1,721,007 research outputs found
Non-destructive estimation of leaf area in (Solanum lycopersicum L.) and gerbera (Gerbera jamesonii H. Bolus).
No full textThe empirical relationship between leaf area and leaf dimensions was investigated by many authors in several crops because simple and accurate models eliminate the need for expensive measuring devices (e.g. digital planimeter) and time consuming destructive measurements. In this research, two empirical models were developed and tested for non-destructive determination of leaf area of two important greenhouse crops, tomato and gerbera, as a function of leaf length and width. The model for tomato was validated in different cultivars (Jama, Naomi and Daniela). In both crops the most accurate regression equation (R2 = 0.884 and RMSE = 35.02, in tomato; R2 = 0.910 and RMSE = 14.71, in gerbera) included maximum length and width. The correlation coefficient between predicted and measured leaf area was highly significant
Evaluation of quick test kits for the determination of nitrate, ammonium and phosphate in soil and in hydroponic nutrient solutions
No full textGrowth, yield and quality of hydroponically cultivated green leafy vegetables as affected by nutrient solution and growing season
No full textLettuce (Lactuca sativa L.) var. ‘Lollo rossa’ was grown in a floating hydroponic system. Six saline treatments were used, adding different concentrations of calcium chloride (CaCl2) to the nutrient solution (mol m−3): 0, 2.5, 5, 10, 15, 20, which, respectively, corresponds to an electrical conductivity of 2.5, 3, 3.5, 4.4, 5.4, 6.3 dS m−1. In plants subjected to moderate salinity stress the growth was not affected and yields were not statistically significant; however, the data shows a slight decline in 20 mol m−3 CaCl2 treatments. Nitrate contents in the leaf decreased when the concentration of CaCl2 in nutrient solutions increased. Other quality parameters were positively affected by treatment with CaCl2, especially at moderate concentrations such as 5 and 10 mol m−3. In fact, both the content of phenols and antioxidant power increased at moderate salt concentrations and reduced in the treatment with 20 mol m−3 CaCl2. The content of chlorophyll and carotenoids were not affected by treatment even at high salt concentrations. The use of CaCl2 did not result in nutrition imbalances in plants either. In fact, the ratio K/Na remained unchanged in the various treatments, as well as the contents of microelements
Spatial and temporal distribution of mineral nutrients and sugars throughout the lifespan of Hibiscus rosa-sinensis L. flower
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Wild edible plant species grown hydroponically with crop drainage water in a Mediterranean climate: Crop yield, leaf quality, and use of water and nutrients
Full text linkThere is an increasing interest in the cultivation of wild edible plants (WEP) in consideration of their quality attributes and salt tolerance, which makes these species good candidates for cascade cropping systems (CCS). In these systems, saline effluents from a salt-sensitive donor crop are used to irrigate a receiving crop with greater salt tolerance. The objective of this study was to evaluate two WEP species, Picris hieracioides (PH) and Plantago coronopus (PC) as candidate crops for CCS. Both species were grown hydroponically with saline effluent from a semi-closed substrate culture of tomato (the donor crop). Both PH and PC were grown in floating system for 36 days during spring using one of the following nutrient solutions: i) standard nutrient solution (CNS, control); ii) NaCl-enriched (50 mmol L-1) standard nutrient solution (SNS); iii) effluent from tomato substrate culture (TE); iv) artificial effluent (ATE), i.e. a nutrient with ion concentrations and salinity level (approximately 50 mmol L-1 NaCl) very close to those of TE. Compared with CNS, leaf production was significantly reduced in both TE (-33.6%) and ATE (-33.6%) plants of PH, and only in TE (-23.3%) plants of PC. In both species, leaf Na content increased in SNS (+858.1% in PH; +279.4% in PC), TE (+704.7% in PH; +226.3 in PC) and ATE (+697.7% in PH; +229.4% in PC) plants compared with the controls. Leaf antioxidant capacity was positively correlated with total phenol content and, in PC, increased in SNS (+74.3%), TE (+53.9%) and ATE plants (+37.7%) compared with the controls. In conclusion, both PH and PC could be grown in CCS with saline greenhouse hydroponic effluents since the moderate reduction of leaf production could be partially compensated by reduced production costs because of zero costs for fertilisers. The growth inhibition observed in both WEPs species cultivated with the hydroponic effluent was primarily due to its high salinity with minor or no effects due to the suboptimal nutrient levels and/or the presence of phytotoxic root exudates or microbial metabolites
Accumulo di sali (NaCl) e consumo minerale in pomodoro coltivato in sistemi idroponici a ciclo chiuso
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