Drought resistance of sugar-cane crop for different levels of water availability in the soil

Soil water availability is the main cause of reduced productivity, and the early development period most sensitive to water deficit. This study aimed to evaluate the drought resistance of the varieties of sugar-cane RB867515 and SP81-3250 during the early development using different levels of water deficit on four soil depths. The experiment was conducted at the Department of Biosystems at Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ/USP) in a greenhouse in soil classified as Oxisol, sandy loam texture (Series "Sertãozinho"). Once exhausted the level of available water in the soil, the dry strength of the studied strains are relatively low. Water balance with values less than -13 mm cause a significant decrease in the final population of plants, regardless of the variety, and values below -35 mm, leads to the death of all plants.

Trickle irrigation: effects on papaya crop

The objective of this study was to evaluate growth and yield of papaya cv. Sunrise solo under trickle irrigation system configurations. A random block design was used with six treatments and four replications. Treatments were: T1- a 32 L h-1 micro sprinkler; T2 - a 43 L h-1 micro sprinkler and T3 - a 60 L h-1 micro sprinkler for four plants; T4 - Drip system with four emitters per plant on one lateral line per crop row; T5 - Drip system with eight emitters per plant on two laterals line per crop row; T6 - Drip system with four emitters per plant on one lateral line distributed as pig tail. The dripper flow rate was 4 L h-1and they were apart each other 0.50 m. Crop growth variables were measured every two weeks. Production variables were evaluated during harvest. The treatment that presented superiority was irrigated by micro sprinkler system with flow rate of 43 L h-1.

Determination of total accumulated rainfall, global radiation, evapotranspiration and degree-days originated from the ECMWF model to sugar cane crop

The climate variability between the growth and harvesting of sugar cane is very important because it directly affects yield. The MODIS sensor has characteristics like spatial and temporal resolution that can be applied to monitoring of vegetative vigor variability in the land surface and then, temporal profiles generation. Agro meteorological data from ECMWF model are free and easy to access and have a good representation of reality. In this study, we used the period between sugar cane growth and harvest in the state of Sao Paulo, Brazil, from temporal profiles selecting of NDVI behavior. For each period the precipitation, evapotranspiration, global radiation, length (days) and degree-days were accumulated. The periods were presented in a map format on MODIS spatial resolution of 250 meters. The results showed the spatial variability of climate variables and the relationship to the reality presented by official data.

Swine wastewater associated with mineral fertilization on corn crop (Zea mays)

This study aimed to evaluate the agronomical and environmental aspects in corn, soil characteristics and leachate resulting from the material combination of swine wastewater and mineral fertilizer in the long run. The experimental area has a history of swine wastewater application for experiments conducted since 2006, this being the seventh crop cycle in the area. Four doses of swine wastewater (0; 100; 200 and 300 m³ ha-1) associated with presence and absence of mineral fertilizer were applied, consisting of eight treatments. The results obtained were subjected to variance analysis and means compared by Tukey test at 5% significance. We conclude that the swine wastewater can be partially used as an alternative fertilizer, since the P and Mn are complemented with specific fertilization. There must be carefulness about Fe+2, Cu+2 and Zn+2 accumulation in soil, and also to the concentrations of Fe+2, Cu+2, Zn+2, NO3- + NO2- and Na+ in leachate which exceeded the limits at the highest SWW applied levels.

Spatial statistics applied to soybean production data from Paraná State for 2003-04 to 2009-10 crop-years

In the current study, we performed a soybean production spatial distribution analysis in Paraná State. Seven crop-year data, from 2003-04 to 2009-10, obtained from the Paraná Department of Agriculture and Supply (SEAB) were used to develop a Boxmap for each crop-year, show soybean production throughout this time interval. Moran's index was used to measure spatial autocorrelation among municipalities at an aggregate level, while LISA index local correlation. For each index, different contiguity matrix and order were used and there was a significance level study. As a result, we have showed spatial relationship among cities regarding the production, which allowed the indication of high and low production clusters. Finally, identifying main soybean-producing cities, what may provide supply chain members with information to strengthen the crop production in Paraná.

