Biocontrol of Crown Gall by Rhizobium rhizogenes: Challenges in Biopesticide Commercialisation

The biocontrol of crown gall has been practised in Australia for 48 years. Control is so efficient that it is difficult to find a galled stone fruit tree, when previously, crown gall had been a major problem. This paper explains how it works and why only pathogens are inhibited. A commercial biopesticide is available in Australia, Canada, Chile, New Zealand, Turkey, the USA, South Africa and Japan. The challenges of commercialising a biopesticide are outlined. Rigid regulations are preventing the wider use of biocontrol organisms.

Viroid Diseases in Pome and Stone Fruit Trees and Koch’s Postulates: A Critical Assessment

Composed of a naked circular non-protein-coding genomic RNA, counting only a few hundred nucleotides, viroids—the smallest infectious agents known so far—are able to replicate and move systemically in herbaceous and woody host plants, which concomitantly may develop specific diseases or remain symptomless. Several viroids have been reported to naturally infect pome and stone fruit trees, showing symptoms on leaves, fruits and/or bark. However, Koch’s postulates required for establishing on firm grounds the viroid etiology of these diseases, have not been met in all instances. Here, pome and stone fruit tree diseases, conclusively proven to be caused by viroids, are reviewed, and the need to pay closer attention to fulfilling Koch’s postulates is emphasized.

Detection of the phytosanitary status of stone fruit cultivars under in vitro conditions in Hungary

Prunus species are prone to infections by a range of pathogens (LAIMER 2002). Stone fruit plantations are mainly affected by Plum pox virus (PPV), Prune dwarf virus (PDV), Prunus necrotic ringspot virus (PNRSV) and European Stone Fruit Yellows phytoplasma (ESFY). The production of elite plants of pathogen-free stone fruit cultivars includes the application of effective methods for the detection and elimination of the major stone fruit tree viruses and phytoplasmas. The method of micropropagation offers a quick possibility for breeders to introduce new cultivars into the production. Virus testing by molecular techniques of in vitro plants requires only tiny samples and reduces the danger of false negatives. First results of the virus testing originated from in vitro peach cultivars are presented.

Weed Management in Plums

Revised! These 3-4 page fruit and nut fact-sheets by Jeffrey G. Williamson from the Weed Management Guide have been updated. They provide tables of chemical weed control recommendations. Published by UF Department of Horticultural Sciences, November 2007. HS93/WG020: Weed Management in Stone Fruit Tree Crops (Nectarine, Peach, and Plum) (ufl.edu)

Weed Management in Nectarines

Revised! These 3-4 page fruit and nut fact-sheets by Jeffrey G. Williamson from the Weed Management Guide have been updated. They provide tables of chemical weed control recommendations. Published by UF Department of Horticultural Sciences, November 2007. HS93/WG020: Weed Management in Stone Fruit Tree Crops (Nectarine, Peach, and Plum) (ufl.edu)

Weed Management in Peaches

Revised! These 3-4 page fruit and nut fact-sheets by Jeffrey G. Williamson from the Weed Management Guide have been updated. They provide tables of chemical weed control recommendations. Published by UF Department of Horticultural Sciences, November 2007. HS93/WG020: Weed Management in Stone Fruit Tree Crops (Nectarine, Peach, and Plum) (ufl.edu)