Effects of chicken manure and low rate of chemical fertilizer on fresh root yield and starch content of Huay Bong 60 cassava variety | เธœเธฅเธ‚เธญเธ‡เธเธฒเธฃเนƒเธŠเน‰เธ›เธธเน‹เธขเธกเธนเธฅเน„เธเนˆเธฃเนˆเธงเธกเธเธฑเธšเธ›เธธเน‹เธขเน€เธ„เธกเธตเธญเธฑเธ•เธฃเธฒเธ•เนˆเธณเธ—เธตเนˆเธกเธตเธ•เนˆเธญเธœเธฅเธœเธฅเธดเธ•เธซเธฑเธงเธชเธ”เนเธฅเธฐเธ›เธฃเธดเธกเธฒเธ“เนเธ›เน‰เธ‡เธ‚เธญเธ‡เธกเธฑเธ™เธชเธณเธ›เธฐเธซเธฅเธฑเธ‡เธžเธฑเธ™เธ˜เธธเนŒเธซเน‰เธงเธขเธšเธ‡ 60

Effects of chicken manure and low rate of chemical fertilizer on fresh root yield and starch content of Huay Bong 60 cassava variety was carried out using a split-plot in RCB designed with 4 replications. Main plots were the rates of chicken manure + rice hull (CM) (0 4 8 and 12 ton/rai) and the sub plots were the rates of chemical fertilizers (CF) formula 15-7-18 0 25 and 50 kg/rai). Huay Bong 60 (HB 60) cassava variety was planted at the experimental field of the Tapioca Research and Development Center, Huay Bong sub-district, Dankhuntod district, Nakhon Ratchasima province. The experimental period was 26 June 2005-25 May 2006. The results revealed that input CM at rate 4 8 and 12 ton/rai gave the same average fresh root yield. But the average fresh root yield in control gave the lowest and the differences were significant. The same was true for CF, however, the differences were not significant (4,296 4,520 and 4,650 kg/rai). Root starch content in CM rate 0 4 ton/rai are the same but difference from Root starch content in CM rate 8 12 ton/rai were gave the lowest root starch content. The CF rate at 0 ton/rai was gave the highest root starch content that difference from CF rate at 25 50 ton/rai. Interaction between CM x CF was also observed and the differences were significant where CM 12 ton/rai x CF 25 kg/rai gave the lowest root starch content of 23.0 percent . Root dry matter increased with the increase in CM rate up to 8 ton/rai after which it declined (1,224 1,577 1,623 and 1,442 kg/rai for 0,4,8 and 12 ton/rai). No differences were detected among rate of CF and CM x CF interaction was not significant. Considering top weight, CM rate and CF rate did not affect top weight and so as interaction (CM x CF). The same was true for Harvest Index (ranged from 0.45-0.55).