Plant selection in F2 segregating populations of papaya from commercial hybrids

Horse drawn cart driving between piles of hay.GrayscaleSorensen Safety Negatives, Binder: Europe

Cover plants and performance of shanks depths under corn productivity

The direct sowing system is characterized by minimum soil rotation and maintenance of vegetal residues in cover. However, incorrect management excessive traffic of machines have caused the emergence of compacted layers, which can cause decrease of crop productivity. The objective of this work was to evaluate the soil parameters and maize crop yield after management with different performance depths of fertilizer shanks, associated to the cultivation of winter coverage plants, in compacted Latosol, conducted in a direct sowing system. The experiment was carried out in two agricultural years (2013/2014 and 2014/2015), in a dystroferric Red Latosol, with a very clayey texture. The experiment was conducted in a randomized complete block design, with treatments arranged in the strip scheme, with two factors and four replications, totaling 32 experimental units. The main treatments were composed by the combination of four performance depths of fertilizer shank (0.065, 0.095, 0.125 and 0.150 m) in the corn sowing process and the secondary ones by the cultivation of two winter coverage plants (black oats and turnip forage). The use of coverage plants and performance depths of the shank, among themselves, did not change the parameters of soil density and porosity, in the intercrop line. The final population of plants, seedling emergence speed index and maize production components did not vary as a result of the performance depth of the shank

Conditions of use of boom sprayers in the micro-region of Pato Branco, PR, Brazil

The technical inspection of agricultural sprayers is responsible for generating important subsidies to inform and guide their users. In this sense, the aim of this study was to evaluate the working conditions of boom sprayers regarding their conservation status in order to identify the problems that interfere with quality sprayings. Sixty-three agricultural sprayers from rural properties were evaluated in the micro-region of Pato Branco, PR. Less than half of applicators (42.9%) performed some type of training and 58.7% of the operators had knowledge about the working pressure indicated by the spray tip manufacturer, but 24.3% of them were working with the pressure out of the recommended or with a damaged manometer. The manometer was present and operative in only 71.4% of the sprayers. Only 54% of the collected flows were in accordance with that informed by the operator. Most of the interviewed producers still do not have adequate criteria for choosing spray tips nor frequency of their replacement

Evaluation of genetic resources of yellow passion fruit

O objetivo deste trabalho foi caracterizar e avaliar recursos genéticos de maracujazeiro-amarelo (Passiflora edulis) quanto às principais características de importância econômica. Foram realizadas avaliações agronômicas e estimados parâmetros genéticos em 38 acessos do Banco Ativo de Germoplasma de Maracujazeiro da Embrapa Mandioca e Fruticultura, tendo-se utilizado cinco testemunhas provenientes de seleções ou melhoradas geneticamente. Foram avaliadas duas características produtivas, três características de qualidade química e sete atributos físicos dos frutos. Utilizou-se o delineamento de blocos aumentados, com quatro repetições e parcela de dez plantas. O elevado coeficiente de variação genética, o índice de variação maior que a unidade e os altos valores de herdabilidade indicam a existência de grande variabilidade genética ainda não explorada, bem como de condições favoráveis ao melhoramento genético. Para a maioria das características avaliadas, os acessos foram superiores às testemunhas. Os acessos BGM185 e BGM051 são mais promissores para o mercado de frutas frescas, pela qualidade dos frutos, enquanto os acessos BGM181, BGM034, BGM123 e BGM079 são indicados para a indústria de sucos, por apresentar alta produtividade e rendimento de polpa.The objective of this work was to characterize and evaluate genetic resources of yellow passion fruit (Passiflora edulis) for its main economic traits. Agronomic evaluations were made and genetic parameters were estimated in 38 germplasm accessions from the passion fruit germplasm bank of Embrapa Mandioca e Fruticultura, using five controls from selections or genetically improved material. Two productive characteristics, three chemical qualities, and seven physical attributes of fruit were evaluated. An augmented block design with four replicates and ten plants per plot was used. The high coefficient of genetic variation, the index of variation greater than one, and the high heritability values indicate the existence of high genetic variability not yet explored, as well as favorable conditions to implement a breeding program. For most of the traits evaluated, accessions were superior to the controls. Accessions BGM185 and BGM051 are more promising for the fresh fruit market, due to fruit quality, while accessions BGM181, BGM034, BGM123, and BGM079 are recommended for the fruit juice industry, due to high productivity and pulp yield

A novel seed treatment-based multiplication approach for cassava planting material.

Cassava (Manihot esculenta Crantz) is an important food security crop in many parts of the developing world. The crop?s high yield potential and multitude of uses?both for nutrition and processing?render cassava a promising driver for the development of rural value chains. It is traditionally propagated from stem cuttings of up to 30 cm in length, giving a multiplication rate as low as 1:10. Propagating cassava traditionally is very inefficient, which leads to challenges in the production and distribution of quality planting material and improved cultivars, greatly limiting the impact of investments in crop breeding. The work described in the present study aimed to develop a seed treatment approach to facilitate the use of shorter seed pieces, increasing the multiplication rate of cassava and thus making the crop?s seed systems more efficient. After several tests, formulation was identified, consisting of thiamethoxam 21 g ha-1, mefenoxam 1.0 g ha-1, fludioxonil 1.3 g ha-1, thiabendazole 7.5 g ha-1 and Latex 2% as a binder. Plant growing from seed pieces treated with this formulation displayed increased crop establishment and early crop vigor, leading to an improved productivity throughout a full growing cycle. This allowed to reduce the cassava seed piece size to 8 cm with no negative effects on germination and crop establishment, leading to yields comparable to those from untreated 16 cm pieces. This, in turn, will allow to increase the multiplication ratio of cassava by a factor of up to 3. Notably, this was possible under regular field conditions and independently of any specialised treatment facilities. Compared with existing seed production protocols, the increased multiplication rates allowed for efficiency gains of between 1 to 1.9 years compared to conventional five-year cycles. We believe that the technology described here holds considerable promise for developing more reliable and remunerative delivery channels for quality cassava planting material and improved genetics

