Assessing nut germination protocols for macadamia cultivar 'Beaumont'

A rapid rate and high percentage of macadamia nut germination, together with production of vigorous seedlings, are required by nurseries and breeding programs. Germination of nuts is typically protracted, however, and rarely reaches 100%. Many studies have been conducted into macadamia germination, but most have assessed percent germination only. This study investigated the effects of various treatments on percent germination, germination rate, and plant, shoot and root dry weights. The treatments tested were combinations of: (i) soaking or not soaking seeds in a dilute fungicide solution prior to planting; (ii) four different planting media; and (iii) leaving seed trays open or placing them inside clear plastic bags. For freshly harvested nuts, sowing in potting mix under clear plastic and without soaking produced the highest percent germination and germination rate, the largest shoots, and longest lateral roots.

Atividades de matemática e de ciências no horto de Amato Lusitano

Relatório de Estágio apresentado à Escola Superior de Educação do Instituto Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Educação Pré- Escolar e Ensino do 1.º Ciclo do Ensino Básico.

PRODUÇÃO DE MUDAS DE UMBUZEIRO ( Spondias tuberosa Arruda Câmara) EM DIFERENTES SUBSTRATOS E TAMANHO DE RECIPIENTES

A espécie Spondias tuberosa Arr. Cam. (umbuzeiro) destaca-se como uma das espécies arbóreas de maior potencial do semiárido brasileiro. Apesar de sua relevante importância socioeconômica e ambiental, há falta de estudos voltados para o estabelecimento de um modelo de produção de mudas da espécie. O objetivo desse trabalho foi avaliar a produção de mudas de Spondias tuberosa utilizando diferentes substratos e tamanho de recipientes. O experimento foi conduzido no viveiro do Laboratório de Ecologia Vegetal (LEV) do Centro de Ciências Agrárias (CCA) da Universidade Federal da Paraíba (UFPB), Areia - PB. O delineamento experimental usado foi em blocos casualizados em esquema fatorial 2 x 7 e parcelas subdivididas, sendo que os recipientes representaram as parcelas e os substratos as subparcelas. Foram utilizados substratos formulados a partir da mistura de terra de subsolo (37,5-100%), areia lavada (12,5- 25%) e esterco bovino curtido (10-50%). Os recipientes utilizados foram sacos de polietileno preto com volumes de 1900 cm3 (15 x 27 cm) e 5000 cm3 (25 x 26 cm). Para a obtenção das plântulas, sementes de Spondias tuberosa foram semeadas em sementeira de alvenaria até a repicagem (90 dias após o semeio). Aos 78 dias, após a repicagem, as mudas foram avaliadas quanto à altura, diâmetro do colo, relação altura/ diâmetro do colo, diâmetro do xilopódio, comprimento de raiz, massa seca da parte aérea e raiz. Os dados obtidos foram submetidos à análise de variância e ao teste F, sendo as médias comparadas pelo teste de Tukey ao nível de 5% de probabilidade, utilizando o software SISVAR®. Os substratos com esterco bovino curtido proporcionaram os maiores valores em altura e comprimento de raiz. Para a produção de mudas de Spondias tuberosa, é recomendado o substrato contendo terra de subsolo (45%) + Areia (15%) + Esterco bovino (40%).

Response of some chickpea ( Cicer arietinum L.) genotypes to Orobanche foetida Poir. parasitism

In Tunisia, broomrape ( Orobanche foetida Poir.) causes major drawbacks especially in faba bean ( Vicia faba L.) Chickpea ( Cicer arietinum L.) suffers little damage compared to faba bean, but with the winter sowing chickpea cultivars, broomrape might become a serious problem for chickpea cultivation. The development of resistant cultivars remains the most efficient way to solve this problem. The behavior of six chickpea genotypes to O. foetida was studied under field natural infestation and artificial inoculation in pots and petri dishes in greenhouse conditions. During the cropping seasons 2010-2011 and 2012-2013 the level of infection was very low. The number of emerged parasites per host plant varied from 0.18 to 0.43 and the incidence from 6.5% to 23%. Among the six tested genotypes, G1, G2, and G4 showed partial resistance to O. foetida with low number and dry weight of emerged parasite and high grain yield compared to the other genotypes, although no significant differences were recorded. In pot experiments, the number and total dry weight of broomrape per plant were lower for G1 and G2 genotypes than the other genotypes. Parasitism does not affect significantly the shoot dry weight and number of pods of these genotypes. The total chlorophyll content was significantly reduced under infestation in all genotypes. In Petri dishes experiments, results showed that percent germination of O. foetida seeds varied from 49% to 65% and does not play a role in the resistance of chickpea genotypes. In contrast, broomrape attachment was lower and slower for the genotypes G1, G2, and G4 than the other genotypes. Resistance in chickpea genotypes was characterized by few parasite attachments on roots and a limited growth of established tubercles. No necrosis of attached tubercles was observed in the different experiments.

