Internal conductance under different light conditions along the plant profile of Ethiopian mustard (Brassica carinata A. Brown.)

This study focused on the internal conductance (g i ) along the plant profile of Ethiopian mustard under two light conditions: (i) light from the top only (I1); (ii) light from the top integrated by supplementary lateral light along the whole plant profile (I2). Lateral light strongly increased the productivity (e.g. +104% of seed oil) and net photosynthesis (A). The latter appeared more driven by g i (r=0.78 ** ) than by stomatal conductance (g s ) (r=0.51 * ). Importantly, irradiance also considerably shortened the time from leaf appearance to senescence, which means that corresponding leaves in I1 and I2 had different ages. Therefore, since leaf age and irradiance have counteracting effects on g i , I1 sometimes showed higher g i values than I2. With respect to irradiance, leaf age had clearly higher effects on g i , which radically declined from the top to the basal leaves, even under constant light conditions. The internal conductance caused a significant drawdown of CO 2 from the sub-stomatal cavity (C i ) to the site of carboxylation (C c ) that, in turn, led to a substantial underestimation of V cmax calculated using the A/C i model. Again, the trends of g i and g s were not consistent along the plant profile, and so the ratio between stomatal and internal limitations to A changed from top to bottom leaves, accordingly. This study suggests that g i may be a valuable trait for increasing photosynthetic capacity and productivity; nonetheless, it suggests caution in selecting leaves for high g i , as the latter can considerably change along the plant profile due to leaf age and irradiance effects

A Prognostic Model to Predict Ruxolitinib Discontinuation and Death in Patients with Myelofibrosis

Most patients with myelofibrosis (MF) discontinue ruxolitinib (JAK1/JAK2 inhibitor) in the first 5 years of therapy due to therapy failure. As the therapeutic possibilities of MF are expanding, it is critical to identify patients predisposed to early ruxolitinib monotherapy failure and worse outcomes. We investigated predictors of early ruxolitinib discontinuation and death on therapy in 889 patients included in the "RUX-MF" retrospective study. Overall, 172 patients were alive on ruxolitinib after ≥5 years (long-term ruxolitinib, LTR), 115 patients were alive but off ruxolitinib after ≥5 yrs (short-term RUX, STR), and 123 patients died while on ruxolitinib after <5 yrs (early death on ruxolitinib, EDR). The cumulative incidence of the blast phase was similar in LTR and STR patients (p = 0.08). Overall survival (OS) was significantly longer in LTR pts (p = 0.002). In multivariate analysis, PLT < 100 × 109/L, Hb < 10 g/dL, primary MF, absence of spleen response at 3 months and ruxolitinib starting dose <10 mg BID were associated with higher probability of STR. Assigning one point to each significant variable, a prognostic model for STR (STR-PM) was built, and three groups were identified: low (score 0-1), intermediate (score 2), and high risk (score ≥ 3). The STR-PM may identify patients at higher risk of failure with ruxolitinib monotherapy who should be considered for alternative frontline strategies

Ruxolitinib in cytopenic myelofibrosis: Response, toxicity, drug discontinuation, and outcome

Background: Patients with cytopenic myelofibrosis (MF) have more limited therapeutic options and poorer prognoses compared with patients with the myeloproliferative phenotype. Aims and methods: Prognostic correlates of cytopenic phenotype were explored in 886 ruxolitinib-treated patients with primary/secondary MF (PMF/SMF) included in the RUX-MF retrospective study. Cytopenia was defined as: leukocyte count <4 × 109 /L and/or hemoglobin <11/<10 g/dL (males/females) and/or platelets <100 × 109 /L. Results: Overall, 407 (45.9%) patients had a cytopenic MF, including 249 (52.4%) with PMF. In multivariable analysis, high molecular risk mutations (p = .04), intermediate 2/high Dynamic International Prognostic Score System (p < .001) and intermediate 2/high Myelofibrosis Secondary to Polycythemia Vera and Essential Thrombocythemia Prognostic Model (p < .001) remained associated with cytopenic MF in the overall cohort, PMF, and SMF, respectively. Patients with cytopenia received lower average ruxolitinib at the starting (25.2 mg/day vs. 30.2 mg/day, p < .001) and overall doses (23.6 mg/day vs. 26.8 mg/day, p < .001) and achieved lower rates of spleen (26.5% vs. 34.1%, p = .04) and symptom (59.8% vs. 68.8%, p = .008) responses at 6 months compared with patients with the proliferative phenotype. Patients with cytopenia also had higher rates of thrombocytopenia at 3 months (31.1% vs. 18.8%, p < .001) but lower rates of anemia (65.6% vs. 57.7%, p = .02 at 3 months and 56.6% vs. 23.9% at 6 months, p < .001). After competing risk analysis, the cumulative incidence of ruxolitinib discontinuation at 5 years was 57% and 38% in patients with cytopenia and the proliferative phenotype (p < .001), whereas cumulative incidence of leukemic transformation was similar (p = .06). In Cox regression analysis adjusted for Dynamic International Prognostic Score System score, survival was significantly shorter in patients with cytopenia (p < .001). Conclusions: Cytopenic MF has a lower probability of therapeutic success with ruxolitinib as monotherapy and worse outcome. These patients should be considered for alternative therapeutic strategies

