The weeds if not properly controlled have great ability to settle in agricultural systems, affecting crop production. The objective of this work was to determine the interference and level of economic damage in different density of crop. The treatments were composed of canola hybrids (Hyola 50, Hyola 76, Hyola 433, Hyola 571 CL, Hyola 575 CL and Diamond) and twelve infestation turnip density in crop. The variables evaluated to estimate the competitiveness of the hybrids were plant density, leaf area, soil cover and dry mass of the turnip. Grain yield, canola price, herbicide efficiency, and control cost were used to determine the weed's level of economic damage on the crop. The canola hybrids Hyola 575 CL, Hyola 50, Hyola 76 and Hyola 571 CL are more competitive with turnip. The values of economic damage levels range from 2.86 to 5.95, 2.43 to 5.05, 2.22 to 5.43 and 2.99 to 6.22 turnip plants m-2 for hybrids Hyola 50, Hyola 76, Hyola 571 CL and Hyola 575 CL, respectively, as a function of simulated variables. The increased grain yield, canola price, herbicide efficiency and lower control costs reduce the level of economic damage, justifying the adoption of control.

The increase in flower cultivation in recent years has been reflecting the higher incidence of soil pathogens that can cause serious problems. This study aimed to evaluate the biological control of Fusarium wilt in gerbera with Trichoderma asperellum. The evaluated treatments were: T1) Control, only sterile substrate; T2) Substrate + Fusarium oxysporum; T3) Substrate + Fusarium oxysporum + Trichoderma asperellum; and T4) Substrate + Trichoderma asperellum. For this, the pathogen was isolated from gerbera with disease symptoms and, subsequently, it was identified according to morphological characters. Furthermore, the degree of antagonism of T. asperellum against F. oxysporum was evaluated through the culture pairing test. For greenhouse evaluations, commercial autoclaved substrate was used and infested with corn grains infected by the pathogen. Morphological identification confirmed the pathogen species as Fusarium oxysporum. In the culture pairing test, it was found that T. asperellum did not present a high degree of antagonism. The plants cultivated on substrate infested by the pathogen had no visible symptoms of wilt, but the substrate infestation with the pathogen provided lower values of fresh and dry mass of shoots and roots. The treatment with T. asperellum obtained higher values of fresh and dry mass of both shoots and roots, and also more vigorous inflorescences in relation to the plants treated with the pathogen

The application of glyphosate associated with other herbicides is an important alternative for weed control in maize, to increase control spectrum and to minimize problems with resistance and tolerance from some species to the product. The objective of this work was to evaluate the efficacy, selectivity and effects on the grain yield components of glyphosate-resistant maize as a function of its application, associated or not with other pre- and postemergence herbicides. The design used was randomized blocks with four replications. Treatments consisted in the use of glyphosate combined with the herbicides: atrazine, [atrazine + simazine], [atrazine + oil], [atrazine + S-metolachlor], applied pre- and/or postemergence and [nicosulfuron + mesotrione] only postemergence, plus two controls, one weeded and one infested. The evaluated variables were maize phytotoxicity, weed control, ear insertion height, number of rows per ear, number of grains per row, one thousand grain mass and grain yield. Herbicide treatments caused low phytotoxicity to maize, less than 6%; control greater than 88, 95 and 95% for alexandergrass, turnip and sunflower, respectively, and did not affect grain yield components. The tested herbicides are selective to the hybrid Forseed 2A521 PW and effective in weed control. Weed control with weeding or herbicide increased maize Forseed 2A521 PW yield by 43%. The association of glyphosate with pre- or postemergence herbicides increased maize grain yield by approximately 14%.

One of the big challenges to the soybean cultivation is the control of weed plants, because of the competitive potential that they presente and the resistance index in relation to the herbicides. In front of this, the work had as objective to evaluate the mix of herbicides in tanks to initial control of weed plants in the soybean culture. The experiment was installed in field in sistem of no-tillage in an área that presented the cultute of the wheat as precedente. The design used was that one of randomized blocks, with four repetitions. The herbicide’s treatments used in the test were: glyphosate, glyphosate + (diuron+sulfentrazone), glyphosate + diclosulam, glyphosate + (imazethapyr + flumioxazin), glyphosate + flumioxazin, glyphosate + 2,4-D, glyphosate + S-metolachlor, amônio-glufosinate + (diuron + sulfentrazone). The variable used was phytotoxicity in the culture, weed plants’ control Urochloa plantaginea and Raphanus sp., thousand grains weight and productivity of the soybean. The data were submitted to analysis of variance by the F test and the compared averages by the Scott-Knott test, in 5% of error probability. The phytotoxicity caused by the herbicides in the culture is not significative in the point of decrease the grains yield. The herbicides that presented better control of U. plantaginea were the associations of glyphosate with diuron + sulfetrazone, imazethapyr + flumioxazin and s-metolaclhor. Already in the control of Raphanus sp., the association of diclosulam and imazethapyr + flumioxazin with glyphosate presents results next of 100% of control. The variable thousand grains weight it was not affected by the association of the herbicides. In relation to the soybean grains productivity the herbicides (glyphosate + diclosulam and glyphosate + (imazethapyr + flumioxazin)) that provide low phytotoxicity and high control of the weed plants had their productivity compared to the weeded control.

