Impact of drip and overhead sprinkler irrigation on the persistence of attenuated Escherichia coli O157:H7 in the lettuce phyllosphere was investigated using a split-plot design in four field trials conducted in the Salinas Valley, California, between summer 2007 and fall 2009. Rifampicin-resistant attenuated E. coli O157:H7 ATCC 700728 (BLS1) was inoculated onto the soil beds after seeding wit...

Table 1. Percentage of larvae surviving on cabbage cultivar Round Up and diamondback moth-resistant glossy-leafed cabbage NY 2518, and relative resistance of NY 2518 (survival on NY 2518 expressed as a percentage of that on ‘Round Up’) at five plant ages and two inoculation schemes. Knowledge of age-dependent expression of resistance is critical for evaluation of breeding lines and for effectiv...

Meloidogyne hapla-resistant plants grown from cuttings and inoculated with M. hapla larvae were free of galls. However, 35 to 48% of the seedling intercross progeny of resistant genotypes that were inoculated in the germinated seed stage were galled. There was an inverse relationship between the age of plants grown from seed and the percentage of plants galled by M. hapla; the older the plants ...

In the presence of potato plants cv. Golden Wonder, Globodera pallida exhibited delayed in-soil hatch compared to that of G. rostochiensis, with significantly fewer G. pallida second-stage juvenile nematodes hatching in the first two weeks, though the difference disappeared after four weeks. Inoculation of potato plants with arbuscular mycorrhizal fungi eliminated this delay in G. pallida hatch...

Phoma black stem and leaf spot disease (Phoma medicaginis) not only destroys annual Medicago spp. forage seed yield but also reduces herbage quality by consequent phytoestrogen production that ovulation of grazing animals. Two controlled environment studies evaluated the effects plant developmental stage in rugosa ‘Paraponto’ M. scutellata ‘Sava’ different inoculum concentrations P. medicaginis...

Hunt et al. (2) and Norton (4) showed that the northern root-knot nematode, Meloidogyne hap/a Chitwood, increased the incidence of bacterial wilt in alfalfa. Hunt et al. (2) also f o u n d t h e b a c t e r i a l wilt organism, Corynebacterium insidiosum (McCuU) H. L. Jens., in plant tissue that had been inoculated only with the bacteria. This would indicate that the role of M. hapla is somethi...