Potential of Pinus elliottii Engelm. needles as substrate conditioner for the production of “Fepagro C37 reck”Citrus rootstocks”

Potencial da acícula de Pinus elliottii engelm. como condicionador de substrato para produção do porta-enxerto de citros “Fepagro C37 Reck”

Abstract

The production of citrus seedlings in protected environment requires a large amount of substrate, which must have adequate physical and chemical characteristics. The use of acidic conditioners, such as Pinus needles mixed with alkaline substrates, allows the cultivation of seedlings with better quality. The objective of this work was to evaluate the development of the “Fepagro C37 Reck” rootstock grown in different alkaline commercial substrate mixtures (Humosolo ES®) with Pinus elliottii needles. The experiment was carried out by testing alkaline substrate mixed with 5-month old of decomposition Pinus needles in situ decomposition and two granulometry sizes, 3.5 and 8.0 mm. The mixtures were performed in proportions between the needles with the Humosolo, (v / v) 0%; 25%; 50%; 75% and 100%. Expanded cellular polystyrene trays were used to accommodate the mixtures and seeding of the rootstock. Physical and chemical evaluateons of the mixtures were carried out, as well as the development of the seedlings. The use of Pinus needles acidified the substrate Humosolo ES®, reduced its electrical conductivity and increased the percentage of porous space of the mixtures and reduced water retention. The treatments containing 25 and 50% of the Pinus needles mixture, regardless of the granulometry, provide greater development of rootstock plants “Fepagro C37 Reck”.

Index terms
physical-chemical characteristics of substrates; protected environment; seedlings; pH