A simple method to improve the estimation of the relationship between rainfall and crop yield

The time-course of rainfall is commonly presented as bar, line or scatter plots, which may sometimes be chaotic, while leading to subjective and vague assertions. More objective criteria quantifying rainfall distribution may therefore be helpful, e.g. when different years are examined concurrently. Here, some practical indices are presented based on the distance between cumulative rainfall curves and the respective theoretical evenness rainfall lines, the line joining the lowest and highest cumulative rainfall values within the considered period. After an introduction to the theory and calculation of the indices, the relationships between the indices and two major crops, maize and sugar beet, are evaluated for a period of 33 years. The results show good correlations between the indices and crop yields, up to r = 0.81, especially when the evenness index was weighted on the mean daily rainfall, i.e. the slope of the evenness line. Significant correlations were also found by recalculating the indices over strategic short-term periods for maize, which indicates how the effectiveness of these indices may be increased by choosing appropriate periods for different crops. Finally, the different indices showed no correlation, indicating little redundancy and thus suggesting a profitable conjoint use of them

Interaction between agronomic and mechanical factors for fiber crops harvesting: italian results. Note II: Hemp.

This paper considers the first steps in some of the production chains of hemp. Effects of agronomic techniques (such as crop density, sowing and harvesting period, and variety) are evaluated. Their influence on biometric characteristics of the crops is studied on the basis of harvesting and first transformation machines. Effects of the interaction between agronomic techniques and machines are considered with respect to the qualitative and quantitative characteristics of the product obtained

Evaluation of productivity of 18 genotypes of switchgrass for energy destination in northern Italy

Switchgrass (Panicum virgatum, L.) is a perennial herbaceous energy crop that could be cultivated on a wide variety of sites. To introduce switchgrass in the EU agriculture and convert it into specific energy products the crop needs to be environmentally acceptable and economically sustainable for farmers. For that reason high biomass yields are essential. Moreover the biomass quality needs to be suitable for the energy plants, i.e. with a very low humidity and ash content at harvest. A good strategy to introduce switchgrass is to identify the most promising varieties considering different site and climatic conditions. With reference to the habitat preferences, morphological features, ploidy level, and molecular markers, switchgrass ecotypes are clustered into two types: “lowlands” and “uplands”. Lowland switchgrass ecotypes are generally more productive but also less resistant to low temperature. Upland ecotypes may have a stronger early vigor and a shorter cycle than lowland types. Since the highest yield varieties should be preferred for the energy destination lowland types may be favored when the winter frost is not too hard. Anyway considering the farmers activity and the possibility to make more than one moving for year it may be a good alternative to establish both types and move them early or late in the season. Moreover this may cover a larger harvest window with more advantages for the energy plants

Effects of Plant Density, Seeding and Harvest Time on the Growth of Two Kenaf (Hibiscus Cannabinus L.) Varieties

Kenaf is an annual C3 multipurpose crop for the fibre and energy industry, whose growth has been widely investigated in the tropics, but not at relatively-high latitudes. This work aimed at evaluating the effects of two genotypes (Tainung 2 and Everglades 41), two plant densities (20 and 40 plants m-2), two seeding times (S1 and S2) and two harvest times (H1 and H2) on growth and its relations with climatic factors over three years (2003-2005) in Northern Italy (c. 45° N). Fitting curves for whole-plant dry biomass (DB) and dry stems (DS) on heat sums always gave a reliable description of the growth pattern along the season, explaining over 90% of the total variation. In general, the best-fitting models were the sigmoid and the exponential one for DB and DS, respectively. Among the four studied factors, only seeding time originated consistent growth differences among years, whereas the two varieties showed an equivalent behaviour, as well as the two densities. Furthermore, the thinner density allowed savings in the cost of seed at no prejudice for yield potential. S1 in general showed higher asymptotic yields than S2 in 2003 and 2004, while S2 consistently grew faster than S1 in all the three years. RUE showed a generally low value (e.g., 1.35 g MJ-1 for DB in S1), indicating a moisture constraint on crop growth, especially in the first year. As for the correlations, three traits, plant height, base stem diameter and fresh biomass, resulted significantly associated to DB and DS, with correlation coefficients (r) ranging from 0.65 to 0.90; a higher degree of association with DB and DS was achieved by the multiple linear regressions of the same three traits (adj. R2 of about 0.85). A high dependence of DB and especially of DS on associated heat and rain (adj. R2 0.76 and 0.86, respectively) was also observed in the variable environmental conditions among the three years, which attributes a non-negligible power of prediction to the two environmental parameters. These results offer the opportunity of estimating growth through the measure of non-destructive crop variables of easier assessment, and encourages their adoption, in association with that of simple climatic factors (temperatures, precipitation) as tools of potential support to facilitate biomass assessments in commercial fields

