Effect of Chemical and Organic Substances Treated Stem on Germination and Yield of Cassava INTRODUCTION Cassava stem treatment was conducted for keep high quality stem which free from disease and insect born. There was using various rates of chemical substance for stem protection, theses substances can use natural organic substance in term of save the cost. Also these substances can bring from natural resources or wasting substances. Treated sweet corn seed by chemical and organic substances had the higest germination and less diseases and insects infection than non treated seed (Ngamprasitthi, 2012). Study of substance for stem treatment can keep high quality and germination of cassava. ABSTRACT Cassava stem treatment was conducted for keep high quality stem which free from disease and insect born. The effect of chemical and organic substances treated stem on germination and yield of cassava was conducted at National Corn and Sorghum Research Center, Pakchong district, Nakhonrachasima province with the objective for keep high quality and germination of cassava, during January 2010 to July The experiment was laid out as the Split plot in RCBD with 4 replications, main plot was variety composed of 3 cassava cultivars, Kasetsart 50 (KU.50), Huay Bong 60 (HB 60) and Huay Bong 80 (HB 80), sub plot was 5 treated substances composed of S1= physic nut oil, S2= by-product of mallas (ethyl-alcohol 40%), S3= bacteria suspension KPS 46, S4= chlopiriphos-methyl, S5= non treated. The objective of research was compared to the effect substance stem treatment on germination, growth, and yield of 3 cassava cultivars. The results revealed that substance stem treatment had affected germination as significantly difference. HB 80 had maximum germination at percent and the next were HB 60 and KU 50 at and percent respectively. Between stem treated substances found that non-treated (S5) had maximum germination at percent; physic nut oil (S1) had minimum germination at 68.92%. For insect appearance of cassava stem at 2 months after planted found that non-treated (S5) had 11.27% infected which higher than the various substance stem treatments. For yield found that KU 50 had maximum fresh root yield at 12 months after planted and got average yield components of 131,000 number of fresh root per hectare (20,960 no. fresh root rai-1), weight 101,295 kg. per hectare (19.62 t rai-1). RESULT AND DISCUSSION Table 1 Yield was found that KU. 50 had maximum fresh root yield average yield components of 13.1 number of fresh root per plant; weight kg per plant and got 131,000 number of fresh root per hectare, weight 101,295 kg per hectare Table 2 found that substance stem treatment in cassava cultivar KU 50, HB 60 and HB 80 affected to stem germination percentage in highly significant difference. Stem treated by substance before planted had germination percentage lower than untreated except HB 80 treated stem by KPS 46 had maximum germination at 83.5 percent. From assessment at 2 months after planted found that substance stem treatment had higher insect resistance than untreated. CONCLUSIONS From the results of this study: Substance stem treatment in cassava affected to stem germination percentage, fresh root yield and insect infection percentage but was not affected to growth (plant height, No. of shoot per plant) and root starch content. Before planted,should be use fresh stem and high moisture soil condition. CultivarsSubstancesGermination (%) Plant height (cm) Shoot per plant Insect infected (%) 2 months after planted Root start content (%) Kasetsart 50 (KU 50) Physic nut oil68.0 g b23.7 Alcohol 40%74.2 d-f b26.2 KPS a-c b23.3 Chlopyriphos e-g b20.8 Non treated77.2 b-e a19.6 Huey Bong 60 (HB 60) Physic nut oil69.2 f-g b24.0 Alcohol 40%73.5 e-g b22.6 KPS c-e b23.5 Chlopyriphos a-d b23.8 Non treated84.0 a a21.2 Huey Bong 80 (HB 80) Physic nut oil69.5 f-g b21.0 Alcohol 40%81.7 a-c b19.6 KPS a b23.3 Chlopyriphos a-b b24.6 Non treated85.5 a a23.1 mean C.V. (%) F-Test*NS * MATERIALS AND METHODS The research was conducted at Suwanwajokkasikij Research Center. Study method compose of sub-plot sized 5 mx10 m., harvesting area sized 3 mx8 m. Planted on ridge row and hill spacing 1mx1 m., stem length 25 cm. Weed control was done at days after plant and collected the data of germination percentage, growth of plant (height, number of shoot), insect infected, fresh weight yield and root starch content (%) S. Ngamprasitthi 1*, K. Panitnok 2, S. Chaisri 3, P. Chaisri 3, P. Changlek 1 and P. Thongluang 1 (1)Suwanwajokkasikit Field Crop Research Station, Kasetsart University, Bangkok, Thailand, (2)Khao Hin Son Research Station, Kasetsart University, Bangkok, Thailand, (3)Lop Buri Research Station, Kasetsart University, Bangkok, Thailand, (4)Agro-Ecological system Research and Development Institute, Kasetsart University, Bangkok, Thailand, (5) Thamrongsilpa pothisoong National Corn and Sorghum Research Center, Kasetsart University, Bangkok, Thailand, Table 2. Effect on germination percentage, agronomy of characteristic, insect infected and root starch content of 3 cassava cultivars planted during January 2010 to July CultivarsGermination (%) No fresh root (tuber/ha) Weight of fresh root yield (kg/ha) Kasetsart b131, ,295.0 a Huey Bong b114, ,400.0 b Huey Bong a108, ,280.0 b mean , ,673.3 C.V. (%) F-Test*NS* Table 1. Effect on germination percentage and fresh root yield of 3 cassava cultivars planted during Jan to Jul KU. 50 HB. 60 HB. 80 * Correspondence Reference Ngamprasitthi, S., K. Panitnok, Y. Oumsamniang, W. Wongpila and P. Thongluang Effect of Chemical and Organic Substances Seed Treated on Germination and Yield of Sweet Corn. Pp , In The 5 th Workshop of Corn and Sorghum Research Project of Kasetsart University. 31 May-1 June. Kasetsart University, Kampangsean, Nakhonpthom.