Francisca Santiveri

Patterns of grain filling of spring and winter hexaploid triticales

Abstract Eight hexaploid triticale genotypes, five of spring and three of winter growth habit were used to study the genetic variability of grain filling characteristics and their relationship with grain yield. Four trials were carried out under rainfed and irrigated conditions in Northeast Spain. Grain dry weight data was fitted to a logistic curve. Genetic variability existed for the length of the period from sowing to anthesis, maximum grain filling rate and maximum grain weight. Most of this variation was associated to the growth-habit of the genotypes. Winter triticales required 11% more thermal-time from sowing to anthesis, and had a maximum grain weight, which was 25% lower than that of spring genotypes. The maximum grain filling rate was 40% higher in spring than in winter triticales. Grain filling duration was mainly controlled by environmental conditions, and was not correlated with grain yield. A negative phenotypic correlation was detected between grain filling duration and maximum grain filling rate (rp=−0.41, P

Growth and yield responses of spring and winter triticale cultivated under Mediterranean conditions

Eight hexaploid triticale genotypes, five of spring and three of winter growth habit were used to study biomass production, contribution of the pre-anthesis assimilates to the grain yield, and their relationship to grain yield. Genetic effects for biomass production were found at anthesis but not at maturity. Growth-habit explained most of the detected differences for biomass production: winter triticale had around 15% higher dry matter than spring triticale at anthesis. However, the higher accumulated thermal time from sowing to anthesis could explain the observed differences, since the correlation coefficient between both variables was 0.78 (P<0.001, n=24). Dry matter translocation (DMT) was 30% higher for winter than for spring triticales, representing a contribution to the grain yield of 60.9% for winter genotypes and 42.0% for spring ones. However, grains were 26.8% heavier in spring than in winter triticales, and, finally, spring triticales yielded around 21% more than winter types. For spring genotypes, crop dry weight at anthesis was positively related to yield, whereas for winter triticales the relationship for these two variables was negative. Highest values of triticale grain yield were reached when time from sowing to anthesis was comprised, approximately, between 1350 and 1420 growing degree-days (GDD), decreasing before and after this interval. Thus, time to anthesis for spring triticales were included into the optimum interval, which permitted to reach higher grain yield. We could conclude that spring triticales are much more adapted than winter triticales for grain production under Mediterranean conditions.

Hemp and Flax Biomass and Fiber Production and Linseed Yield in Irrigated Mediterranean Conditions

Abstract Field trials were conducted in the irrigated areas of the Ebro valley, one of the most important irrigated areas in Spain, in order to study the feasibility of flax and hemp as possible alternative crops. Field experiments were established in 2000 and 2001, and three varieties of hemp and five of flax (two fiber types and three oilseed types) were compared under irrigation. Stem dry matter yields for hemp averaged 9,118 kg ha−1 and 7,635 kg ha−1, with average bark contents of 32.2% and 22.5%, in 2000 and 2001, respectively. Straw yields and bark contents for flax averaged 4,790 and 4,259 kg ha−1 and 27.0 and 20.1%, in 2000 and 2001, respectively, whereas average linseed yields were of 1,741 and 468 kg ha−1, in 2000 and in 2001, respectively. The results suggest that in the irrigated conditions of the Ebro valley hemp seems a more appropriate crop than flax for the pulp paper industry, although in order to obtain higher yields earlier sowing and longer cycle varieties should be studied.