Marco Antonio Camillo de Carvalho

Soja em sucessão a adubos verdes no sistema de plantio direto e convencional em solo de Cerrado

The green manures aim to preserve the environment quality without discarding the largest yield of economic crops. The objective of this work was to evaluate the performance of soybean grown after green manures under no-tillage and conventional tillage (one disk harrow + two leveling harrow) systems. The experiment was carried out in a Distrophic Red Latossol (typic Hapludox), covered by savannah vegetation, in Selviria, MS, Brazil. The green manures utilized were: black velvet bean, pigeon pea, sunn hemp, millet and fallow area (spontaneous vegetation). The green manures previously grown in spring do not affect the soybean yield, in both no-tillage and conventional tillage systems. In year without dry periods, the conventional tillage provided greater grain yield.

POTENCIAL FISIOLÓGICO DE SEMENTES DE SOJA DESSECADAS COM DIQUAT E PARAQUAT

4 ABSTRACT The type, mode of action and time when the desiccant is applied on soybean, are factors that can affect the physiological quality seeds. But if the operation is performed adequately, it may occur in anticipation of the harvest a few days, getting seeds of higher quality. This work aimed at evaluating the desiccant effect of pre-harvest in the physiological performance of soybean seed. The design was blocks at randomized in a factorial 3 x 4 (desiccants x time) with four replications. The desiccants were Diquat and Paraquat, both in the dose of 400 g.i.a. ha -1 , + control (without desicantion). The times of application were in stages R6.0, R7.1, R7.2 and R7.3. Seeds were subjected to fermenation test, first count of germination, the germination speed rate, accelerated aging, cold testing and electrical conductivity. All tests were carried out at analysis seed laboratory analysis and technology of the University of the State of Mato Grosso. The desiccants were compared by Tukey (p<0.05). In spite of have provided anticipation of crop in only two days in relation to the control, the most favorable time to disecation, so much with Diquat as Paraquat, is at the stage R7.3, and disecateds lots with Paraquat presented better performance in some of the appraised quality tests.

Influência da temperatura e da luz na germinação de sementes de couve-cravinho (Porophyllum ruderale (Jacq.) Cass.)

The knowledge of the biology and of the ecology of weeds precede the elaboration of agronomic strategies for weed control, reducing the costs of the productive process. Certain plants, in addition to other biological characteristics of importance, have their germination capacity influenced by abiotic factors such as temperature and brightness. With the objective of evaluating the germinative response of Porophyllum ruderale seeds, in function of temperature and brightness, two experiments were carried out: in experiment 1, seeds of P. ruderale were put to germinate at three temperatures (20, 25 and 30oC) in two substrates (among and on-paper); in the second experiment, the effect of the light was evaluated in the germination of P. ruderale seeds. The influence of white light, red wavelength, extreme red and light absence were evaluated. Greaterer germination was obtained at temperatures of 25 and 30oC. As the light influenced the germinative process it was verified that seeds of P. ruderale are sensitive to brightness, where the light absence provoked the drastic reduction in the germination of the seeds.

Produtividade de arroz no sistema integração lavoura-pecuária com o uso de doses reduzidas de herbicida

Because to the great area of degraded pastures in the northern region of Mato Grosso, become necessary to search for alternatives that seek to recover the same. This study aimed to evaluate of the low doses effects of cyhalofop butil and sowing dates of forage in the consortium of Brachiaria brizantha cv Marandu and upland rice. The work was carried out in 2005/06 and 2006/07 seasons in experimental design of randomized blocks with four replications in a factorial scheme 2x6, constituted by the combination of two cultivars of rice (BRS primavera and BEST 2000) and six options for renewal, and four low doses of herbicide cyhalofop butil (0, 0.40, 0.80 and 1.2 L ha-1) and two in broadcast sowing at 10 and 20 days after rice emergence and second year the scheme was used 2x8, where first year treatments were sowing Brachiaria in the furow in between lines, 20 and 30 days after rice emergence. Were evaluated: number of tillers and panicles m-2, hulling yield, 100 grains mass and productivity. The BRS primavera has better performance when satisfactory forage development of fodder. The broadcast sowing forage was not viable and doses greater than or equal to 0.80 L ha-1 cyhalofop butil were effective as an alternative in the recovery of pastures.

Quality of soybean seeds produced with different doses of molybdenum and cobalt

The present work study assessed the effect of foliar application of different doses of cobalt (Co) and molybdenum (Mo), and seed inoculation with Bradyrhizobium japonicum on the productive characteristics of the soybean crop and the quality of its seeds. The study was carried out in 2005/06, in a Red-Yellow Latosol (Hapludox) dystrophic soil, in the city of Santa Carmen, MT. The experimental design was a randomized block in a 6 X 2 factorial design, with a combination of 12 treatments with four replications for each treatment. The treatments resulted from the combination of six doses of the product Quimifol CoMo Plus (0.0; 0.25; 0.5; 1.0; 1.5; and 2.0 L ha-1), applied foliarly, with and without inoculation of the seeds with a liquid formulation of Bradyrhizobium japonicum, RizoLiq. Based on the results, the following conclusions were drawn: seed inoculation with Bradyrhizobium increased the number of pods per plant and the number of seeds per plant;

Qualidade de sementes de arroz utilizadas no norte de Mato Grosso

The work target was to evaluate the quality of the seeds used by the farmers in five districts (Matupa, Novo Mundo, Nova Guarita, Alta Floresta and Terra Nova do Norte) in the northern area of Mato Grosso state, aiming to characterize their physiologic and physical quality. Forty-five rice seed samples of the Cirad 141 cultivar were collected from producers in the area, in the 2004/05 agricultural season. The seed quality was evaluated by the tests of physical purity, germination and weed seeds. The analysed seeds presented lower physiologic quality than demanded by legislation, concerning the germination, presence of more weed seeds than acceptable, being an important restrictive factor to obtain productive plantations and later on, a high quality product.

