the highest yielding variety used as the source
of lines. However, this program was discontinued, due to difficulties in seed production. In
addition, some new Carribbean germp1asm was introduced such as Tequisate Golden Yellow, which
yielded as high as the newly developed single cross
hybrids.
In the 1960's a new effort was established to develop hybrids. The single crosses
generated at that time produced ~ higher than Harapan, a high yielding open pollinated variety
(SUbandi et al., 1987). But the program was again discontinued.
In 1983, the government released a double top cross C1 hybrid maize developed by Cargill
Co. In 1985 Pioneer released the hybrid variety P2, and CPI-1 was released by CIP (Charoen
Pokhand Co.). Also in 1985, a hybrid developed at Bogar Agric. Univ. was later released (Table
2). Evaluation of these maize hybrids at three sites for two seasons in E. Java showed that the
hybrids yielded 23-42% higher than the OPV Arjuna (Table 3). These hybrids require 100 days to
maturity and are not suitable for cropping systems normally practiced by farmers in some areas.
In 1987, the Malang Res. Inst. for Food Crop (MARIF) initiated a breeding program to
develop hybrid maize with less than 100 days to maturity. Base populations used for inbreeding
were CIMMYT populations, Ma1ang composites, and Bogor pools. The heterotic pattern among these
base populations was unknown. SUWan 1, SUwan 2, and Suwan 3 are also used in developing inbreds.
S3 lines were crossed with GM15 to find lines with good combining ability with the tester parent.
In 1992, two maize hybrids, Semar 1 and Sernar 2 were released. These hybrids are three way
crosses developed using S4 lines. The parental lines of Semar 1 were extracted from Population
28 (CIMMYT) and Malang Comp.9. Semar 2 was developed by using lines extracted from Population 31
(CIMMYT) , Acer (Malang Comp.) and Bogar Pool 1. Evaluation of Semar 1 at 13 locations in E. Java
showed that it yielded 27% more than the OPV Arjuna, 11% higher than the OPV Rama and as high as
CPI-1 hybrid (Table 4). Semar 1 is later in maturity than the OPV Arjuna, but it is earlier than
CPI-1. The yield of Semar 2 was 17% higher than that of OPV Arjuna and 9% lower than that of
CPI-1 (Table 5). The maturity of var. Arjuna is 90 days and that of Semar 2 is similar, both
being earlier than CPI-1. The difficulties in developing a hybrid using S4 lines is the maintenance
of the parental lines.
Recently, MARIF also introduced lines from CIMMYT. These lines were crossed with several
lines developed by MARIF. However, CIMMYT's lines are later in maturity than MARIF's lines.
56