•Tomato yield had a positive linear correlation with seasonal evapotranspiration while the quality had an opposite trend.•Tomato fruit quality is mainly affected by water stress during fruit ...ripening.•Quantitative relationship between tomato yield, fruit quality and water deficit is helpful in tomato irrigation scheduling making.
Deficit irrigation is widely used in tomato production because of water shortage. Many studies indicate that tomato yield is reduced but the fruit quality is improved under certain degree of water deficit. In order to investigate the quantitative relationship between tomato yield, fruit quality and water deficit, two experiments with different irrigation treatments were conducted in solar greenhouse in an arid region of northwest China from winter in 2008 to spring in 2009 (2008–2009 season) and from winter in 2009 to spring in 2010 (2009–2010 season). Results showed that the application of 1/3 (T1) and 2/3 (T2) of full irrigation at seedling stage (Stage I) did not significantly influence greenhouse tomato water consumption, total yield and fruit quality. Tomato water consumption and total yield were decreased by the application of 1/3 (T3) of full irrigation at flowering and fruit development stage (Stage II), and 1/3 (T5) or 2/3 (T6) of full irrigation at fruit maturation stage (Stage III). But the fruit contents of total soluble solids (TSS), reducing sugars (RS), organic acids (OA) and vitamin C (VC) as well as fruit firmness (Fn), sugar/acid content ratio (SAR), color index (CI) and water use efficiency (WUE) were significantly increased. However, no significant effects were found on tomato yield and fruit quality in the application of 2/3 full irrigation at Stage II (T4). The relative yield (Y/YCK) had a significant positive correlation with relative seasonal evapotranspiration (ET/ETCK), while negative correlations were found between the relative values of fruit quality parameters and ET/ETCK. Tomato yield is sensitive to water deficit during Stage II and Stage III, but fruit quality is mainly affected by water stress during Stage III. The regression equations between tomato yield, fruit quality parameters and ET could provide important basis for making irrigation strategies with the compromise between tomato yield and fruit quality
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•Imperceptible physical damage reduces the quality of tomatoes.•Compressed tomatoes had their ethylene production increased.•Compressed tomatoes had their color development ...delayed.•Oxylipin pathway enzymes activity was transiently affected.•Emission of volatile compounds linked to sweet and fruity notes were reduced.
Improper postharvest handling often impairs horticultural quality even when damage is visually imperceptible. In this study, tomato fruit were subjected to controlled compressive forces (196.13 N) and the effects of this mechanical damage were evaluated. The following parameters were assessed: production of CO2, ethylene (C2H4), color, enzymatic activity (LOX, HPL and ADH) and volatile compounds. Ethylene production increased in tomatoes subjected to compression. Damaged tomatoes were unable to develop the typical red color when compared to the control fruit and showed a transient increase in the activity of the enzymes LOX, HPL and ADH. The imperceptible damage applied to tomatoes modified the profile of volatile compounds produced by the fruit, reducing the emission of compounds perceived as fruity and sweet.
Four pilot-scale conductive dryers, namely a vacuum drum dryer (VDD), a drum dryer (DD), an agitated thin film dryer (ATFD) and a refractance window dryer (RWD), were used to dry tomato puree. Drying ...induced colour differences between the reconstituted puree and the original puree and strongly affected the volatile and non-volatile profiles of the powders. Principal component analysis (PCA) identified four separated groups corresponding to the different drying methods, indicating that the drying methods caused significant variance in compound profiles. Subsequently, pairwise comparison of different dried powders was performed by partial least square discriminant analysis (PLS-DA). This resulted in a selection of discriminative volatile and non-volatile markers. RWD and VDD produced powders with high volatile markers that may be related to aroma retention. Conversely, DD dried products contained more non-volatile markers that can be related to taste perception. ATFD processed powders had a lower level of discriminant compounds.
Tomato products are frequently thermally processed and dehydrated. However, processing negatively affects the sensory quality of tomato products. In this study, four conductive drying processes, i.e. vacuum drum drying (VDD), drum drying (DD), agitated thin film drying (ATFD) and refractance window drying (RWD) were studied for being energy-efficient drying methods, while suitable for mild (e.g. due to the reduced pressure) drying of pastes and slurries, such as tomato puree. The pilot-scale drying experiments and subsequent statistical analyses of results on quality markers contributed to unravel the impact of the different conductive drying technologies on tomato powder quality. This study may be considered a starting point for selection of conductive drying technologies for the efficient production of high quality tomato powders and other vegetable powders.
