Effect of bacterial blight (Pseudomonas syringae pv. pisi) on the growth and yield of single pea (Pisum sativum) plants under glasshouse conditions

Single pea ( Pisum sativum ) plants cvs Kelvedon Wonder and Solara, growing in pots in a glasshouse, showed significant reductions in seed yield of 24, 47 or 71% following inoculation with pea bacterial blight ( Pseudomonas syringae pv. pisi ) during reproductive, vegetative or both reproductive and vegetative growth stages, respectively. These yield reductions were seen as reduced numbers of seeds per pod combined with changes in the numbers of pods per plant. Examination of the importance of different disease parameters on yield showed that mean disease on the whole plant was the most important. Equations describing the relationship between seed yield or the natural log of the total weight and mean disease were derived.