Current Agricultural Science and Technology

Defoliation at different vegetative stages and assessment of morphological and yield components

Fri, 07 Oct 2016 09:16:37 +0000

Objective was to evaluate the influence of defoliation of a soybean cultivar indeterminate growth in different vegetative stages on morphological characters and yield components. The study was conducted in the years 2010/11 and 2011/12. The experimental design was a randomized block design with seven treatments and four replications for each year. The treatments were: T1: No defoliation; T2: Defoliation in V4, T3: Defoliation in V4 and V5, T4: Defoliation in V4, V5 and V6, T5: Defoliation in V4, V5, V6 and V7, T6: Defoliation in V4, V5, V6, V7 and V8 and T7: Defoliation in V4, V5, V6, V7, V8 and V9. The variables analyzed were: main stem height, number and length of branches, first pod, number of pods per node on the main stem, and the branches per plant, number of reproductive nodes on the main stem, the branches, number of us total on the main stem, the branches, distance between us and grain yield. Grazing did not influence most of the morphological characters and increments the number of pods on the stem in years with good water availability and high levels of defoliation, and yield of soybean.

Postharvest treatments to mitigate the internal browning in ‘Bartlett’ pears

Fri, 07 Oct 2016 09:16:38 +0000

Internal browning is an important disorder in pear fruit which can lead to considerable economic losses. Pears (Pyrus communis L. cv. Bartlett) were harvested at early harvest maturity of 90 N from a commercial orchard in southern Brazil. Methyl jasmonate, ethanol, and 1-methylcyclopropene vapor treatments were carried out for 24 hours in order to mitigate the internal browning disorder. Fruit were stored for up to 150 days at 0 ± 1 °C and 90 ± 5 % RH. Pears exhibited internal browning in the control samples after 90 days of cold storage. However, no internal browning symptoms were observed in the 1-MCP treatment. The first symptoms in 1-MCP samples were noticed after 120 days of cold storage (12 %) and reached 100 % in five days at room temperature. 1-MCP-treated pears showed flesh firmness values of 82 N after 90 days of cold storage and 18.7 N when they were removed from the cold storage and kept at 20 °C. The greatest acceptance index was attributed to 1-MCP pears after 90 days at 0 ± 1 °C followed by 5 days at 20 ± 1 °C (89.35). High acceptance indexes were attributed to MeJa (77.95) and control pears (76.40) after 30 days in cold storage followed by 5 days at room temperature. 1-MCP (0.3 µL L^-1, 24 hours at 0 ± 1 °C) treatment delays ripening and mitigates the internal browning in early harvested ‘Bartlett’ pears, that can be stored for up to 90 days at 0 ± 1 °C.

Physicochemical and sensory properties of popcorn grain stored at different temperatures

Wed, 08 Mar 2017 00:00:00 +0000

Popcorn is produced and consumed worldwide, requiring storage to address the demands of consumers throughout the year because production is generally seasonal. Several factors can affect the quality of stored grains, including storage temperature. This study aims to evaluate the effects of different storage temperatures (5, 15, 25 and 35 °C) on the physicochemical, technological, pasting and sensory properties of popcorn grains stored for 6 months. The storage at 35 °C for 6 months promoted an increase in the expansion time and a decrease in the weight of the expanded popcorn as well as a decrease in electrical conductivity, pH and protein solubility of popcorn. Moreover, the greater residue content after the expansion was found for grains stored at 35 °C. These characteristics were reflected in the purchase intent test and in the sensory evaluation. Expanded popcorn prepared with grains stored at 15 °C exhibited larger flower and higher purchase intent characteristics than expanded popcorn prepared from other treatments when evaluated by the sensory panel. Considering these benefits, storage at lower temperatures of approximately 15 °C is preferable to preserve the physical, sensory and technological properties of popcorn.

Produção de pimentão amarelo sob lâminas de água e coberturas de solo em ambiente protegido

Domingos Rodrigues, Rumy Goto — Fri, 17 Mar 2017 00:00:00 +0000

Compararam-se diferentes lâminas de água e diferentes coberturas de solo na cultura do pimentão, para estabelecer uma quantidade de água racional e cobertura de solo adequada para a produtividade e qualidade dos frutos de pimentão em ambiente protegido. O experimento foi realizado em São Manuel/SP, no período de maio a dezembro. O delineamento experimental adotado foi parcelas subdivididas com quatro blocos. As lâminas foram comparadas nas parcelas e as coberturas de solo nas subparcelas. Utilizaram-se quatro lâminas de água com 120, 100, 80 e 50% do volume de água evapotranspirada, para os respectivos tratamentos. O controle da irrigação foi feito baseado na evaporação do tanque classe A. As coberturas de solo foram: C1- solo sem cobertura (testemunha); C2-cobertura de solo com bagacilho de cana; C3- cobertura de solo com filme de polietileno da cor preta; C4- cobertura de solo com filme de polietileno da cor prata, C5- cobertura de solo com filme de polietileno da cor laranja e C6 - cobertura de solo com filme de polietileno da cor verde. As coberturas de solo com filmes plásticos de cor preta e cor verde proporcionaram maiores temperaturas do solo, controle de plantas invasoras, maior desenvolvimento das plantas e maior produtividade. Utilizando-se a cobertura de solo com filmes plásticos, as lâminas de água calculada com 80% e 100% de reposição de água proporcionaram maior número de frutos e produtividade.

Prohexadione calcium controls shoot growth of pear trees under mild winter conditions

Thu, 25 May 2017 16:25:54 +0000

The aim of this study was to evaluate the effects of prohexadione calcium (ProCa) on vegetative growth and yield of ‘Carrick’, ‘Packham’s Triumph’ and ‘William’s’ pear trees. The trial was performed at the experimental orchards of the Federal University of Pelotas, Capão do Leão, RS, Brazil (31° 52’ 00" S; 52° 21’ 24" W), during the growing seasons of 2011/12 and 2012/13. Treatments were applied to single-tree replications in a randomized complete block design with four replications as follows: Control (unsprayed), ProCa (ProCa - 750 g ha^-1 i.a.). The ProCa was split in four (187.5 g ha^-1 a.i. each) or three timings (250 g ha^-1 a.i. each) applications in the 2011/12 and 2012/13 growing seasons, respectively. The assessed parameters were: one-year-old shoot length, number of nodes per shoot, average internode length per shoot, trunk cross sectional area (TCSA) increment, pruning weight, number of fruit per tree, average fruit weight, yield per tree and return bloom. The application of ProCa at 750 g ha-1 a.i. satisfactorily controlled shoot growth through the reduction of internode length of ‘Carrick’, ‘Packham’s Triumph’ and ‘William’s’ pears. Besides, return bloom was not negatively affected by ProCa. Therefore, this plant growth regulator is a potential management tool to reduce shoot growth and the need for pruning in pear orchards.