Sap flow of sweet cherry reveals distinct effects of humidity and wind under rain covered and netted protected cropping systems

Protected cropping systems (PCS) alter the plant growing environment, though understanding of this in ventilated systems and how the new climate affects tree water uptake is limited. Sap flow sensors and weather stations were deployed in 16-year-old 'Lapins' on 'Colt' rootstock cherry trees under a ventilated Voen PCS and in an adjacent bird netted PCS. Average and maximum temperatures were consistently higher (14.7 °C and 22.9 °C) while total daily solar radiation and average wind were consistently lower (12.9 MJ/m2 and 0.2 m/s) in rain covered, in contrast to netted, PCS (13.9 °C, 21.3 °C, 13.7 MJ/m2 and 0.9 m/s). Over the season, a threefold lower daily sap flow rate was observed under rain covered PCS. Using generalised additive modelling (GAM), the influence of individual climate parameters on sap flow were predicted. Whilst sap flow was only slightly affected by relative humidity (RH) less than 60%, above this threshold sap flow rapidly declined under rain covered PCS whereas sap flow more gradually declined above 20% RH under netted PCS. Overall, our novel modelling approach led to the discovery of the 60% RH critical threshold on predicted sap flow and the indirect effect that wind speeds have on sap flow under PCS.

'Atypical Ugi' tetrazoles

Amino acid-derived isocyano amides together with TMSN3, oxocomponents and 1° or 2° amines are common substrates in the Ugi tetrazole reaction. We surprisingly found that combining these substrates gives two different constitutional isomeric Ugi products A and B. A is the expected classical Ugi product whereas B is an isomeric product ('atypical Ugi') of the same molecular weight with the tetrazole heterocycle migrated to a different position. We synthesized, separated and characterized 22 different isomorphic examples of the two constitutional isomers of the Ugi reaction to unambiguously prove the formation of A and B. Mechanistic studies resulted in a proposed mechanism for the concomitant formation of A and B.

Relationship between viticultural climatic indices and grape maturity in Australia

Historical temperature data and maturity records were analyzed for 45 vineyard blocks in 15 winegrowing regions across Australia in order to evaluate the suitability of common viticultural indices to estimate date of grape maturity. Five temperature-based viticultural indices (mean January temperature, mean growing season temperature, growing degree days, biologically effective degree days, Huglin Index) along with four springtime temperature indices (mean and maximum temperature summations for September, October, and November; growing degree days and biologically effective degree days modified to include September) were compared to maturity data in order to investigate index relationship to observed maturity timing. Daily heat summations for the months of September, October, and November showed the best correlation to day of year of maturity, suggesting that springtime temperatures are important relative to the timing of grape maturity. Mean January temperature, a commonly used index, had the poorest correlation with day of year of maturity of all the indices included in this study. Indices that included the month of April had poorer correlation than indices that shifted the months included in the growing season to be from September to March inclusive. Calculated index values for the past 30 years for every region included in this study showed increasing temporal trends to various degrees, indicating that all regions studied are experiencing warming temperatures during the growing season. These results emphasize the need to reevaluate viticultural indices in the context of a changing climate.

Towards a better understanding of crop water requirement in orchards: a case study from the Goulburn Valley

