Dallacort 5RESUMO -Com o objetivo de indicar qual ambiente, telado ou campo aberto, fornece melhores condições para a produção e maior resistência ao pendoamento de diferentes cultivares de alface lisa, para as condições climáticas de Cáceres-MT, desenvolveu-se esse trabalho no período de fevereiro a abril de 2011. Foram avaliados vinte tratamentos, empregando o delineamento experimental em blocos casualizados em esquema fatorial 5 x 4, sendo cinco ambientes de cultivo (telas de sombreamento 30 e 50%, telas termo-refletoras 30 e 50% e campo aberto) e quatro cultivares de alface tipo lisa (Elisa, Elizabeth, Regiane e Regina), com quatro repetições. A colheita foi realizada aos 30 dias após o transplante. As cultivares de alface lisa mais produtivas foram Regiane, que obteve maior número de folhas e Regina com menor comprimento de caule. Os ambientes de cultivo que aumentaram a resistência ao pendoamento da alface foram as tela de sombreamento e termorefletora 50%. As cultivares não apresentaram diferenças significativas entre si quanto à resistência ao pendoamento. Palavras-chave:Lactuca sativa L. Cultivo protegido. Florescimento. Tela de sombreamento. Tela termorefletora.ABSTRACT -This work was developed during the period of February to April, 2011, with the objective of indicating which environment, greenhouse or open field, provides better conditions for production, and greater resistance to bolting of different cultivars of loose-leaf lettuce, for the climatic conditions of Cáceres, Mato Grosso, Brazil, Twenty treatments were evaluated, using a randomized block experimental design in a 5 x 4 factorial of five environmental conditions (shading screens of 30 and 50%, heat-reflective screens of 30 and 50%, and open field) and four cultivars of loose-leaf lettuce (Elisa, Elizabeth, Regiane and Regina), with four replications. Harvesting was carried out 30 days after transplanting. The most productive lettuce cultivars were Regiane, which obtained the greatest number of leaves, and Regina with the smallest stem length. The environmental conditions that increased resistance to bolting in the lettuce were the shading and 50% heat-reflective screens. The cultivars themselves showed no significant differences for resistance to bolting.

The purpose of this review was to characterize the wheat crop phenology under drought conditions, at different stages of crop growth. Effects of drought on wheat plants are variable, and depend on the phenological stage of the plant as well as the duration, intensity and frequency of the drought. The crop evapotranspiration increases over the course of the phenological cycle, reaching a maximum in the growth stage (from the beginning of heading until the end of flowering), which is the most sensitive stage of the crop to drought. At ripening, the evapotranspiration decreases to save and allocate the energy to grain yield. The drought affects the plant density in the initial phase, tiller number per plant in the tillering phase, and plant height in the stretching phase, most severely. At the flowering stage, the processes related to fertilization and fixation of grain are most severely affected, i.e., the number of viable seeds per area decreases. In the grain formation stage, the ability of the source (leaf) to use and translocate the assimilates to the grain is most severely affected, thus affecting the grain weight.

ResumoObjetivou-se, no presente trabalho, avaliar as trocas gasosas e sua influência na produtividade e qualidade de cultivares de melão conduzidas com um e dois frutos por planta. O experimento foi conduzido de setembro a dezembro de 2013. Utilizouse o delineamento de blocos ao acaso, em esquema fatorial 3 x 2, com seis repetições. No primeiro fator foram alocadas as cultivares de melão pertencentes aos tipos amarelo, rendilhado e pele de sapo e no segundo fator, a condução das plantas com um e dois frutos por planta. Foram utilizadas três cultivares de melão para cada tipo. As avaliações foram realizadas aos 40 e aos 56 dias após o transplantio. As características avaliadas foram: taxa de assimilação líquida de CO 2 (A), transpiração foliar (E), condutância estomática (g s ) e concentração interna de CO 2 (C i ). A partir dessas medidas foi calculada a eficiência no uso da água (WUE). O teor de sólidos solúveis foi determinado por leitura direta, enquanto que a massa média dos frutos foi mensurada no momento da colheita, estimando-se a produtividade. Diante dos resultados, pode-se concluir que as diferenças nos índices de trocas gasosas para as cultivares de melão do tipo pele de sapo não influenciaram na produtividade e no teor de sólidos solúveis. Como melão do tipo amarelo e do tipo rendilhado recomendam-se as cultivares Goldex e Louis, respectivamente. Independente da cultivar, recomenda-se o cultivo de melão com dois frutos por planta, por assim as plantas apresentarem maior produtividade sem alterar de forma expressiva os índices de trocas gasosas delas.Palavras-chave: Cucumis melo L., taxa assimilatória líquida de CO 2 , transpiração, condutância estomática, eficiência no uso da água.Gas exchange and productivity from three cultivars of melon conduced with one and two fruit per plant AbstractThe objective of the present work was to evaluate gas exchange and its influence on productivity and quality of melon cultivars conducted with one and two fruits per plant. The experiment was conducted from September to December, 2013. The experimental design was of randomized blocks in factorial design 3 x 2 with six replications. In the first factor were allocated the melon cultivars, belonging to types canary melon, net melon and frog skin melon; and the second factor was the conduction of plants with one and two fruits per plant. Three melon cultivars were used for each type. The evaluations were performed at 40 and 56 days after transplanting. The characteristics evaluated were: CO 2 assimilation rate (A), transpiration (E), stomatic conductance (gs), the internal CO 2 concentration (Ci). From these measurements was calculated water use efficiency (EUA). The soluble solids content was determined by direct reading, while the average fruit weight was measured at harvest, estimating productivity. With the results, it can be concluded that differences in gas exchange indexes to cultivars of frog skin melon type have no influence on productivity and soluble solids content. To cultivars of canary melon and net melon ...