Yield of cotton/cowpea and sunflower/cowpea crop rotation systems during the reclamation process of a saline-sodic soil

The objective of this study was to evaluate the use of subsoiling, gypsum and organic matter associated with the cultivation of cotton, sunflower and cowpea in crop rotation, seeking the reclamation and use of a saline-sodic soil. The treatments were arranged in a randomized block design in split plots with four replications, during two crop cycles (2009/2010 and 2010/2011). The plots were formed by the treatments: T1. Subsoiling (S); T2. S + 20 Mg ha-1 of gypsum; T3. S + 40 Mg ha-1 of organic matter; T4. S + 10 Mg ha-1 of gypsum + 20 Mg ha-1 of organic matter; T5. S + 20 Mg ha-1 of gypsum + 40 Mg ha-1 of organic matter and the sub-plots consisted of the cotton-cowpea (C/CP) and sunflower-cowpea (S/CP) crop rotation. The use of gypsum and organic matter contributed to decrease the soil salinity and sodicity. Cotton was not affected by the treatments, while the sunflower crop was favored by the application of amendments only in the second production cycle. Higher yields of cowpea in T5 treatment, during the 2009/2010 cycle, are indicative that higher doses of gypsum and organic matter applied in this treatment accelerate the reclamation process. For other treatments with amendment application there was a beneficial effect for this crop only in the second cycle, when the values of productivity were similar to T5.

Application of artificial neural networks as an alternative to volumetric water balance in drip irrigation management in watermelon crop

Precision irrigation seeks to establish strategies which achieve an efficient ratio between the volume of water used (reduction in input) and the productivity obtained (increase in production). There are several studies in the literature on strategies for achieving this efficiency, such as those dealing with the method of volumetric water balance (VWB). However, it is also of great practical and economic interest to set up versatile implementations of irrigation strategies that: (i) maintain the performance obtained with other implementations, (ii) rely on few computational resources, (iii) adapt well to field conditions, and (iv) allow easy modification of the irrigation strategy. In this study, such characteristics are achieved when using an Artificial Neural Network (ANN) to determine the period of irrigation for a watermelon crop in the Irrigation Perimeter of the Lower Acaraú, in the state of Ceará, Brazil. The Volumetric Water Balance was taken as the standard for comparing the management carried out with the proposed implementation of ANN. The statistical analysis demonstrates the effectiveness of the proposed management, which is able to replace VWB as a strategy in automation.

Desiccation time of the spring sorghum as a predecessor crop for summer soybean and autumn bean in a no-tillage system

ABSTRACT Several authors have been questioned the desiccation interval between the coverage plants and sowing plants for the soybean crop. Therefore, this study aimed to evaluate the desiccation time of the spring sorghum as a predecessor crop for summer soybean and then for autumn bean, focusing on the straw formation for maintenance of the no-tillage system and to evaluate the yield of soybeans and beans grain, as well as analyzing the interference of sorghum straw in these cultures. The experiment was developed in the Teaching and Research Farm of FE/UNESP located in Ilha Solteira/SP where it was used an experimental design of randomized blocks with five treatments and six repetitions. The treatments consisted of five different intervals between sorghum desiccation and soybean sowing (being with D7 - Drying sorghum seven days before the soybean sowing; and successively for D14, D21, D28 and D35). In order to analyze the results, it was used the Tukey test for a 10% level of significance and the statistical program called Sisvar. The "Cober Crop" sorghum exerted influence on soybean yield but this effect was not lasting for the bean crop in succession to the soybeans.

Avaliação de microcalcificações mamárias de acordo com as classificações do Breast Imaging Reporting and Data System (BI-RADS TM) e de Le Gal