PARTITION OF DRY BIOMASS AND NUTRIENT IN MINISTUMPS OF Eucalyptus INFLUENCED BY NPK FERTILIZATION

O estado nutricional da planta-matriz \ue9 de grande import \ue2ncia para a manuten\ue7\ue3o do seu vigor vegetativo, o que determina a produ\ue7\ue3o de brotos e tamb\ue9m os \uedndices de enraizamento e velocidade de forma\ue7\ue3o das ra\uedzes, uma vez que os macronutrientes e os micronutrientes est\ue3o envolvidos nos processos bioqu\uedmicos e fisiol\uf3gicos vitais \ue0 planta. Nesse sentido, o objetivo deste trabalho foi avaliar a influ\ueancia da aduba\ue7\ue3o NPK sobre a parti\ue7\ue3o de biomassa seca e nutriente em minicepa de eucalipto em solu\ue7\ue3o nutritiva. O trabalho foi realizado de novembro de 2008 a janeiro de 2009, em casa de vegeta\ue7\ue3o. Foi utilizado delineamento inteiramente casualizado em esquema fatorial fracionado (4x4x4)\ubd, perfazendo 32 tratamentos com tr\ueas repeti\ue7\uf5es. Os tratamentos se constitu\uedram de quatro doses dos nutrientes de N (50; 100; 200 e 400 mg L-1) na forma de ureia, P (7,5; 15; 30 e 60 mg L-1) na forma de \ue1cido fosf\uf3rico e K (50; 100; 200 e 400 mg L-1) na forma de cloreto de pot\ue1ssio em solu\ue7\ue3o nutritiva. Houve efeito significativo apenas para as doses de N isoladamente, para a biomassa seca das miniestacas e biomassa seca da parte a \ue9rea e raiz das minicepas com efeito linear decrescente, com o aumento das doses de N. A dose de 50 mg L-1 de N proporcionou maior ac\ufamulo de biomassa seca das miniestacas e minicepas. A distribui\ue7\ue3o percentual da biomassa seca e dos nutrientes na biomassa seca das miniestacas, parte a \ue9rea e ra \uedzes das minicepas variou em rela\ue7\ue3o \ue0s doses de N. A extra\ue7\ue3o de macronutrientes pelas miniestacas de 6 cm na dose de 50 mg L-1 de N seguiu a seguinte ordem decrescente de N > S > P > K > Ca > Mg e micronutrientes de Cu > B > Mn > Fe > Zn.The nutritional status of the matrix plant has a great importance for the maintenance of its vegetative vigor, which determines the sprouts production and also the rooting percentage and the speed of root formation, since the macro and micronutrients are involved in biochemical and physiological vital processes for the plant. Thus, this study aimed to evaluate the influence of NPK fertilizer on dry biomass production by minicuttings and mini-stumps and the percentage distribution of nutrients in a simple hybrid plant of Eucalyptus urophylla in nutrient solution. The experiment was realized from November, 2008 to January, 2009 in a vegetation environment. The experimental design was a completely randomized in factorial scheme with a fractional factorial (4x4x4)1/2, adding up to 32 treatments with three replicates. The treatments consisted of four levels nutrients of nitrogen (50, 100, 200 and 400 mg L-1) in the urea form, P (7.5, 15, 30 and 60 mg L-1) in the phosphoric acid form and K (50, 100, 200 and 400 mg L-1) in the potassium chloride form, in the nutrient solution. There was significant effect only to the N doses to the dry mass of mini-cuttings and the dry mass of shoots and roots of mini-stumps with decreasing linear effect against N doses increasing. The doses of 50 mg.L-1 of N promoted higher accumulation of dry mass in mini-cuttings and mini-stumps. The percentage distribution of dry mass and of the nutrients in dry mass of mini-stumps, shoots and roots of mini-stumps varied in relation to N doses. Macronutrients extraction from mini-stumps of 6 cm at a dose of 50 mg L-1 of N followed the order of decreasing N > S > P > K > Ca > Mg and micronutrients Cu > B > Mn > Fe >Zn

AMMI analysis of the adaptability and yield stability of yellow passion fruit varieties

High yield stability and adaptability of yellow passion fruit varieties (Passiflora edulis Sims. f. flavicarpa Deg.) are highly desirable attributes when exploring different environments. This study aimed to evaluate the adaptability and yield stability of yellow passion fruit varieties using AMMI (additive main effects and multiplicative interaction) and other ancillary statistics. Twelve varieties were evaluated in eight environments. Analysis of variance showed effects attributable to the varieties (G), environment (E) and their interaction (G × E). The first two multiplicative components of the interaction accounted for 69% of the sum of squares. The scores of the principal interaction components showed high variability for the environments relative to the variety effects. High varietal phenotypic stability was observed in three environments; which can be used in yellow passion fruit breeding programs for initial selection trials. A biplot-AMMI analysis and yield stability index incorporating the AMMI stability value and yield capacity in a single non-parametric index were useful for discriminating genotypes with superior and stable fruit yield. AMMI analysis also allowed for the identification of more productive varieties in specific environments, leading to significant increase in passion fruit productivity

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio