Effect of Biofertilizer (PGPR – 3) Organic and Chemical Fertilizers on Growth Yield and Quality of Rayong 9 and Kasetsart 50 Cassava Varieties on Korat Soil Series

Abstract

This research objective is aimed to developmental Technology appropriated fertilizer management for cassava cultivation on Korat soil series (Kt). A split-split plot design was carried out with 3 replications. Main-plot consists of non-applied PGPR 3 bio-fertilizer (PGPR-3-BF) cassava cultivars: Rayong-9 and Kasetsart-50 assigned as sub-plot. The sub-sub plot comprises of 6 fertilizer formulas recipe (FR); 1) FR-1: with-out fertilizer, 2) FR-2 organic fertilizers (OF) combined with chicken manure and husk (OF-mix-CH) at 500 kg/rai, 3) chemical fertilizer (CF) grade 16-8-16 (N-P₂O₅-K₂O) kg/rai, 4) FR-4: CF grade 8-4-8 (N-P₂O₅-K₂O) kg/rai, 5) FR5: OF combined CH at 500 kg/rai with CF grade 16-8-16 (N-P₂O₅-K₂O) combined kg/rai, 6) FR-6: OF combined CH at 500 kg/rai with CF grade 8-4-8 (N-P₂O₅-K₂O) combined kg/rai. Results found that PGPR-3-BF application treatment increased the tuber yield by 13.89% in comparison with non-PGPR-3-BF application treatment were statistical significantly. The cassava cultivars Rayaong 9 and Kasetsart 50 exhibited significance difference in the tuber yield. Kasetsart 50 produced higher tuber yield (18.06%) than Rayong 9. In addition, fertilizer formulas gave significant difference tuber yield. The FR-5 gave the highest tuber yield 6,794 kg/rai, but there was not significantly different with PR-6. There were combination factors effects between PGPR-3-BF and FR, in the present study fertilizer application of PGPR-3-BF with FR-6 gave tuber yield as 7,470 kg/rai. Three combination factors effects were not significantly different in tuber yield, but Kasetsart-50 in PGPR-3-BF and FR-6 treated, while profit obtained maximum of 8,861 bath/rai. This study indicates that fertilizing of PGPR-3-BF and FR-2 can be reduced CF by 50% of the recommendation of nitrogen, phosphorus and potassium in Korat soil series.