Nível crítico de boro em cenoura cultivada em um solo sob cerrado

Assunção

et al. 2015

Rev. Bras. Ciênc. Solo

Farmers must carefully choose the cultivar to be grown for a successful carrot crop. The yield potential of the cultivar may influence nutrient demand and should be known to plan for fertilization application. The aim of this study was to evaluate the cultivar effect on carrot yield and on the nutrient content and quantities allocated to leaves and roots. Three experiments were set up in two crop seasons in Rio Paranaíba, MG, Brazil. In the first season, typical summer, 10 summer cultivars were sown. In the second season, summer-winter (transition), two experiments were set up, one with summer cultivars and the other with winter cultivars. The treatments consisted of the carrot cultivars distributed in randomized blocks with four replications. Fresh and dry matter of the roots and leaves was quantified. Yield was calculated based on fresh matter of the roots. The nutrient content in leaves and roots was determined at the time of harvest. These contents and the dry matter production of roots and leaves were used to calculate nutrient uptake and export. The greatest average for total and commercial yield occurred in the crop under summer conditions. Extraction of N and K for most of the cultivars in the three experiments went beyond the amounts applied through fertilizers. Thus, there was contribution of nutrients from the soil to obtain the yields observed. However, the amount of P taken up was considerably less than that applied. This implies that soil P fertility will increase after cropping. The crop season and the cultivars influenced yield, nutrient content in the leaves and roots, and extraction and export of nutrients by the carrot crop.

Section: Introductionmentioning

confidence: 99%

Nutrient Demand by the Carrot Crop Is Influenced by the Cultivar

Assunção

et al. 2015

Rev. Bras. Ciênc. Solo

“…Recommendations of B were also constant in relation to the intended yield. However, these recommendations were generated in the system to supply the demand of the crop and raise the soil content to the critical level, that is, 0.55 mg dm -3 (Mesquita Filho et al, 2005).…”

Section: Resultsmentioning

confidence: 99%

Nutrient Recommendation Model for Carrot Crop – Ferticalc Carrot

Dezordi

Novais

et al. 2015

Rev. Bras. Ciênc. Solo

the literature on fertilization for carrot growing usually recommends nutrient application rates for yield expectations lower than the yields currently obtained. moreover, the recommendation only considers the results of soil chemical analysis and does not include effects such as crop residues or variations in yield levels. the aim of this study was to propose a fertilizer recommendation system for carrot cultivation (ferticalc carrot) which includes consideration of the nutrient supply by crop residues, variation in intended yield, soil chemical properties, and the growing season (winter or summer). to obtain the data necessary for modeling nutritional requirements, 210 carrot production stands were sampled in the region of alto paranaíba, State of minas Gerais, Brazil. the dry matter content of the roots, the coefficient of biological utilization of nutrients in the roots, and the nutrient harvest index for summer and winter crops were determined for these samples. to model the nutrient supply by the soil, the literature was surveyed in regard to this theme. a modeling system was developed for recommendation of macronutrients and B. for cationic micronutrients, the system only reports crop nutrient export and extraction. the ferticalc which was developed proved to be efficient for fertilizer recommendation for carrot cultivation. Advantages in relation to official fertilizer recommendation tables are continuous variation of nutrient application rates in accordance with soil properties and in accordance with data regarding the extraction efficiency of modern, higher yielding cultivars.

“…Dentre os micronutrientes o boro (B) é citado como o mais limitante para a cultura da cenoura, sendo o que mais limita o rendimento das culturas no Brasil (Mesquita Filho et al, 2005), visto que, desempenha funções no desenvolvimento das plantas tais como: síntese da parede e alongamento celular, integridade estrutural da parede celular e transporte de carboidratos, na fertilidade dos grãos de pólen e alongamento do tubo polínico (MARSCHNER, 1995). De acordo com Volkweiss (1991), na aplicação de micronutrientes via solo, busca-se aumentar sua concentração na solução do solo, que é de onde as raízes os absorvem, e assim, proporcionar maior eficácia Portanto, o presente trabalho teve por objetivo avaliar o desempenho agronômico da cultura da cenoura submetida a doses e formas de aplicação de B. Para implantação da cultura foi realizado o preparo do solo com aração e gradagem, posteriormente, feita a calagem 15 dias antes do plantio com calcário Filler com 100% de reatividade, correspondendo a 1.176 kg ha -1 para elevação da saturação de bases à 65% (RIBEIRO et al, 1999).…”

Section: Introductionunclassified

Formas e doses de Boro no cultivo da cenoura na Amazônia Ocidental

Souza

Noronha

Silva

et al. 2017

PESQ. AGROP. GAÚCHA

A deficiência de micronutrientes pode limitar a produtividade das hortaliças. Diante disso, o presente estudo avaliou o desempenho agronômico da cenoura em função de formas de aplicação e doses de Boro. O delineamento experimental adotado foi em blocos casualizados, com tratamentos arranjados em esquema fatorial 7 x 3 que consistiram em 7 doses (0, 1, 2, 3, 4, 5 e 8 kg ha-1 ) de B na forma de bórax (11,3% de B) e 3 formas de aplicação: via solo; via foliar e solo e somente via foliar com 3 repetições em Latossolo Vermelho-amarelo distrófico. As variáveis analisadas foram: biomassa fresca média das raízes; diâmetro médio das raízes; comprimento longitudinal; espessura do córtex, diâmetro do coração e produtividade média. A maior biomassa fresca de raízes e produtividade foi obtida na dose de 3,68 kg ha -1 . A aplicação de B via solo é a mais indicada para a cultura da cenoura.