Background: Microbial resistance to medically important antibiotics is of international concern. There is considerable attention paid to the medical and veterinary use of antibiotics but there is a paucity of data on their use in global crop production. The only well documented use of antibiotics on crops is that on top fruit in the USA. Due to the absence of other data it is generally assumed that this use comprises the bulk of antibiotics applied to plants. The goal of this study was to investigate the scale and diversity of antibiotics being recommended for managing crop health problems in LMICs and the crops and types of problems for which they are selected. Methods: Plantwise is an international program which assists with the provision of agronomic advice to smallholder farmers in LMICs. Recommendations relating to the management of crop problems are stored in an international database, comprising over 400,000 records collected over 8 years. The extent of antibiotic use in crop production when grouped by the WHO regions was analysed using descriptive statistics. Results: Within our data all WHO regions of the world are using antibiotics on crop plants with the exception of Africa (no data for Europe) and the main crop on which they are used is rice. In some years, and in one region, nearly 10% of the management recommendations for rice contained an antibiotic. Eleven antibiotics are being recommended on crops (often blended together) and there is considerable regional variation as to where they are used. The problems against which antibiotics are recommended are extremely varied and we speculate that they are often used as a prophylactic spray to prevent, or control, low levels of bacterial disease. Conclusions: The data reveals that antibiotics are being recommended far more frequently and on a much greater variety of crops than previously thought. Relative to medical and veterinary use the quantities used globally are comparatively small, but this niche does provide some unique avenues by which resistance could develop in human pathogens. Results presented here have implications for those wanting to limit the spread of antibiotic resistance.

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A phytoplasma was initially detected in Dypsis poivriana by nested and real-time PCR from the botanical gardens in Cairns, Queensland, Australia in 2017. Further surveys in the Cairns region identified phytoplasma infections in eight additional dying ornamental palm species (Euterpe precatoria, Cocos nucifera, Verschaffeltia splendida, Brassiophoenix drymophloeodes, Burretiokentia hapala, Cyrtostachys renda, Reinhardtia gracilis, Carpoxylon macrospermum), a Phoenix species, a Euterpe species and two native palms (Archontophoenix alexandrae). Analysis of 16S rRNA gene sequences showed that this phytoplasma is distinct as it shared less than 97.5 % similarity with all other ‘Candidatus Phytoplasma’ species. At 96.3 % similarity, the most closely related formally described member of the provisional 'Ca. Phytoplasma' genus was 'Ca. Phytoplasma noviguineense', a novel taxon from the island of New Guinea found in monocotyledonous plants. It was slightly more closely related (96.6–96.8 %) to four palm-infecting strains from the Americas, which belong to strain group 16SrIV and which have not been assigned to a formal 'Candidatus Phytoplasma’ species taxon. Phylogenetic analysis of the 16S rRNA gene and ribosomal protein genes of the phytoplasma isolate from a dying coconut palm revealed that the phytoplasma represented a distinct lineage within the phytoplasma clade. As the nucleotide identity with other phytoplasmas is less than 97.5 % and the phylogenetic analyses show that it is distinct, a novel taxon 'Candidatus Phytoplasma dypsidis' is proposed for the phytoplasma found in Australia. Strain RID7692 (GenBank accession no. MT536195) is the reference strain. The impact and preliminary aspects of the epidemiology of the disease outbreak associated with this novel taxon are described.

revealed that considerable quantities of volatile hydrocarbons and a nonvolatile ketone are present in the wood of Guarea thompsonii. This ketone has recently been identified as dihydrogedunin and additional evidence in favour of its formulation as (I; R = 0, R' = a-OAc) is now advanced. Minor components of the timber include methyl angolensate 4a and 7-oxodeacetoxydihydro-a-gedunol (I ; R = a-OH, R' = 0 ) . Guarea thom$sonii (Nigerian peanvood) and G. cedrata (boss6, African cedar) are the source of two timbers imported into the United Kingdom as substitutes for mahogany. G. thom$sonii came to our notice from a report that nasal bleeding occurred amongst workers handling the timber but the several specimens of G. thomfisonii and of G. cedrata used during 1954-1956 in a full investigation of its extraneous constituents1 did not possess this property. Light-petroleum extraction of both woods gives considerable quantities of steam-volatile hydrocarbons. These have not been investigated in detail although one sample yielded impure (+)-cadinene 2 and in another bisabolene was also Investigations in 1954Investigations in -1956

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