Respuesta del babaco (Carica Pentagona) a cuatro tipos de fertilizaciones, bajo condiciones de invernadero

Medir o evaluar los efectos de cuatro tratamientos de fertilizaciones del babaco bajo condiciones de Invernadero durante doce meses de edad desde el transplante, combinando fertilizantes liquidos y granulados

Developing a commercial hot water treatment to control post-harvest rots on ‘Fiji Red’ papaya

Fiji exports approximately 800 t year-1 of 'Solo Sunrise' papaya marketed as 'Fiji Red' to international markets which include New Zealand, Australia and Japan. The wet weather conditions from November to April each year result in a significant increase in fungal diseases present in Fiji papaya orchards. The two major pathogens that are causing significant post-harvest losses are: stem end rot (Phytophthora palmivora) and anthracnose (Colletotrichum spp.). The high incidence of post-harvest rots has led to increased rejection rates all along the supply chain, causing a reduction in income to farmers, exporters, importers and retailers of Fiji papaya. It has also undermined the superior quality reputation on the market. In response to this issue, the Fiji Papaya industry led by Nature's Way Cooperative, embarked on series of trials supported by the Australian Centre for International Agricultural Research (ACIAR) to determine the most effective and economical post-harvest control in Fiji papaya. Of all the treatments that were examined, a hot water dip treatment was selected by the industry as the most appropriate technology given the level of control that it provide, the cost effectiveness of the treatment and the fact that it was non-chemical. A commercial hot water unit that fits with the existing quarantine treatment and packing facilities has been designed and a cost benefit analysis for the investment carried out. This paper explores the research findings as well as the industry process that has led to the commercial uptake of this important technology.

Investigation into various fungicides and alternative solutions for controlling postharvest diseases in papaya fruit

In Australia, Sportak® (a.i., prochloraz) has been registered since the early 1980's for the postharvest control of both anthracnose and stem-end rots in papaya fruit, despite the persistence of fruit breakdown due to disease during transit and at market destinations. Consequently, the Australian papaya industry has been concerned over the efficacy of prochloraz and whether substitute or alternative solutions were available for better disease control, particularly during times of peak disease pressure. This study therefore investigated the effects of various postharvest treatments for disease control in papaya. Fruit were harvested at colour break from coastal farms in Far North Queensland and treated with commercial rates of various fungicides, including prochloraz, imazalil, thiabendazole and fludioxonil. Additional solutions known to inhibit disease were examined, including chitosan and carnauba wax both with and without ammonium carbonate (AC). Following treatment, fruit were ripened and assessed for quality over their shelf life. Fludioxonil when applied as a hot dip was found to be a more efficacious treatment for control of disease in papaya than prochloraz. The other fungicides were moderately effective, as both thiabendazol and prochloraz exhibited an intermediate response and imazalil was the least effective. Disease severity was lowest in fruit treated with AC followed by chitosan, whilst chitosan delayed degreening. Overall, the study found that hot fludioxonil provided an effective replacement of the currently registered chemical prochloraz, and that alternate solutions such chitosan and AC may also be beneficial, particularly for low chemical input farming systems.

Effect of proteolytic enzyme and fiber of papaya fruit on human digestive health

The World Health Organization (WHO, 2005) recommends consumption of fruits and vegetables as part of a healthy diet with daily recommendation of 5 servings or at least 400 g per day. Fruits and vegetables are good sources of vitamins, minerals, antioxidants, and fiber. Papaya fruit is known for his high nutrient and fiber content, and with few exceptions, it is generally consumed ripe due to its characteristic flavor and aroma. Digestion improvement has been attributed to consumption of papaya; this we speculate is attributed to the fiber content and proteolytic enzymes associated with this highly nutritious fruit. However, research is lacking that evaluates the impact of papaya fruit on human digestion. Papain is a proteolytic enzyme generally extracted from the latex of unripe papaya. Previous research has focused on evaluating papain activity from the latex of different parts of the plant; however there are no reports about papain activity in papaya pulp through fruit maturation. The activity of papain through different stages of ripeness of papaya and its capacity of dislodging meat bolus in an in vitro model was addressed. The objective of this study was to investigate whether papain activity and fiber content are responsible for the digestive properties attributed to papaya and to find a processing method that preserves papaya health properties with minimal impact on flavor. Our results indicated that papain was active at all maturation stages of the fruit. Ripe papaya pulp displayed the highest enzyme activity and also presented the largest meat bolus displacement. The in vitro digestion study indicated that ripe papaya displayed the highest protein digestibility; this is associated with proteolytic enzymes still active at the acidity of the stomach. Results from the in vitro fermentation study indicated that ripe papaya produced the highest amount of Short Chain Fatty Acids SCFA of the three papaya substrates (unripe, ripe, and processed). SCFA are the most important product of fermentation and are used as indicators of the amount of substrate fermented by microorganisms in the colon. The combination of proteolytic enzymes and fiber content found in papaya make of this fruit not only a potential digestive aid, but also a good source of SCFA and their associated potential health benefits. Irradiation processing had minimal impact on flavor compounds of papaya nectar. However, processed papaya experienced the lowest protein digestibility and SCFA production among the papaya substrates. Future research needs to explore new processing methods for papaya that minimize the detrimental impact on enzyme activity and SCFA production.

