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.

FOLIAR SPRAYING OF DOSES OF BORIC ACID IN CORIANDER (Coriandrum sativum L.)

Coriander (Coriandrum sativum) is a species highly appreciated in Brazilian cuisine and of high nutritional importance due to the presence of vitamins, calcium, and iron. Leafy vegetables are considered nutritionally demanding as their cycles are relatively short and the lack of any essential element affects their growth, yield and quality. This study aimed to evaluate the response of coriander plants (Coriandrum sativum L.) to foliar spraying of boron doses. The experiment was carried out in a greenhouse at The State University of Goiás, Campus Ipameri, in Ipameri-GO. The experimental design was completely randomized, with five treatments and four replications. The treatments consisted of five boron doses applied by foliar spray (0, 1.0, 1.5, 2.0 and 3.0 kg ha-1) using boric acid (17% of Boron) as the source. Fresh and dry matter of shoot and root and leaf boron contents were evaluated. Data were subjected to analysis of variance (F test) and the effect of boron doses were evaluated by regression analysis. The application of 3.0 kg ha-1 of boron increases the boron content of coriander plants, and the fresh and dry matter of roots and shoots was not significantly increased.

Soil Fertilization and Texture on Boron Accumulation and Wood Volume in Corymbia citriodora (Hook) K.D. Hill & L.A.S Johnson

This study aimed to evaluate the effects of soil fertilization and texture on leaf Boron (B) accumulation and its relation with wood volume of Corymbia citriodora Hill & Johnson. The experiment was set in randomized block with four replications, four B fertilization levels (0, 1.1, 2.2 and 4.4 g.plant-1) in two soils types (sandy and clayey). To determine leaf B content, 25 leaves were collected from the median portion of four trees for each treatment. Leaves were dried on oven and B content was determined by the Azomethine-H method using extract obtained by dry digestion. The diameter at breast height and the total height of 25 trees were collected in all treatments and wood volume was calculated. Data were submitted to analysis of variance and the means adjusted to regression equations. The regression coefficients were evaluated by t-test at 1 and 5% probability. It was verified that clay soil produces more wood, compared to sandy soil. There was a gain increase in foliar B as B doses increased in both soil types. Leaf B affected Corymbia citriodora productivity only in clay soil.

Respostas de cultivares de girassol a doses crescentes de boro na entressafra do Cerrado Tocantinense

<p class="Default">No cerrado brasileiro a deficiência de boro no solo ocorre com maior frequência. A cultura do girassol é muito sensível à deficiência deste micronutriente, além de apresentar pouca eficiência em seu aproveitamento. Neste contexto, objetivou-se com este estudo avaliar as respostas de cultivares de girassol a doses crescentes de boro no período da entressafra no cerrado tocantinense. O experimento foi conduzido em Gurupi, (TO), com sistema de plantio direto em sucessão a soja, sobre Latossolo Vermelho Amarelo distrófico. O delineamento experimental utilizado foi de blocos casualizados, com quinze tratamentos e quatro repetições. Os tratamentos foram dispostos num esquema fatorial simples 3 x 5, constituído por três cultivares de girassol (variedade Br 122, híbridos Aguará 4 e Helio 863) e cinco doses de ácido bórico (0, 1, 2, 3 e 4 kg ha^-1). As características avaliadas foram: altura de planta, diâmetro da haste, diâmetro do capítulo, concentração de boro foliar, massa de mil aquênios e produtividade de aquênios. A dose de 3 kg ha^-1 de boro proporcionou, em sua grande maioria, as melhores respostas das cultivares Br 122, Aguará 4 e Helio 863 quanto às características avaliadas. No entanto, com esta dose, a cultivar Aguará 4 apresenta melhor aproveitamento para produção de aquênios.</p><p class="Default" align="center"><strong><em>Responses of sunflower cultivars to increasing doses of boron in the </em></strong><strong><em>between harvests the Cerrado Tocantinense</em></strong><strong><em></em></strong></p><p class="Default"><strong>Abstract</strong><strong>:</strong> In the brazilian cerrado soil boron deficiency occurs more frequently. The sunflower crop is very sensitive to this micronutrient deficiency, and have little efficiency in its use. In that context, aimed to of this study was to evaluate the response of sunflower cultivars to increasing doses of boron during the between harvests in the cerrado tocantinense. The experiment was conducted in Gurupi (TO), with no-tillages soybeans in succession on dystrophic Red Yellow Latosol. The experimental design was a randomized block design with fifteen treatments and four replications. The treatments were arranged in a factorial 3 x 5 simple, composed of three cultivars of sunflower (variety Br 122, hybrid Aguará 4 and Helio 863), and five doses of boric acid (0, 1, 2, 3, and 4 kg ha^-1). The characteristics evaluated were: plant height, stem diameter, head diameter, leaf boron concentration, weight of thousand achenes and productivity achenes. The dose of 3 kg ha^-1 resulted boron, mostly, the best responses of the cultivars Br 122, Aguará 4 and Helio 863 on the characteristics evaluated. However, at this dose, the cultivar Aguará 4 has better use for achene production.</p><p class="Default"> </p>

The studies on redistribution of boron in apple trees as a result of leaf boron application

Redistribution of boron (B) within apple trees (Malus domestica Borkh.) as a result of leaf B application was examined. The experiments were canied out in a greenhouse on M.26 apple rootstock and in field conditions on five-year-old 'Elstar' and 'Szampion' apple trees grafted on M.26 rootstock. Boron was applied in a form of boric acid solution. It was found that leaf B application resulted in movement of B to leaves, flowers and apple fiuits untreated with B. These results clearly showed that B was retranslocated within apple tree. The retranslocation of B within apple trees took place when leaf B applications were done both in summer and autumn. Additionally, it was observed that B from leaf application had paiticularly high ability of movement within plant at insufficient B content (0,2μM) in solution. Generally, these data indicated that B within apple trees was transported in phloem, however mechanism of this phenomenon has not been well known yet. Thus, leaf B application of apple trees can be more successful treatment in reduction of B deficiency in plants compared to soil B application.