Adventitious root formation in leaf petiole cuttings of lemon (Citrus limon L. Burm.)

Abstract

Lemon (Citrus limon Burm.) is a valuable citrus fruit for its adaptability, market value, and uses in food,
cosmetics, and pharmaceutical industries. The demand for quality planting materials of lemon is rising; however,
propagation by hardwood cuttings requires a relatively large number of mother plants. Therefore, a study on
the rooting behaviour of leaf petiole cuttings in lemons and identification of suitable rooting substrates was
conducted to potentially improve multiplication efficiency while reducing the maintenance cost of mother
plants. A leaf petiole cutting of lemon cv. “Assam Lemon” was planted in five different substrates, viz., river
sand, cocopeat, vermicompost, river sand + cocopeat (1:1 v/v) and river sand + vermicompost (1:1 v/v) under
polyhouse conditions. Results indicated that leaf petiole cuttings have potential for rooting, though vary
significantly with substrates. The river sand recorded the lowest rooting attributes, except for the number of
primary roots (3.67±0.4). Cocopeat produced the maximum number of secondary roots (14.07±0.33) and root
diameter (0.49±0.011 mm). Furthermore, the highest rooting percentage (44.67±3.4) and root traits (length, surface
area, volume, tips, forks, and crosses) were recorded in cocopeat + river sand, followed by vermicompost +
river sand. Therefore, the leaf petiole cuttings of lemons showed positive rooting; however, there was no shoot
initiation or formation. The most suitable substrates for root initiation and growth were found in cocopeat +
river sand. The study demonstrated the preliminary rooting capability of lemon leaf petiole cuttings in suitable
substrates, indicating potential for the future development of an alternative propagation system.