SCREENING OF AFRICAN AND FRENCH MARIGOLD GERMPLASMS AGAINST Tetranychus urticae KOCH (ACARI: TETRANYCHIDAE) UNDER FIELD CONDITIONS
KARUNA BAMEL *
Department of Zoology, CCS Haryana Agricultural University, Hisar, Haryana, Pin Code: 125004, India.
RACHNA GULATI
Department of Zoology, CCS Haryana Agricultural University, Hisar, Haryana, Pin Code: 125004, India.
. KHUSHBU
Department of Zoology, CCS Haryana Agricultural University, Hisar, Haryana, Pin Code: 125004, India.
MONIKA JANGRA
Department of Zoology, CCS Haryana Agricultural University, Hisar, Haryana, Pin Code: 125004, India.
KESHAV BAMEL
Department of Civil Engineering, Deenbandhu Chhotu Ram University of Science and Technology, Murthal, India.
*Author to whom correspondence should be addressed.
Abstract
The germplasms of African and French marigold were screened at Research Farm Area, Department of Horticulture, CCS Haryana Agricultural University, Hisar, Haryana against the two spotted spider mite, Tetranychus urticae (TSSM) in the winter season from first week of October to first week of March, 2018. The germplasm tall orange African sheltering lowest mite population (9.82 mites/leaf) was marked as the least susceptible and Hisar Jafari-2 French with 32.21 mites/leaf was categorized as highly susceptible for T. urticae infestation. Mite population was recorded weekly and significantly higher number of mites was recorded on grown up leaves followed by tender and older leaves of marigold plants. Irrespective of the germplasm, the mite number was found to significantly increase with each observation period till the attainment of peak in population in the month of January (35.51 mites/ leaf) while their least population was recorded in the month of October (6.65 mites/leaf). In general, French germplasms were comparatively more susceptible to T. urticae infestation as compared to African germplasms.
Keywords: Leaf stage, infestation, susceptibility, two spotted spider mite, Tagetes