Up to 14 DAD the moisture content of the sample composed of leaf, culm and panicle was above 70%, with no significant differences among treatments, including control (without application) (Figure 3E). Although, at 21 DAD there was a reduction in moisture content of the sample in plants sprayed with both doses of glyphosate and in the control. At 28 DAD, the treatment with the highest glyphosate dose showed greater moisture removal, presenting around 60% in moisture content of the sample. Plants receiving paraquat, paraquat + diuron and glufosinate-ammonium remained with moisture content of the sample above 70%, with no statistical difference between these herbicides. The treatment with the lowest glyphosate dose did not differ from the control and presented moisture content of the sample around 68%. In general, the regression analysis shows that all insecticide treatments had a stronger tendency in reducing leaf and panicle moisture contents than control (Figures 4A and 4C). However, only the treatments with glyphosate have stronger tendency in reducing culm moisture content (Figure 4B). It was possible to visibly notice the herbicidal action on plant leaves in all treatments when compared to the control (Figure 5). In addition, treatments with glyphosate and paraquat + diuron mixture resulted in plants whose culms had a whitish appearance, indicating moisture loss.
There have been several positive results as to the effectiveness of desiccants in reducing the moisture content and preserving the quality of seeds of soybean (Daltro et al., 2010; Guimarães et al., 2012), bean (Santos et al., 2004) and canola (Silva et al., 2011). The use of glyphosate desiccation for earlier harvest is becoming frequent, mainly because glyphosate offers low cost and product versatility. However, several studies have reported negative effects of this herbicide, when it is used for desiccation of soybeans between stages R6 and R7.2, on physiological seed quality and early seedling performance, especially on the seedling root system (Daltro et al., 2010; Guimarães et al., 2012). Penckowski et al. (2005), while assessing the effect of pre-harvestdesiccation on bean seed quality, observed that treatments with glufosinate- ammonium + etephon, diquat and glufosinate-ammonium were efficient in desiccating the crop and did not affect germination and vigor, but paraquat (240 g a.i.ha -1 ) and
To control late-appearing weeds and to speed up the drying process of agricultural crops to ensure quick and efficient harvesting, nonselective herbicides are applied prior to harvesting the plants (Bresnahan, Manthey, Howatt, & Chakraborty, 2003). Once the seeds reach physiological maturity, they are prone to physiological damage if they experience exposure to weather conditions. Thus, crop desiccation during the preharvest period indirectly reduces seed deterioration (Bellé et al., 2014). While this is a common practice in many countries, it must be emphasized that the current legislation must be complied with, in terms of the addition of the active ingredients and the grace period permitted until commercialization of the yield.
application. The seeds of plants desiccated at 39 DAF had the lowest weight (Figure 1). These results are similar to those described by Kamikoga et al. (2009) and Coelho et al. (2012), who observed a linear and growing relationship in seed weight when the number of applications increased from 28 to 43 DAF. No direct influence of hundred seed weight was observed on yield. This is contrary to the results obtained by Penckowski, 2005; Kappes et al. (2012), who reported the occurrence of a positive linear effect on yield as desiccation was delayed. It should be noted that yield is dependent on genotype, crop and environment, as well as the interaction between these factors, achieved through assessments of adaptability and stability (Rocha et al., 2010).
Clethodim drastically diminished the percentage of normal wheat seedling in the first count of the germination test in both sites (table 2), being below the control group (no application) by 23% in Site 1 and 35.75% in Site 2. Carfentrazone-ethyl and diquat also reduced the vigor of wheat seeds. Glufosinate-ammonium and glyphosate had performances equal to the control group in both Sites. As for desiccated wheat seeds germination percentage (table 2), it is evident that herbicides that had diminished the vigor did not influence final germination, because no difference was observable between germination of the treated groups and that of the control group. these data partially corroborate those of Santos and Vicente (2009), who observed in their study that the pre-harvest utilization of herbicides reduced neither germination nor Yield of the seeds.
