-The spider mite Tetranychus evansi Baker & Pritchard can cause severe damage to tomato crops. The predatory mite Phytoseiulus longipes Evans was recently reported in association with T. evansi in Uruguaiana, Rio Grande do Sul State, Brazil. The objective of the present study was to evaluate the effects of P. longipes on the population of T. evansi on tomatoes under screenhouse condition. The study consisted on four experiments, in each of which 80 potted plantlets were distributed in two plots of 40 plantlets each. Two weeks later, each plantlet of both plots was infested with eight adult females of T. evansi; one week after, four adult females of P. longipes were released onto each plant of one plot. The population levels of T. evansi and the damage caused by these mites were signifi cantly lower (P ≤ 0.05; linear mixed-effect model) in the plots where P. longipes had been released. The results indicate the potential of this predator as a candidate for classical biological control of T. evansi by inoculative releases on tomato plants.
Brazil is a large producer and exporter of crops in global terms. Weeds may be responsible for ~14% of crop losses, depending on the crop system. Herbicides occupy 58% of the Brazilian pesticide market; however, the continuous use of these products and the high selection pressure have led to the emergence of weeds resistant to herbicides. Today, there are 51 weed species reported as being resistant to herbicides in Brazil, of which 17 involves cross and multiple-resistance. Acetolactate synthase (ALS), acetyl coenzyme A carboxylase (ACCase) and 5-enolpiruvylshikimate-3-phosphate synthase (EPSPs) inhibitors are the herbicidal groups with the most resistance cases. Soybean, corn, rice, wheat and cotton present 30, 12, 10, 9 and 8 cases, respectively, occurring mainly in herbicide-resistant crop fields from the Southern and Central West regions of the country. To better understand the dimensions of herbicide resistance, in this chapter, we will explore the size of agricultural activity in Brazil, the pesticide market and the use of herbicides in the main crops. In addition, the agronomic, scientific-technical and economic aspects that have contributed, directly or indirectly, to the selection of resistant weeds will be discussed in order to have an overview of the economic impact of herbicide resistance management.
Glyphosate is the main tool for weed management in Brazilian citrus orchards, where weeds, such as Conyza bonariensis and Digitaria insularis, have been found with resistance to this herbicide. Field prospections have allowed the identification of a possible new case of glyphosate resistance. In this work, the susceptibility levels to glyphosate on three Amaranthus viridis L. populations, with suspected resistance (R1, R2, and R-IAC), collected in citrus orchards from the São Paulo State, Brazil, as well as their accumulation rates of shikimic acid, were determined. The fresh weight of the susceptible population (S) was reduced by 50% (GR50) with ~30 g ea ha−1 glyphosate, while the GR50 values of the R populations were between 5.4 and 11.3 times higher than that for S population. The LD50 (herbicide dose to kill 50% of individuals of a weed population) values of the S population were ≤150 g ea ha−1 glyphosate, while the LD50 of the R populations ranged from 600 to 920 g ea ha−1. Based on the reduction of fresh weight and the survival rate, the R1 population showed the highest level of glyphosate resistance, which had GR50 and LD50 values of 248 and 918 g ea ha−1 glyphosate, respectively. The S population accumulated 240 µg shikimic acid at 1000 µM glyphosate, while the R1, R2, and R-IAC populations accumulated only 16, 43, and 33 µg shikimic acid, respectively (between 5.6 to 15 times less than the S population). Enzyme activity assays suggested that at least one target site-type mechanism was involved in resistance. This result revealed the first report of glyphosate resistance in A. viridis reported in the world.
The study deals with the reuse of Polyurethane (PU) obtained from a kitchen sponge added to plaster for use in civil engineering. The kitchen sponge is an item widely used by the population in their daily lives, generating a significant accumulation of waste. Thus, from the analysis of the properties of the kitchen sponge, it was seeking possible reuse of the kitchen sponge using it as an aggregate in plaster. The objective is to evaluate the properties of the material and consequently the search for an alternative of reuse of the waste to reduce the impact of the waste on the environment from the disposal. The methodology is composed of the collection of kitchen sponges already used, the processing, its application as an aggregate to gypsum and water, the preparation of plates for the tests and the evaluation of the properties. In general, the mixture presents significant results, highlighting excellent impact resistance and maintaining characteristics of the plaster, such as its pick time and compressive strength.
An integrated weed management system is perfectly aligned with the aim of producing healthy and environmentally sustainable vegetables. This integrated management is fundamental for vegetables, more than in other crops, due to its high commercial value, intensive culture, lack of competitiveness and low availability of registered herbicides. The integration of available weed control methods with a long-term strategy based on preventive and agronomic (cultural) practices is necessary to obtain a desired level of control, decrease the accumulation of the weed seed bank, increase weed diversity and decrease herbicide dependence and minimize their negative impacts. Thus, this book provides essential and updated subjects of information regarding the general characteristics of herbaceous vegetables, critical periods of control, main weeds in the crop, integrated management methods (preventive, cultural, physical, mechanical, biological and chemical); and it is intended for professors, researchers, extensionist, undergraduate and graduate students, rural producers and other professionals involved in the area of weed science.
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