157 Susceptibility of Poinsettia Cultivars to Whiteflies

Susceptibility of Cultivars to Biotic Stresses

Effect of Pseudomonas putida on Growth and Anthocyanin Pigment in Two Poinsettia (Euphorbia pulcherrima) Cultivars

Pseudomonas putida is plant growth promoting rhizobacteria (PGPR) that have the capacity to improve growth in plants. The purpose of this study was to determine growth and anthocyanin pigmentation of the bracts in two poinsettia Euphorbia pulcherrima cultivars (Prestige and Sonora Marble) using three strains of P. putida, as well as a mixture of the three (MIX). Comparison with the control grou...

Relative susceptibility of selected cultivars, of potato to Pratylenchus penetrans.

Pratylenchus penetrans suppressed the tuber yields of potato cultivars 'Katahdin', 'Kennebec', and 'Superior', but did not affect yields of 'Russet Burbank'. In comparison with noninfested controls, all initial nematode densities (P(i)) of P. penetrans (P(i) = 38, 81, 164, 211/ 100 cm(3) of soil) suppressed yields of Superior; a moderate P(i) (81/100 cm(3) soil) suppressed yields of Kennebec; a...

Susceptibility of Viburnum Species and Cultivars to Phytophthora ramorum1

Phytophthora ramorum causes ramorum blight on Viburnum species, which are commonly grown as ornamentals. This study evaluated 24 different species or cultivars for susceptibility to P. ramorum. Whole plants were inoculated with an NA1 isolate of P. ramorum and placed in dew chambers at 20C (68F). After 5 days, the percentage of necrotic leaves for each plant and the percentage of necrotic area ...

Using Paclobutrazol to Control Height of Poinsettia ‘Freedom’

Late-season height control of poinsettia (Euphorbia pulcherrima) is difficult since most chemical growth retardants adversely reduce bract size when applied after first bract color. Paclobutrazol (Bonzi) controls stem elongation late in poinsettia crop development but can excessively reduce bract size if improperly applied. Two experiments were conducted to quantify how paclobutrazol applicatio...