Limitation on Growth and Yield of Phaseolus vulgaris L. Due to Telfairia Mosaic Virus

Aims: To assess limitation on growth and yield of P. vulgaris due to Telfairia mosaic virus (TeMV).

Study Design: The study was conducted in a randomized block design.

Place and Duration: Department of Botany, University of Calabar, Calabar, Nigeria between April and August, 2016.

Methodology: Seeds of P. vulgaris were obtained, sorted, planted in polyethylene bags, and on germination, inoculated with TeMV, growth and yield limitation assessed at 2, 4, 6, 8 and 12 weeks after inoculation.

Results: Results showed that the virus decreased growth of P. vulgaris resulting in yield loses. Growth parameters were severely limited by TeMV with percentage reduction in Leaf area, shoot height, number of primary shoot, petiole length and number of leaves produced of 44.5%, 52.8%, 44.0%, 44.9% and 51.45 respectively at 10 weeks after inoculation (WAI). Leaf fresh weight (38.4%) and dry weight (32.3%) were significantly (P=0.05) reduced. Relative growth rate, net assimilation rate and leaf area ratio were negatively impacted by the virus with reductions of 26.5%, 36.7% at 4 WAI and 33.5% at 12 WAI respectively. Limitation on yield due to TeMV was significant (P=0.05) with reduction in pod length of 36.9%, number of pods per plant of 36.5%, number of seeds per pod of 26.5%, number of seeds per plant of 53.3% and weight of 100 seeds of 18.5%. Limitation induced on fresh and dry weight of shoot and root, pod width, seed length and seed width was not significant.

Conclusion: The study confirmed the threat of TeMV necessitating control of the virus on this important legume.