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Resumo

PEREIRA, Miréia Aparecida Bezerra et al. POSTHARVEST CONSERVATION OF STRUCTURAL LONG SHELF LIFE TOMATO FRUITS AND WITH THE MUTANT RIN PRODUCED, IN EDAPHOCLIMATIC CONDITIONS OF THE SOUTHERN STATE OF TOCANTINS. Ciênc. agrotec. [online]. 2015, vol.39, n.3, pp. 225-231. ISSN 1981-1829.  http://dx.doi.org/10.1590/S1413-70542015000300003.

The high temperature of growth environment can affect the postharvest quality of tomato fruits. In this situation, an alternative for the farmers is the use of hybrid cultivars that produce long shelf life fruit with longer postharvest shelf life when compared to normal varieties of fruits. The objective of this research was to compare the postharvest conservation of fruits of structural long shelf life tomato hybrids and with the mutant rin. The fruits evaluated were from fifteen tomato genotypes produced under the edaphoclimatic conditions of the southern State of Tocantins, being four of them long shelf life type hybrids (with rin allele) which Continue reading

Resumo

ROTTA, Leonardo Ricardo et al. PHOSPHORUS FRACTIONS AND AVAILABILITY IN A HAPLIC PLINTHOSOL UNDER NO-TILLAGE SYSTEM IN THE BRAZILIAN CERRADO. Ciênc. agrotec. [online]. 2015, vol.39, n.3, pp. 216-224. ISSN 1981-1829.  http://dx.doi.org/10.1590/S1413-70542015000300002.

Soil use and fertilizer management as well as cropping systems influence phosphorus (P) availability in the soil. This study evaluated P fractions and availability in a chronosequence of anthropic influence in a Haplic Plinthosol, in sites under no-till for different time periods: seven (NT7), eleven (NT11), and sixteen (NT16) years. Labile P concentrations in the soil accounted for 10%, 8%, and 9% of the total P for treatments NT7, NT11, and NT16, respectively. The labile P values ranged between 99 and 122 mg dm-3andindicatied no time in no-tillage influence on labile P under in the studied Plinthosol. However, moderately labile P contents increased with time: NT7 < NT11 < NT16 (237, 341, and 375 mg dm-3, respectively). This increased followed the elevation in iron oxide contents, indicating a relationship between mineralogy and P accumulation. Regardless of no-tillage period, P contents extracted by Mehlich-1 were lower, underestimating the available P content, when compared with the extraction using a P selective resin. The stocks of labile P were sufficient to maintain high crop yields, according to the recommendations for the Cerrado region. Even if labile P contents are reduced, when adopting no-till system, the contents and stocks of P in the soil after several years were high enough to provide for adequate crop yields.

Palavras-chave : Phosphorus adsorption; available phosphorus; tillage system.

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VIBRANS, Alexander Christian; MOSER, Paolo; OLIVEIRA, Laio Zimermann  e  MACANEIRO, João Paulo de. HEIGHT-DIAMETER MODELS FOR THREE SUBTROPICAL FOREST TYPES IN SOUTHERN BRAZIL. Ciênc. agrotec.[online]. 2015, vol.39, n.3, pp. 205-215. ISSN 1981-1829.  http://dx.doi.org/10.1590/S1413-70542015000300001.

Total tree height (h) is often difficult to measure in natural forests. Regression models based on easily accessed variables like DBH (d) can be an alternative, since their assumptions are validated. The aims of this study are to: (i) calibrate specific and generic h-d models for three forest types (Seasonal Deciduous Forest, DEC; Mixed Ombrophilous Forest, MIX; and Dense Rainforest, DEN) in Santa Catarina state testing the regression assumptions and evaluating model quality; (ii) verify different h-d relationship between forest types. The dataset (1,766 measured tree Continue reading

ROSA, Daniele Penteado et al. Modelagem matemática da cinética de secagem de semente de laranja. Ciênc. agrotec. [online]. 2015, vol.39, n.3, pp. 291-300. ISSN 1981-1829.  http://dx.doi.org/10.1590/S1413-70542015000300011.

A secagem de sementes de laranja que representam produtos residuais do processamento de suco foi estudada nas temperaturas de 40, 50, 60 e 70 °C e velocidades de secagem de 0,6, 1,0 e 1,4 m/s. As cinéticas de secagem experimental de sementes de laranja foram obtidas utilizando um secador de ar forçado por convecção. Três modelos de camada fina: modelo de Page, modelo Lewis, e o modelo de Henderson-Pabis e o modelo difusivo foram utilizados para Continue reading

Resumo

MADEIRA, Raul Antônio Viana et al. Caracterização tecnológica e classificação de linhagens de trigo cultivadas no cerrado mineiro.Ciênc. agrotec. [online]. 2015, vol.39, n.3, pp. 283-290. ISSN 1981-1829.  http://dx.doi.org/10.1590/S1413-70542015000300010.

Para alcançar melhor rentabilidade, o produtor necessita de cultivares de trigo de alta produtividade. Porém, só isso não é suficiente, pois, para atender aos moinhos, à indústria de alimentos e, mais especificamente, aos panificadores, as cultivares de trigo devem apresentar requisitos mínimos de qualidade, para resultar em produtos finais também de qualidade superior. Este trabalho foi conduzido com o objetivo de realizar a caracterização tecnológica da farinha de trigo de cinco linhagens de trigo desenvolvidas para o plantio no Cerrado Mineiro; Continue reading