Evaluación de nueve accesiones de higo (Ficus carica L.) en la estación experimental del austro del INIAP, cantón Gualaceo provincia del Azuay-Ecuador

La presente investigación lleva por título “Evaluación de nueve accesiones de higo (Ficus caricaL.) en la Estación Experimental del Austro del INIAP, Cantón Gualaceo, provincia del Azuay-Ecuador. El trabajo tuvo como objetivo principal disponer de un ecotipo de higo de calidad y alta productividad, adaptado a las condiciones ambientales del Cantón Guacaleo, provincia del Azuay. Para ello se utilizó el método empírico, cuyas técnicas fueron la observación, la medición, encuestas y métodos teóricos, posterior a los cuales se realizaron los respectivos análisis y síntesis de la información. Se emplearon: la toma de datos en el campo, sobre 45 plantas que fueron analizadas y estudiadas; la encuesta a la población, con la finalidad de determinar el grado de aceptación de los frutos de higo por ecotipo por parte de los consumidores; así mismo, se elaboró un test organoléptico sobre 69 personas de la ciudad de Cuenca y de los cantones Gualaceo, Paute y Guachapala de la provincia del Azuay. Como principal conclusión se evidenció que el ecotipo Guayaquil es el que posee mayor diámetro, el que genera un fruto de mayor peso, así como un mayor número de frutos; también es el más productivo, el que menos tiempo requiere para producir yemas hinchadas y para la aparición de las primeras hojas. Además, se lo identificó como el ecotipo más llamativo de acuerdo al color de la pulpa, y considerado de mayor calidad por la textura del fruto. Finalmente, es el ecotipo que genera mayor rentabilidad en relación a los demás.

The Prehistory of Potyviruses: Their Initial Radiation Was during the Dawn of Agriculture

Background: Potyviruses are found world wide, are spread by probing aphids and cause considerable crop damage. Potyvirus is one of the two largest plant virus genera and contains about 15% of all named plant virus species. When and why did the potyviruses become so numerous? Here we answer the first question and discuss the other. Methods and Findings: We have inferred the phylogenies of the partial coat protein gene sequences of about 50 potyviruses, and studied in detail the phylogenies of some using various methods and evolutionary models. Their phylogenies have been calibrated using historical isolation and outbreak events: the plum pox virus epidemic which swept through Europe in the 20th century, incursions of potyviruses into Australia after agriculture was established by European colonists, the likely transport of cowpea aphid-borne mosaic virus in cowpea seed from Africa to the Americas with the 16th century slave trade and the similar transport of papaya ringspot virus from India to the Americas. Conclusions/Significance: Our studies indicate that the partial coat protein genes of potyviruses have an evolutionary rate of about 1.1561024 nucleotide substitutions/site/year, and the initial radiation of the potyviruses occurred only about 6,600 years ago, and hence coincided with the dawn of agriculture. We discuss the ways in which agriculture may have triggered the prehistoric emergence of potyviruses and fostered their speciation.

Candidatus Phytoplasma australiense is associated with pumpkin yellow leaf curl disease in Queensland, Western Australia and the Northern Territory

Pumpkin plants (Cucurbita maxima and C. moschata) with pumpkin yellow leaf curl (PYLC) disease were observed at production fields in Queensland, Western Australia and the Northern Territory. Diseased samples were positive for a phytoplasma indistinguishable from Candidatus Phytoplasma australiense, the phytoplasma associated with papaya dieback and strawberry lethal yellows. This is the first time Candidatus Phytoplasma australiense has been detected in pumpkin.

