EFFECT OF PHOSPHORUS DOSE AND POTASSIUM SOURCES ON YIELD AND EXPORT QUALITY OF POTATO

Abstract

The experiment was conducted in the experimental field of Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka from the period of November, 2018 to February, 2019 to assess the effect of phosphorus dose and potassium sources on yield of processing and export quality of potato. The potato variety BARI Alu-28 (Courage) was used as test crop for this experiment. The experiment consisted of two factors: Factor A: Phosphorus dose (4 dose) as- P 1 = 240 kgha = 200 kgha -1 -1 TSP @ 41.84 kg P ha TSP@ 50.21 kg P ha -1 and P 4 -1 xi

; P 2 = 220 kgha = 260 kgha -1 -1 TSP @ 46.03 kg P ha TSP @ 54.39 kg P ha , and potassium sources (3); K 1 = KCl (250 kg ha -1 KCl @130 kg K ha -1 ), K 2 = KH 2 (452.19 kgha -1 KH 2 PO 4 @130 kg K ha -1 ) and K 3 = K 2 SO 4 (288.6 kgha -1 K 2 SO 4 PO 4 @130 kg K ha ). The two factorial experiment was laid out in split-plot design with three replications. Data were recorded on different yield attributes, yield and quality of potato tuber. For different dose of phosphorus, number of tuber per hill, average tuber weight, yield, chips potato (45-75), french fry (>75), TSS, firmness, Reducing sugar, non-reducing sugar content, increased with increasing phosphorus dose and negative relation was observed increase of canned potato (2045),

dry matter content, specific gravity, starch, anti-oxidant and polyphenol content. In case of different sources of potassium, the highest yield of potato tubers (34.30 t ha , but dry matter content (21.10%), specific gravity (1.0808 gcm -3 ), firmness (46.80), starch (15.985%), anti-oxidant (567.87 Trolox µ Mol 100 g -1 FW) and polyphenol (85.243 GA mg 100 g -1 FW) was recorded from K 3 , whereas the lowest was found from K 2 . Due to combined effect of different dose of phosphorus and different sources of potassium, the highest yield of potato tubers (35.35 tha -1 ) from P 3 k 2 , but dry matter content (22.85%), specific gravity (1.0998 gcm -3 ), starch (17.936%), anti-oxidant (630.12 Trolox µ Mol 100 g FW) and polyphenol (92.994 GA mg 100 g -1 FW) were found from P 1 K 3 , whereas the lowest dry matter and specific gravity content were recorded from P 1 K 2 treatment combination. Among potassium sources, inspite of KH 2 PO 4 producing highest yield of potato, KCl and K 2 as a source of potassium and 50.21 kg P ha -1 produced good processing quality potato. However, considering economic condition of Bangladesh and availability, KCl would be used as a source of potassium for producing processing quality of potato without sacrificing yield.