POPULATION DYNAMICS OF SUCKING PEST COMPLEX OF CASTOR (Ricinus communis Linnaeus)

B.C. PATEL¹*, P.S. PATEL², J.B. TRIVEDI³, S.A. PATEL^4
1Department of Entomology, C. P. College of Agriculture, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar – 385 506 (Gujarat), India
²Department of Entomology, C. P. College of Agriculture, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar – 385 506 (Gujarat), India
³Department of Entomology, C. P. College of Agriculture, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar – 385 506 (Gujarat), India
⁴Department of Entomology, C. P. College of Agriculture, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, 385 506 (Gujarat), India
* Corresponding Author : pbipin124@yahoo.com

Received : 23-07-2015     Accepted : 04-08-2015     Published : 07-11-2015
Volume : 7     Issue : 8       Pages : 596 - 600
Int J Agr Sci 7.8 (2015):596-600

Keywords : Castor, Population dynamics, Sucking pest
Academic Editor : Preetha P, Er. Ashokkumar Naralasetty
Conflict of Interest : None declared
Acknowledgements/Funding : None declared

The experiment on population dynamics against sucking pest complex of castor,a field experiment was conducted during 2012-13 on castor (Ricinus communis) at Main Castor and Mustard research station, Sadarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar. The studies on population dynamics of leafhopper, Empoasca flavescens revealed that the pest remained active during second week of September to third week of April. The population attained three peak periods of activity i.e., the first peak (5.44 nymphs/three leaves/plant) during fourth week of October, second (6.08 nymphs/three leaves /plant) in third week of November and third peak (3.88 leafhoppers/three leaves/plant) in second week of March. Leafhopper population had non-significant and positive correlation with morning relative humidity as well as mean bright sunshine (r = 0.11 and r = 0.13, respectively), whereas it had significant and negative correlation with minimum temperature, evening relative humidity as well as wind velocity (r = - 0.58, - 0.53 and -0.41, respectively). Thrips, Scirtothrips dorsalis first appeared in second week of September and continued throughout the crop season. The population reached peak level of activity twice, the first (3.44 thrips/three leaves/plant) during first week of November and second (3.68 thrips/spikes/ plant) during fourth week of March. Thrips population had negative and significant correlation with minimum as well as morning and evening relative humidity (r = -0.45, -0.38 and -0.55, respectively). Population study of whitefly, T. ricini revealed that the pest remained active from second week of September to third week of April. Three peaks were observed for whitefly, the first (1.64 whiteflies/three leaves/plant) during second week of October, second (2.44 whiteflies/three leaves/plant) during fourth week of November and third (3.08 whiteflies/three leaves/plant) during second week of March. Whitefly population exhibited significant negative correlation (r = -0.59) with morning relative humidity.