Plant hosts of the phytoplasmas and rickettsia-like-organisms associated with strawberry lethal yellows and green petal diseases

Candidatus Phytoplasma australiense (Ca. P. australiense) is associated with the plant diseases strawberry lethal yellows (SLY), strawberry green petal (SGP), papaya dieback (PDB), Australian grapevine yellows (AGY) and Phormium yellow leaf (PYL; New Zealand). Strawberry lethal yellows disease is also associated with a rickettsia-like-organism (RLO) or infrequently with the tomato big bud (TBB) phytoplasma, the latter being associated with a wide range of plant diseases throughout Australia. In contrast, the RLO has been identified only in association with SLY disease, and Ca. P. australiense has been detected only in a limited number of plant host species. The aim of this study was to identify plant hosts that are possible reservoirs of Ca. P. australiense and the SLY RLO. Thirty-one plant species from south-east Queensland were observed with disease between 2001 and 2003 and, of these, 18 species tested positive using phytoplasma-specific primers. The RLO was detected in diseased Jacksonia scoparia and Modiola caroliniana samples collected at Stanthorpe. The TBB phytoplasma was detected in 16 different plant species and Ca. P. australiense Australian grapevine yellows strain was detected in six species. The TBB phytoplasma was detected in plants collected at Nambour, Stanthorpe, Warwick and Brisbane. Ca. P. australiense was detected in plants collected at Nambour, Stanthorpe, Gatton and Allora. All four phytoplasmas were detected in diseased Gomphocarpus physocarpus plants collected at Toowoomba, Allora, Nambour and Gatton. These results indicated that the vector(s) of Ca. P. australiense are distributed throughout south-east Queensland and the diversity of phytoplasmas detected in G. physocarpus suggests it is a feeding source for phytoplasma insect vectors or it has a broad susceptibility to a range of phytoplasmas.

Developing and communicating strategies for controlling virus diseases in vegetable cucurbit crops

Virus diseases cause serious yield and quality losses in field grown cucurbit crops worldwide. In Australia, the main viruses of cucurbits are Papaya ringspot virus (PRSV), Squash mosaic virus (SqMV), Watermelon mosaic virus (WMV) and Zucchini yellow mosaic virus (ZYMV). Plants infected early have severely distorted fruit. High infection incidences, of ZYMV and PRSV in crops cause losses of marketable fruit of up to 100% and infected crops are often abandoned. Two new alternative hosts of ZYMV were identified, the native cucurbit Cucumis maderaspatanus and wild legume Rhyncosia minima. No new alternative hosts of PRSV, SqMV or WMV were found in Western Australia or Queensland. Seed transmission of ZYMV (0.7%) was found in seedlings grown from ZYMV-infected fruit of zucchini but not of pumpkin. None was detected with PRSV or SqMV in zucchini or pumpkin seedlings, respectively. ZYMV spread to pumpkins by aphids was greater downwind than upwind of a virus source. Delaying sowing by 2 weeks decreased ZYMV spread. Millet non-host barriers between pumpkin plantings slowed ZYMV infection. Host resistance gene (zym) in cucumber cultivars was effective against ZYMV. Pumpkin cultivars with resistance gene (Zym) became infected under high virus pressure but leaf symptoms were milder and infected plants higher yielding with more market-acceptable fruit than those without Zym. Most zucchini cultivars with Zym developed severe leaf and fruit symptoms. ZYMV, PRSV, WMV and SqMV spread readily from infected to healthy cucurbit plants by direct leaf contact. ZYMV survives and remains infective on diverse surfaces for up to 6 hours but can be inactivated by some disinfectants. Phylogenetic analysis indicates at least three separate introductions of ZYMV into Australia, with new introductions rarely occurring. ZYMV isolates clustered into three groups according to collection location i) Kununurra, ii) Northern Territory and iii) Carnarvon, Qld and Vic. A multiplex Real-Time PCR was developed which distinguished between the three groups of Australian isolates. Integrated disease management (IDM) strategies for virus diseases of vegetable cucurbit crops grown in the field were improved incorporating the new information gathered. These strategies are aimed at causing using minimal extra expense, labour demands and disruption to normal practices.

Improved domestic profitability and export competitiveness of selected fruit value chains in the southern Philippines and Australia program

The goal of the Program is to contribute to economic growth in the Philippines through increased income and improved livelihoods of tropical fruit growers in southern Philippines. The purpose of the Program is to improve the smallholder and industry profitability and export competitiveness of selected tropical fruits industries in the southern Philippines. Fruit crops to be targeted are mango, papaya, durian and jackfruit. The primary audience for the outcomes of this Program are medium to large scale commercial fruit growers and farmers predominantly in the regions of Leyte (VIII), northern Mindanao/Cagayan de Oro (X) and southern Mindanao/Davao (XI).

