Trichoderma atroviride Enhances Impatiens walleriana Hook. f Growth and Flowering in Different Growing Media.

Trichoderma spp. are widely reported to regulate plant growth by improving nutrient uptake, photosynthesis, and abiotic stress tolerance. However, their possible application for bedding plants is little explored, especially when comparing different growing media. Considering that coconut coir dust is finding broader application in the ornamental plants sector as a peat substitute, this work was aimed to test the combination of Trichoderma atroviride AT10 and coconut coir dust on Impatiens walleriana plants. Four treatments were tested as a mix of: (i) two growing media (70:30), peat:perlite or coconut coir dust:perlite; and (ii) the absence or presence of a T. atroviride treatment. At the end of the production cycle, the biomass and ornamental parameters, leaf pigments, nutrient content of the plant tissues, and Trichoderma abundance were assessed. The results revealed that T. atroviride can readily colonize coir, and the same positive effects of inoculum were found in plants grown on both substrates. The biostimulant effect of T. atroviride was observed as an increase in the aboveground biomass, number and weight of flowers, pigments and nutrient concentration, thereby improving the commercial quality of I. walleriana. Thus, T. atroviride has shown its potential in making bedding plant cultivation more sustainable and improving the yield and aesthetic parameters of plants grown on peat and coconut coir dust substrates.

Combined effect of silicon and non-thermal plasma treatments on yield, mineral content, and nutraceutical proprieties of edible flowers of Begonia cucullata.

Edible flowers are becoming popular as a nutraceutical and functional food that can contribute to human nutrition with high antioxidant molecules and mineral elements. While comparative studies between different flower species have been performed, less is known about the best agronomical practices to increase yield and nutraceutical proprieties of blooms. Silicon stimulates plant resistance against stress and promotes plant growth while non-thermal plasma (NTP) technology has been applied for the disinfection and decontamination of water, as well as for increasing plant production and quality. The application of silicon and NTP technology through nutrient solution and spraying was investigated in edible flowers given that the combination of these treatments may play a role in promoting their nutritional and nutraceutical proprieties. The treatments were applied on two varieties of Begonia cucullata Willd. (white and red flowers) to explore their effects on different flower pigmentations. Plants with red flowers showed higher nutraceutical proprieties than the white ones but yielded a lower flower number. While the NTP treatment did not improve flower yield and quality, the silicon treatment increased anthocyanins and dry weight percentage in red flowers. NTP treatment increased zinc concentration, while it decreased potassium, magnesium, and manganese, and increased silicon concentration in white flowers. The combination of silicon and NTP showed negative effects on some nutraceutical proprieties of red flowers thus highlighting that the two treatments cannot be combined in edible flower production. In conclusion, the positive effect of silicon use in edible flower production has been demonstrated while the NTP technology showed contrasting results and its use should be explored in greater depth, including a consideration of its role in biotic attack prevention and reduced chemical input.

Non-Thermal Plasma Treatment Influences Shoot Biomass, Flower Production and Nutrition of Gerbera Plants Depending on Substrate Composition and Fertigation Level.

Non-thermal plasma (NTP) appears a promising strategy for supporting crop protection, increasing yield and quality, and promoting environmental safety through a decrease in chemical use. However, very few NTP applications on containerized crops are reported under operational growing conditions and in combination with eco-friendly growing media and fertigation management. In this work, NTP technology is applied to the nutrient solution used for the production of gerbera plants grown in peat or green compost, as an alternative substrate to peat, and with standard or low fertilization. NTP treatment promotes fresh leaf and flower biomass production in plants grown in peat and nutrient adsorption in those grown in both substrates, except for Fe, while decreasing dry plant matter. However, it causes a decrease in the leaf and flower biomasses of plants grown in compost, showing a substrate-dependent effect under a low fertilization regime. In general, the limitation in compost was probably caused by the high-substrate alkalinization that commonly interferes with gerbera growth. Under low fertilization, a reduction in the photosynthetic capacity further penalizes plant growth in compost. A lower level of fertilization also decreases gerbera quality, highlighting that Ca, Mg, Mn, and Fe could be reduced with respect to standard fertilization.