Name: ELMO PEREIRA RAMOS
Publication date: 28/02/2024
Advisor:
Name |
Role |
|---|---|
| SARA DOUSSEAU ARANTES | Advisor |
Examining board:
| Name |
Role |
|---|---|
| SARA DOUSSEAU ARANTES | Advisor |
Summary: Lithothamnion sp. is a calcareous algae used in agriculture as a mineral fertilizer. However, studies indicate a biostimulant effect in several crops, but progress is still needed in identifying the mechanisms. The present study consists of four chapters that address the biostimulant effects on plants of the algae Lithothamnion sp. The first chapter is a literature review that addresses applications in agricultural crops. In the second and third chapters, the biostimulant effects of different sources of Lithothamnion sp. were evaluated. to identify the dose that reflects the best development in the quality of the seedlings and the accumulation of nutrients in the ‘Aliança’ papaya tree. In the fourth chapter, the biostimulant effect in interaction with indolebutyric acid on the development of the root system, vegetative growth, gas exchange and seedling quality of two black pepper cultivars ‘Bragantina’ and ‘Kottanadan White Bud’ was evaluated. Through the biobliographic review, it was possible to highlight the positive effects on plant growth, fruit quality, productivity and gas exchange, highlighting the auxinic action and the induction of resistance to stress. The incorporation of Lithothamnion sp. in the substrate (Chapter 2) and foliar application via drenching (Chapter 3) promoted changes in the quality of seedlings and nutritional contents, mainly calcium, potassium, manganese and zinc. In general, it was noted that Lithothamnion sp. extracted from deposits in Espírito Santo have a greater biostimulant effect on papaya seedlings. The ideal dose varied between 5 and 6 g L-1 when applied foliarly and 4 kg m-3 when incorporated into the substrate. In black pepper seedlings it was noted that the effect of Lithothamnion sp. was independent of indolebutyric acid and cultivars. Lithothamnion sp. promoted shoot growth and root length, with a better response at a dose of 1.80 kg m-3, however, with increasing concentration there was inhibition of adventitious rhizogenesis. The presence of indolebutyric acid obtained the best averages in biomass accumulation, root volume, shoot growth and water use efficiency, providing better seedling development. The cultivar ‘Kottanadan White Bud’ with the presence of indolebutyric acid was the one that best expressed seedling development. Based on the studies conducted, the biostimulant effect on papaya seedlings was evident, however, for black pepper clonal seedlings, Lithothamnion sp. should be applied in smaller doses.
Key words: Calcareous algae, bioinput, seedlings, Carica papaya L., Piper nigrum L.