The present study aimed at evaluating the intensity of Tifton 85 conditioning using a mower conditioner with free-swinging flail fingers and storage times on dehydration curve, fungi presence, nutritional value and in vitro digestibility of Tifton 85 bermudagrass hay dry matter (DM). The dehydration curve was determined in the whole plant for ten times until the baling. The zero time corresponded to the plant before cutting, which occurred at 11:00 and the other collections were carried out at 8:00, 10:00, 14:00, and 16:00. The experimental design was randomised blocks with two intensities of conditioning (high and low) and ten sampling times, with five replications. The high and low intensities related to adjusting the deflector plate of the free iron fingers (8 and 18 cm). In order to determine gas exchanges during Tifton 85 bermudagrass dehydration, there were evaluations of mature leaves, which were placed in the upper middle third of each branch before the cutting, at every hour for 4 hours. A portable gas analyser was used by an infrared IRGA (6400xt). The analysed variables were photosynthesis (A), stomatal conductance (gs), internal CO2 concentration (Ci), transpiration (T), water use efficiency (WUE), and intrinsic water use efficiency (WUEi). In the second part of this study, the nutritional value of Tifton 85 hay was evaluated, so randomised blocks were designed in a split plot through time, with two treatments placed in the following plots: high and low intensity of cutting and five different time points as subplots: cutting (additional treatment), baling and after 30, 60, and 90 days of storage. Subsequently, fungi that were in green plants as well as hay were determined and samples were collected from the grass at the cutting period, during baling, and after 30, 60, and 90 days of storage. It was observed that Tifton 85 bermudagrass dehydration occurred within 49 hours, so this was considered the best time for drying hay. Gas exchanges were more intense before cutting, although after cutting they decreased until ceasing within 4 hours. The lowest values of acid detergent insoluble nitrogen were obtained with low conditioning intensity after 30 days of storage, 64.8 g/kg DM. The in vitro dry matter of Tifton 85 bermudagrass did not differ among the storage times or the conditioning intensities. There was no fungi present in the samples collected during the storage period up to 90 days after dehydration, with less than 30 colony forming units found on plate counting. The use of mower conditioners in different intensities of injury did not speed up the dehydration time of Tifton 85.

This work aimed to control the root-knot nematode Meloidogyne incognita in tomato Solanum lycopersicum L plants with high-diluted solutions of Thuya occidentalis, and to study its effects on growth and plant defense responses. The in vivo experiment was carried out over two years (2013 and 2014) at a climatized greenhouse, whilst the in vitro experiment was carried out in the laboratory. Eight treatments were used [6, 12, 24, 50, 100, 200 and 400CH (Hahnemannian centesimal) of T. occidentalis, with water as control treatment]. For the in vivo assay, in 2013 plants were inoculated with about 4850 eggs and second-stage juveniles (J2), while in 2014 they were inoculated with 5050 eggs and J2. The treatments were applied once a week, as 0.1% aqueous solutions onto the plant shoots, for 50 and 40 days respectively. For the in vitro experiment, the nematodes were directly exposed to the same 0.1% treatments. The treatments did not show nematostatic or nematicide effects in the in vitro assay, and had no influence on the hatching of the eggs. For the in vivo assay in 2013, T. occidentalis 100CH decreased the number of J2 present in the roots, whilst the dynamization of 200CH stimulated root development and increased the weight of the fruits of the first cluster. In 2014, 100CH decreased numbers of J2 in the soil. Some dynamization increased the plant's defense enzyme activity, such as peroxidase (24, 50, 200 and 400CH), polyphenoloxidase (200CH), and phenylalanine ammonia-lyase (24 and 50CH). In this study, T. occidentalis 100CH showed potential for the control of M. incognita, whilst 24 and 200CH influenced the growth of plants.

