Avaliação do efeito do corte horizontal da copa, com máquina de podar de discos, em pomares de pera “Rocha

Current pear pruning making use of pneumatic shears still is a very labour intensive operation. The Proder project “Avaliação da poda mecânica em pomares de pera” was designed to contribute to solutions that would reduce the present dependence in labour and therefore to promote a reduction in pruning costs. This paper shows the results of a trial made to evaluate the influence of mechanical topping in manual pruning complement field work and pear yield. Topping was performed using a Reynolds 6DT 3.0m cutting bar with six hydraulic-driven circular disc-saws mounted in the three point tractor linkage system. The field trial was performed in a commercial orchard with 20 years, planted in an array of 4m x 2m with tree lines oriented in North-South direction. Trees were trained as the central leader system. In this trial, in a randomised complete block design with four replications, two treatments are being compared leading to 8 plots with one line of 14 trees per plot. The treatments tests were: T1 - manual pruning performed by workers using pneumatic shears, in each year; T2 - Topping the canopy parallel to the ground, using a discs-saw pruning machine mounted in a front loader of an agricultural tractor, followed by manual pruning complement performed by workers with pneumatic shears. Tree height and width was measured, before and after pruning. Work was timed and pear yields evaluated. Mechanical topping seems to be effective in the control of tree height, which can contribute to increase 14% of work rates on manual pruning complement. No significant differences in pear yield were found between treatments.

História(s) de máquinas e a máquina da história (1a parte)

A prática e a história da Máquina Real afirma-se como um elemento central do teatro de marionetas peninsular, sobretudo a partir dos estudos empreendidos por Francisco J. Cornejo Vega. Estes estudos permitiram relançar os termos da pesquisa da presença de companhias e de repertório da máquina real no espaço português entre os séculos XVI e XVIII, equacionando influências e interrogando o significativo desenvolvimento setecentista de um teatro de bonecos português — tanto ligado à ópera como às formas de teatro popular, como os presépios —, até ao lento declinar oitocentista daquela tipologia de teatro. O que quero propor é que a máquina real, enquanto objecto histórico e desafio historiográfico, se perspective à luz da sua vocação compósita, território onde confluem objectos animados, maquinismos e práticas espectaculares gímnicas e mecânicas, às quais poderiam acrescentar-se as luminárias e fogos de artifício, as touradas e paradas equestres, as assembleias e outeiros poéticos que caracterizam de forma insistente as práticas espectaculares do nosso século XVIII (como atestam inúmeros títulos de entremezes seetecentistas), alargando assim algum tanto o corpus de objectos mal-amados das histórias do teatro que tradicionalmente se situam nas franjas do sistema teatral. Esta é a primeira etapa desse desiderato.