Silicon fertilization increases gas-exchange and biomass by silicophytolith deposition in the leaves of contrasting drought-tolerant sugarcane cultivars under well-watered conditions

Autor(es)

Camargo, Monica Sartori ^[1] ; Fernandez Honaine, Mariana ^[2] ; Osterrieth, Margarita ^[2] ; Bozza, Natalia Ganzaroli ^[3] ; Silva, Vicente da Mota ^[4] ; Laura Benvenuto, Maria ^[5] ; Silva, Marcelo de Almeida ^[4]

Afiliação do(s) autor(es)

^[1] Agencia Paulista Tecnol Agronegocios APTA, Polo Ctr Sul, BR-13412050 Piracicaba, SP - Brazil

^[2] Univ Nacl Mar del Plata, CONICET, Inst Invest Marinas & Costeras IIMyC, Fac Ciencias Exactas & Nat, CC1250, RA-7600 Mar Del Plata - Argentina

^[3] Fac Tecnol Piracicaba, BR-13414141 Piracicaba - Brazil

^[4] Sao Paulo State Univ, UNESP, Lab Ecophysiol Appl Agr LECA, Dept Crop Prod, Sch Agr Sci, BR-18610034 Botucatu, SP - Brazil

^[5] Univ Nacl Mar del Plata, Inst Invest Prod Sanidad & Ambiente IIPROSAM, Consejo Nacl Invest Cient & Tecn, Ctr Assoc Simple CIC PBA, Funes 3250, RA-7600 Mar Del Plata - Argentina

• Tipo de documento: Artigo Científico
• Fonte: PLANT AND SOIL; v. 466, n. 1-2 JUL 2021.
• Citações Web of Science: 0

Resumo

Purpose Silicon (Si) fertilization provides benefits to sugarcane. However, information remain scarce about the relationship between Si fertilization, gas exchange responses, biomass and silicophytolith accumulation in contrasting drought tolerant sugarcane cultivars under well-watered conditions Methods Sugarcane cultivars (drought-tolerant and drought-sensitive) were grown in pots containing soil with low available Si and were treated (at rates equivalent to 0, 250, 500, 750, and 1000 kg ha(-1) Si) with Si as silicate. The silicophytolith contents, morphotype descriptions, Si concentrations and gas exchange were evaluated in the top visible dewlap leaves. Stalk length and stalk biomass were also evaluated. Results The silicophytolith, Si contents, net CO2 assimilation rate (A), plant transpiration (E), stomatal conductance (gs) and electron transport rate (ETR) of leaves and fresh biomass and length of stalks increased linearly as functions of the Si application rate, independent of cultivar. RB86-7515 showed the highest stalk length, fresh stalk and green leaf biomass, relative water content, and water potential, while RB85-5536 showed superior values for A, E, gs, and ETR. Conclusions Si fertilization improved photosynthesis, transpiration, stalk length, and stalk biomass production in sugarcane. The highest silicophytolith content was reflected in a diversity of silicified cells, which may favor a higher photosynthesis and biomass. The increase of silicification in stomata complexes and trichomes with Si may be associated to a higher Si availability and transpiration. Contrasting drought-tolerant cultivars showed similar silicification and gas exchange responses with Si. Considering these benefits, Si should be included in the fertilization program of sugarcane. (AU)

• Processo FAPESP: 18/05843-0 - Adubação com silício em cana-de-açúcar: doses, cultivares e déficit hídrico
• Beneficiário: Mônica Sartori de Camargo
• Modalidade de apoio: Auxílio à Pesquisa - Regular