Daniela Deitos Fries

Effect of water stress on the growth of Arachis pintoi plants under different nitrogen levels

The objective was to evaluate the growth of Arachis pintoi fertilized with nitrogen and water deficiency conditions. The study was developed in a 4 × 4 factorial arrangement with four nitrogen levels (0, 40, 80 and 120 kg N/ha) and four irrigation levels (25, 50, 75 and 100% of field capacity), in a completely randomized experimental design, with four replications. High doses of N benefited the production of root shoots while the root increased its production at a dose of 40 kg N/ha. The number of green and senescent leaves were influenced by N fertilization and the water regime, where higher doses of N provided greater total number of green leaves (364 leaves/pot) and the limitation of water resulted in a greater number of senescent leaves (78 leaves/pot). Observing the maximum point, the water regime of 90% of field capacity and 120 kg N/ha favored leaf appearance rate of 1.2 leaves/day and less phyllochron (4.6 days/leaf) at 85% of field capacity and 115 kg N/ha. The dose of 120 kg N/ha resulted in ultimate greater width (1.4 cm) and length (2.4 cm) of the leaf at 100% of field capacity. The final length of stolons showed quadratic effect for N, having greatest length (58.1 cm) at 75 kg N/ha and 100% of field capacity.

Influence of plant growth regulators and nitrogen sources on the production and development of Brachiaria decumbens cv. Basilisk

The aim was to evaluate the effect of seed treatment with plant growth regulators and nitrogen fertilization methods in Brachiaria decumbens cv. Basilisk on the growth and development through germinative characteristics, dry matter yield and physiological composition. Plant growth regulators increased germination and mass yields of plant structures in coated seeds. From the regression estimates, higher germination percentages and root dry mass production were obtained with the use of Plant growth regulators for the initial growth (10.3; 12.8 mL.kg−1 seed, respectively). Leaf and pseudostem mass production had a significant interaction effect between seed type and the use of growth regulator. Coated seeds had greater performance with absence or at lower levels of growth regulators, and embryo quality contributed to the greater formation of plant tissues. More efficient levels (8.85 and 9.57 mL.kg−1 seed) were observed for the yields of plant structures (leaf and pseudostem). Soil N-fertilization resulted in higher dry mass productions of leaf, stem, shoot and root, as well as for root volume. Rates of photoassimilate were increased by soil fertilization and use of plant growth regulators. The use of exogenous hormonal compounds acts on the organogenesis of plant tissues and increases the development of Brachiaria decumbens cv. Basilisk. Soil N-fertilization increase mass yields as it maximizes photosynthetic processes and growth rates.

Chlorophyll and carbohydrates in Arachis pintoi plants under influence of water regimes and nitrogen fertilization

In this experiment the chlorophyll and carbohydrate contents of Arachis pintoi were evaluated to verify if the presence of nitrogen in the soil could contribute to the effectiveness of the establishment of this legume. The design was completely randomized, in a 4 × 4 factorial arrangement, with four N rates (0, 40, 80 and 120 kg ha-1) and four irrigation levels (25, 50, 75 and 100% of field capacity), with four replications. The biochemical evaluations of chlorophylls a and b and total chlorophyll and total soluble sugars, sucrose and starch were performed. The highest contents of chlorophyll a and b and total chlorophyll in leaves were found at the dose of 120 kg ha-1. The water regime of 25% of field capacity was responsible for the lowest content of reducing sugars and total soluble sugars in leaves, stolons and roots. In the roots, the sucrose contents were higher in these conditions, which can be associated with a slight tolerance of the plant to water stress. The water deficiency was responsible for the decrease of reducing sugars and total N in the whole plant and positively influenced the levels of chlorophyll and sugars in the stolon, promoting growth, especially of shoots, at the beginning of establishment.

Aspectos produtivos e sanitários do rebanho leiteiro nas propriedades do sudoeste da Bahia

Milk is a food of great nutritional importance. In addition, the dairy can be highlighted by the economic and social development that promotes in the rural properties. Thus, the objective of this study was to characterize milk production and animal health management of properties in the dairy region of the southwestern region of Bahia. The methodology proposed is made by applying a questionnaire with objective questions, using a sample of 94 producers participating in the research that provide milk for dairy cooperatives and dairy in the region registered in the preliminary farm diagnosis in program Geraleite. The data obtained are important to know and to compare the profile of dairy farms in this region, 54.7% of producers did not take husbandry notes and 64.9% did not take notes related to the economics. Of the respondents 82% make one milking and 18% two milkings per day in properties, the natural mating uncontrolled was the reproductive management more used. The average milk production on farms was 1125 liters of milk /cow/year and 3.1 liters/cow/day. This low productivity is due mainly to technological deficiency, non specialized animals and lack of technical assistance in the farms.

Nitrogen fertilization on the establishment of Arachis pintoi cv. Belmonte

The objective was to evaluate the effect of nitrogen fertilization on the establishment of forage peanut (Arachis pintoi cv. Belmonte) propagated vegetatively. The experiment was conducted in a greenhouse in a completely randomized design with treatments arranged in a 2 × 4 factorial design - two ages (70 and 85 days after planting) and four nitrogen doses (0, 40, 80 and 120 kg/ha) - with four replications. Morphogenetic and structural characteristics and production were evaluated. The nitrogen accelerated the establishment of the forage peanut with an increase in dry weight of green leaves and stolons. The greatest length of stolons (48.0 cm) was obtained with a dose equivalent to 86 kg N/ha and higher density of stolons (20 stolons/vase) between 78 and 82 kg N/ha. Nitrogen fertilization also reduced the phyllochron from 6.7 to 4.6 days/leaf. These data were more intense at 85 days, suggesting greater photosynthetic contribution during this period related to the large number of leaves after 70 days. Therefore, nitrogen can be an important tool to accelerate the establishment of pure stands of forage peanut.