Prediction of annual weed seed emergence in garlic (Allium sativum L.) using soil thermal time

Avena fatua L. and Polygonum aviculare L. are two competitive weeds in garlic (Allium sativum L.) fields. Knowledge of the temporal pattern emergence will contribute to optimizing the timing of control measures, thus maximizing efficacy. The development of predictive models can contribute to control measures at early growth stages. The objective of this study was to develop and validate predictive empirical models of emergence for A. fatua and P. aviculare based on thermal time. Cumulative seedling emergence data were obtained during two years from a garlic field and used to develop and validate the models. The relationship between cumulative seedling emergences and cumulative thermal time (TT) under field conditions was analyzed using the Gompertz function. The models accounted for 98% and 96% of the variation observed in A. fatua and P. aviculare, respectively. Model validation performed well in predicting the seedling emergence of both species. According to this model, A. fatua emergence started at 381 TT after sowing and reached 50% and 90% of total emergence at 407 and 478 TT, respectively, with a soil base temperature of 1. °C. P. aviculare started emergence at 410 TT after sowing and reached 50% and 90% of total emergence at 505 and 590 TT, respectively, with a base temperature of 0. °C. Results indicate that these models could be useful as predictive tool contributing to a effective control of A. fatua and P. aviculare populations in garlic crops. © 2014 Elsevier B.V.LG-A was supported by FEDER and the Spanish Ministry of Economy and Competitiveness funds (AGL2009-07883).Peer Reviewe

Distribution and Biogeography of Bactrocera and Dacus Species (Diptera: Tephritidae) in Papua New Guinea

Based on literature records and the results of an extensive trapping program, presence records for 194 species of Bactrocera and Dacus in the 19 provinces of Papua New Guinea are presented: of the 770 records over 500 are new. Based on species accumulation curves, Central, Morobe, Madang, Eastern Highlands, Western Highlands, New Ireland and Bougainville provinces, plus the province pairs of East and West Sepik, East and West New Britain, and Southern Highlands and Enga, can be regarded as having been adequately sampled. The remaining provinces should still be regarded as being under-collected. On mainland PNG, Morobe and Central provinces have the richest faunas and highest levels of endemism, approximately 15% each. All other mainland provinces have very low levels of endemism and are essentially subsets of the faunas of Morobe and Central Province. Although also with very low levels of endemism, the Highlands provinces have a statistically distinct fauna, suggesting that a pool of the PNG species are able to utilise both lowland and highland habitats. The fruit fly fauna of the island provinces is distinct from the mainland fauna, with further separation between the islands of the Bismark Archipelago (New Britain and New Ireland) and Bougainville. The greatest diversity of flies in PNG are associated with major northern geological elements, ie the New Guinea orogen, New Guinea accreted terranes and the off-shore islands, rather than the primary southern geological element, the Australian creton