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Optimizing rooting of jojoba stem cuttings: Effects of basal wounding, rooting medium and depth of insertion in medium
Author(s) -
Palzkill David A.,
Feldman William R.
Publication year - 1993
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02564229
Subject(s) - perlite , vermiculite , cutting , peat , horticulture , seedling , botany , chemistry , biology , ecology
Seedling populations of jojoba are extremely heterogeneous; about 50% of the plants are nonproducing males, and many of the females are low‐yielding or are otherwise undesirable. Asexual propagation methods allow the increase and use of only desirable plants. Rooting of stem cuttings is the most commonly used asexual method; however, unsatisfactory results sometimes still occur when using this method, so it requires further refinement. In this study, three factors suspected to play an important role were studied: rooting medium, basal wounding and depth of insertion in the medium. Three media [perlite/vermiculite, 1:1 (vol/vol); peat/perlite/vermiculite, 1:1:1 and peat/perlite, 1:1], wounding vs. not wounding, and insertion of one or two nodes below the surface of the medium were compared. The base (2.5 cm) of each cutting was treated with potassium salt of indole butyric acid, 1000 ppm prior to insertion into the medium, and cuttings were rooted on a heated propagation bench under intermittent mist. The experimental design was a 3×2×2 factorial and was replicated five times. Sixteen cuttings were used per experimental unit. The study was repeated. Rooting percentage was significantly affected only in the first repetition and then only by media. The peat/perlite medium resulted in significantly less rooting than did the other two media. However, averaged over both repetitions, rooting averaged 74% for perlite/vermiculite, 78% for peat/perlite/vermiculite and 64% for peat/perlite. Depth of insertion and wounding did not affect rooting percent in either repetition of the study. Both deeper insertion and wounding resulted in roots emerging from along a greater length of the stem at the basal end of the cuttings. Cuttings with two nodes inserted into the medium averaged root emergence along a 54% greater length of the stem than those with only one node inserted. With wounding, roots emerged along 17.3 mm of the stem, while without wounding, emergence occurred only along 7.0 mm of the stem. The better root system resulting from wounding and deeper insertion into the medium would likely result in better performance of the cutting when transplanted to a field.