Calcium silicate (CaSiO 3 ) applied to the soil may increase Si content in the soil and plants, as well as reduce sweating and increase water use efficiency. In this study, we aimed to investigate whether the application of CaSiO 3 increased Si content in plants and interfered with gas exchange and production components in Brachiaria. The experiment was performed using 8-L plastic pots in a greenhouse. Treatments were arranged in a randomized block design in a 3 × 5 factorial: three soils (Rhodic Acrudox, Rhodic Hapludox, and Arenic Hapludult) and five silicate rates (0, 1, 2, 4, and 6 t ha -1 of CaSiO 3 /MgSiO 3 ) were used; four replications were performed. CaSiO 3 application to the soil increases Si concentration in the leaves. Si in plants reduces internal CO 2 concentration and increases the efficiency of water use and instantaneous carboxylation efficiency. In soils with low pH and a high Al +3 level, which is toxic, reduction in plant sweating increases the intrinsic efficiency of water use in Brachiaria. Si helped to alleviate the toxic effects of Al .

This study evaluated the tolerance of U. ruziziensis under severe water stress conditions and its recovery when rehydrated, based in responses of relative leaf water content and gas exchange of the crop. The experiment was conducted in green house in Oxisol. The experimental design was a randomized block design, totaling five treatments, was represented by inoculation of A. brasilense strains AbV5 + AbV6, as follow: seed inoculation, foliar spray application, seed inoculation + foliar spray application, a non-inoculated control with water deficit treatment and a irrigated control without inoculation. Drought was imposed 45 days after sowing, after the vessel was irrigated until saturation of the substrate, by total removal of irrigation for six days, and evaluated three days after the resumption of water, evaluating gravimetric soil moisture, relative leaf water content and gas exchange. Soil moisture showed non variation to treatments non irrigated, but the relative leaf water content was lower in the control without water. The control and the treatment inoculated with A. brasilense in seeds exhibited lower rates of gas exchange. Recovery full of photosynthetic activity occurred three days after rehydration in all treatments. A. brasilense foliar sprayed is efficient to increase the tolerance of U. ruziziensis to water deficit and presented higher photosynthetic rates even under conditions of severe water deficit.

The effects of diazotrophic bacteria inoculation associated to phosphate fertilization on plant growth and leaf gas exchange parameters in maize plants (Zea mays L.) were investigated in the present study. Maize plants were grown in 13-L pots filled with clayey Rhodic Hapludox in a greenhouse. Treatments were arranged in a randomized block design in a 4 × 2 factorial: four seed inoculation treatments [control (non-inoculated); inoculation with Azospirillum brasilense strain AbV5; inoculation with Herbaspirillum seropedicae strain SmR1; and inoculation with two bacteria strains (A. brasiliense + H. seropedicae)] and two phosphate fertilization levels [no fertilized or fertilized with phosphorus (300 mg dm-3 of P 2 O 5)]. Phosphorus fertilization resulted in higher plant height, stem diameter, number of leaves per plant, leaf area, dry matter yield of leaves, stems and sheaths of maize plants, regardless of seed inoculation with diazotrophic bacteria. Seed inoculation with A. brasilense and H. seropedicae increased in 42% of the volume root, in 52% of the root dry matter and 25% of the plant height of maize, indicating an increase in the phosphorus solubilization or higher phosphorus use provided by the maize root system. Seed inoculation with A. brasilense associated to phosphorus fertilization increased in 23% of the relative chlorophyll content, resulting in higher metabolic structure to the photosynthetic activity of maize plants. The leaf CO 2 assimilation rate was not affected by the phosphorus fertilization and maize seed inoculation with A. brasilense and H. seropedicae.