trafik ceza easy agario agario games agario agario unblocked agario modded agarioprivate A Global Perspective of Rice Brown Planthopper Management Ⅱ- After Green Revolution Era | KRISHNAIAH | Molecular Entomology

A Global Perspective of Rice Brown Planthopper Management Ⅱ- After Green Revolution Era  

N.V. KRISHNAIAH
Principal Scientist (Retired), Directorate of Rice Research, Rajendranagr, Hyderabad-500030, INDIA
Author    Correspondence author
Molecular Entomology, 2014, Vol. 5, No. 6   doi: 10.5376/me.2014.05.0006
Received: 05 May, 2014    Accepted: 03 Jun., 2014    Published: 30 Jun., 2014
© 2014 BioPublisher Publishing Platform
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Rice Brown Plant hopper, Nilaparvata lugens (Stal) (BPH) has started becoming a major pest in tropical rice growing countries only after major areas were covered by dwarf varieties or high yielding varieties (HYVs). Detailed discussion both historical and experimental evidence on several possible causes like Changed architecture of rice plant, Associated change in agricultural practices, change in micro-climate in rice crop ecosystem, Lack of insect resistance in dwarf varieties, Increased use of insecticides, Consequent destruction of natural enemies, Development of insecticide resistance is presented. Among these, microclimatic factors in rice ecosystem, notably optimum temperature, low wind movement, high water vapor pressure and consequent high relative humidity among abiotic factors and nitrogen rich plant sap among biotic factors appeared to be the most important. Lack of BPH resistance in HYVs does not appear to be the primary cause. Higher insecticide usage in HYVs appeared to be responsible for persistence of BPH menace partially due to destruction of natural enemies and more importantly through development of insecticide resistance and resurgence. However this seems to be secondary cause for BPH problem in all tropical rice growing countries of Asia including China and India.
Keywords
Rice; Brown plant hopper; Nilaparvata lugens; Biotypes; Long range migration; Insecticide resistance

INTRODUCTION
Rice Brown Plant hopper, Nilaparvata lugens (Stal) (BPH) is an ancient insect associated with rice ecosystem in all tropical rice growing areas in Asia. However it is a well-recognizedfact that BPH has started becoming a major pest and later even as a threat to rice production in these countries only after major areas were covered by dwarf varieties or high yielding varieties(HYVs). The initial period of such flare up slightly differed among the tropical countries depending on the accessibility of HYVs to the local farmers. That is probably the reason why the first international symposium on BPH held at International Rice Research Institute (IRRI) in 1978 was titled as “Brown PlantHopper: Threat to Rice Production in Asia”.In The Philippines, major BPH damage was observed in 1973, although there was gradual rise from 1969 onwards. This might be due to proactive approach of IRRI in extension activities in the country along with research at that time. In fact the first country that tasted green revolution in rice was the Philippines as seed of IR8 “the wonder rice”, which was termed at that time, was made available to farmers by IRRI itself from 1969. In India, the most severe outbreak of BPH was reported from Kerala state at the end of 1973 and early in 1974. But author’s own experience shows that it has started its demonic form in kharif 1973 in Krishna-Godavari delta of A.P. on Jaya variety and probably in other major rice growing deltas of the country. In Indonesia, Sri Lanka,Thailand and Solomon Islands BPH damaged rice in a significant way in 1974, from 1975 in Malaysia and Vietnam, from 1976 in Bangladesh.Interestingly no recorded evidencewas available from China at that time (Dyck and Thomas,1979).
CAUSES OF BPH OUT-BREAKS IN TROPICAL RICE GROWING COUNTRIES AFTER GREEN REVOLUTION ERA:
If one examines the possible causes of sudden demonic emergence of BPH after 1972 and increased and persistent devastation it causes every year, many points could emerge.
1. Historical evidence from temperateand tropical countries
2. Changed architecture of rice plant
3. Associated changed agricultural practices
4.Possible change in micro-climate in rice crop ecosystem
5. Lack of insect resistance in dwarf varieties
Molecular Entomology
• Volume 5
View Options
. PDF(208KB)
. FPDF
. HTML
. Online fPDF
Associated material
. Readers' comments
Other articles by authors
. N.V. KRISHNAIAH
Related articles
. Rice
. Brown plant hopper
. Nilaparvata lugens
. Biotypes
. Long range migration
. Insecticide resistance
Tools
. Email to a friend
. Post a comment