•Statistical comparison revealed variance in quality of conductively dried tomato purees.•Conductive drying technologies induced colour changes of reconstituted tomato purees.•Technologies showed distinct variance in (non-)volatile profiles.•Refractance window drying and vacuum drum drying led to more volatile retention.•Tomato powders dried by drum drying contained more non-volatiles markers.
Pesticides can affect all receiving compartments, especially soils, and their fate and effects may be enhanced by temperature, increasing their risk to ecological functions of soils. In Brazil, the ...most widely used pesticides are the insecticide Kraft 36 EC® (a.s. abamectin) and the fungicide Score 250 EC® (a.s. difenoconazole), which are commonly used in strawberry, often simultaneously as a mixture. The aim of this study was to evaluate the toxicity of realistic environmental applications, single and in mixtures, for both pesticides to the springtail Folsomia candida and the plant species Allium cepa (onion) and Lycopersicum esculentum (tomato). Mesocosms filled with Brazilian natural soil (lattosolo) were dosed with water (control), Kraft (10.8 g a.s/ha), Score (20 g.a.s/ha) and Kraft + Score (10.8 + 20 g a.s./ha). The applications were repeated every 7 days, during 18 days of experiment, and simulating rainfall twice a week. Collembola reproduction tests were conducted with soils from the first (day 1) and last day (day 18) of experiment for each treatment. Plant toxicity tests were carried out in the experimental units. The experiments were run at 23 °C and 33 °C. Kraft, alone and in the binary mixture, showed high toxicity to the springtails in soils from both days 1 and 18, especially at 23 °C where it caused 100% mortality. Score however, was not toxic to the springtails. Plant growth was reduced by Score, but responses varied depending on temperature. This study indicates a high environmental risk of the insecticide Kraft, particularly at lower temperatures (23 °C), and an influence of temperature on pesticide fate and effects.
•Abamectin was more toxic than difenoconazole to Folsomia candida and plants (A. cepa and L. esculentum).•The abamectin toxicity was modified by temperature.•Mesocosm experiment can be used to simulate a realistic pesticide application scenario.
ABSTRACT Tomato is an important economic crop due to its consumption and production worldwide. However, like other crops, it is susceptible to pathogens, being necessary agrochemicals to prevent ...diseases and improve the production of fruits. Among the sustainable alternatives to crop production, microbial inoculants are used as biofungicide and biostimulants for plant development. Thus, this work aimed to evaluate the biocontrol potential of seven Trichoderma spp. isolates (T1, T2, T3, T4, T15, T17, and T19) against tomato pathogens in vitro experiments, and their potential to improve tomato growth. The Trichoderma spp. antagonism was investigated against Alternaria sp. 003/09, Botrytis sp. 006/13, Fusarium sp. 007/09, and Stemphylium sp. A73. Dual culture, volatile, and diffusible compounds activity tests showed that all new Trichoderma spp. tested could reduce the mycelial growth of all tested pathogens, highlighting T15 and T17 isolates. Seed and soil inoculation revealed very contrasting results: Trichoderma sp. T17 showed a beneficial effect when inoculated in soil, reducing the percentage of yellowish leaves, and increasing dry weight and stem diameter. Inoculation of Trichoderma sp. T17 in the seed increases hypocotyl and radicle lengths, and the seed vigor index. Finally, the strains studied present the potential to be used to develop biocontrol products.
▶ Risks and benefits assessed on crops irrigated with macrophyte treated wastewater TWW. ▶ TWW physico-chemical quality is suitable for irrigation but health risks remain. ▶ TWW provided very ...variable nutrients supply depending on year and element (N, P, K). ▶ TWW improved (less than fertilizer) eggplant yield but extra nutrients (N, P) are needed. ▶ Remaining health risks call for precaution measures when reusing TWW in West-Africa.
