Academic literature on the topic 'Weeds – Hawaii – Maui'

Inoculations of Septoria passiflorae for biological control of banana poka (Passiflora tripartita var. tripartita) at different forest sites in Hawaii, Kauai, and Maui resulted in successful establishment of the Septoria leaf spot disease at all sites during 1996. Semi-annual monitoring of sites in 1997 revealed low disease incidence and no disease spread to adjacent non-inoculated plants. Site inspections in March 1998 revealed light disease epidemics causing visible defoliation at inoculated sites on Kauai and Maui. Banana poka biomass reduction at sites with light epidemics of the disease in Kauai and Maui were estimated to be less than 10% in 1998, whereas in 1999 biomass reduction ranged from 50 to 95%. Five of 11 inoculation sites in 1996 on the island of Hawaii showed no disease. These five sites on Kaloko had frequent acid rainfall averaging 3.2 pH, which inhibited spore germination and infection. Six sites, free of acid rain, three at Hilo Forest Reserve and three at Puuwaawaa Wildlife Sanctuary, had severe disease epidemics by 1998, and vine defoliation was >90%. Widespread epidemics of the disease occurred in 1999, resulting in estimated 80 to 95% biomass reductions in more than 2,000 hectares of native forest infested with banana poka.

In compliance with its mandatory seat belt law, Hawaii is a high-use state. Seat belt use from 1998 to 2001 has averaged 81%, compared with 70% nationally. Efforts to increase belt use beyond 90% have not been successful, at least until the most recent effort, which entailed a combined enforcement and public information campaign. Described are patterns of belt use over time and the effects of the "Click It or Ticket" campaign that was launched this year. In January 2002, before the program was started, there was an overall belt use rate of 83.5%. After increased enforcement and publicity, Hawaii experienced an immediate increase in belt use by 6.9%. Belt use increased dramatically in each of the state’s four counties: in Honolulu, a 7.5% increase; Maui, 10.1% increase; and Kauai, 5% increase. The county of Hawaii, however, increased its rate by only 2.7%. Additional surveys in the months following the campaign indicated that in the days and weeks immediately after the Click It or Ticket campaign, there was a significant drop-off in belt use; but 144 days after, belt use in Honolulu County has stabilized at above 90%. This is surprising because the actual observed current rate is higher than the rate projected on the basis of observations conducted during the weeks immediately after the campaign was initiated. While more surveys and analysis are planned, the campaign was successful in Hawaii. Comments are provided about increasing belt use in a high-use state and implications are described for other traffic safety programs and initiatives.

The viability of many species has been jeopardized by numerous negative factors over the centuries, but climate change is predicted to accelerate and increase the pressure of many of these threats, leading to extinctions. The Hawaiian honeycreepers, famous for their spectacular adaptive radiation, are predicted to experience negative responses to climate change, given their susceptibility to introduced disease, the strong linkage of disease distribution to climatic conditions, and their current distribution. We document the rapid collapse of the native avifauna on the island of Kaua‘i that corresponds to changes in climate and disease prevalence. Although multiple factors may be pressuring the community, we suggest that a tipping point has been crossed in which temperatures in forest habitats at high elevations have reached a threshold that facilitates the development of avian malaria and its vector throughout these species’ ranges. Continued incursion of invasive weeds and non-native avian competitors may be facilitated by climate change and could also contribute to declines. If current rates of decline continue, we predict multiple extinctions in the coming decades. Kaua‘i represents an early warning for the forest bird communities on the Maui and Hawai‘i islands, as well as other species around the world that are trapped within a climatic space that is rapidly disappearing.

AbstractMiconia (Miconia calvescens DC.) is a tropical tree species from South and Central America that is a highly invasive colonizer of Hawaii's forested watersheds. Elimination of satellite populations is critical to an effective containment strategy, but extreme topography limits accessibility to remote populations by helicopter operations only. Herbicide Ballistic Technology (HBT) is a novel weed control tool designed to pneumatically deliver encapsulated herbicide projectiles. It is capable of accurately treating miconia satellites within a 30 m range in either horizontal or vertical trajectories. Efficacy was examined for the encapsulated herbicide projectiles, each containing 199.4 mg ae triclopyr, when applied to miconia in 5-unit increments. Experimental calibrations of the HBT platform were recorded on a Hughes 500-D helicopter while conducting surveillance operations from November 2010 through October 2011 on the islands of Maui and Kauai. Search efficiency (min ha−1; n = 13, R2 = 0.933, P< 0.001) and target acquisition rate (plants hr−1, n = 13, R2 = 0.926, P< 0.001) displayed positive linear and logarithmic relationships, respectively, to plant target density. The search efficiency equation estimated target acquisition time at 25.1 sec and a minimum surveillance rate of 67.8 s ha−1 when no targets were detected. The maximum target acquisition rate for the HBT platform was estimated at 143 targets hr−1. An average mortality factor of 0.542 was derived from the product of detection efficacy (0.560) and operational treatment efficacy (0.972) in overlapping buffer areas generated from repeated flight segments (n = 5). This population reduction value was used in simulation models to estimate the expected costs for one- and multi-year satellite population control strategies for qualifying options in cost optimization and risk aversion. This is a first report on the performance of an HBT helicopter platform demonstrating the capability for immediate, rapid-response control of new satellite plant detections, while conducting aerial surveillance of incipient miconia populations.

