Veitchia Merrillii Research Articles

First report of Raoiella indica Hirst (Acari: Tenuipalpidae) and its damage to coconut palms in Puerto Rico and Culebra Island

This is the first report of the occurrence of the red palm mite, Raoiella indica Hirst, and its damage in Puerto Rico and Culebra Island. Raoiella indica is a new invasive pest threatening ornamental palm, coconut, and banana plantations. The mite was observed in eastern Puerto Rico and on Culebra Island infesting and causing damage to coconut, Cocos nucifera L., and Veitchia merrillii L.

First Report of Lethal Yellowing Disease of Coconut Palms Caused by Phytoplasma on Nevis Island.

Coconuts (Cocos nucifera) are an important small-holder's crop in many tropical countries and are used to enhance esthetics of coastal areas. Lethal yellowing (LY) is the single most important plant disease affecting the coconut industry in Jamaica. It affects many palm species in Jamaica, Florida, and Guatemala. This coconut disease was first recorded in Grand Cayman Island in 1834 and Jamaica in 1884. Symptoms of LY disease include premature nut fall, necrosis of the inflorescence, yellowing of the leaves, and defoliation. Thirty-eight coconut palms displaying symptoms indicative of LY disease were sampled in April, 2005 at several locations in Nevis. Immature leaf tissues (leaf bases adjacent to the apical meristem) and nondestructive (boring with a bit and braces) samples were collected from disease and healthy control coconut trees. DNA was extracted (2). The first round of polymerase chain reaction (PCR) with phytoplasma universal primer pair P1/P7 (1,3) resulted in an rDNA fragment of 1.8 kb, and a subsequent nested PCR using LY16-23Sr/LY16Sf primers yielded an amplicon of 1.74 kb (4). Purified product was cloned for sequencing. Sequences obtained were analyzed with Vector NTI Software Suite. The sequence of LYN 18-3 was entered in Genbank and Accession No. DQ378279 was assigned. LYN 18-3 has approximately 99% homology with LY Phytoplasma U18747 from Florida (Manila palm [Veitchia merrillii]). The disease-associated phytoplasma was reliably detected in immature tissues and trunk phloem at the onset of foliar symptoms in palms by PCR. On the basis of the results obtained from this study, it is clear that LY phytoplasma (16SrIV group) was found in the samples collected from Nevis. To our knowledge, this is the first report on lethal yellowing disease in Nevis.

Conservation Biology for Seven Palm Species from Diverse Genera

Arecaceae are a relatively large family with a considerable number of species of local and global socioeconomic importance. Many species are also under threat of impending extinction, indicating an urgent need to improve their conservation prospects. Here we present studies on seven palm species (Adonidia merrillii, Caryota urens, Livistona muelleri, Ravenea rivularis, Sabal [minor var. louisiana], Trachycarpus latisectus, and Wallichia disticha) from diverse genera in relation to various seed traits, including germination, desiccation tolerance, and weight. Germination varied from ca. 12-100% and mean time to germinate ranged from four days to four and one-half weeks at 30°C. Six of the species were newly screened for seed conservation biology and of these two were found to possess desiccationtolerant seeds, indicating opportunities for longer-term storage and improved use.

Influence of Seed Treatments on Germination and Initial Growth of Ornamental Palms

Experiments were conducted in the Dominican Republic to determine the effect of physical and chemical treatments on the germination of the ornamental palms Roystonea hispaniolana Bailey (Royal palm), Acrocomia quisqueyana Bailey (Corozo palm), Sabal umbraculifera Mart (Cana palm), Phoenix canariensis (Canary Islands date palm), Veitchia merrillii (Becc) Bailey (Manila palm), Chrysalidocarpus lutescens Wendl (Areca palm), and Caryota urens (Fishtail palm). Treatments were seed immersion in water or gibberellic acid 3 (GA3) solution for 72 hours, immersion in concentrated nitric acid for 5 minutes, or cracking of the seed coat. Rate and percentage of emergence 90 days after treatment were measured. The best results for Roystonea, Phoenix, Veitchia, Caryota, and Chrysalidocarpus were obtained soaking the seeds in water or a 200-ppm gibberellic acid solution. Nitric acid and seed coat cracking significantly reduced the germination percentage in all the species, except Acrocomia guisqueyana and Sabal umbraculifera. Seeds of Acrocomia did not germinate as a response to any of the treatments tested. Sabal seeds germinated only after coat cracking or nitric acid treatment.

Growth Regulation of Some Tropical Species

One-gram a.i. flurprimidol tablets (Cutless®Tree Implant) were inserted into the trunks of golden shower trees (Cassia fistula) on August 8,1993. Plants were topped in June 1994 and again in December 1994. Regrowth after each topping was measured. There was no consistent influence of flurprimidol on growth of C. fistula. Paclobutrazol (Profile®) applied as a basal drench reduced growth of Queen palm (Syagras romanzoffiana) and Manila palm (Veitchia memllii) 11 months after application.

DNA Probes for Detection of Mycoplasmalike Organisms Associated with Lethal Yellowing Disease of Palms in Florida

Five EcoRI restriction fragments consisting of chromosomal DNA of the mycoplasmalike organism (MLO) associated with lethal yellowing (LY) disease of Manila palm (Veitchia merrillii) in Florida were cloned and identified. When used individually as [ 32 P]dATP-labeled probes in dot and Southern hybridizations at high stringency, four of five probes consistently hybridized to DNA extracts derived from LY-affected palms only (...)

Transmission of the coconut cadang‐cadang viroid to six species of palm by inoculation with nucleic acid extracts

Seedlings of Areca catechu (betel nut palm), Corypha elata (buri palm), Adonidia merrillii (manila palm), Elaeis guineensis (oil palm), Chrysalidocarpus lutescens (palmera) and Oreodoxa regia (royal palm) were inoculated with nucleic acid extracts from coconut palms with cadang‐cadang disease. Within 2 years of inoculation, analysis using a 32P‐labelled DNA probe complementary to the coconut cadang‐cadang viroid (CCCV) showed that RNA sequences identical to CCCV were present in the inoculated seedlings. Electrophoresis in polyacrylamide gels showed that these palms also contained an RNA with mobility identical to CCCV. Four to five years after inoculation, the infected palms of four species were usually stunted compared with uninoculated palms, while betel nut and palmera were not stunted. Yellowing of leaflets was observed with defined spots or mottling of the older fronds in all except betel nut palms. All infected palms showed mild or severe yellow‐leaf spotting. These results widen the known host range and. hence, the potential number of viroid reservoir species in the field.

Transmission of Palm Lethal Decline to Veitchia merrillii by a Planthopper Myndus crudus123

Myndus crudus Van Duzee was implicated as a vector of the agent that causes lethal decline of the Manila palm, Veitchia merrillii (Becc.) H. E. Moore. Five of 7 Manila palms in cages into which M. crudus captured in the vicinity of lethal decline-infected palms were introduced showed symptoms of the disease. The presence of mycoplasmalike organisms (MLO) in sieve tubes of these palms was confirmed by electron microscopic examination. Seven Manila palms in cages free of M. crudus remained healthy, and MLOs were not observed in samples from these palms.

Reduction in Spread of Mycoplasma-like Organism-Associated Lethal Decline of the Palm, Veitchia merrilli, by Use of Insecticides12

An experiment was conducted in southern Florida in an area where Manila palms, Veitchia merrillii (Becc.) H. E. Moore, were infected with mycoplasmalike organism-associated lethal decline. Manila palms were given foliar applications of insecticides (diazinon AG 500 at 13 ml/10 liters and dimethoate 400 at 26.4 ml/10 liters) biweekly for 15 months. Myndus crudus (Van Duzee) (Homoptera: Cixiidae) was the most abundant auchenorrhynchous insect sampled from the leaves of Manila palms. There were fewer M. crudus in samples from palms treated with diazinon than in samples from untreated palms (P <0.05). The apparent rate of spread of the disease declined significantly in the diazinon and dimethoate-treated plots but not in the untreated plots (P <0.05). The results suggest that a leaf-feeding insect, possibly M. crudus , is the vector of the disease agents.

Field Biology and Control of Haplaxius crudus on St. Augustinegrass and Christmas Palm12

Haplaxius crudus (Van Duzee) develops readily on St. Augustinegrass, Stenotaphrum secundatum (Walt.) Kunze, Bahiagrass, Paspalum notatum Flugge, and Bermudagrass, Cynodon dactylon (L.) Pers. Adults feed on these turfgrasses and on at least 9 species of palms including the Christmas palm, Veitchia merrillii (Becc.) Moore, and coconut palm, Cocos nucifera L. Mean populations of 3.1/leaf on Christmas palms and 23.7/0.09m2 on St. Augustinegrass were reported. Populations of H. crudus were controlled with aldicarb and with carbofuran and dimethoate soil drenches at rates of 28 g AI/tree on mature Christmas palms. Chlorpyrifos, diazinon, and propyl thiopyrophosphate provided 100% control, while carbaryl and carbofuran gave excellent control of H. crudus on St. Augustinegrass. Malathion also provided good control, but acephate, dimethoate, and methomyl did not give control on this grass.