Relationship of Growth, Yield and Root Characters of Hybrid Corn Varieties in Cambodia

Abstract

This study was carried out to obtain basic information about the improvement of corn breeding in Cambodia. Different varieties of Corn seeds; 4 varieties from Korea and 2 check varieties were sown in the CARDI field in wet season, which is located at 11.4 latitude and 104.8 longitudes. The study results are summarized as follows: The precipitation during the experimental period in 2012 was 790 mm which is higher compared in 2011, which is 538 mm. The rainfall in August to September 2012 is three times than in same periods in 2011. Minimum temperature, accumulative temperature and solar radiation in 2012 were the same in 2011. The maximum temperature in 2012 is 41.8 compared to 33.3 in 2011 (which is over threshold temperature 35oC for corn). Due to heavy rains, soil moisture was not maintained effectively. High rainfall at a maximum 43mm per hour affect the drainage and influenced, the growth and root development. Seed weight of Korean varieties (175 kg~242 kg/10 a) were less than that of check varieties, of Cambodia and Thailand. The result showed a positive correlation between yield and agronomic characteristics which include seed weight, silking day, stem height, ear height rate, number of ear per 100 plants, ear length, ear width and weight of 100grain. Therefore, when agronomic characteristics increase, the yield of corn also increases. The study also showed a positive correlation coefficient between root characters, such as root length, fresh and dry root weight, and agronomic characters. It is therefore concluded that when root becomes better, agronomic characters are also better and consequently seed weight also increases. Likewise, CP888 variety was the best in root characters, and produces high yield. In contrast with the Korean varieties, which are not good in root characters, hence the yield decreases. The result of Korean varieties experiments in wet season (Kwangpyeongok, Cheongdaok, Dapyeongok, Andaok) are poorer than that of CP888 in terms of root, growth and yield characteristics. Therefore, Korea varieties provide fewer yields than CP888. The causes are estimated to be poor root due to a lot of rainfall and high temperatures in wet season. Experimental result illustrates that Korean varieties cannot adapt in Cambodia. To respond to this issue, we should develop adaptive variety to the Cambodia weather condition in wet season.