strictly terrestrial beetles and those occupying deeper water such as many diving beetles (Dytiscidae) (Beament, 1961; Holdgate, 1956; Wigglesworth, 1945). However, it is difficult to establish a comparative framework because of the few existent data on desiccation resistance traits in adult aquatic insects and the multiple and contrasting approaches and/or experimental conditions used to measure them. The water contents of the four Enochrus species (60%–68% of fresh mass) were consistent with the typical 62% of most beetles (Hadley, 1994). Water loss rates, ranging from 2.2 to 3.6% of initial mass at 20% RH, appear to be comparable to those reported for the extraordinary desiccation resistant P. muticus, which lost ca. 5.4% of initial mass per hour under more severe conditions (0% RH) (Arlian & Staiger, 1979). Nevertheless, the total water losses that the studied species reached after the desiccation treatment (Table S2) were close to the limit of dehydration tolerance of most insects (20–30% of water content) (Hadley, 1994). Although such water loss was measured under an unrealistic humidity in natural conditions (20% RH), a combination of high temperatures (>30 ◦ C) and low humidity (40%–50% RH) is frequent in the natural
Paula F.J.A., Guiné R.P.F., Cruz-Lopes L., Duarte A.C., Fragata A.O.S., Reis M.A.L. (2015): Effects of pre- and post-harvest factors on the selected elements contents in fruit juices. Czech J. Food Sci., 33: 384–391. Pre- and post-harvest factors determine the levels of the selected risk elements in100% fruit juices. The juices samples closely followed the Brix international reference values. Fruit juices presented the following order of the elements mean concentrations: cadmium (1.597 μg/l), chromium (2.767 μg/l), lead (20.75 μg/l), nickel (73.37 μg/l), zinc (545.9 μg/l), and iron (1792 μg/l), measured by AAS. The pre-harvest factors (origin, fruit, and agriculture) and the post-harvest factors (blending, packaging, conservation, pasteurisation, and process) were evaluated according to the manufacturers information and were correlated with the elements concentrations of fruit juices. A strong relationship was detected between the fruit species used for the juice production (i.e. pre-harvest factor) and their elements concentrations. Furthermore, multiple correspondence analysis was used for reducing the data dimension by grouping the factors. The zinc concentration was detected as a potential proxy for the identification of the fruit juices manufacturing process.
An alternative little explored is the use of legumes in the production of silage, it is known that the addition of legumes into grass silage improves the quality of the ensiled mass by increasing the protein content, improving nutrient digestibility, intake and aspects related to the production like weight gain and milk production, due to its high nutritional value (Epifanio et al., 2016; Santana, Cisneros, Martínez, & Pascual, 2015). It is possible to ensile almost all types of forage; however, few species meet the requirements of quantity and quality, and it is important to analyze which species are more economically and nutritionally desirable. Silages of legume alone have poor quality due to high buffering power and low soluble carbohydrate content (Lima, Lourenço, Díaz, Castro, & Fievez, 2010). Nevertheless, the use of legumes mixed with grasses improves the quality of the ensiled mass and increases the protein content when compared to the silage of corn or sorghum alone (Leonel et al., 2008; Lima-Orozco, Castro-Alegría, & Fievez, 2013).
photosystem II (PSII) is fully oxidized and the reaction center (P680) is open, indicating the activation of the photochemical reactions (Baker & Rosenqvst, 2004). In a study withsorghum and salinity, the emission of the initial fluorescence (F 0 ) increased with an increase in the electrical conductivity (Nabati et al., 2013). The increase in F 0 in plants subjected to some type of stress may be related to the increase in leaf thickness (Munns & Tester, 2008) due to lipid peroxidation by reactive oxygen species (Yamane et al., 2008).
The sorghum genotype (Sorghum bicolor L. Moench) used was VOLUMAX, grown at the Experimental Farm of Embrapa Corn and Sorghum, located in the municipality of Nova Porteirinha, northern State of Minas Gerais, at 15º 48’10” South Latitude and 43º18’03” West longitude. Leucaena was harvested from the agrostólogico field of the State University of Montes Claros, in plants with approximately 0.8 cm thickness of branches, 12 months of age and 2 m height. The experimental design was completely randomized design with four treatments and five replications. The ensiled material consisted of sorghum alone and sorghumwith 15, 30 and 50% leucaena on a natural matter basis. The forage was ensiled in PVC tubes with 100 mm diameter and 500 mm length; sorghum and legumes were harvested on the same day and chopped separately, in a forage harvester, adjusted to 1 to 2 cm particle size, later weighed the appropriate proportions of each treatment, mixed and compacted in the silos with a wooden socket, taking care to obtain a density of 500 to 600 kg m - 3. Silos were closed with a PVC cap with Bunsen valves, sealed with
The coating based on neem oil (0.5%) + chitosan (1.0%) resulted in a longer storage time for the ‘Paluma’ guava, possibly by forming a barrier that minimised the rate of respiration and reduced water loss (which did not differ from the other treatments). However, the different temperatures were also a factor influencing storage, as it was found that when fruit treated with neem oil (0.5%) + chitosan (1%) were exposed to a temperature of 10 ± 1 °C, they showed a smaller loss, equal to 10.41% on the 16 th day, compared to those submitted to the treatment with neem oil (0.5%) + chitosan (1%) and exposed to a temperature of 24 ± 1 °C, which showed losses of 12.81% on the 8 th day of storage.
