Relationship between Tomato yellow leaf curl viruses and the whitefly vector.
Tomato Yellow Leaf Curl Virus (TYLCV) and Tomato Leaf Curl Virus (ToLCV) are the currently known begomoviruses in Uganda. The relationship with their whiteflies (Bemisia tabaci) vector and its management were not known in Uganda. A direct relationship was expected between these begomoviruses and whiteflies at Buwama in Mpigi district of Uganda. Farmer practices were expected to have limited efficacy. To investigate this, a completely randomised block design was used for all trials with six treatments replicated three times. Treatments evaluated were farmer whitefly pest management practices. These included both chemical pesticide and non-pesticide applications. Data on whitefly population and tomato yellow leaf curl virus disease incidence was recorded weekly, and analysed using SAS and SPSS statistical programmes for ANOVA, and correlations. Ranked means, coefficients of variation and standard errors were noted. Virus-vector relationship field studies established that virus occurrence varied in space and time, and with management practices, crop development stage, and weather conditions. A negative relationship (R = -0.14, p 0.04) was established between number of plants infected with TYLCV (sensu lato) and percentage marketable tomato yield. Tomato maturity was inversely propotional to whitefly infestation (R = -0.5, p 0.0001). Uprooting and application of dimethoate was most effective of the six treatments. Tomato leaf curl virus diseases and whitefly management options were established in Uganda.
Ssekyewa
Charles
C
University of Ghent, Faculty of Bioscience Engineering, Coupure Links 653, Ghent, Belgium. cssekyewa@umu.ac.ug
Van Damme
Patrick L J
PL
Hofte
Monica
M
D000383:Agriculture / Q000379:methods; D000704:Analysis of Variance; D000818:Animals; D053839:Begomovirus / Q000302:isolation & purification* / Q000472:pathogenicity; D004197:Disease Reservoirs / Q000821:virology; D006430:Hemiptera / Q000821:virology*; D007303:Insect Vectors / Q000821:virology*; D018551:Solanum lycopersicum / Q000821:virology*; D010935:Plant Diseases / Q000821:virology*; D014454:Uganda