Influence of Soil and Irrigation Management on the Quality of Seedless Crimson Table Grapes

The market for table grapes is moving into mass production of specialty seed-less grapes in covered areas, aiming at obtaining premium prices with early or late production of high quality products. Production of quality seedless grapes is not straightforward since it is requires the correct combination of various independent characteristics, such as color, sugars, size and quantity at the right moment for successful harvesting and marketing. The present study was carried out at the two largest Portuguese producers located in Alentejo, and has the objective of studying the effect of irrigation management strategies and two different soils on the various relevant parameters for successful production and marketing. The management strategies were the application of ten day stress at the end of the cycle, in order to promote early maturing of the grapes. Three different timings of the stress were applied. Soil moisture, sap flow, bark thickness, as well as leaf water potential, stomatal conductance and chlorophyll content were measured regularly during the production season. The results indicate that the roots explore a rather large soil volume and the plants can successfully withstand reasonable periods of drought without significant changes to the plant physiology. Additionally late rains can mask the effect of any farmer applied drought and invalidate any farmer induced stress to the plants. Water-logged soils tend to cause early onset of maturity, but cause the ripening stage to extend over a longer period of time, and thus, in effect result in a delay in the harvest date. Topography also has some effect on the ripening, since hot air tends to accumulate under the plastic at the higher areas of the field. This work is funded by PRODER, 4.1, within the scope of project MORECRIMSON

Methods of earth building in the Huila Province, Angola

In Angola, the construction made of raw earth is a cultural heritage widely used by low income households, representing over 80% of the population [1, 3]. In Huila province is evident construction in raw earth in a large scale, either in urban or in periurban and rural areas. The construction methods follow the ancestral standards, distributed throughout the region of Huila, being built by the several ethnic groups. Among the construction techniques in earth, stand out: the adobe, wattle-and-daub and more recently on CEB (Compressed Earth Block). The type of soil used to make the adobes is mainly silty-clayed sand [1]. The most applied materials are: rods, reeds, wood, grass, straw, soil and stone, almost with the same characteristics [2]. The manufacture of adobe, consists essentially in mixing clay and grass (plant fibers), then put the mixture inside a wooden mold, having a size of 42 cm long and 18 cm high and taking three to four days to dry and be applied in housing construction. The application of these materials makes the construction less expensive because they are collected, transformed and applied by the owner himself of housing without any project, based only on the result of the practice and experience acquired from their ancestors. They are simple constructions, presenting a typology of grouped and isolated single-family housing, ranging between 2 and 3 bedrooms [2]. The construction techniques used in such small housings have positive environmental aspects, both as regards the materials employed, such as the manner in which the constructions are raised, showing special concerns for the quality improvement of them, as regards the resistance, durability and comfort [4].