scholarly journals Studies on Water Management in the Ill-drained Paddy Field : V. The effect of surface drainage on the rice plant lodging

1959 ◽  
Vol 28 (1) ◽  
pp. 58-60 ◽  
Author(s):  
Toshiaki KOYAMA ◽  
Akira MIYASAKA ◽  
Takeyasu MUSYA ◽  
Eiji ITO ◽  
Kazuo EGUCHI
Keyword(s):  
Water Management ◽  
Paddy Field ◽  
Rice Plant ◽  
Surface Drainage ◽  
Effect Of Surface

scholarly journals Studies on Water Management in the Ill-drained Paddy Field : VI. Effects of surface drainage on tillering of rice plants.

1960 ◽  
Vol 29 (1) ◽  
pp. 37-39
Author(s):  
Toshiaki KOYAMA ◽  
Akira MIYASAKA ◽  
Eiji ITO ◽  
Kazuo EGUCHI
Keyword(s):  
Water Management ◽  
Paddy Field ◽  
Rice Plants ◽  
Surface Drainage

Assessment of a three-stage sampling strategy to investigate the spatial distribution and population density of Aphelenchoides besseyi among Oryza sativa seeds

Nematology ◽  
2010 ◽  
Vol 12 (3) ◽  
pp. 373-380
Author(s):  
Katsumi Togashi ◽  
Shigeru Hoshino
Keyword(s):  
Spatial Distribution ◽  
Oryza Sativa ◽  
Paddy Field ◽  
Rice Plant ◽  
Spatial Scales ◽  
Sampling Strategy ◽  
Paddy Fields ◽  
Nematode Density ◽  
Aphelenchoides Besseyi ◽  
The Mean

AbstractThis study aimed to determine the spatial distribution patterns of Aphelenchoides besseyi among Oryza sativa seeds on panicle, plant hill, and paddy field spatial scales and to present a three-stage sampling method for estimating the mean density per seed in paddy fields. Living and dead nematodes were extracted individually from 20 seeds sampled from each of five panicles, which were sampled from each of six rice plant hills in each of eight paddy fields, where all plants had leaves exhibiting the 'white tip' symptom. Nested ANOVA indicated that A. besseyi density per seed was significantly different among the eight paddy fields, among rice plant hills in paddy fields, and among panicles in rice plant hills. The proportion of nematode-infested seeds (prevalence) increased and reached an upper limit as the mean density per seed on the panicle scale increased, whereas linear relationships were observed between nematode prevalence and the mean density on plant hill and paddy field scales. Relationships between mean density and mean crowding of nematodes per seed indicated that the nematodes exhibited clumped distribution on each of panicle, plant hill and field scales. Using these relationships, a three-stage sampling plan for estimating nematode density per seed at a specified precision level is presented.

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