Responses of fruit trees to reduced irrigation in micro-irrigated peach and apple orchards in the Goulburn Valley, Victoria were investigated during the 2000–01 season. Field experiments examined the effects of applying 2 irrigation levels on soil water content, crop water relations, vegetative growth, yield, yield components and fruit quality. Irrigation regimes were 50% and 100% of current management practice where inputs are scheduled from pan evaporation and locally derived crop coefficients. Water was applied to only one side of the tree rootzone in the 50% treatment (0.5I) while the current management practice treatment (1.0I), received water on both sides of the tree. Over the season, the irrigation inputs for peach and apple equated to a crop coefficient of 0.93 and 0.87, respectively. Orchard water use (ETpeach and ETapple) was predicted using reference crop evapotranspiration (ET0) and published crop coefficients (Kc) with adjustment for the fraction of shade cast by the trees on the orchard floor at solar noon (effective canopy cover, ECC). Throughout the season, ECC measured as midday tree canopy radiation interception, remained low for both peach and apple (<35%). ETpeach and ETapple were substantially lower than current water scheduling practices (1.0I treatments). For the 0.5I apple regime, irrigation closely matched ETapple suggesting that these trees were adequately irrigated. This was supported by no detrimental effects on crop production, vegetative growth, and fruit quality measures of the 0.5I irrigation regime. However, in the peach orchard the 0.5I regime reduced fruit volume suggesting that these trees may have been water stressed. Based on ECC, we calculated the full crop water requirement Kc for the peach and apple orchards to be 0.42 and 0.37, respectively. In summary, for the apple orchard, our 0.5I treatment was close to predicted full crop water requirement (ETapple). But for the peach orchard, the ETpeach was greater, albeit slightly, than our 0.5I regime. Taken overall, these results demonstrate that better matching of water application to the evaporative surface of the orchard canopies (i.e. ECC) can substantially reduce irrigation water use in Goulburn Valley orchards. It is also apparent that ECC in these orchards where row spacing is typically 4–5 m can be relatively low.

The effect of valvular heart disease on maternal and fetal outcome of pregnancy

OBJECTIVES

The aim of this study was to evaluate the association between valvular heart disease (VHD) and maternal and fetal outcome in a relatively large group of patients by a comparison to a well-matched control group.

BACKGROUND

Available information regarding outcome of pregnancy in women with VHD is limited to either anecdotal reports or small series of patients without an appropriate control. A better understanding of the effects of valvular abnormalities on pregnancy outcome is of value for risk assessment and the design of a therapeutic plan.

METHODS

A retrospective evaluation was made of 66 pregnancies in 64 women with VHD cared for at a tertian-care center with a high-risk obstetrics/cardiology clinic and 66 individually selected normal pregnant women matched in age, ethnicity, obstetrical and medical history, time of initial prenatal care, and year of pregnancy.

RESULTS

Women with VHD had a significantly higher incidence of congestive heart failure (38% vs. 0%; p < 0.00001), arrhvthmias (15% vs. 0%, p = 0.002), initiation or increase of cardiac medications (41% vs. 2%, p < 0.0001), and hospitalizations (35% vs. 2%, p < 0.0001). Mortality, however, occurred in only one patient (2% vs. 0%, p = NS) with aortic stenosis (AS) and coarctation. Moreover, VHD also had an effect on fetal outcome, resulting in an increased preterm delivery (23% vs. 6%, p = 0.03), intrauterine growth retardation (21% vs. 0%, p < 0.0001), and a reduced birth weight (2,897 +/- 838 g vs. 3,366 +/- 515 g, p = 0.0003). Increased maternal morbidity and unfavorable fetal outcome were seen mostly in patients with moderate and severe mitral stenosis (MS) and AS.

CONCLUSIONS

Pregnancy in women with MS and AS is associated with marked increase in maternal morbidity and unfavorable effect on fetal outcome, which are related to severity of disease. Despite high maternal morbidity, mortality is rare.

The Preparation and Acetolyses of 5-Deuteriated exo-2-Norbornyl-p-bromobenzenesulfonates

The deuterionorborneols 2a, b, c, and e have been prepared and converted to the brosylates 1a, b, c, and e. The deuterium isotope effects determined spectrophotometrically for solvolysis in HOAc–KOAc are 1.00 ± 0.01, 1.01 ± 0.01, 0.99 ± 0.01, and 1.11 ± 0.01, respectively. These data establish that: (a) a steric deuterium isotope effect does not operate at C-5 and therefore probably not at C-6; (b) hyperconjugative stabilization of the norbornonium ion to the C-5 hydrogens is confirmed to be not important, and (c) provides the first experimental evidence that the hydrogen (deuterium) shift – internal return pathway contribution to the γ-deuterium isotope effects observed for 1d and e is minor.