Effects of chemical treatment and harvest date on the quality of potato tubers
その他（別言語等）
のタイトル
茎葉枯凋処理および収穫時期が馬鈴薯の品質におよ ぼす影響
著者（英） Ishibashi Ken‑ichi, Hironaka Kazunori journal or
publication title
Research bulletin of Obihiro University.
Natural science
volume 18
number 3
page range 163‑166
year 1993‑10‑25
URL http://id.nii.ac.jp/1588/00001960/
Res. Bull. Obihiro.， 18ρ993) : 163‑166 163
Effects of chemical treatment and harvest date on the quality of potato tubers
Ken‑ichi ISHIBAsHP and Kazunori HIRONAKAl (Received : May 31， 1993)
Abstract
Effects of vine desiccant and harvest date on the quality of potato tubers、IVereln vestigated in 1986 and 1987. Diquat was used in this study as a chemical desicc町lt.
Killing potato vines made no effect on the moisture， reducing sugar and starch contents of potato tubers. Starch cont叩 tsof the tubers at the lower position in the furrow were higher than those of the upper position due to the inf1uence of low air temperature.
Key words Potatoes， Chemical desiccant， Quality， Harvest date.
Introduction
Commercial production of potatoes (Solanum tuberosum L.， cv， Norin‑ichigo) in Hokkaido is mainly practiced in Tokachi district， In 1989， 938，100 tons of potatoes were harvested from this area， which amounted to 36% of total production in Japan
Desiccation of potato vines with chemicals have been reported almost half a century ago. SP AR‑
KS (1958) found that water uptake and trans location were among the factors inf1uencing mal formation in potatoes， Reduction of pathogen in vasion may be dependent on effective periderm formation. STRUCKMEYER and BINNING (1983) reported that tubers treated with paraquat had a less developed periderm than出euntreated ones， but it would serve as a barrier against the invasion of pathogens， Periderm was most highly differentiated in untreated tubers fol1owed by paraquat， Dow General， and diquat treated
tubers.
Chemical desiccants have some advantages， although， they may have an effect on the pro‑ cessed product， In this study， the effect of vine desiccant on the quality of potato tubers before harvest was investigated.
Materials and Metbods
This study was carried out a farmer's field during 1986田ld1987. Norin‑ichigo variety was treated with diquat (6， 7 ~ dihydrodipyrido (1， 2 ~a: 2'， 1 '~c) pyrazinediium dibro‑ mide) at the rate of 3 L /加onSeptember 28， 1986. Potato凶berswere taken from the furrow at various time intervals before and after harvest for the determination of moisture， reducing sugar and starch contents in the laboratory.
In 1986， the tubers were picked up at random from the furrow， while in 1987， they were picked up separately from the upper and lower positions of the furrow，
1 Department of Bioresource Chemistry， Obihiro University of Agriculture & Veterinary Medicine， Obihiro， Hokkaido 080， Japan
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