• Title/Summary/Keyword: direct-seeded

Search Result 191, Processing Time 0.023 seconds

Weed Occurrence and Competitive Characteristic under Different Cultivation Types of Rice(Oyriza sativa L.) - 1. Distribution and Dominance of Weed and Rice (수도(水稻) 재배유형별(栽培類型別) 잡초발생양상(雜草發生樣相)과 경합특성(競合特性) - 제(第) 1 보(報). 잡초발생양상(雜草發生樣相)과 우점도(優占度) 변이(變異))

  • Im, I.B.;Guh, J.O.;Park, K.Y.
    • Korean Journal of Weed Science
    • /
    • v.13 no.1
    • /
    • pp.26-35
    • /
    • 1993

  • Differences in weed occurrence was investigated among five types of rice (Oryza sativa L.) cultivation. The five types employed were three transplanting cultivations such as conventional hand transplanting, machine transplanting with 30-day-old seedling, and machine transplanting with 10-day-old seedling and two direct-seedings such as flood direct-seeded rice by pregerminated seed and dry direct-seeded rice by dry seed. Weed specie, occurred varied from 7 to 20, depending on the different cultivation types. Weeds were more diverse in transplanting with l0-day-old seedling than in other transplanting cultivations and in direct-seeding than in transplanting practice. Dominant weed species also varied with cultivation types. In transplanting cultivations Scirpus juncoides Roxb., Echinochloa crus-galli (L.) P. Beauv., and Eleocharis kuroguwai Ohwi were dominant, whereas occurrence of annual weeds such as Cyperus difformis L. and Monochoria vaginalis Presl. aside from the three weed species increased in direct-seeded cultivations.

  • PDF

Rapid and Direct Detection of Vibrio vulnificus in Small Octopus (Octopus variabilis) Using Polymerase Chain Reaction

  • Choi, Sang-Ho;Lee, Jee-Yeon
    • Journal of Microbiology and Biotechnology
    • /
    • v.5 no.4
    • /
    • pp.181-187
    • /
    • 1995

  • The cells of Vibrio vulnificus can be induced to the viable but nonculturable (VBNC) state by natural environmental parameters. The V. vulnificus cells in the VBNC state can not be recovered by ordinary laboratory techniques. This nonculturability could often hamper development of effective processing strategies to minimize the number of V. vulnificus in seafoods. Even with V. vulnificus cells in a culturable state, the length of time required to identify the bacteria in contaminated food by phenotyphic characterization may prevent appropriate in-time responses by public health agencies to infections of the bacteria. In the present study, we used polymerase chain reaction (PCR) to develop a rapid and direct detection method for V. vulnificus in small octopus (Octopus variabilis) which is consumed as a raw food in Korea. The region targeted was a 704-base pair (bp) portion of the hemolysin gene, vvhA, of V. vulnificus. The primers designed for PCR amplification were specific for all V. vulnificus sp. tested. Several methods were examined to extract total DNA directly from V. vulnificus seeded into the octopus homogenate and the guanidine isothiocyanate (CITC) method appeared to be most effective. From the octopus homogenate seeded by V. vulnificus at an initial level of $10^2$ CFU/ml of the homogenate and then incubated for 12 h, the targeted sequence was successfully amplified by PCR and the 704-bp DNA fragment was observed by gel electrophoresis. The total completion of this assay requires less than one day.

  • PDF

Occurrence of Volunteer Rice Plants at Paddy Field Harvested with Combine (콤바인 수확답에서 벼 이형주 발생양상)

  • 이승필;김상경;윤영석;이광석;최대웅
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.36 no.4
    • /
    • pp.305-309
    • /
    • 1991

  • This experiment was conducted to investigate the effect of shattered grain by combine harvesting at the previous year on rice plant emergence at different planting methods and plant characteristics, The results are follows : Combine harvesting greatly influence on shattered grain of Samgangbyeo as Tongil variety (49.5kg/10a) compared to that of Nagdongbyeo as Japonica variety(27.8kg/10a), while Nagdong-byeo showed higher germination rate than Samgangbyeo, whether transplanted and direct seeded. Emergence of volunteer and seed mixture were lower in transplanted than in direct seeded. In variety test. Japonica variety showed higher emergence of volunteer rice and seed mixture than Tongil variety. Generally, no significant difference in yield components were observed with different varieties by the volunteer rice. But the volunteer rice caused by combine harvesting decreased culm length, panicle length, spikelet number, panicle number and ripening ratio. except l000-grain weights.

  • PDF