Yield and test weight are attributes of particular economic importance in wheat production systems and are strongly affected by environmental conditions. This study was conducted to determine the effects of sowing date and seeding rate on grain yield and test weight of fifteen bread wheat varieties and five advanced lines from Portuguese Wheat Breeding Program (Plant Breeding Station, Elvas, Portugal) under irrigated Mediterranean systems. Field experiments were conducted at two locations of Southeast Portugal, during 2011/2012 growing season. Two seeding rates were compared (200 and 350 seeds.m −2 ) in two different sowing dates in each location. Results showed that sowing date and seeding rate affects yield and test weight under irrigation field conditions, for Mediterranean region of Southeast Portugal, but only sowing date had significant effects among the varieties. At Elvas, higher yield was obtained with the 2nd sowing date (21 December) for most of the varieties studied. In opposite, in Beja trials, the highest values for yield were found when varieties were sown earlier (1st sowing date -26 October). Test weight had a similar performance in the two sites, though top values for this trait were found with the 1st sowing date. Comparing the results obtained in the two studied locations, Beja showed, for the majority of the varieties, 3t/ha higher average yield than Elvas.

Two durum wheat trials were carried out in Mediterranean conditions during 2010/2011 and 2011/2012 growing seasons at Plant Breeding Station-Elvas (Portugal). The experiments were conducted under rainfed conditions however, in 2012, due to extreme drought it was necessary to use artificial irrigation between booting and mid grain filling stage. Thirty durum wheat genotypes were studied and six quality parameters were evaluated: thousand kernel weight (TKW), test weight, vitreousness, protein content, SDS test and pigment content through Minolta CR 300 Colorimeter (L*a*b*) analysis. ANOVA showed that all sources of variation for four quality traits were highly significant (P < 0.001) for both years, except for SDS volume and index b* that were not significant during the two years of trials. Environmental effects showed that total water input during grain filling, appears to affect negatively grain quality by reducing test weight, TKW and semolina yield. Maximum temperatures during the same period reduced test weight, TKW, semolina yield and pigment content (L*), but increased protein content. A negative correlation was found between protein content and test weight and a positive correlation between test weight and semolina yield. Technological trait associated with pasta quality pigment index (b*) was significant different among the genotypes.

Cereals are a group of cultivated plants belonging to the grass family that produces grains rich in starch with specific dough properties. These grains are easily harvested, due to the structure and, if under appropriate storage, the mature seeds preserve its qualities and nutritional value for a long time. The gradual shift to a steady-production based agriculture has been the main driving force behind the domestication of wheat, namely durum wheat. The world durum wheat steady-production, which prevails in the Mediterranean region, is mostly used in the production of pasta, yet the quality definition requires the control of fungal phytopathogens, industrial unit operations and additives applications. This paper reviews some aspects of durum wheat production and industrial processing, further considering phytopathogenic infections and the application of food additives.

Restricted water availability and yield reductions derived from climate changes have become a strong concern as regards fundamental crops, such as wheat. There is an increasing need to characterize germplasm diversity in order to highlight drought tolerant genotypes and to assist Portuguese wheat breeding programs. Bread wheat (Triticum aestivum) varieties were selected from four different evolutive and/or breeding groups: ancient landraces, traditional varieties, modern currently used and advanced lines. The aim of this work was to identify physiological traits that contribute to drought tolerance during grain filling period. Plants were cultivated in pots, under semi-controlled greenhouse conditions. Drought was imposed by withholding irrigation after anthesis. Well irrigated and water stressed plants were compared as regards leaf gas exchanges (net photosynthetic rate, Pn; leaf stomatal conductance, gs; transpiration, E), instantaneous water use efficiency (iWUE), membrane electrolyte leakage, osmotic potential and leaf pigments. Subsequently, plants were maintained under a controlled irrigation (droughted plants: 50% of the water given to fully irrigated controls) until harvest, to quantify yield. Pn and gs were significantly reduced by drought in all varieties. As regards membrane integrity ancient and traditional varieties presented lower membrane injury, what may reflect a higher protoplasmic tolerance to drought. More evolved varieties (modern and advanced) showed higher spike weight per plant and number of grains per spike, disregard the water regime. Under water deficit 1000 kernel weight was reduced in all varieties except in traditional Pirana, which also showed an increase in the number of spikes per plant. Higher membrane stability, increased pigments and lower osmotic potential under drought may underly such improved response to drought, pointing this variety as an interesting genetic resource for breeding purposes.

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