Ecosystems of Hawaii and other Pacific Islands have been greatly affected by invasive pest plants,and ongoing, deliberate plant introductions make it likely that additional pest plants will become established. We tested the ability of a modified version of the Australian and New Zealand weed risk-assessment system to identify pest plants in Hawaii and other Pacific Islands. We used information taken from outside Hawaii to predict the behavior-"pest" or "not a pest"-of almost 200 plant species introduced to Hawaii and other Pacific Islands. The screening system initially recommended further evaluation of 24% of these species, but an additional secondary screening was applied to this group, thereby reducing the rate of indecision to only 8%. To independently test the accuracy of the screening system, we compared its decisions-pest or not a pest-to opinions of 25 expert botanists and weed scientists who had substantial field experience in Hawaii or other Pacific Islands. We asked the experts to rate each species as "major pest," "minor pest," or "not a pest" in native or managed ecosystems. The screening system correctly identified 95% of major pests and 85% of nonpests. Among minor pests identified by the experts, 33% were classified as nonpests by the screening system. Use of the screening system to assess proposed plant introductions to Hawaii or other Pacific Islands and to identify high-risk species used in horticulture and forestry would greatly reduce future pest-plant problems and allow entry of most nonpests. The screening process is objective, rapid, and cost-efficient. With minor modifications, it is likely to be useful in many parts of the world. Un Sistema de Evaluación de Riesgo para Seleccionar Plantas Invasoras Nocivas de Hawai'i y Otras Islas del PacíficoResumen: Los ecosistemas de Hawai'i y otras islas del Pacífico han sido muy afectados por plantas invasoras nocivas y, a la fecha, con la introducción deliberada de plantas es probable que se establezcan plantas nocivas adicionales. Pusimos a prueba la capacidad de una versión modificada del sistema australiano y neozelandés de evaluación del riesgo de hierbas para identificar plantas nocivas en Hawai'i y otras islas del Pacífico. Utilizamos información obtenida fuera de Hawai'i para predecir el comportamiento ("nociva" y "no nociva") de casi 200 especies introducidas a Hawai'i y otras islas del Pacífico. El sistema de selección inicialmente recomendó una mayor evaluación para 24% de esas especies, pero se aplicó un monitoreo secundario a este grupo, con lo que la tasa de indecisión se redujo a solo 8%. Para probar la precisión del sistema de selección independientemente, comparamos sus decisiones (nociva o no nociva) con las opiniones de 25 botánicos y expertos con sustancial experiencia de campo en Hawai'i u otras islas del Pacífico. Les pedimos que calificaran a cada especie como "muy nociva," "poco nociva" y "no nociva" en ecosistemas nativos o bajo gestión. El sistema de selección identificó correctamente a 95% de las muy nocivas e identificó c...

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The present investigation was carried out to evaluate the potential of chitosan alone and in combination with various agricultural wastes for the management of rootknot nematode, Meloidogyne incognita on eggplant cv. 'BR-112' under greenhouse conditions. The results showed that chitosan as a single or joint treatment with agricultural wastes significantly (p ≤ 0.05) reduced root-knot indices, and the nematode population in soil. As a result, of this, the growth and growth yielding attributes of eggplant were remarkably augmented. Chitosan as an elicitor induced plant mediated systemic resistance against M. incognita in eggplant. The results of the study demonstrated that maximum reduction in eggmass/root, eggs/eggmasses, nematode population and root-knot indices, was acquired by the treatments: chitosan + onion and chitosan + mentha. It was followed by chitosan + Brassica, chitosan + urad and chitosan + coconut whereas, chitosan combined with corn cob waste was found to be the least effective when compared to the control. The application of chitosan alone was effective but not very satisfactory. Compared to the control applications of all the treatments significantly increased plant growth in terms of length, fresh and dry weights, pollen fertility, yield and biochemical parameters such as chlorophyll, carotenoid content and antioxidant enzymes. This may have been due to the eliciting activity of chitosan, causing systemic resistance in the plant and the release of various toxic chemical compounds during decomposition which have lethal effects against the second stage juveniles of M. incognita and nematode multiplication.

SummaryThe root-knot nematode Meloidogyne incognita is a major soil parasite of lentil crops. Increasing restrictions of chemical nematicides have triggered a growing attention and interest in alternate root-knot nematode management. The present study was conducted to examine the level of resistance and/or susceptibility of fi ve lentil cultivars (PL-456, KLS-218, Desi, DPL-62, Malika), grown in pots, against the root-knot nematode M. incognita. Root-knot nematode reproduction and host damage were assessed by recording the nematode infestation levels and reduction percentage of plant growth parameters. Nematode response and plant growth diff erentiated amongst the lentil cultivars. None of the cultivars was found immune or highly resistant. The cultivar Malika was found moderately resistant as it showed the lowest number of galls and egg masses/root as well as the lowest reduction of plant fresh weight (10.4%) and dry weight (6.9%). On the other hand, the cultivar Desi manifested the highest susceptibility exhibiting the highest number of galls and egg masses. There was a signifi cantly negative correlation between the number of galls and plant growth parameters (plant fresh and dry weight and plant height).