Mikania micrantha Kunth (Asteraceae) (Mile-a-Minute): Its Distribution and Physical and Socioeconomic Impacts in Papua New Guinea

Mikania micrantha or mile-a-minute is regarded as a major invasive weed in Papua New Guinea (PNG) and is now the target of a biological control program. As part of the program, distribution and physical and socioeconomic impacts of M. micrantha were studied to obtain baseline data and to assist with field release of biological control agents. Through public awareness campaigns and dedicated surveys, M. micrantha has been reported in all 15 lowland provinces. It is particularly widespread in East New Britain, as well as in West New Britain and New Ireland. A CLIMEX model suggests that M. micrantha has the potential to continue to spread throughout all lowland areas in PNG. The weed was found in a wide range of land uses, impacting on plantations and food gardens and smothering papaya, young cocoa, banana, taro, young oil palms, and ornamental plants. In socioeconomic surveys, M. micrantha was found to have severe impacts on crop production and income generated through reduced yields and high weeding costs, particularly in subsistence mixed cropping systems. About 89% of all respondents had M. micrantha on their land, and 71% of respondents had to weed monthly. Approximately 96% of respondents in subsistence mixed cropping systems used only physical means of control compared with 68% of respondents in other farming systems. About 45% of all respondents estimated that M. micrantha causes yield losses in excess of 30%. These studies suggest that there would be substantial benefits to landholders if biological control of M. micrantha were to be successful.

The effect of lycopene on the PI3K/Akt signalling pathway in prostate cancer

Prostate cancer is common in men with very high mortality which is one of leading causes of cancer-related deaths in men. The main treatment approaches for metastasized prostate cancer are androgen deprivation and chemotherapeutic agents. Although there are initial responses to castration, the resistance to the treatment will eventually occur, leading to castration-resistant prostate cancer. The common chemotherapeutic agents for the treatment of prostate cancer are docetaxel and taxane but outcomes of using these drugs have not been satisfactory. Therefore, it is necessary to find better treatment approaches for prostate cancer and to search for compounds that are effective in prostate cancer prevention. Lycopene extracted from tomato and other fruits or plants such as Gac, watermelon, pink grapefruit, pink guava, red carrot and papaya has been shown to be effective on prostate cancer prevention and treatment. The advantage of the application of lycopene for its anti-prostate cancer activity is that lycopene can reach much higher concentration in prostate tissue than other tissues. In this review, the effect of lycopene on PI3K/Akt pathway is summarised, which could be one of major mechanisms for anti-cancer activity of lycopene.

Evaluación de alternativas para el manejo de la roya (Hemileia vastatrix Berk y Br) en el cultivo del café (Coffea arabica L) en fincas de los departamentos de Carazo, Granada y Masaya

El presente trabajo tuvo como objetivo evaluar diferentes alternativas de manejo para la roya del café (Hemileiavastatrix Berk & Br)de Octubre 2003 a Junio 2004 en las fincas Vista Alegre (LaConcepción Masaya),Esquipulas (San Marcos-Carazo), Santa Mónica(Niquinohomo-Masaya), San Luis (Masatepe-Masaya) y Los Jirones (Diría-Granada). Los muestreos se realizaron mensualmente en cada finca. Los tratamientos evaluados fueron 7 y se establecieron en parcelas conformadas por 300 plantas. Las variables evaluadas fueron incidencia de roya, hojas totales y número de palmillas. Los resultados indican que la menor área bajo la curva de progreso de la enfermedad (ABCPE) por finca fueron: Vista Alegre el tratamiento cobre+fertilización diluida+vidateL,Esquipulas el tratamiento biofertilizante+nim+fertilización diluida, Santa Mónica el tratamiento testigo absoluto, San Luis el tratamiento gallinaza+biofertilizante+caldo sulfocálcico aunque numéricamente y Los Jirones el tratamiento gallinaza+biofertilizante+caldo sulfocálcico. En relación al mayor número de hojas lo presenta en Vista Alegre el tratamiento cobre+fertilización diluida+vidate-L, Esquipulas el tratamiento biofertilizante+nim+fertilización diluida, Santa Mónica el tratamiento gallinaza+biofertilizante+papaya, San Luis el tratamiento biogreen+biofertilizante+limonaria y Los Jirones el tratamiento gallinaza+biofertilizante+papaya aunque numéricamente. Los resultados confirman el comportamiento de enfermedades, como la roya del café presentándose con mayor incidencia en aquellos cafetos con problemas nutricionales. Por lo que determinamos que la mayoría de los productos que constituyen estos tratamientos, a pesar de que no tienen efecto fungicida, contribuyen al fortalecimiento de las plantas, volviéndolas mas vigorosasy tolerantes al ataque de la enfermedad.

