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Studies in controlled environmentconditions investigated the effects ofirradiance and nutrients (NPK) on morphologicaland physiological characteristics of Albizia guachapele stockplants, and rootingability of subsequently severed cuttings innon-mist propagators. The study assessed gasexchange and chlorophyll fluorescence ofstockplants before cutting severance and ofcuttings during the propagation period. Anegative interaction was found betweenincreasing irradiance(200–500 μmol mminus 2 sminus 1) andincreasing nutrient supply (0.25–1.25% NPK)on stockplant growth, and a similar effect wasfound in the subsequent rooting of cuttings.Rooting percentage decreased from 53.8% withlow irradiance/low nutrients to 11.2% withhigh irradiance/high nutrients. Single-node,leafy cuttings from high irradiance/highnutrient stockplants were much shorter thanthose from any other treatment, whichnegatively affected their rooting ability. Nodifferences were found among treatments inchlorophyll fluorescence ratios duringpropagation, suggesting that A.guachapele cuttings are dependant for rootingnot only on current photosynthesis, but also ontheir initial pre-severance reserves ofcarbohydrate. It was concluded that A.guachapele, which can be propagated with thenon-mist propagation system utilized in thisstudy, was markedly affected by pre-severancestockplant environment through its impact oncutting size and products of photosynthesis.Growing stockplants under low irradiance andlow nutrients resulted in longer cuttings withhigher rooting ability. |
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