Comparing application methods for N-fertilizer in the sugar beet crop

Sugar beet seeders have been developed in other countries, in order to place nitrogen into the soil at a few centimeters from the seed. Placing fertilizer has proved safe for seedling emergence, successful in reducing soil residual nitrogen at harvest, sometimes even better-yielding than broadcast applications. In a 3-year research on sugar beet, spreading fertilizer on the soil surface followed by incorporation was compared with placing in rows 6 and 3 cm far from the seed ones, slightly deeper than the seed, in combination with two rates of urea-N, 60 and 120 kg ha-1, plus an unfertilized check. The course of soil mineral nitrogen and that of N-uptake were evaluated during crop cycle. Yield and quality were evaluated at harvest. Nitrogen placement close to the seed (3 cm) negatively affected crop emergence. In the plant-soil system, placement showed a higher soil N-content in the first phases and a lower plant uptake at harvest. As for yield, placement attained a slightly-lower level than broadcasting at 60 kg N ha-1 of N, almost the same at 120. No significant difference in quality was observed between the two patterns. At a certain distance from the seed, placement proved a safe way of applying fertilizer. Its yield and quality, the uptake by the plant and the amount of soil residual-N are comparable with those of broadcast fertilizer; in the case of soil nitrogen, it is perceived that the year/location effect is potentially stronger than that of rate/pattern of application

Sweet and fibre sorghum (Sorghum bicolor (L.) Moench), energy crops in the frame of environmental protection from excessive nitrogen loads

Sweet and fibre sorghum (Sorghum bicolor (L.) Moench) are multipurpose cereals of potential interest for several non-food uses. In order to assess the effects of nitrogen (N) fertilization on crop growth, yield and N budget during crop cycle, field trials were carried out in Northern Italy (44°33’N, 11°21’E) in the years 1997 to 1999. Sweet and fibre sorghum were grown in combination with three N rates (0, 60, 120 kg ha-1). Both crops depicted a sigmoidal growth-pattern, but fibre sorghum showed an earlier and steeper growth. Sweet sorghum recovered due to a longer cycle, 118 vs. 105 days in the three years’ average, and attained a similar final yield. Nitrogen fertilization did not affect growth pattern, nor yield partitioning among plant organs: the sweet type allocated more photosynthates to stems (about 75% of total dry weight) compared to the fibre one (55-60%), due to a limited partitioning to panicles. Total dry weight at harvest showed an interaction with years: fibre sorghum yielded significantly more than sweet sorghum in 1997 (23.8 vs. 17.7 Mg ha-1), but the opposite happened in 1998 and 1999 (20 vs. 24.2 Mg ha-1 as average), when a different sweet hybrid was grown, involving a longer season. When only the stem was considered of potential interest, such as in the case of ethanol production or fibre extraction, fibre sorghum showed a slight advantage in the first year (14.4 vs. 12 Mg ha-1), whereas the sweet type prevailed in the following two years (18.7 vs. 11 Mg ha-1). Fertilization did not significantly influence total yield, although interacted with sorghum type in plant N concentration and uptake: fibre sorghum rose in both parameters, due to bulkier panicles acting as a late-season sink for the nutrient, while the sweet type was not affected. Nitrogen budget at harvest was clearly influenced by applied fertilizer and plant uptake, whereas nutrient losses as ammonia volatilization and nitrate leaching and natural supplies along with precipitation played a less relevant role. The expected variations in soil reserves ranged between -216 and +77 kg ha-1 of N, depending also on the plant portion removed from the field (whole plant or stem). A slight decrease in soil reserves, more favourable in environmental terms, is achieved when the whole biomass is removed from the field and when fertilizer rates are tight-suited to crop needs in specific growth conditions