OBJETIVO: avaliar a acurácia da mamografia para o diagnóstico de microcalcificações mamárias suspeitas, com as classificações do Breast Imaging Reporting and Data System (BI-RADS TM) e Le Gal em comparação com o resultado histopatológico utilizado como padrão-ouro. MÉTODOS: foram selecionados dos arquivos dos blocos cirúrgicos, 130 casos operados com mamografias contendo somente microcalcificações mamárias, inicialmente classificadas como suspeitas sem lesões detectáveis ao exame clínico. Estas foram reclassificadas por dois examinadores, utilizando as classificações de Le Gal e BI-RADS TM, obtendo-se diagnóstico de consenso. As biópsias foram revistas por dois patologistas e foi obtido diagnóstico de consenso. A leitura das mamografias e a revisão das lâminas foram feitas em duplo-cego. As análises estatísticas utilizadas neste estudo foram o teste do chi2, o modelo Fleiss quadrático para VPP e o programa Epi-Info 6.0. RESULTADOS: a correlação entre a análise histopatológica e mamográfica, usando BI-RADS TM e Le Gal, mostrou a mesma sensibilidade de 96,4%, especificidade de 55,9 e 30,3%, valor preditivo positivo (VPP) de 37,5% e 27,5% e acurácia de 64,6 e 44,6%, respectivamente. Quando discriminamos por categorias de BI-RADS TM, obtivemos VPPs: categoria 2, 0%; categoria 3, 1,8%; categoria 4, 31,6% e categoria 5, 60%. Os VPPs pela classificação de Le Gal foram: categoria 2, 3,1%; categoria 3, 18,1 %; categoria 4, 26,4%; categoria 5, 66,7% e não classificável, 5,2%. CONCLUSÕES: observou-se uma maior precisão com a classificação de BI-RADS TM, porém não se conseguiu reduzir a ambigüidade na avaliação das microcalcificações mamárias.

Screening of antigenemia and isolation of Cryptococcus neoformans and C. gattii from cloaca and crop of birds in the state of Paraná, Brazil

Cryptococcus neoformans and C. gattii are associated with dry bird excreta but rarely recovered from birds' digestive tract. The objective of the present study was (1) to verify the existence of C. neoformans and C. gattii in crop and cloaca of wildlife and captivity birds hypothesizing about a possible primary source of this yeast in the excreta, and (2) to determine the fungi's invasive capability in avian species through latex agglutination. For that purpose, 172 cloacal and 77 crop samples of domestic pigeon, Passerine, and Psittacine birds were collected. None of these samples was positive, suggesting that the yeast is not saprobiotic in the digestive tract of these birds. Only one out of 82 serum samples collected from pigeons and Psittacine birds was positive (title 1:2) showing that Cryptococcus sp. probably has a low invasive capability in birds, and is thus considered only a dry excreta colonizer.

Phenotypical characterization of Candida spp. isolated from crop of parrots (Amazona spp.)

The purpose of this study was to characterize Candida isolates from crop of parrots. Forty baby parrots of genus Amazona, species aestiva and amazonica that were apprehended from wild animal traffic were used: 18 presented ingluvitis and 22 other alterations, but showing general debilitation. Samples were seeded on Sabouraud dextrose agar with chloramphenicol after be obtained by the introduction of urethral probe through the esophagus. Based on morphology and biochemical reactions (API 20C) Candida was confirmed; it was still searched the production of proteinase and phospholipase, virulence factors for Candida species. Candida spp. were isolated from 57.5% parrots, being 72.2% from birds with ingluvitis and 45.5% from without ones. Twenty-five strains of Candida were isolated, 60% and 40%, respectively from parrots with and without ingluvitis, and were speciated: 28% C. humicola, 24% C. parapsilosis, 20% C. guilliermondii, 20% C. famata, and 8% C. albicans. These results demonstrate that C. albicans is not the most frequent species isolated, and it is the first report that shows C. guilliermondii, C. famata, and C. humicola causing infection in parrots. Many isolates presented filamentation (76%), 100% produced proteinase and 68% phospholipase. The observation of Candida spp. producing virulence factors reinforce the pathogenic role of these yeasts in the cases studied.

A field survey of crop management practices and distribution of ALS resistant Euphorbia heterophylla in two states in southern Brazil

Herbicide resistance was reported in Brazil almost ten years ago. One of the main weeds with herbicide resistance is wild poinsettia (Euphorbia heterophylla). This work evaluates the distribution of ALS-resistant E. heterophylla in two states in southern Brazil and determines the major contributing management causes for weed resistance selection in the area. E. heterophylla seeds from 148 sites located in Paraná and Rio Grande do Sul were sampled during 2001 and 2002. Farmers provided specific site data for weed control, tillage system, crop rotation and harvesting operations during previous years. ALS resistant E. heterophylla biotypes were found widely distributed in the survey area. Data analysis suggests seed dissemination is unlikely to explain the widespread distribution of resistance. The most probable factor for the selection of the resistant E. heterophylla is the persistent high use of ALS-inhibiting herbicides over time. Indirect evidence is presented demonstrating the need to educate legislators and farmers about the importance of herbicide mixtures as a strategy to prevent herbicide resistance.

