CO-FREE Alternative Test Products for Copper Reduction in Agriculture

The project CO-FREE (2012-2016) aimed to develop strategies to replace/reduce copper use in organic, integrated and conventional farming. CO-FREE alternative test products (CTPs) were tested and integrated together with decision support systems, disease-tolerant varieties, and innovative breeding goals (ideotypes) into improved management strategies. CO-FREE focused on apple/apple scab (Venturia inaequalis), grape/downy mildew (Plasmopara viticola), and tomato and potato/late blight (Phytophthora infestans). Starting point of the project were ten CTPs with direct or indirect modes of action including Trichoderma atroviride SC1 and protein extract SCNB, Lysobacter spp., yeast-based derivatives, Cladosporium cladosporioides H39, the oligosaccharidic complex COS-OGA, Aneurinibacillus migulanus and Xenorhabdus bovienii, sage (Salvia officinalis) extract, liquorice (Glycyrrhiza glabra) extract, PLEX- and seaweed plant extracts. As the project progressed, further promising CTPs were included by the partners. Field trials were performed in different European countries in 2012-2015 following EPPO standards. In the first years, stand-alone applications of CTPs were tested. In the following years these were integrated into complete strategies. Effects on main and further diseases, on yield and on non-target organisms were assessed. Here, field trial results with CTPs are summarized

Enriched H3K4me3 marks at Pm-0 resistance-related genes prime courgette against <i>Podosphaera xanthii</i>

Abstract Powdery mildew (PM) disease, caused by the obligate biotrophic fungal pathogen Podosphaera xanthii, is the most reported and destructive disease on cultivated Cucurbita species all over the world. Recently, the appearance of highly aggressive P. xanthii isolates has led to PM outbreaks even in resistant crops, making disease management a very difficult task. To challenge this, breeders rely on genetic characteristics for PM control. Analysis of commercially available intermediate resistance courgette (Cucurbita pepo L. var. cylindrica) varieties using cytological, molecular, and biochemical approaches showed that the plants were under a primed state and induced systemic acquired resistance (SAR) responses, exhibiting enhanced callose production, upregulation of salicylic acid (SA) defense signaling pathway genes, and accumulation of SA and defense metabolites. Additionally, the intermediate resistant varieties showed an altered epigenetic landscape in histone marks that affect transcriptional activation. We demonstrated that courgette plants had enriched H3K4me3 marks on SA-BINDING PROTEIN 2 and YODA (YDA) genes of the Pm-0 interval introgression, a genomic region that confers resistant to Cucurbits against P. xanthii. The open chromatin of SA-BINDING PROTEIN 2 and YDA genes was consistent with genes’ differential expression, induced SA pathway, altered stomata characteristics, and activated SAR responses. These findings demonstrate that the altered epigenetic landscape of the intermediate resistant varieties modulates the activation of SA-BINDING PROTEIN 2 and YDA genes leading to induced gene transcription that primes courgette plants.</jats:p

Effect of variety choice and use of resistant rootstock on crop yield and quality parameters of tomato plants grown in organic, low input and conventional production systems/growth media

Soil-borne diseases are one of the most important problems in organic and other ‘low input’ soil-based greenhouse production systems. While chemical soil disinfection has been the method of choice in conventional farming systems, soil steaming has been the main strategy for the control of soil borne diseases in organic production. Both methods are extremely expensive and have been increasingly restricted for environmental reasons by government and organic standard setting bodies respectively. The use of tolerant varieties and of grafting onto resistant rootstocks were evaluated as potential replacements for soil steaming in organic and low input systems and found to be as effective in reducing root disease and increasing root fresh weight, fruit yield and number. The effects on fruit yield and quality characteristics were then further evaluated using different varieties for grafting and different growth media typically used in (a) organic (soil amended with manure), and (b) conventional (perlite fertilised with mineral fertilisers via the irrigation system) growth media/fertilisation regimes, and also a (c) novel “low input” growth medium designed to provide better aeration of the rooting zone. Fruit numbers, diameters and weights and total fruit yields were significantly different between growth media and highest for plants grown in the “low input” system, slightly lower for plants grown in the perlite and lowest for plants grown in the organic system. The potential for replacing chemical and steam soil disinfection methods in organic and ‘low input’ soil based greenhouse production systems is discussed

Development of a botanical plant protection product from Larix by-products to protect grapevine from Plasmopara viticola

Extracts from European Larch (Larix decidua) were shown to be efficient to control grapevine downy mildew (Plasmopara viticola) under controlled and field conditions. Larixyl acetate and larixol were identified as the active compounds