Effect of Pyroligneous Acid on the Productivity and Nutritional Quality of Greenhouse Tomato

Abstract

Pyroligneous acid (PA) is a reddish-brown liquid obtained through the condensation of smoke formed during biochar production. PA contains bioactive compounds that can be utilized in agriculture to improve plant productivity and quality of edible parts. In this study, we investigated the biostimulatory effect of varying concentrations of PA (i.e., 0%, 0.25%, 0.5%, 1%, and 2% PA/ddH2O (v/v)) application on tomato (Solanum lycopersicum ‘Scotia’) plant growth and fruit quality under greenhouse conditions. Plants treated with 0.25% PA exhibited a significantly (p < 0.001) higher sub-stomatal CO2 concentration and a comparable leaf transpiration rate and stomatal conductance. The total number of fruits was significantly (p < 0.005) increased by approximately 65.6% and 34.4% following the application of 0.5% and 0.25% PA, respectively, compared to the control. The 0.5% PA enhanced the total weight of fruits by approximately 25.5%, while the 0.25% PA increased the elemental composition of the fruits. However, the highest PA concentration of 2% significantly (p > 0.05) reduced plant growth and yield, but significantly (p < 0.001) enhanced tomato fruit juice Brix, electrical conductivity, total dissolved solids, and titratable acidity. Additionally, total phenolic and flavonoid contents were significantly (p < 0.001) increased by the 2% PA. However, the highest carotenoid content was obtained with the 0.5% and 1% PA treatments. Additionally, PA treatment of the tomato plants resulted in a significantly (p < 0.001) high total ascorbate content, but reduced fruit peroxidase activity compared to the control. These indicate that PA can potentially be used as a biostimulant for a higher yield and nutritional quality of tomato.

Foliar application of pyroligneous acid acts synergistically with fertilizer to improve the productivity and phytochemical properties of greenhouse-grown tomato

“…Brix content is commonly used to determine the quality of tomato concentrate and correlates with the fruit TDS 25 . Consistently, PA and other biostimulants were reported to increase the Brix of tomato fruits 20,25 . This indicates that PA can be used to enhance tomato fruit avour and taste 25 .…”

“…The impact of PA on crop yield has been reported extensively by several authors 16, [19][20][21][22]31 . Similarly, our results showed that 2% PA irrespective of NPK fertilizer rate increased the total number of fruits and fruit weight followed by 0.5% PA combined with full NPK rate.…”

“…In this study, 0.5% PA with half and full NPK rates enhanced fruit carotenoid and phenolics contents respectively, while 2% PA increased fruit avonoid content. Accordingly, several studies have reported that PA application increased phenolics and avonoid contents in tomato fruits 20,23 .…”

“…However, these chemical properties are dependent on the feedstock, heating rate, temperature and resident time 9,10 . PA has been used extensively in agriculture as a biostimulant to increase seed germination and seedling growth [12][13][14] , crop photosynthetic performance [15][16][17][18] , crop biomass, crop yield (fruit number and weight) [19][20][21][22] and the nutrition and phytochemical properties of food crops 16,[23][24][25] . Additionally, PA has recently been used as a herbicide 26 and antimicrobial agent to control major plant diseases 27,28 .…”

In Vitro Evaluation of Wood Vinegar (Pyroligneous Acid) VOCs Inhibitory Effect against a Fungus-like Microorganism Ovatisporangium (Phytopythium) Isolate Recovered from Tomato Fields in Iran

“…For instance, in comparison to wood vinegar, a combination of compost and wood vinegar had the ability to decrease up to 67% of the symptoms of muskmelon root rot caused by Monosporascus cannonbalus [74]. Recent reports targeting the antibacterial, antifungal, and antioomycete wood vinegar effects highlighted the huge potential of wood vinegar for controlling plant pests and diseases [75]. This resulted in a significantly reduced disease incidence of many pests in greenhouse and field conditions [76].…”