Abstract - Choosing species with high phytomass production to be cropped in no tillage system is extremely important in dry winter regions. The purpose of this research was to study plant biomass production and accumulation of nutrients in shoots of Giant Guinea sorghum plants (Sorghum bicolor subspecies bicolor race Guinea) sown in different sowing dates. A randomized complete block design with six treatments and four replications was performed. Treatments consisted of six sowing dates (09/25/2000; 10/25/2000; 11/24/2000; 12/22/2000; 02/22/2001 and 04/03/2001). At flowering, dry matter production, number and diameter of stems and plant height were evaluated. Macro and micronutrient levels and accumulation were determined as well as C/N ratio. Plant cycle decreased as sowing date was delayed and, consequently, dry matter production and C/N ratio decreased as well. The opposite was observed for nutrient contents. “Giant Guinea” sorghum is sensitive to photoperiod thus late sowing reduces plant development, which leads to low biomass production and nutrient accumulation. “Giant Guinea” sorghum cultivated as cover crop is a good option when implementing no tillage system due to high dry matter production and N, P, and K recycling.
Bean crop, Phaseolus vulgaris L., was also seeded in the same period for all treatments in the NTS area, in succession to soybean. In addition, 11 seeds per meter of the Rubi cultivar was planted together with 250 kg ha -1 of the sowing fertilization that has the following commercial formula 02- 30-20. In top-dressing, was applied 100 kg ha -1 of urea in all plots. We evaluated the parameters plant height, height insertion of the first pod, number of pods per plant, dry mass, grain production and 100-grain weight. In this way, it was weighed 100 grain of 10 plants collected at random in each plot using an analytical balance and finally, the weight was converted to a moisture of 13%.
Weed management consists of a fundamental practice in cassava, with mechanical and chemical control widely used. The objective of this work was to evaluate the efficacy of pre-emergence herbicides, as well as to determine the interaction of these with weeding complementation in the weed management in cassava. Two experiments were conducted in Junqueiro (Alagoas). In 2015/16, the experimental design was based on randomized blocks, with treatments distributed in a split-split-plot scheme, with four replications. In the main plot, four pre-emergence associations of clomazone + flumioxazin in different doses were evaluated, in addition to a control without herbicide. In the subplots, the Caravela and Pretinha cassava cultivars were evaluated, while in the sub-subplots the control complementation was evaluated using or not the manual weeding. In the 2016/17, the plot design and layout remained the same as for 2015/16, except for the composition of the herbicide treatments, since the standardization of clomazone dose has been chosen, varying only the doses of flumioxazin. The association of clomazone and flumioxazin has shown efficacy in weed control, with a greater residual as higher doses are used. This association provided higher shoot and root yield. Weeding complementation along the cassava cycle can increase its yield.
The SOD activity was determined according to a method adapted from Peixoto (1999). Using this method, the inhibition of the reduction of nitro blue tetrazolium (NBT) by the enzyme extract was determined, avoiding, therefore, the formation of chromophore. In this assay, one unit of enzyme activity (AU) of SOD was regarded as the amount of enzyme required to reach 50 % inhibition of NBT reduction by the SOD contained in the enzyme extract. For the reaction, the following components were added to a test tube: 1 mL of potassium phosphate buffer at 100 mM (pH 7.8), 400 µL of 70 mM methionine, 20 µL of 10 mM EDTA, 390 µL of ultrapure water, 150 µL of 1 mM NBT, 20 µL of 0.2 mM riboflavine and 20 µL of the extract. Then, the tubes were exposed to a 15 W bright fluorescent lamp chamber, for 10 min, and the 560 nm absorbance was recorded. Tubes without extract, exposed and not exposed to light, were considered as blanks in the reaction. The activity was determined by calculating the amount of extract that inhibited 50 % of the NBT reaction and expressed in AU mg -1 protein min -1 .