Evaluación de opciones alternativas al uso de agroquímicos para el manejo de nematodos fitoparasitos en el cultivo del cafe (Coffea arabica) en fincas de Masaya, Granada y Carazo

El presente estudio se realizó de octubre 2003 a marzo 2004, en cinco fincas de pequeños productores de Masaya, Granada y Carazo, con el objetivo de evaluar el efecto de alternativas de manejo no sintéticas sobre la población de nematodos fitoparásitos asociados al cultivo de café. En cada finca, se establecieron siete parcelas en las que se evaluaron los tratamientos:Gallinaza + biofertilizante + te de papaya (1); Gallinaza + biofertilizante + caldo sulfocálcico (2); Bio green + biofertilizante + te limonaria (3); Biofertilizante + torta de nim + fertilización diluida(4); Biofertilizante + pacelyn + fertilización diluida (5); Testigo absoluto (6); Cobre + fertilización diluida + Vidate L (7). Mensualmente se tomaron muestras de suelo y de raíz, las cuales fueron procesadas en el laboratorio de Nematología Agrícola de la Universidad Nacional Agraria, mediante las técnicas de tamizado más filtro de algodón, para las muestras de suelo; y licuadora más tamices para las muestras de raíz. Las muestras fueron tomadas utilizando barreno y pala, en el área comprendida entre los 15 centímetros del tronco de la planta y a 15 centímetros de profundidad. Las variables evaluadas fueron: Número de nematodos fitoparásitos por género presentes en 100 g de suelo y Número de nematodos fitoparásitos por género presentes en 25 g de raíces.Los resultados indican que tanto en muestras de suelo como de raíces, los géneros predominantes en las cinco fincas fueron Meloidogyne spp y Helicotylenchusspp. El tratamiento que presentó las poblaciones más bajas de nematodos fue Cobre + fertilización diluida + VidateL (7), y el que presentó las poblaciones más altas fue Gallinaza + biofertilizante + te de papaya. Con relación a la fluctuación población de los géneros de nematodo en las cinco fincas fue Meloidogynespp, el género que presentó las poblaciones más altas, alcanzando poblaciones hasta de 5000 nematodos en 25g de raíces en la finca Vista Alegre.En general las poblaciones de nematodos fueron altas en los meses de Noviembre y Enero, reduciéndose en los meses de Febrero y Marzo.

Evaluación de alternativas de manejo para la mancha de hierro (Cercospora coffeicola Berk y cook) en el cultivo del café (Coffea arabica L.) en fincas de los departamentos de Granada, Masaya y Carazo

Este estudio se realizó de Octubre 2003 a Junio 2004, en las fincas Vista Alegre, Santa Mónica, San Luís, Esquipulas y Los Jirones, ubicadas en los departamentos de Masaya, Carazo y Granada respectivamente, con el objetivo de evaluar alternativas para el manejo de mancha de hierro (Cercospora coffeicola Berk &Cook) en el cultivo del café (Coffea arabica L.). El estudio se desarrolló en parcelas establecidas en cada finca, estas parcelas estaban constituidas por 300 plantas por tratamiento, donde se llevaron a efecto los muestreos. Las variables evaluadas fueron: incidencia de mancha de hierro, número de hojas totales, número de palmillas y al finalizar el estudio se realizó una estimación de cosecha. Los resultados del trabajo en cuanto al Área Bajo la Curva de Progreso de la Enfermedad (ABCPE), fueron los siguientes: en la finca Vista Alegre en tratamiento que obtuvo menor ABCPE fue biofertilizante más pacelyn más fertilización diluida, en Esquipulas el tratamiento gallinaza más biofertilizante más caldo sulfocalcico, en Santa Mónica el tratamiento testigo absoluto, en San Luís el tratamiento biogreen más biofertilizante más té de limonaria y en los Jirones el tratamiento biofertilizante más torta de nim más fertilización diluida. En lo que respecta al número de hojas en la finca Vista Alegre el tratamiento que presentó mayor número de hojas fue cobre más biofertilizante más vidate L, en Esquipulas el tratamiento biofertilizante más torta de nim más fertilización diluida, en la finca Santa Mónica el tratamiento gallinaza más biofertilizante más té de papaya, en San Luís el tratamiento biogreen más bi ofertilizante más té de limonaria y en la finca los Jirones el tratamiento gallinaza más biofertilizante más té de papaya. Los resultados del presente estudio, determinó que los productos que constituyen estos tratamientos a pesar que no todos tienen efectos fungicidas, contribuyen al fortalecimiento de las plantas, volviéndolas más vigorosas y tolerantes al ataque de esta enfermedad.