Produção de biomassa e composição química de adubos verdes cultivados no Vale do Ribeira

The contribution of green manure to soil improvement and crop production depends primarily on biomass production and its chemical composition, which vary depending on the species, region and growing season. The aim of this research was to evaluate the chemical composition of biomass produced by green manures in Vale do Ribeira, São Paulo, Brazil. In order to develop this research, was carried an experiment in Pariquera-Acu, in 2006/2007, in completely randomized blocks design with four treatments (three green manure and spontaneous vegetation) and five replications. At 30, 60, 90 and 120 after sowing samples were collected in 1m(2) of the shoots and determined fresh and dry, and chemical composition biomass. Sunhemp, pigeon pea and mucuna produced, in decreasing order, the largest quantities of biomass and were more efficient than the spontaneous vegetation. The biomass produced by green manure had higher quality than that produced by spontaneous vegetation. Sunhemp and pigeon pea have a higher proportion of dry matter in stems which have low N, high C/N and L/N ratio, variables indicating slow decomposition of residues. The analysis of dry matter partitioned to better indication of the chemical composition of the residues and the prevision of the availability of nutrients in the soil.

Nutrient content in aboveground biomass of Brazilian peanut cultivars in conservation tillage on sugarcane straw and pasture area.

Fields studies were conducted in 2004/2005 in order to evaluate the effects of tillage on nutrient content in aboveground biomass of two peanut cultivars, cultivated in rotation after mechanical harvested sugarcane and pastures. These trials were carried out in two types of soils; Oxisol and Ultisol, respectively in Ribeir?ao Preto and Mirassol, S?ao Paulo State, Brazil. The experimental design was split-plot with four replications. Tillage treatments (conventional, minimum and no-tillage) were main plots while sub-plots were peanut genotypes IAC-Tatu ST (Valencia market-type, erect growth habit, red seed coat, maturity range around 100 days after planting) and IAC-Caiap´o (Runner market-type, prostate growth habit, pink testa, maturity range more than 135 days). From 15 to 90 days after emergence, samples of leaves and stems were harvested, dried, weighted and ground to determine macro and micronutrient concentration. At 75 days after sowing, the cultivar IAC-Caiap´o showed higher contents of N, P, K, Cu, and Zn while IAC-Tatu presented higher concentrations of Ca, Mg, and S. Zn content was higher in conservation tillage than in conventional, mainly in Oxisoil for both of cultivars.

Drought impact on rainfed common bean production areas in Brazil.

Common bean production in Goiás, Brazil is concentrated in the same geographic area, but spread acrossthree distinct growing seasons, namely, wet, dry and winter. In the wet and dry seasons, common beansare grown under rainfed conditions, whereas the winter sowing is fully irrigated. The conventional breed-ing program performs all varietal selection stages solely in the winter season, with rainfed environmentsbeing incorporated in the breeding scheme only through the multi environment trials (METs) wherebasically only yield is recorded. As yield is the result of many interacting processes, it is challengingto determine the events (abiotic or biotic) associated with yield reduction in the rainfed environments(wet and dry seasons). To improve our understanding of rainfed dry bean production so as to produceinformation that can assist breeders in their efforts to develop stress-tolerant, high-yielding germplasm,we characterized environments by integrating weather, soil, crop and management factors using cropsimulation models. Crop simulations based on two commonly grown cultivars (Pérola and BRS Radi-ante) and statistical analyses of simulated yield suggest that both rainfed seasons, wet and dry, can bedivided in two groups of environments: highly favorable environment and favorable environment. Forthe wet and dry seasons, the highly favorable environment represents 44% and 58% of production area,respectively. Across all rainfed environment groups, terminal and/or reproductive drought stress occursin roughly one fourth of the seasons (23.9% for Pérola and 24.7% for Radiante), with drought being mostlimiting in the favorable environment group in the dry TPE. Based on our results, we argue that eventhough drought-tailoring might not be warranted, the common bean breeding program should adapttheir selection practices to the range of stresses occurring in the rainfed TPEs to select genotypes moresuitable for these environments.