The scarcity of freshwater resources is a critical problem in semi-arid zones and marginal quality water is increasingly being used in agriculture. This paper aimed at evaluating the physico-chemical and biological risks on irrigated soils and fruits of macrophyte treated wastewater (TWW), the nutrients supply, and the effect on tomato and eggplant production in semi-arid Burkina Faso. During three years of experiments, treated wastewater was used, with fresh water as control, in combination with or without mineral fertilizer application at recommended rate (140
kg N/ha
+
180
kg P
2O
5/ha
+
180
kg K
2O/ha). The study revealed that the treated wastewater provided variable nutrients supply depending on year and element. The treated wastewater without mineral fertilizer improved eggplant yield (40% in average) compared to the freshwater. Both crops responded better to mineral fertilizer (52% for tomato and 82% for eggplant) and the effects of the treated wastewater and fertilizer were additive. As the N supply of TWW was very unsteady (8–227% of crop need), and P
2O
5 supply did not satisfy in whole crop need (3–58%) during any of the three years of experiment, we recommended that moderate N and P
2O
5 fertilizers be applied when irrigating with TWW in semi-arid West-Africa. On the contrary, the K
2O supply was more steady and close to crop requirement (78–126%) over the three years of experiment and no addition of K fertilizer may be needed when irrigated with TWW. Faecal coliforms and helminth eggs were observed in treated wastewater and irrigated soils at rate over the FAO and WHO recommended limits for vegetable to be eaten uncooked. Tomato fruits were observed to be faecal coliform contaminated with the direct on-foliage irrigation with treated wastewater. Our results indicate that treated wastewater can effectively be used as both nutrients source and crop water supply in market gardening in the semi-arid Sub-Saharan West Africa (SSWA) where freshwater and farm income are limiting. Yet consumers should properly cook or disinfect treated-wastewater irrigated vegetables before eating, and market gardeners should also be careful manipulating treated wastewater to avoid direct health contamination in this environment.
A hydroponic experiment was conducted based on completely randomized design (CRD) to study the effects of Selenium (Se) on tomato (Lycopersicum esculentum L), cv. Foria with three replications. ...Treatments included 3, 5, 7, and 10 µM sodium selenite (Na
2
SeO
3
) and 0 as control. The results showed that selenium (Se) at 7 µM was beneficial to photosynthesis pigments. The highest relative water content was resulted from the 3 µM Se treatment. The membrane stability index was decreased with increasing Se concentration up to 10 µM Se. An increase in peroxidase (POD) activity occurred at the 3 µM Se level, and the catalase (CAT) activity was 80% higher than the control at the 7 µM Se level. In general, the highest root volume, leaf numbers, carotenoids content, and CAT activity were found at the 5 µM Se level, and Chlorophyll content increased at the 7 and 10 µM Se levels.
Nowadays more and more attentions are paid to fruit quality in the production of tomato. In order to better understand the effects of deficit irrigation on tomato yield and fruit quality, four years ...of deficit irrigation experiments were investigated to simulate water-yield and water-fruit quality relationships of tomato in greenhouses. The yield and fruit quality parameters like total soluble solids (TSS), reducing sugars (RS), organic acids (OA), sugar/acid content ratio (SAR), vitamin C (VC), firmness (Fn), color index (CI) were correlated with seasonal evapotranspiration (ET) and ET deficit at flowering and fruit development stage (Stage II) and fruit ripening stage (Stage III) using linear regression. Three water-yield models (Jensen, Stewart, Minhas) and three water-fruit quality models (multiplicative, additive, exponential) were applied to simulate the relationships of tomato yield and fruit quality parameters with water deficit at various growth stages. The water deficit sensitivity indexes (λ/Ky/δ or γ/Kq/ψ) of the models were calculated with the method of multiply linear regression. The performance and sensitivity analysis of the models were evaluated. Results showed that the relative yield decreased linearly with the drop of relative seasonal ET, mainly due to the yield depression by ET deficit at Stage II and Stage III; the relative values of fruit quality parameters increased with the drop of relative seasonal ET, mostly because of the enhancement by ET deficit at Stage III. The calculated water deficit sensitivity indexes indicated that both the yield and fruit quality were hardly sensitive to water deficit at Stage I, but sensitive to water deficit at Stage II and that at Stage III; TSS, RS, SAR and VC were much more sensitive to water deficit at Stage III than that at Stage II; RS, SAR and VC were more sensitive to water deficit than TSS, OA, Fn and CI. The Minhas model with its water deficit sensitivity indexes was recommended to simulate water-yield relations of greenhouse tomato in the study area; multiplicative model and additive model were, respectively, recommended to simulate the relationships of fruit quality parameters like TSS, RS, SAR, Fn and fruit quality parameters like OA, VC, CI with water deficit at various growth stages. The water-yield and water-fruit quality models would be helpful to optimally allocate irrigation water during the growth season, thus achieving efficient production of tomato in greenhouses in consideration of the compromise between tomato yield and fruit quality.
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