Abstract The insecticides were evaluated at the Kula Research Station, Maui Agricultural Park, from April to May. The field was set up in a CRB design with eight treatments and four replications (blocks). Treatments were applied using a CO2 backpack sprayer set at 60 psi with an output of 100 GPA. One hollow cone nozzle (TX-26) was used per row. The first treatment was applied one week after transplanting into the field on 9 Apr. Subsequently, six applications were made weekly until the week before harvest on the following dates: 16, 23, 30 Apr, 7, 14, 21 May. The treated check treatment consisted of Bacillus thuringienis aizawai (BTA) or Proclaim applied using the University of Hawaii DBM resistance management protocol. BTA products are used prior to the cupping stage of growth. Proclaim 0.15 EC @ 6.0 oz./A is applied if DBM densities exceed 1.0 larva per plant. Proclaim is used after cupping if DBM densities exceed 0.5 larva/plant and 1-2 applications are made during the two weeks prior to harvest if DBM is present. Larval thresholds were determined by making larval counts on 10 plants/treatment replication. Mattch at 2.0 qt./acre was the BTA product used and it was applied on 16 and 23 Apr. Proclaim was applied on 30 Apr, 7 and 14 May.

Bacterial black spot of mango (Mangifera indica) caused by Xanthomonas citri pv. mangiferaeindicae (Xcm), is an economically important disease in tropical and subtropical areas (3). Xcm can infect a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Fruit symptoms appear as small, water-soaked spots on the lenticels that become star-shaped, erumpent, and exude an infectious gum (3). The bacterium can also cause latent infections (2). Immature mango fruit with black spots on the epidermis were collected in August 2012 from mango trees of the cvs. Raposa and Pirie at a residence in Pukalani, Hawai'i, on the island of Maui. Similar symptoms were seen on a tree of the mango cv. Common (also known as ‘Spanish’ or ‘Lahaina’) at a nearby golf course. Mango fruit with black lesions, and leaves showing black lesions with yellow halos, were collected in August 2012 from mango trees of the cv. Haden at a residence in Kaimuki, Hawai'i, on the island of O'ahu. Xanthomonas-like bacterial colonies were isolated on TZC agar. Suspect colonies were non-pigmented on YDC agar. A fruit strain of the bacterium from Maui (A6081A) and a strain from each of a fruit (A6081B) and a leaf (A6082) from O'ahu were each gram-negative, oxidative, positive for both starch and esculin hydrolysis, and negative for nitrate reduction, resulting in presumptive identification as a Xanthomonas sp. The three strains were further characterized by Microlog (Biolog, Inc. Hayward, CA), which showed the closest match with X. campestris. In addition, 16S rDNA PCR assays showed the closest match (99% similarity) with X. citri strains, and RIF marker analysis of dnaA (4) grouped the three strains with Xcm strain LMG 941 (Accession No. CAHO01000002.1). Hypersensitivity responses typical of xanthomonads were observed when these strains were infiltrated into tobacco leaves, whereas no response was observed using sterile water. Leaves of 3-week-old mango seedlings were infiltrated using 10 μl (~108 CFU/ml) of each strain suspended in sterilized water (six to eight inoculations per leaf, four leaves per plant, and three replicate plants per strain). The negative control treatments consisted of inoculation with sterile water, as well as an incompatible pathogen, X. hortorum pv. vitians (A6076), isolated from lettuce. Typical symptoms of bacterial black spot were observed for all strains assayed approximately 2 weeks after inoculation. No lesions were observed on the negative control plants. Koch's postulates were satisfied following reisolation and identification of the Xanthomonas strains from the infected plant tissues, using the biochemical and PCR methods described above. Results for strains from the two islands confirmed published descriptions of the pathogen, indicating that the pathogen causing symptoms on these mango trees is Xcm (1). Cultures and infected plant samples were sent to USDA APHIS and CPHST NPGLB facilities where this identification was confirmed. To our knowledge, this is the first report of bacterial black spot of mango in Hawai'i or anywhere in the United States. It is unknown whether this disease is a new occurrence or has not been reported previously. The origin of the primary inoculum is unknown. References: (1) B. Manicom and F. Wallis. Int. J. Syst. Bacteriol. 34:77, 1984. (2) O. Pruvost et al. Microbial Ecol. 58:928. (3) O. Pruvost et al. Plant Dis. 95:774, 2011. (4) K. Schneider et al. PLoS 6:e18496, 2011.