Evaluation of the reaction of watermelon parent and F1 plants to Meloidogyne enterolobii.

The aim of this study was to evaluate the performance of progenies from Citrullus lanatus var. lanatus (cultivated watermelons) when crossed with progenies from C. lanatus var. citroides (fodder watermelon with a historic of resistance to the nematode Meloidogyne enterolobii). The parents and their F1s were evaluated for resistance to this nematode. In the initial stages of eleven treatments, watermelon seedlings plantlets were transplanted to plastic bags of six kilograms once the first leaves developed. Ten inoculated plants with 5,200 eggs in the soil near the stem of the plant and four non-inoculated ones were used in each treatment, in a complete block design. Sixty-two days after sowing, the following characteristics were evaluated: the length of the aerial part of the plant (LAP, in m), fresh mass of the aerial part (FMAP, in g), root fresh mass (RFM, in g), egg number (EN) and reproduction factor (RF). A comparison between the averages of inoculated and non-inoculated plants was performed using Scott-Knott test at 5% and the diallelic analysis was performed using the GENES program. The morphological characteristics did not allow for the identification of the parent plants or the F1s with respect to nematode resistance, but the variables EN and RF were useful for such identification. The analyses of the general and specific combining abilities indicate highly significant effects with respect to this resistance, showing additive gene effects as well as dominance and epistatic gene effects, allowing for identification of parents and F1s that can be used in watermelon breeding programs to improve resistance to the M. enterolobii.

Estimativas de parâmetros de adaptabilidade e estabilidade de genótipos de alface (Lactuca sativa L.) em diferentes épocas e condições de cultivo

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, Programa de Pós-Graduação em Agronomia, 2016.

Potential for agricultural production on disturbed soils mined for apatite using legumes and beneficial microbe

Christmas Island has been mined for rock phosphate for over 100 years, and as mining will finish in the next few decades there is a need to develop alternative economies on the island, such as high value crop production. However, to conserve the unique flora and fauna on the island, only land previously mined will be considered for this purpose. As these soils have been severely perturbed by mining, strategies to improve soil quality parameters need to be undertaken before plant based industries can be considered. For instance, legumes and beneficial microbes have demonstrated a positive role in the remediation of degraded soils. Therefore, this study aimed to establish the scientific basis upon which agriculture can effectively be developed on s oils post phosphate mining. Six legume species (Glycine max (Soybean), Vigna radiata (Mungbean), V. unguiculata (Cowpea), Phaseolus vulgaris (Navybean), Cajanus cajan (Pigeon pea), and Lablab purpureus (Lablab)) were sown onto a two ha rehabilitated site t hat had previously been mined for rock phosphate. The soil had a pH of 7.0, and was high in P but low in Bo, Cu, K, Mg, N and S and had low organic C. The legumes were inoculated with their respective rhizobial inoculant or co-inoculated with the rhizobia and a plant growth promoting bacteria (PGPB) at three different fertilizer rates (nil, a low rate, and five times the low rate). With the exception of P. vulgaris, all the legume species survived. The application of fertilizer was essential for maximum biomass yields 18 weeks after sowing, however the lower fertilizer rate was sufficient to obtain maximum yields for some cultivars. The PGPB increased yields and nodulation of some of the legumes at different fertilizer levels. Although the legumes (except P. vulgaris) grew in the Christmas Island environment, selection of appropriate legume cultivars and inoculants plus optimization of the fertilizer regime is required for reliable agricultural productivity on the island.

