Modeling growth and development of hydroponically grown dill, parsley, and watercress in response to photosynthetic daily light integral and mean daily temperature

In controlled environments, crop models that incorporate environmental factors can be developed to optimize growth and development as well as conduct cost and/or resource use benefit analyses. The overall objective of this study was to model growth and development of dill ‘Bouquet’ (Anethum graveolens), parsley ‘Giant of Italy’ (Petroselinum crispum), and watercress (Nasturtium officinale) in response to photosynthetic daily light integral (DLI) and mean daily temperature (MDT). Plants were grown hydroponically in five greenhouse compartments with MDTs ranging from 9.7 to 27.2 °C under 0%, 30%, or 50% shade cloth to create DLIs ranging from 6.2 to 16.9 mol·m^‒2·d^‒1. MDT and DLI interacted to influence dill fresh mass and height, and watercress maximum quantum yield of dark adapted leaves (F_v/F_m), height, and branch number while only MDT affected dill leaf number and watercress fresh mass and branch length. Besides dry matter concentration (DMC), parsley was influenced by MDT and not DLI. Increasing MDT from ≈10 to 22.4 °C (parsley) or 27.2 °C (dill and watercress), linearly or near-linearly increased fresh mass. For dill, increasing DLI decreased fresh mass when MDT was low (9.7 to 13.9 °C) and increased fresh mass when MDT was high (18.4 to 27.2 °C). DMC of dill, parsley, and watercress increased as MDT decreased or DLI increased, indicating a higher proportion of plant fresh mass is water at higher MDTs or lower DLIs. With these data we have created growth and development models for culinary herbs to aid in predicting responses to DLI and MDT.

Irrigation dose and plant density affect the volatile composition and sensory quality of dill (Anethum graveolens L.)

BACKGROUND

Two independent field experiments were carried out to investigate the influence of (i) three irrigation treatments (ID0 = 1585 m³ ha^-1 , considered as a control; ID1 = 1015 m³ ha^-1 ; and ID2 = 2180 m³ ha^-1 ) and (ii) three plant density treatments (PD0 = 5.56 plants m^-2 , considered as a control; PD1 = 4.44 plants m^-2 ; and PD2 = 7.41 plants m^-2 ) on the production, volatile composition of essential oil, and sensory quality of dill.

RESULTS

The highest plant yield was obtained with intermediate conditions of both irrigation dose (ID0) and plant density (PD0). The main compounds of the essential oil were α-phellandrene, dill ether and β-phellandrene. The highest irrigation dose (ID2) produced the highest concentrations of most of the main compounds: α-phellandrene (49.5 mg per 100 g), β-phellandrene (6.89 mg per 100 g) and limonene (2.49 mg per 100 g). A similar pattern was found for the highest plant density (PD2): α-phellandrene (71.0 mg per 100 g), dill ether (16.7 mg per 100 g) and β-phellandrene (9.70 mg per 100 g). The use of descriptive sensory analysis helped in reaching a final decision, and the dill plants with the highest sensory quality were those of the ID2 and PD0 treatments.

CONCLUSION

The final recommendation is to use the irrigation dose ID2 and the plant density PD2 if the objective is to produce dill samples with the highest aromatic and sensory quality; however, if the only objective is to produce high amounts of dill, the best options are ID0 and PD0. © 2016 Society of Chemical Industry.

Phytochemical contents and enzyme inhibitory and antioxidant properties of Anethum graveolens L. (dill) samples cultivated under organic and conventional agricultural conditions

Inhibitory effect of the n-hexane, dichloromethane, ethyl acetate, and ethanol extracts from Anethum graveolens L. (dill) cultivated under organic (AG-O) and conventional (AG-C) conditions was tested against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase at 200 μg mL⁻¹. Their antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), N,N-dimethyl-p-phenylendiamine (DMPD), and nitric oxide (NO) radical scavenging assays as well as ferric ion-chelation capacity, ferric-(FRAP), and phosphomolybdenum-reducing antioxidant power (PRAP). The phytochemical analyses have been performed on both of the plant samples. GC-MS analysis pointed out that α-phellandrene was the main component in both of the essential oils in varying amounts (47.75% for AG-O and 27.94% for AG-C), while oleic acid was the dominant in the fruit oils of two samples (36.39% for AG-O and 53.87% for AG-C). HPLC analysis showed that both of the extracts contained rosmarinic acid as the major phenolic acid. The extracts inhibited BChE at moderate level, while the ethanol extracts exerted remarkable NO scavenging effect. The results emphasize that cultivation conditions may have effect on bioactivity and phytochemical content on plant samples.

Mycotoxicogenic fungal inhibition by innovative cheese cover with aromatic plants

BACKGROUND

The use of aromatic plants and their extracts with antimicrobial properties may be compromised in the case of cheese, as some type of fungal starter is needed during its production. Penicillium verrucosum is considered a common cheese spoiler. The aim of this study was to evaluate the innovative use of certain aromatic plants as natural cheese covers in order to prevent mycotoxicogenic fungal growth (P. verrucosum). A collection of 12 essential oils (EOs) was obtained from various aromatic plants by solvent-free microwave extraction technology, and volatile characterisation of the EOs was carried out by gas chromatography/mass spectrometry.