RAINFALL AND DEFORESTATION IN THE MUNICIPALITY OF COLÍDER, SOUTHERN AMAZON

Deforestation may have effects on the hydrological cycle, directly reflecting in the rainfall rates. Therefore, studies pointing out evidence of climate changes caused by deforestation are extremely important, because they help understanding the way how these changes are related to forms of using and occupying the territory, as well as to the way how information obtained can to be useful for mitigating their effects. In this context, this paper aimed to analyze rainfall variations occurring in the municipality of Colider, Mato Grosso, southern Amazon,Brazil, within a temporal scale of 28 years (daily data), correlating them to the regional and local deforestation patterns by determining Spearmans ρ coefficient. Annual rainfall presented a large variation, with a minimum of 1,296 mm in 1987 and a maximum of 2,492.8 mm in 1990. The rainy season was concentrated between October and April, and the driest period was within June and August. Spearmans coefficient pointed out negative correlations between regional and local deforestation and local rainfall, showing that the larger the deforested area, the lower the rainfall rate observed.

Effects of environmental factors induced in the germination of Chaptalia nutans (L.) Polack seeds

Chaptalia nutans is species whose medicinal value has been studied thoroughly, and aspects regarding seed germination are important to define better propagation practices. The objective of the present study was to evaluate the germination response of C. nutans seeds to conditions of light and temperature, as well as osmotic and saline stresses and potassium nitrate. Four experiments were conducted: a) combination of four temperatures (20oC, 25oC, 30oC and laboratory atmosphere) with two light conditions (presence or absence); b) ten levels of osmotic stress induced with manitol (0.0; -0.05; -0.1; -0.2; -0.3; -0.4; -0.5; -0.6; -0.7 and -0.8 MPa); c) eight levels of saline stress induced with NaCl (0.0; -0.1; -0.2; -0.3; -0.4; -0.5; -0.6 and -0.7 MPa) and d) combination of two levels of potassium nitrate (presence or absence) with two temperatures (20 and 25 oC) and two levels of light (presence or absence). Germination of C. nutans seeds was maximized under light, at constant temperatures of 25 , 30 oC, or room temperature between 19 and 31 oC. There was no germination reduction with osmotic stress of up to -0.6 MPa and saline stress of up to -0.5 MPa. The addition of potassium nitrate did not promote any increase in the germination.

ESTRESSE HÍDRICO E SALINO NA GERMINAÇÃO DE SEMENTES DE FEIJÃO-CAUPI ( Vigna unguiculata cv. BRS Tumucumaque)

The objective of this work was to evaluate seeds of cowpea, cultivar BRS Tumucumaque, subjected to different water stresses induced by polyethylene glycol (PEG-6000) and mannitol and different salt stresses induced by NaCl and CaCl2 solutions. The water and salt stresses was evaluated in laboratory using completely randomized experimental designs in 2x6 factorial arrangements, with six osmotic potentials (0.0, -0.2, -0.4, -0.6, -0.8 and -1.0 MPa) and two stress inducers for each experiment, with four replications of 50 seeds. The percentage of germination, germination speed index, root and shoot lengths and seedling fresh weight were evaluated at the tenth day (end of the evaluation period). The simulated water stress showed effects on the cowpea seed germination and seedling initial growth by decreasing the rates of the variables evaluated, which had greater effect in treatments with PEG-6000. The salt stress induced by NaCl showed greater effect on the variables evaluated than that induced by CaCl2, due to the sodium toxicity in the salt chemical composition.

Overcome dormancy and quality of light in the germination of Murdannia nudiflora (L.) Brenans seeds

The study of seed germination physiology, especially of weeds, has been intensified due to the importance of knowledge on this subject to improve and create new techniques for weed management. Experiments were conducted in two phases to study the effects of different methods of overcoming the dormancy of Murdannia nudiflora (L.) Brenans seeds and light quality. In the first stage, the treatments consisted of seven methods of overcoming dormancy: mechanical scarification with sandpaper for 60 seconds; chemical scarification with sulfuric acid for 30, 60 and 300 seconds, sodium hydroxide 20% for 5, 15 and 25 minutes, sodium hypochlorite 2.5% for 24 hours, potassium nitrate (20 mM) for 24 and 48 hours, gibberellic acid (1 mM) for 24 hours and witness. A randomized complete statistical design was used with four repetitions. The germinated seeds were counted daily, and at the end of 30 days, the IVG was determined. In the second step, the quality of the light treatments consisted of 5 light filters (blue, green, red, transparent, and total absence of light). A higher percentage of seed germination was obtained using mechanical scarification (sanding) (84%), followed by chemical scarification with sulfuric acid for 1 minute (74%), sodium hypochlorite for 24 hours (46%) and sodium hydroxide for 25 minutes (26%). Quanto a porcentagem de germinacao de sementes em funcao da qualidade de luz verificou-se as se Regarding the percentage of seed germination in function of the light quality of light,d the following germination percentages were observed: blue - with maximum reflectivity at 450 nm (58%), green - 500 nm (64%), red - 700 nm (75%), absence of light (0%) and transparently - without absorptivity in the region of 380 nm to 760 nm (87%). Seeds of M. nudiflora can be considered positive photoblastics.