The current struggles in controlling LOLMU and URPLA in corn post-emergence indicates the need for a more efficient burndown and preemergent herbicide program. The emergence pattern of LOLMU and URPLA may vary with seasons depending upon environmental conditions; however, in the corn fields of Rio Grande do Sul, this variation is still poorly understood. In this way, the hypothesis of the present study were that corn sown early in the growing season is exposed to more significant interference from LOLMU. Differently, corn sown at the end of the growing season is subject to more significant interference from URPLA. In addition, residual herbicide applied at corn pre-emergence can improve the control of both LOLMU and URPLA post-emergence. Therefore, the objectives of this work were to evaluate the influence of corn-sowing date on LOLMU and URPLA densities and their control provided by residual herbicide treatment in corn pre-emergence followed by post-emergence herbicides programs.
Contents of total and soluble tannins were determined by spectrophotometry using the Follin-Ciocalteu reagent (50%), according to Taira (1995). One gram (1 g) of ground pulp was used to prepare a final volume of 100 mL of extract, from which a 1 mL aliquot was taken. This aliquot was added with Follin-Ciocalteu reagent (50%), plus 1 mL of supersaturated sodium carbonate solution, and 7.5 mL of distilled water. The reading was performed in a Biochrom- Libra S22 spectrophotometer with absorbance at 725 nm. The results were expressed as g of tannin per 100 g of fresh pulp (fp).
Feed and orts samples were then dried in a forced 60ºC drying oven, for 72 hours, and ground with a hammer mill (willey mill grinder produced by Arthur H. Thomas, Philadelphia, PA) to pass a 2.0 mm screen. Sample preparation (feed, orts) and the analysis of dry matter (DM), organic matter (OM), mineral matter (MM), nitrogen compounds (N), ether extract (EE), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were performed according to Silva & Queiroz (2002). The NDF and ADF were analyzed without sodium sulphite and values were not corrected for residual ash. The contents of total carbohydrates (CHO) were calculated as
GODOY, P.B.; BUENO, I.C.S.; NOZELLA, E.F. et al. Intake and digestibility of tanniniferous browse species fed to sheep in three different levels of protein supply. (Compact disc) In: ANNUAL MEETING OF THE BRITISH SOCIETY OF ANIMAL SCIENCE. 2004. York. Proceedings… Penicuik: BSAS, 2004. KOMOLONG, M.K.; BARBER, D.G.; McNEILL, D.M. Post-ruminal protein supply and N retention of weaner sheep fed on a basal diet of lucerne hay (Medicago sativa) with increasing levels quebracho tannins. Anim. Feed Sci. Technol., v.92, p.59-72, 2001 MAKKAR, H.P.S.; BLUMMEL, M.; BECKER, K. Formation of complexes between polyvinyl pyrrolidones or polyethylene glycols and tannins, and their implication in gas production and true digestibility in vitro techniques. British J. Nutrition. v.73, p.897-913, 1995.
and the lowest sprouting scores, the cultivars Frontana, IPR 85 and Ônix were identified as the most resistant to pre-harvest sprouting. Considering the average sprouting of the parents, it was inferred that dormancy occurs only in the parents Frontana, IPR 85 and Ônix. In crosses that exclude these parents, segregation for dormancy would only occur if there were complementary genes. One can also observe from Table 1 that the most sensitive parent is PFAU*, probably devoid of dormancy genes. In the populations derived from crosses Frontana, IPR 85 and Ônix with PFAU*, it was observed that both populations, the one derived from Frontana and the one derived from Ônix, segregate at a ratio of 57:7, indicating the presence of three recessive and two duplicate genes, the third being complementary to the first. The population derived from IPR 85 x PFAU* however segregated at a ratio of 63:1, indicating the segregation of three complementary recessive genes. Although this segregation of 63:1 should be evaluated with caution for this population size, segregation is to be expected in this population, since one parent is dormant and the other not.