Delimitation of guava water productivity in the Brazilian Northeast.

The intensification of agricultural crops in the Brazilian northeast results in a change of natural vegetation, making the quantification and evaluation of the additional water use important. Applications of a Geographic Information System (GIS) are presented in this paper to estimate the guava water productivity (GWP) on a large scale. Long-term weather data were used together with regression models involving crop coefficient (Kc), reference evapotranspiration (ET0) and accumulated degree days (DDac) to quantify the guava water requirements (GWR) in the Brazilian Northeast producer states, considering an average growing season of six months and the cultivar ‘Paluma’ as a reference. By coupling GWR data with total precipitation for a growing season, it was possible to quantify the guava water deficit (GWD) giving an estimate about irrigation needs. Considering the whole region, the variation of the averaged GWD values ranged from 50 mm for pruning dates in January to 520 mm, with pruning done in May. Associating the average GWR values with yield data for 2010 from the Brazilian Geographical and Statistical Institute (IBGE), the average biophysical and economic values of GWP were estimated for each guava producer state. The biophysical values were between 0.86 and 4.95 kg m-3 for pruning dates in July and January in Rio Grande do Norte and Pernambuco states, respectively, while the economic ones ranged from 0.40 to 3.18 R$ m-3 for the same pruning periods, however, with the lowest averaged value being for Paraíba state. The states of Pernambuco, Bahia and Piauí presented the largest biophysical and economic GWP values. The spatially presented analyses can subsidize programs for the expansion of rainfed guava crop as well as water allocation criteria under irrigation conditions, aiming at improvements for water resource use.Edição do Proceedings of the III International Symposium on Guava and other Myrtaceae, Petrolina, sept. 2012

Up scaling guava water balance in the Petrolina-Juazeiro growing area, Northeast Brazil.

Made available in DSpace on 2017-06-17T00:36:21Z (GMT). No. of bitstreams: 1 Heriberto12012.pdf: 894482 bytes, checksum: 08c140b450852815e3c3183f5056e2af (MD5) Previous issue date: 2012-10-222012Edição do Proceedings of the III International Symposium on Guava and other Myrtaceae, Petrolina, sept. 2012

Modelagem hídrica na cultura da mangueira no pólo produtor brasileiro Petrolina-PE/Juazeiro-BA.

Dados climáticos de um rede de estações agrometeorológicas automáticas e resultados de experimentos de balanço de energia foram usados para modelar variáveis hídricas na cultura da mangueira no pólo brasileiro de produção Petrolina-PE/Juazeiro-BA. Foi evidenciada uma maior necessidade de aplicação de água nas fases do florescimento ao crescimento dos frutos, chegando à 150 mm mês-1. Dados adicionais de produção de mangas permitiram as análises da produtividade da água (PA), resultando em menores valores para Petrolina, com média de 1,60 kg m-3, enquanto que para Juazeiro esta foi de 1,80 kg m-3. Pôde-se concluir que no primeiro município, o manejo de água da cultura deve ser mais ineficiente, existindo espaço para uma melhoria em PA.IV Winotec 2012

Up scaling guava water balance in the Petrolina/Juazeiro growing area, Northeast Brazil.

Weather data for 2011, from a net of 15 automatic agro-meteorological stations and previous field energy balance results, were used together with regression models for modelling the guava water requirement (GWR) in the growing area of Petrolina (Pernambuco state) - Juazeiro (Bahia state), Brazil, considering a 6.5-months average growing season (GS). GWRGS joined with rainfall, allowed the acquirement of the regional water balance and the application of a guava water indicator (GWIGS) calculated as the ratio of the total precipitation during a growing season (PGS) to GWRGS. The variation of the averaged GWRGS values for Petrolina, was from 750±6.9 to 950±10.5 mm, while for Juazeiro, it was from 730±6.2 to 900±9.2 mm, with pruning periods in January and June, respectively. Considering the GWIGS indicator, its values for both municipalities were found similar, which were around 0.38 and 0.08 for pruning done in January and June, respectively. Quantifying the differences between PGS and GWRGS, it was evident that a higher amount of irrigation water needed to be applied between September and October for growing cycles starting in June. Additional data from IBGE (Brazilian Geographical and Statistical Institute) allowed the inspection of the guava water productivity (GWP) at the municipality level. The GWP values for Petrolina were 4.1 and 3.3 kg m-3, while for Juazeiro they were 1.8 and 1.5 kg m-3, for pruning periods in January and June, respectively. It could be concluded that the lower GWP values for Juazeiro was because of a poorer crop management, resulting in lower yield, evidencing scope for improvements. The analyses spatially presented, can subsidize water allocation and irrigation management criteria, when aiming improvements on guava water productivity and yet, avoiding environmental damage by the fast climate and land use changes in the Brazilian semi-arid areas.Edição do Proceedings of the III International Symposium on Guava and other Myrtaceae, Petrolina, sept. 2012

Effect of baculovirus spodoptera isolates in Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) larvae and their characterization by RAPD.

The total of 22 Baculovirus isolates surveyed in different corn producing regions in Brazil were used against fall armyworm, Spodoptera frugiperda (J.E. Smith). The viruses were purified and their suspensions were used to feed fall armyworm larvae from 4th and 5th instar. The mortality rate was checked daily and the infected larvae were frost after death, what generally occurred between the 5th and 7th day after virus ingestion. The 22 Baculovirus isolates were used in six concentrations (from 103 to 108 polyhedra/ml) and one check treatment with water. Mortality rate, larval period, pupal period, pupa weight and lethal concentration (LC50) were determined for all isolates. Significant differences were found among all isolates and different concentrations, also interaction between isolate x virus concentration for all characteristics evaluated, except for pupal period. Amplification patterns of 54 RAPD markers, being 41 polymorphic among the isolates, were used to evaluate the genetic distance and its correlation with the fall armyworm larvae mortality rate. The genetic diversity calculated by the Jaccard's coefficient using the molecular data allowed a division of the isolates into two groups, with a high level of confidence. These groups did not present any association with the mortality rate caused by the isolates or with their geographical distribution. However, a RAPD fragment OPW04.2280 was highly associated with the larvae mortality rate and with LC50, explaining 23 and 65% of the phenotypic variation for these traits among the isolates, respectively.