Different species of basil need different ammonium to nitrate ratio in hydroponics' system

Abstract

Basil is a very important medicinal plant and culinary spice, and is marketed fresh, dried or frozen. In crop nutrition, nitrogen is essential for plant growth and as a macro-element, is part of the proteins' structure and participates in the metabolic processes involved in the synthesis and energy transfer. It has been shown that a balance between ammonium and nitrate favors plant growth and that the degree of benefit varies among crops. This study was conducted to evaluate the growth of two varieties of basil in function of four nutrient solutions containing different NH 4 + /NO 3 -ratios. Results showed that different variety response differently to nutrient solution. Although the highest yield in both varieties (sweet and purple) was obtained when fed by nutrient solution without ammonium but their response on quality indices were different due to nitrate ammonium ratio in nutrient solutions. The highest total phenol content of sweet and purple basil was 92 and 100 mg gallic acid equivalent per gram of dry weight respectively, while the highest antioxidant capacity was obtained in purple variety grown in nutrient solution 2 (NH 4 + :1/NO 3 :4) and the lowest value were related to sweet variety with the same nutrient solution. Moderate content of total nitrogen can be suitable for sweet variety while for purple variety nutrient solution with low amount of ammonium can be more suitable. Bazilika je zelo pomembna zdravilna rastlina in začimba, ki se prodaja sveža, suha ali zmrznjena. V prehrani rastlin je dušik esencialni makroelement, potreben za rast, sintezo beljakovin, druge presnovne procese in pretvorbo energije. Znano je, da ravnovesje med amonijsko in nitratno obliko dušika izboljšuje rast in, da se njuno ugodno razmerje spreminja glede na posamezne rastline. V raziskavi smo ovrednotili rast dveh biotipov širokolistne bazilike (zeleno-in vijoličnolistno) v štirih hranilnih raztopinah, ki so vsebovale različna razmerja NH 4 + /NO 3 -. Rezultati so pokazali različen odziv obeh biotipov na razmerja hranil v raztopinah. Čeprav je bil pridelek obeh (zelene in vijolične) največji v hranilni raztopini z amonijsko obliko dušika, so kvalitetni kazalci variirali glede na razmerja nitrata in amonija. Največja vsebnost celokupnih fenolov v zeleni in vijolični baziliki je bila 92 in 100 mg ekvivalenta galne kisline na gram suhe mase, vendar je bila največja antioksidativna sposobnost dosežena pri vijolični baziliki, ki je rastla v hranilni raztopini 2 (NH 4 + :1/NO 3 :4) in najmanjša vrednost pri zeleni baziliki, ki je uspevala v isti hranilni raztopini. Zmerna vsebnost celokupnega dušika je primerna za gojenje zelene širokolistne bazilike, medtem ko je za gojenje vijolične primernejša hranilna raztopina z manjšo vsebnostjo amonija.

Valorization of Nutritional Potential and Specialized Metabolites of Basil Cultivars Depending on Cultivation Method

“…Therefore, the results obtained in this study, i.e., the increased content of chlorophyll, carotenoids, and anthocyanins in all basil cultivars grown in floating, can be explained by the fact that plants grown in greenhouses were better protected from the direct effects of irradiation compared to plants grown in open field. Those results can be also supported by the other literature data [33,36,[45][46][47][48].…”

“…'Minimum' from this research. Additionally, Saadatian et al [33] proved significantly higher values of total phenols in purple compared to the sweet (green) basil varieties which is partly consistent with the results from this research in which was determined higher TPC, TFC, and TNFC for cv. 'Dark Opal' (purple basil) compared to the cv.…”

“…Their antioxidant role is associated with the possibility of neutralization of oxidation processes by inhibition of free radicals and detoxification of ROS [50,51]. From results obtained in this research, it can be concluded that all analyzed basil cultivars have high antioxidant capacity which is in agreement with other literature data [11,33,52].…”

“…'Minimum' and 'Genovese'. Additionally, different studies suggest a significant variability of vitamin C content between basil cultivars, for example, Saadatian et al [33], Majkowska-Gadomska et al [34], and Majkowska-Gadomska et al [35] also reported significantly higher vitamin C values in purple basil varieties compared to the sweet basil ones. In general, results of vitamin C content from this study are in agreement with data obtained in other research [11,35,36].…”

Seasonal variation of ascorbic acid and nitrate levels in selected basil (Ocimum basilicum L.) varieties

“…Basil is characterised by significant variability over a broad range of its constituents. There are several factors which determine the content of ascorbic acid, among them external factors (climatic and growing conditions, fertilisation, agronomic methods) as well as internal factors (genotype, development stage) (Dzida, 2011;Nurzynska-Wierdak et al 2011;Saadatian et al 2014;Fraszczak et al 2015).…”