Pasture height and crop direction influence reptile movement in an agricultural matrix

Tackling the global threat of habitat fragmentation on biodiversity requires knowledge of how species move within agricultural landscapes. However, the specific mechanisms influencing dispersal within such landscapes remain poorly understood. The objective of our study was to assess how matrix type (improved pasture, native pasture or crop) and structure (grass height) influence fine-scale reptile movement, as well as influences of crop sowing direction and setting-sun position. In an agricultural region of south-eastern Australia, we first released 20 individuals of an arboreal gecko (Christinus marmoratus) at set distances from trees to determine the distance at which they could perceive their tree habitat (perceptual range). We then translocated 36 individuals into six matrix environments within their perceptual range of isolated trees to examine how gecko movement was modified by the type and structure of the matrix. We also recorded crop sowing direction and setting-sun position and examined all recorded tracks using angular statistics. We found that geckos exhibited a perceptual range of 40–80m. Short matrix environments promoted direct movements towards trees, irrespective of matrix type. Furthermore, movements were significantly affected by crop sowing direction with individuals following the planted lines. Our study has three significant implications: (i) restoring mature tree spacing to 80 m apart will assist gecko movements, (ii) targeted management for low pasture height, such as by maintaining directional narrow strips of low vegetation among taller pastures, might assist movement and facilitate increased connectivity, (iii) directional sowing of crops between habitat patches presents a simple but potentially effective tool for reconnecting fragmented landscapes.

Análisis de los posibles efectos del TLC con Estados Unidos en el subsector del maíz

En el marco del desarrollo del sector primario en Colombia, se observa la existencia de una serie de situaciones o factores adversos que le impiden alcanzar su productividad y competitividad, entre los cuales destacan los altos costos de la materia prima e insumos utilizados en los procesos productivos de siembra y cosecha, la inexistencia de políticas públicas que garanticen un verdadero apoyo al campesinado colombiano, como los subsidios y/o estrategias de protección a la producción nacional, estas últimas, como barrera a la entrada en grandes volúmenes de productos importados, resultantes de los acuerdos internacionales donde se les da mayor participación a los productos importados, como ha sido en los últimos años, los provenientes de Canadá y Estados Unidos, este último, con la firma del TLC. Lo anterior ha coadyuvando a una reducción en las áreas de cultivo, así como en el rendimiento por hectáreas; como es el caso de la agrocadena de cereales, entre los que destaca el maíz amarillo, el cual ha experimentado un alto incremento en su volumen de importación, resultado de los excedentes exportables dados en la producción agrícola norteamericana, siendo los subsidios que a través de la ley Farm Bill, el gobierno norteamericano le otorga a los productores agropecuarios, un incentivo importante para tal fin. Con base en esto, los precios internacionales de comercialización del maíz amarillo han presentado una tendencia de decrecimiento, imposibilitando a los productores colombianos afrontar esta situación. Por medio de esta investigación se busca evaluar y esclarecer los posibles efectos del TLC de Colombia con Estados Unidos sobre los productores de maíz, y así mismo porporcionar alternativas de solución tanto para los campesinos como para el gobierno, identificando las principales variables que afectan la producción del cereal

Effects of dark or of red, blue or white light on germination of subterranean clover seeds

Dry or imbibed seeds of the negatively photoblastic burr burying subterranean clover cv. ‘Seaton Park’ were treated with dark or with red, blue or white light to evaluate the effects of light on seed germination. Dry seeds treated with constant white light, red light or blue light during 8 days and subsequently incubated in dark had final germination and duration of germination reduced, and the distribution of germination changed from highly asymmetric to symmetric respectively. Imbibing seeds incubated under constant blue or white light had final germination strongly reduced seven days after sowing (7.3% and 50.1% of the germination under dark) with significant differences between them. After transferral to dark, true complete recovery of germination of seeds treated with white light was observed 19 days after sowing, but only partial recovery in seeds treated with blue light. Results of dry and imbibed seeds are consistent with no activity of phytochromes, as expected in negatively photoblastic seeds. Results of dry seeds are seemingly contradictory because total germination data imply the inactivity of red and blue light photoreceptors, the opposite being implied by duration and shape of germination. A tentative hypothetical solution for the contradiction is presented. Results of imbibed seeds are fully consistent with cryptochromes but not with phototropins mediation of responses to light of seed germination in ‘Seaton Park’. The ecological and adaptive significance of such responses are discussed in the framework of light attenuation in soil and the requirement and ability of subterranean clover ‘Seaton Park’ to bury seeds.