Effects of glyphosate and endosulfan on soil microorganisms in soybean crop

Transgenic soybean, resistant to glyphosate, is the most dominant transgenic crop grown commercially in the world. Research works on herbicide and insecticide mixtures and their effects on microorganisms are rarely reported. This work aimed to study the impact of glyphosate, endosulfan and their mixtures on the microbial soil activity in soybean crop. The experiment was carried out in a complete randomized block design with four treatments and five replications. The treatments were glyphosate 480 SL [540 g of active ingredient (a.i.) ha-1], endosulfan 350 EC (525 g a.i. ha-1), the glyphosate 480 SL [540 g of active ingredient (a.i.) ha-1] mixed with endosulfan 350 EC (525 g a.i. ha-1) and the control. Microbial activity was evaluated five days after treatment application. Glyphosate application was not an impacting factor for soil CO2 production. Endosulfan application (alone or mixed with glyphosate) suppressed CO2 production by microorganisms in the soil. Microbial biomass and microbial quotient were lower in the treatments using endosulfan alone and in those using endosulfan mixed with glyphosate than in the treatments using glyphosate alone and control.

Weed control via intercropping with gliricidia: I. cotton crop

The majority of cotton grown commercially in the world has white lint, but recently, there has been a growing interest in colored lint cotton in several countries, including Brazil. The use of naturally-colored fiber reduces chemical pollution. The objective of this paper was to evaluate cotton cultivar fiber yield in response to weed control via intercropping with gliricídia. Cultivars BRS-Verde (greenish fibers), BRS-Rubi (reddish brown fibers), BRS-Safira (brown fibers), and BRS-187 8H (white fibers) were submitted to the following treatments: no hoeing, two hoeings (at 20 and 40 days after transplanting), and cotton intercropped with gliricídia. In the intercropped treatment, gliricídia was planted between rows of cotton plants, using one seedling pit-1, in pits spaced 50.0 cm apart. Twelve weed species predominated in the experiment, many of them belonging to the Poaceae family. Weeds occurred at different frequencies and in a non-uniform manner in the experimental area. Cultivars did not influence weed dry matter. Intercropping with gliricídia reduced weed dry matter but did not prevent reductions in cotton fiber and seed cotton yield, which were higher in hoed plots. Cultivar BRS Safira had the highest fiber yield, but no differences were observed between cultivars regarding to seed cotton yield.

Weed control via intercropping with gliricidia: II. corn crop

A reduction in herbicide use is one of modern agriculture's main interests and several alternatives are being investigated with this objective, including intercropping. Gliricídia (Gliricidia sepium) mulch has no allelopathic effect on corn or beans but significantly decreased the population of some weed species. The objective of this study was to evaluate green ear and grain yield in corn cultivars as a response to weed control achieved via intercropping with gliricidia. A completely randomized block design with five replicates and split-plots was used. Cultivars AG 1051, AG 2060, BRS 2020, and PL 6880 (assigned to plots) were submitted to the following treatments: no hoeing, hoeing (performed at 20 and 40 days after sowing the corn), and corn intercropped with gliricidia. Gliricidia was grown in a transplanting system to ensure uniform germination and fast establishment in the field. Seeding was made in 200-cell trays with one seed per cell (35 mL volume). The plants emerged two to three days after sowing and were transplanted to a permanent site two to three days after emergence. Corn was sown on the same day gliricidia was transplanted. Sixteen weed species occurred at different frequencies, with uneven distribution in the experimental area. Cultivars AG 1051 and AG 2060 were the best with reference to most characteristics employed to evaluate green corn yield. Cultivar AG 1051 provided the highest grain yield. The highest green ear yield and grain yield values were obtained with hoeing. However, the fact that intercropped plots showed intermediate yield between the values obtained for hoed and non-hoed plots indicates that gliricidia was beneficial to corn, and exerted a certain level of weed control.