Coconut Industry Board

During survey work for planthoppers associated with palms in Jamaica, one new species of Patara was collected at the Castleton Botanic Garden and is here described as Patara euryfrons sp. n. The species is unusual in having a much broader head than is normally found in members of the genus. Supplementary molecular data for the barcoding region (5' half) of the cytochrome c oxidase subunit I (COI), 18S rRNA gene and D9-D10 expansion region of the 28S rRNA gene is provided to support the placement of the novel taxon in Patara.

SummaryDNA of phytoplasmas in lethal yellowing (LY)‐diseased palms was detected by a nested polymerase chain reaction (PCR) assay employing rRNA primer pair P1/P7 followed by primer pair LY16Sf/ LY16‐23Sr. Polymorphisms revealed by Hinfl endonuclease digestion of rDNA products differentiated coconut‐infecting phytoplasmas in Jamaica from those detected in palms in Florida, Honduras and Mexico. A three fragment profile was generated for rDNA from phytoplasmas infecting all 21 Jamaican palms whereas a five fragment profile was evident for phytoplasmas infecting the majority of Florida (20 of 21), Honduran (13 of 14) and Mexican (5 of 5) palms. The RFLP profile indicative of Florida LY phytoplasma was resolved by cloning into two patterns, one of three bands and the other of four bands, that together constituted the five fragment profile. The two patterns were attributed to presence of two sequence heterogeneous rRNA operons, rrnA and rrnB, in most phytoplasmas composing Florida, Honduran and Mexican LY strain populations. Unique three and four fragment RFLP profiles indicative of LY phytoplasmas infecting Howea forsteriana and coconut palm in Florida and Honduras, respectively, were also observed. By comparison, the Jamaican LY phytoplasma population uniformly contained one or possibly two identical rRNA operons. No correlation between rRNA interoperon heterogeneity and strain variation in virulence of the LY agent was evident from this study.

SUMMARYA wilt disease of coconut palms in Trinidad has been responsible for the death of more than 15 000 palms in the last 2 years. Symptoms of the disease include: loss of nuts, premature browning of successively younger leaves, necrosis of open and unopened inflorescences and of the young unexpanded leaves at the centre of the crown; rotting of the growing point, stem apex and roots.Samples from each of 10 diseased palms contained flagellates which were classified as trypanosomatid protozoans of the genus Phytomonas. The protozoans, which by squeezing could be expressed easily from tissues for observation by phase contrast light microscopy, were 1–1.5 μm wide and 27 μm long including the flagellum which was approximately 7 μm long.Sections of inflorescence rachillae from diseased palms revealed that the phytomonads were restricted to the sieve tubes. Phytomonas was always associated with diseased palms but it was never found in healthy palms.A brief description of the ultrastructure of the presumed pathogen of wilt disease is also given.

Selection and breeding is likely to provide the only answer to Lethal Yellowing disease of coconuts. The present review outlines the short term and long term programmes started in Jamaica and gives details of the exploitation of local varieties and the assembly of genotypes for further work.

POLLEN introduction and exchange have been suggested as a means of broadening the scope of breeding programmes designed to produce disease-resistant and high-yielding coconuts1–3; and at a recent meeting of the Food and Agriculture Organization Technical Working Party on Coconut Production it was stressed4 that the most important material question to be solved concerned the mode of transportation of pollen. It is clear that present methods of storage of coconut pollen5–8, though useful, are inconvenient for routine pollen exchanges over long distances.

IN the coconut, Cocos nucifera Linn., the ovary is tricarpellary and each carpel contains an ovule. Usually only one ovule develops and two abort, and although there are three depressions or ‘eyes’ in the endocarp wall of the mature fruit only one of these is a functional germ pore. From this eye normally a single shoot emerges.

Experimental inoculations indicate that several factors may influence the extent to which anthracnose, caused byGloeosporium musarum, develops on bananas following wound‐infection. Severity of disease increases with increasing ‘grade’ of maturity, ‘full’ fruit being more seriously affected than ‘thin’ fruit. The evidence suggests that Gros Michel fruit is less susceptible to this form of rot than fruit of the Lacatan or Robusta varieties. The amount ofGloeosporium‐rot on fruit imported into the United Kingdom undergoes marked seasonal variation, being greatest during autumn and winter.The presence of perforated ‘Polythene’ bags during cold storage (55° F.) appears to favour slightly the development of disease. Bagging had no significant effect on rotting during the subsequent ripening period. After wound‐inoculation, disease incidence and severity decreased appreciably with increasing periods of storage at tropical temperatures (76–87° F.). Such a decrease was evident even when the humidity at the surface of the fruit was maintained at a high level (92–100%).In several shipping trials, a post‐harvest fruit‐dip treatment with nystatin (200–400 p.p.m.) effected 40–70% control of anthracnose.