O trigo é um cereal importante devido as suas propriedades funcionais, tecnológicas e nutricionais. Contudo, a incidência de doenças como a mancha amarela e a ferrugem da folha, causam perdas significativas de produtividade. Objetivou-se avaliar a eficiência de diferentes fungicidas frente ao progresso e ao controle de mancha amarela e ferrugem da folha em trigo. O experimento foi instalado em delineamento em blocos ao acaso, com quatro repetições, na safra 2018, com a cv. BRS 374, sendo os tratamentos: T1) testemunha; T2) epoxiconazol + fluxapiroxade + piraclostrobina; T3) azoxistrobina + benzovindiflupir; T4) azoxistrobina + ciproconazol e propiconazol; T5) trifloxistrobina + tebuconazol; T6) piraclostrobina + metconazol; T7) piraclostrobina + epoxiconazol; e T8) protioconazol + trifloxistrobina. Avaliou-se a área abaixo da curva de progresso da doença (AACPD) e o controle (%) para mancha amarela e ferrugem da folha; peso hectolítrico (Ph), peso de mil grãos (PMG, g) e produtividade (kg ha-1). O fungicida epoxiconazol + fluxapiroxade + piraclostrobina obteve melhor controle alcançando 85,5% (mancha amarela) e 88,2% (ferrugem da folha). Os tratamentos com epoxiconazol + fluxapiroxade + piraclostrobina, azoxistrobina + benzovindiflupir, piraclostrobina + metconazol e protioconazol + trifloxistrobina apresentaram os melhores resultados, incrementando a produtividade em 37,4%, 38,0%, 39,4% e 43,8%, respectivamente.

The use of herbicides to anticipate harvesting in species with easy seed dehiscence may be an alternative to avoid maturation losses. However, the appropriate time for herbicide application is extremely important as it prevents the seeds from remaining in the field for long periods. The objective of this study was to evaluate the efficiency of the application of maturing herbicides in two distinct seasons, and their effects on the physical, physiological, and sanitary quality of canola seeds. A randomized block experimental design arranged in a factorial scheme (herbicide x season + control) with four replications was used. Hybrid 50 canola plants were matured with the herbicides: glufosinate, paraquat, glyphosate, diquat, saflufenacil, 2,4-D, and paraquat + diuron twice during the crop cycle, G3 and G4, and two controls without application for each epoch, with the first being harvested the day of product application, and the second kept in the field until the final crop cycle. Analyses of one thousand seed weight, electrical conductivity, emergence speed index, and a sanity test were performed. The application of maturing herbicides to canola increases the one thousand seed weight and rate of emergence speed. At the same time, it increases electrical conductivity and the incidence of fungi. Plants that remained in the field until the end of the crop cycle and did not receive herbicide application resulted in higher quality seeds. The most appropriate moment to apply maturation herbicides to canola is in the G4 season.

No abstract

Canola (Brassica napus L. var. oleifera) is a winter growing option for producers, however, harvesting is the phase that requires the most care and decision making to avoid losses in productivity. One of the alternatives that can be used to solve this problem is the application of maturing herbicides. Thus, the objective of this study was to evaluate the physiological quality of canola seeds with the use of herbicides, applied in two seasons, for pre-harvest maturation of the crop. The experimental design was a randomized block design, arranged in a factorial scheme 7x2 + 2 (herbicide x season + control) with four replications. Hybrid 50 canola plants received ammonium glufosinate, paraquat, glyphosate, diquat, saflufenacil, 2,4 -D and paraquat + diuron at two times in the crop cycle (G3 -when the first ten the main stem silica has a width greater than 4 cm, and G4 -when the first ten silicas of the main stem begin to mature), in addition to two unselected controls, for each season, the first being harvested on the day of application of the products, and the second kept in the field until the final cycle of the culture. First germination, germination, seedling length, dry mass, cold test and accelerated aging tests were performed. Herbicides applied in the first season (G3) cause the greatest damage to the seeds, and the plants that remained in the field until the end of the crop cycle and did not receive herbicide application (additional control), result in seeds with better physiological quality. The treatments with diquat, paraquat + diuron and glufosinate of ammonium presented higher efficiency with respect to seed quality, being the best period to carry out the maturation practice in the canola crop in the G4 season.