FIG. 1.

Influence of foliar sodium salicylate and ammonium sulfate amendments on population size of P. syringae Cit7 and Cit7(pNAH7) on tomato leaves. Sodium salicylate (○) and ammonium sulfate (▾) were applied separately or were used in combination (▿). Application of PPB (•) was used as a control. Error bars, standard errors of the means of population size estimated from 20 or 15 leaflets. (A) P. syringae Cit7 in the growth chamber; (B) P. syringae Cit7(pNAH7) in the growth chamber; (C) P. syringae Cit7 in the greenhouse; (D) P. syringae Cit7(pNAH7) in the greenhouse. Experiments were repeated twice in the greenhouse and three times under growth chamber conditions. One representative experiment is presented for each location.