TITLE:
Seasonal Incidence of Diaphorina citri Kuwayama in Assam Lemon and Its Relationship with Weather Factors in Sub-Himalayan Plains of West Bengal
AUTHORS:
Tanuj Debbarma, Tapan Kumar Hath, Deb Sankar Gupta, Swagata Bhowmik
KEYWORDS:
Seasonal Incidence, Citrus Psyllid, Assam Lemon, Citrus limon
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.15 No.12,
December
30,
2024
ABSTRACT: Seasonal incidence of citrus psylla, Diaphorina citri Kuwayama was studied in Assam Lemon (Citrus limon L. Burm) in two consecutive years in sub-Himalayan plains (terai zone) of West Bengal (India). The psyllids appeared with the arrival of new flush which occurred three times a year, the first during January last to early February (4th-5th SW), second during April-May (17th - 18th SW) and the third during September (37th-38th SW). Three peaks were recorded—one at 11th SW (6.11 psyllids/shoot), the second at 21st SW (7.50 psyllids/shoot) and the third peak at 43rd SW (5.06 psyllids/shoot). The second peak recorded the highest psyllid population. The psylla were active throughout the whole year except during the cold winter period when their population was either low or absent. Temperature showed a positive association with psyllid population (r = 0.304 for TMax and r = 0.182 for TMin) while RH% (r = −0.200 for RHMor and r = −0.200 for RHEvn) and rainfall had a negative correlation (r = −0.013). During the 1st peak population (11th SW) the average temperature, RH% and rainfall were 30.82˚C (TMax) and 16.68˚C (TMin), 55.36% (RHMor) and 62.72% (RHEvn) and nought respectively; while the corresponding values were 33.43˚C (TMax) and 24.29˚C (TMin), 76.43% (RHMor) and 75% (RHEvn) and 7.85 mm respectively during the 2nd peak (21st SW). Likewise, at the 3rd peak (43rd SW), the respective values were 30.22˚C and 19.07˚C (TMax and TMin, respectively), 80% and 76.79% (RHMor and RHEvn, respectively) and zero mm respectively.