RESULTS

The most effective EOs against P. verrucosum were obtained from Anethum graveolens, Hyssopus officinalis and Chamaemelum nobile, yielding 50% inhibition of fungal growth at concentration values lower than 0.02 µL mL⁻¹. All EOs showed high volatile heterogeneity, with α-phellandrene, pinocamphone, isopinocamphone, α-pinene, camphene, 1,8-cineole, carvacrol and trans-anethole being found to be statistically significant in the antifungal model.

CONCLUSION

The use of these aromatic plants as natural covers on cheese can satisfactorily inhibit the growth of some mycotoxicogenic fungal spoilers. Among the volatile compounds present, α- and β-phellandrene were confirmed as the most relevant in the inhibition.

The effect of floral resources on parasitoid and host longevity: prospects for conservation biological control in strawberries

The strawberry tortricid, Acleris comariana Lienig and Zeller (Lepidoptera: Tortricidae) is an important pest in Danish strawberry production. Its most common parasitoid is Copidosoma aretas (Walker) (Hymenoptera: Chalcidoidea: Encyrtidae). To identify selective flowering plants that could be used to increase functional biodiversity, the longevity of C. aretas and its host A. comariana was assessed on 5 flowering species: buckwheat, Fagopyrum esculentum Moench (Caryophyllales: Polygonaceae); borage, Borago officinalis L. (Boraginaceae); strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae); phacelia, Phacelia tanacetifolia Bentham (Boraginaceae); and dill, Anethum graveolens L. (Apiales: Apiaceae). Dill was only tested with C. aretas. Sucrose and pollen served as positive controls, and pure water as a negative control. In a subsequent field experiment, A. comariana larval density was assessed at 1, 6, and 11 m distances from buckwheat flower strips in 3 fields. The proportion of field-collected larvae that were parasitized by C. aretas or fungi was assessed. Among the tested floral diets, buckwheat was superior for C. aretas, increasing its longevity by 1.4 times compared to water. Although buckwheat also increased longevity of A. comariana, its longevity and survival on buckwheat, borage, and strawberry was not significantly different, so buckwheat was chosen for field experiments. A. comariana densities in the 3 fields with sown buckwheat flower strips were 0.5, 4.0, and 8.3 larvae per m per row of strawberry respectively. Of the collected larvae, a total of 1%, 39%, and 65% were parasitized by C. aretas, respectively. The density of A. comariana and the proportion parasitized by C. aretas were highly significantly correlated. Distance from floral strips had no significant effect on either A. comariana larval density or on the proportion of individuals parasitized by C. aretas. Few other parasitoids emerged from collected larvae, and no larvae were infected by entomopathogenic fungi. Still, total A. comariana mortality was significantly affected by distance to flower strips, with the highest mortality near the flower strips. As no effect of buckwheat flower strips on C. aretas parasitism was found, the positive effect they had on A. comariana control stems from unknown mortality factors. As literature indicates that buckwheat for flower strips can augment a more complex suite of natural enemies, one such mortality factor could be a non-consumptive predator and/or parasitoid effect, but this requires further study. If confirmed, buckwheat may be utilized together with a selective food plant, once identified.

Application of high-Cu compost to dill and peppermint

A controlled environment experiment was conducted to determine the effect of amending soil with various rates of high-Cu compost (0, 20, 40, and 60% compost/soil by volume) on dill (Anethum graveolens L.) and peppermint (Mentha X piperita L.) yields, on fractionation of Cu and Zn in soils, on elemental composition of soil and tissue, and on the essential oils. The compost contained about 2000 mg kg(-)(1) of Cu. Dill yields were greatest in the 20 or 40% treatments, but peppermint yields were greatest in the 20% treatment. Compost additions increased soil pH and electrical conductivity (EC), HNO(3) extractable soil B, Ca, K, Mg, Mn, P, S, Na, and Pb. Additions of high-Cu compost to soil increased tissue P, S, and Na in both crops and Mn, Mo, and Zn in dill but decreased tissue Ca, Cd, and Fe in both crops and Mn, Mo, and Zn in peppermint, increased Cu in all soil fractions including exchangeable, and increased tissue Cu of dill and peppermint as compared to unamended soil. Addition of 60% of high-Cu compost to soil resulted in 760-780 mg kg(-)(1) Cu in the growth medium. Nevertheless, Cu content in both crops reached only 12 mg kg(-)(1) DW in the 60% compost treatment, which is below the toxicity levels for plants and below the upper chronic dietary exposure for animals. The application of high-Cu compost altered chemical composition of dill and peppermint essential oils, but oils were free of Cu, Zn, Cd, Ni, Cr, and Pb. Results from this study suggest that mature composts with concentrations of Cu and Zn of 2008 and 321 mg/kg, respectively, can be used as a soil conditioner without risk for phytotoxicity or risk of increasing the normal range of Cu and Zn in crop tissue. However, the long-term effect of the accumulation of heavy metals in soils following repeated compost applications needs to be carefully considered.

Influence of orbital flight conditions on formation of genitals in Muscari racemosum and Anethum graveolens

It was shown that under space flight conditions development of male genitals in Muscari racemosum is accelerated compared to that of laboratory and natural field controls. Conditions of space flight produced an inhibitory effect on germination and germinative energy of Anethum graveolens seeds. The first stages of the plant development, right up to the flowering stage, also suffered from the inhibitory influence of space flight conditions. A cytoembryological study of the experiment and control plants found no essential differences between them.