O papel da agricultura de conservação na luta contra a erosão do solo em particular em Angola

A agricultura de conservação, conseguindo reduzir as perdas de solo por erosão e aumentando o seu teor em matéria orgânica, permite aos agricultores produzirem mais alimentos com menos trabalho. Oferece-lhes uma possibilidade de melhorar a sua qualidade de vida. Várias abordagens sobre agricultura de conservação do solo, incluindo rotação e consorciação de culturas, são componentes deste sistema aplicável a diferentes níveis. A sementeira direta e o menor distúrbio de solo, são princípios primordiais da conservação do solo, fornecem benefícios direitos para a agricultura e o meio ambiente, questões da maior relevância para a agricultura Angolana, apesar da pouca importância que atualmente lhes é dedicada. Logo, é preciso uma conversão e transição de tecnologias e técnicas para implementar a agricultura de conservação e o controle da erosão dos solos no país. As técnicas de conservação utilizadas pelos pequenos e grandes produtores, embora sejam bem-intencionadas, não oferecem a proteção contra a erosão do solo e a conservação da água. Tanto as entidades políticas, como o Programa de Acão do Ministério da Agricultura e do Desenvolvimento Rural (MINADER) e os agricultores angolanos devem entender a importância da agricultura de conservação para a segurança alimentar e dar continuidade para as gerações futuras. Não basta a reformulação e consolidação dos objetivos traçados no período de 2009 a 2013, sem que haja a aplicação prática. Portanto, para sair do atual conceito oficial de agricultura tradicional/convencional e optar para agricultura capaz de responder às necessidades de Angola é necessário seguir modelos semelhantes aos desenvolvidos por países tropicais de condições naturais semelhantes às de Angola; The role of conservation agriculture in the fight against soil erosion particularly in Angola ABSTRACT: Conservation agriculture, managed to reduce soil losses by erosion and to increase its content of organic matter, allow farmers to produce more food with less work. It offers them a chance to improve their quality of life. Several approaches to soil conservation agriculture, including rotation and intercropping, are components of this system applicable to different levels. Direct sowing and less soil disturbance, are key principles of soil conservation providiy benefits for agriculture and the environment, issues of great importance for the Angolan agriculture, in spite of the little importance that is currently dedicated to them. Therefore, we need a conversion and transition technologies and techniques to implement conservation agriculture and soil erosion control in the country. Conservation techniques used by small and large producers, although well-intentioned, do not offer protection against soil erosion and water conservation. Both political entities, such as the Program of Action of the Ministry of Agriculture and Rural Development (MINADER) and Angolan farmers should understand the importance of conservation agriculture for food security and continuity for future generations. Not just the redesign and consolidation of the objectives outlined in the period 2009 to 2013, without practical application. Therefore, to exit the current official concept of traditional / conventional farming and opt for agriculture able to meet the needs of Angola is necessary to follow models similar to those developed by tropical countries of natural conditions similar to Angola.

Humified fraction of organic matter due to plant mixture cultivation.

The aim of this study was to assess the organic matter changes in quantity and quality, particularly of the humic fraction in the surface layer (0?20 cm), of a Typic Plinthustalf soil under different management of plant mixtures used as green manure for mango (Mangifera indica L.) crops. The plant mixtures, which were seeded between rows of mango trees, were formed by two groups of leguminous and non -leguminous plants. Prior to sowing, seeds were combined in different proportions and compositions constituting the following treatments: 100% non-leguminous species (NL); 100% leguminous species (L); 75% L and 25% NL; 50% L and 50% NL; 25% L and 75% NL; and 100% spontaneous vegetation, considered a control. The plant mixtures that grew between rows of mango trees caused changes in the chemical composition of the soil organic matter, especially for the treatments 50% L and 50% NL and 25% L and 75% NL, which increased the content of humic substances in the soil organic matter. However, the treatment 25% L and 75% NL was best at minimising loss of total organic carbon from the soil. The humic acids studied have mostly aliphatic characteristics, showing large amounts of carboxylic and nitrogen groups and indicating that most of the organic carbon was formed by humic substances, with fulvic acid dominating among the alkali soluble fractions.