The effect of solar heating of soil on natural and inoculated agrobacteria

Abstract

Solarization trials were carried out over 3 years and in two countries to control crown gall disease on fruit trees and eliminate Agrobacterium. In 1992, agrobacteria in naturally infested soils of two Italian nurseries were monitored before and after solarization. Agrobacteria populations decreased by 99% and 92% after the treatment; however, crown gall incidence did not decrease. In 1993 and 1994 solarization was tested in Oregon in fields artificially infested with two marked strains of A. tumefaciens. In sandy loam soil, the target bacteria were eliminated in 4 weeks, while in silty clay soil the populations were markedly reduced after 2 months of treatment. Crown gall incidence on cherry rootstocks transplanted to the field at the end of 1993 was 3·7% in the sandy loam soil control plots, while no tumours were observed on plants from solarized plots. The use of solarization in combination with reduced doses of metham-sodium was also evaluated.

Effect of white mustard cover crop residue, soil chemical fumigation andTrichodermaspp. root treatment on black‐foot disease control in grapevine

“…Additionally, no positive correlation was observed between DI and DS, suggesting that reduction of DI is not a necessary condition for lowering of DS. These results agree with those of other authors investigating the effects of several strategies for the control of soilborne diseases …”

“…These results agree with those of other authors investigating the effects of several strategies for the control of soilborne diseases. [63][64][65]…”

Silencing of Agrobacterium tumefaciens oncogenes ipt and iaaM induces resistance to crown gall disease in plum but not in apricot

“…Recently, the Bacillus methylotrophicus 39d strain has been proposed as a biological agent for crown gall disease in tomato plants . Chemical and agronomical methods for controlling crown gall disease are only partially effective …”

“…5 Chemical and agronomical methods for controlling crown gall disease are only partially effective. 3,6 Germplasm evaluation is the first step towards breeding for crown-gall-resistant plants. Researchers have evaluated wild germplasm resources and cultivars for selecting crown-gallresistant Prunus genotypes.…”

Susceptibility of Juglans Species and Interspecific Hybrids to Agrobacterium tumefaciens

“…However, the difference was not as large as expected, based on our field observations of sites with "natural" inoculum and anecdotal reports from growers. In our root inoculation trial, crown gall incidence was relatively high ( 60%) on all rootstocks and it is possible that we would have seen greater differences between genotypes had we used less inoculum and consequently had a lower incidence of gall (Raio et al, 1997). Whitham (1989) suggested that plant hybrids, in comparison to their parental species, respond to diseases and insect pests in one of four general patterns: additive, dominant, elevated susceptibility, and elevated resistance.…”