ADUBAÇÃO FOLIAR DE BORO EM DOIS HÍBRIDOS DE CANOLA

A canola (Brassica napus L. var oleífera) é uma oleaginosa, pertencente à família Brassicaceae, resultado do cruzamento interespecífico entre repolho silvestre (Brassica oleracea L.) e mostarda (Brassica rapa L., syn. campestris). O boro é considerado um micronutriente, que atua na translocação de açúcares, formação de proteínas, crescimento do tubo polínico, germinação dos grãos de pólen, desenvolvimento das sementes e das paredes celulares. O objetivo desta pesquisa foi estudar as interferências nos componentes produtivos de dois híbridos de canola com a aplicação de adubação com boro por via foliar. Para tanto, instalou-se um experimento em condições de campo num delineamento experimental de blocos ao acaso em arranjo fatorial 2 x 3. Utilizou-se os híbridos Hyola 433 e Hyola 575 CL e três doses de boro foliar (0;100; 200) g ha-1 de B. As seguintes características foram avaliadas: número de plantas, número de síliquas por planta, massa de parte aérea, massa de 100 grãos e produtividade. Com a aplicação de boro houve aumento da massa de grãos independente do híbrido. Para produtividade houve aumento somente para o híbrido Hyola 433, sendo a maior produtividade alcançada na dose de 200 g ha-1. O híbrido Hyola 575 CL não teve sua produtividade alterada com a aplicação de boro. Palavras-chave: ácido bórico; Brassica napus L. var. oleífera; colza; massa de 100 grãos; oleaginosa. Leaf boron fertilization in two rapessed ABSTRACT: Rapessed (Brassica napus L. var oleífera) is an oilseed, belongs to Brassicaceae family, resultated between inter specific crossing of wild cabbage (Brassica oleracea L.) and mustard (Brassica rapa L., syn. campestris). Boron is considered a micronutrient, acting in sugars translocation, protein formation, pollen tube growth, pollen grain germination, seeds and cell wall development. The aimed was to study the interferences in productive components of two rapessed hybrids with application of boron fertilization by leaf application. For this, a field experiment was installed by using experimental design of randomized blocks in a 2 x 3 factorial scheme. Hyola 433 and Hyola 575CL hybrids and three doses of leaf boron (0; 100 and 200) g ha-1 of B were used. The following characteristics were evaluated: plants number, number of pods per plant, mass of one hundred grains and yield. With boron application there was an increase in grain mass independent of the hybrid. In relation grain yield there was increase only for Hyola 433 hybrid, with the highest yield reached at 200 g ha-1. The Hyola 575CL hybrid did not have its productivity altered with the application of boron. Keywords: boric acid; Brassica napus L. var. oleífera; mustard; mass of a hundred grass; oilseeds.

Nutrient uptake by black gram (Vigna mungo L. Hepper) as influenced by phosphorus and boron fertilization in acid Inceptisol of Meghalaya

Phosphorus and boron are required for growth and development of black gram, and play an important role in the uptake of other nutrients such as N and K. The availability of P and B is less in acid soil because of fixation and leaching losses. Therefore, a field experiment was conducted to investigate the influence of P and B on N and K uptake in black gram with four levels of phosphorus (0, 25, 50, 75 kg ha-1) and four levels of boron (0, 0.5, 1.0, 1.5 kg ha-1) comprising of 16 treatments. The trail was laid out in split plot design and replicated three times. Phosphorus was used as main plot and boron as sub-plot. Significantly highest nitrogen concentration in black gram seed was observed at P75B1.5 as 3.82%, whereas in straw, it was observed at P75B1 as 1.75%. However, significant nitrogen uptake by seed and straw was recorded as 43.85 and 39.55 kg ha-1 at P75B1.5, respectively. Similarly, significantly highest potassium concentration in seed and straw was observed at P75B1.5 as 1.13% and 1.64%. Significant highest uptake of K by seed and straw was recorded at P75B1.5 as 13.00 kg ha-1 and 36.86 kg ha-1, respectively. Therefore, 75 kg P2O5 and 1.5 kg B ha-1 is considered optimum for achieving higher nitrogen and potassium uptake by black gram in acid Inceptisol of Meghalaya.

Nutritional and biomass aspects of Helianthus annuus according to boron application in the soil

Sunflower is considered highly demanding in boron (B); however, it has low efficiency in using this micronutrient. An experiment under protected cultivation was carried out to evaluate the effects of boron fertilization on nutrition and sunflower biomass production (Helianthus annuus). A completely randomized design with four replications was used. Five boron doses: 0 (Control), 1, 2, 3, and 4 kg ha-1, were applied to the soil using boric acid as the source. Biometric assessments, measurements of the relative chlorophyll index (RCI), production of dry biomass and the boron use efficiency by plants were carried out. The data were subjected to analysis of variance and F test (p<0.05), with polynomial regression analysis when significant. Leaf area, RCI evaluated at 15 and 60 days, and biomass increase linearly according to the boron application up to the dose of 4 kg ha-1, which corresponds to an increase of 31, 12, 14, and 61%, respectively, compared to control treatment. However, for plant height and nutritional efficiency, the best results were obtained with the dose of 2.64 kg ha-1 of B, with a decrease in higher doses. Boron fertilization in sunflower crop positively influences the nutritional and growth aspects of plants. In general, the application of up to 3 kg ha-1 of B in soils with low natural content increases the crop yield, without phytotoxicity aspects caused by the nutrient

Nitrogen and boron fertilization in cauliflower

Nitrogen and boron participate concurrently in the growth and development process of plants by changing cell division processes. Therefore, the aim of this study was to evaluate the influence of sources and doses of nitrogen, associated with boron doses and sulfur on the yield and quality aspects of Verona CMS cauliflower. The experimental design was set up under split plot design in randomized blocks, with 3 replicates. The treatments in the plot were sources of ammonium sulphate (NH4)2SO4) and calcium nitrate (Ca(NO3)2) x doses of nitrogen, being 125, 150, 175 and 200 kg ha-1 on topdressing system and in the subplot doses of boron (0, 2, 4 and 6 kg ha-1). The fresh curd mass, curd and stem diameter, total and commercial yield, besides the contents of nitrogen, boron and sulfur in the leaf and curd, were evaluated. The sources and doses of nitrogen and the doses of boron did not influence the fresh curd mass, stem diameter and the total yield of 'Verona CMS' cauliflower. Enhancing doses of Ca(NO3)2 increased curd diameter, however in combination with boron doses there was antagonism effect on curd development. The contents of nitrogen and boron in the leaf were influenced by the fertilization of nitrogen and boron, respectively, when the calcium nitrate source was used.