Infestation and yield losses caused by Cnaphalocrocis medinalis Guenee under differential fertilization and control procedure.

Inoue, Hideaki; Fukamachi, Saburo

doi:10.4241/kyubyochu.36.103

Cited by 4 publications

(2 citation statements)

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“…However, high fertilizer inputs may also lead to increased pest infestation levels, which reduce the expected gains in rice yield. Several reports demonstrate this effect (Hu et al, 1986;Saroja et al, 1987;Inoue and Fukamachi, 1990). In the present study, grain yield per hill was highest in the medium nitrogen treatment, although crop biomass and nitrogen content were higher in the high nitrogen treatment.…”

Section: Implications For Integrated Crop Managementmentioning

confidence: 84%

Impact of nitrogenous-fertilization on the population dynamics and natural control of rice leaffolders (Lep.: Pyralidae)

Kraker

Rabbinge

Huis

et al. 2000

International Journal of Pest Management

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The effect of nitrogenous-fertilization on the population dynamics and natural control of rice leaffolders was studied in an irrigated rice area in the Philippines. Nitrogen was applied at three levels (0, 75 and 150 kg N ha Ð 1 ), and its impact on crop growth and yield, arthropod abundance, and rates of leaffolder parasitism and survival was assessed with weekly samples. Rice plants were taller and had a higher leaf nitrogen content with increasing levels of nitrogenousfertilization, but grain yield was highest at the medium nitrogen level. Herbivores, predators, and parasitoids increased in abundance with nitrogenous-fertilization level. The average density of rice leaffolder larvae at the highest nitrogen level was eight times the density at zero nitrogen level, and the peak percentage injured leaves increased from 5 to 35%. The strong increase in larval density was due to the positive effect of nitrogenous-fertilization on egg recruitment and survival of medium-sized larvae. The percentage parasitism of eggs and larvae was not affected by nitrogenous-fertilization. The increase in survival of medium-sized larvae with nitrogen levels was associated with lower predator to leaffolder ratios. The strong effect of nitrogenous-fertilization in the present small-scale experiment was attributed mainly to allowing the moths an oviposition choice between plots with different application levels of nitrogen. Therefore it is hypothesized that the effect of increasing nitrogenous-fertilization level on leaffolder larval densities will be less pronounced when implemented over a large area.

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Section: Implications For Integrated Crop Managementmentioning

confidence: 84%

Impact of nitrogenous-fertilization on the population dynamics and natural control of rice leaffolders (Lep.: Pyralidae)

Kraker

Rabbinge

Huis

et al. 2000

International Journal of Pest Management

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“…The amount of insect pests emerging varies yearly and seasonally in each field, and the variance relates to the stage in rice growth and the fertilization system (Inoue andFukamachi 1990, Miyashita andKawanishi 2003). In addition, insect pests influence rice quality and the volume of production.…”

Section: Insect Countmentioning

confidence: 99%

Field and Weather Monitoring with Youths as Sensors for Agricultural Decision Support

Togami

Ninomiya

Yamamoto

et al. 2012

Agricultural Information Research

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In Vietnam, proper and continual agricultural engineering guidance for local farmers is required to improve rice cultivation and conserve environment, yet there are issues in the low literacy rate of adults and information dissemination. In order to resolve the issues, the YMC-Viet project, based on the Youth Mediated Communication (YMC) model in which youths mediate communication between local farmers and agricultural experts in remote locations, was proposed. It is inadequate only to unilaterally extract problems from farmers and provide guidance. Advice can be further optimized by providing local quantitative data to agricultural experts. Accordingly, information collection to accurately comprehend local environmental conditions and the rice growth situation is indispensable. However, there is no weather station in the target area and environmental information is severely lacking. In addition, the number of agricultural experts in the area is extremely low and gaining an understanding of the field situation is almost impossible. In this research, therefore, we devised a method to regularly collect environmental and field situation information, by having youths working as weather and field sensors, and utilizing the collected data for agricultural decisions supported by agricultural experts in remote locations, and its efficacy was verified. Then, we created a cultivation knowledge resource and applied it as a contrivance for youths to adequately inform agricultural experts about field growth situations based on collected information. As a result of the experiment, it was revealed that youths met more than 85 percent of the requirements of temperature and humidity measurement and weather observation. Additionally, the data collected and the records showed higher potential by agricultural experts for utilizing the data in agricultural decision support. Moreover, it was confirmed that sometimes youths functioned as disorder and defect detectors. Thus, the efficacy of youths as sensors in terms of collecting information for agricultural support was verified.

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Effects of Rice Leaf Position and Growth Stage on Larval Development and Survivorship of the Rice Leaf Roller Cnaphalocrocis medinalis (Guenee) (Lepidoptera: Pyralidae).

Miyashita¹,

Kawanishi²

2003

Jpn. J. Appl. Entomol. Zool.

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The larvae of the rice leaf roller, Cnaphalocrocis medinalis (Guenèe), fed rice leaves from the vegetative growth period until panicle formation developed to the 5th instar and pupated regardless of the variety and position of leaves given to them. In larvae fed leaves after the booting period, 6th or sometimes 7th instar larvae appeared. The frequency of these extra-molting-type larvae increased as the rice growth stage advanced. In addition, the growth speed of the larvae was reduced even within the same instar. Larvae fed leaves at the ripening stage showed a decrease in pupal weight. These influences on larval development also varied according to the position of the leaves given. Marked negative effects were observed in larvae fed flag leaves as compared to those fed lower leaves. Particularly, many 1st instar larvae fed flag leaves during the ripening period died. Thus, the position of leaves consumed appears to affect larval survivorship. These changes in larval development and survival rate seem to be caused synergistically by differences in the nutritional value and hardness of leaves of the food plant.

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Infestation and yield losses caused by Cnaphalocrocis medinalis Guenee under differential fertilization and control procedure.

Cited by 4 publications

References 0 publications

Impact of nitrogenous-fertilization on the population dynamics and natural control of rice leaffolders (Lep.: Pyralidae)

Impact of nitrogenous-fertilization on the population dynamics and natural control of rice leaffolders (Lep.: Pyralidae)

Field and Weather Monitoring with Youths as Sensors for Agricultural Decision Support

Effects of Rice Leaf Position and Growth Stage on Larval Development and Survivorship of the Rice Leaf Roller Cnaphalocrocis medinalis (Guenee) (Lepidoptera: Pyralidae).

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