Seed of Viola × wittrockiana `Majestic Giant Yellow' were germinated in #406 plug trays at ambient CO2, 25 C and a light intensity of 100 μmol s-1m-2 with an 18 hr photoperiod. At emergence and at successive one week intervals, seedlings were exposed to CO2 levels of 500, 1000 or 1500 μl l-1 and irradiances of 100, 225, 350 μmol s-1m-2 for 7 to 35 days, after which seedlings were transplanted into 10 cm pots and grown to flower in the greenhouse. CO2 at 1000 μl l-1 was as effective as 1500 μl l-1 in accelerating growth in the plug stage. 500 μl l-1 at all irradiances did not accelerate growth significantly. Plants grown at 1000 μl l-1 and 225 μmol s-1m-2 intensity reached the 5 leaf stage up to 14 days earlier than the control, as well as decreasing time to flower during the growing on phase.
Accelerating growth of nursery stock can produce marketable plants in less time, thus potentially increasing profits. The primary objective of this study was to compare adventitious rooting and initial growth of cuttings of three perennials species in response to slow-release fertilizer incorporated into the propagation media. The experiment was a split-plot consisting of four blocks, nine nutrient treatments, three species, and four cuttings per replication within each block-nutrient, species treatment. Treatments consisted of Nutricote 13-13-13 Type 180 and Nutricote 18-6-8 Type 180 incorporated into the rooting media, each at 3, 6, 9, and 12 g·L-1, and a control with no Nutricote. Species studied were Artemisia ludoviciana `Valerie Finnis', Gaura lindheimeri `Whirling Butterflies', and Nepeta ×faassenii `Six Hills Giant'. There were of 144 cuttings per species for a total of 432 cuttings. Fertilizer treatments did not influence rooting percentage, and no significant differences were found between the two formulations of fertilizer for top growth, root growth, rooting percentage, or root number. However, regardless of formulation or rate, the eight fertilizer treatments resulted in greater top and root dry weights when compared to the control. Top and root dry weight increased linearly within both fertilizer formulations.
Foliar application of the synthetic growth regulator BA was evaluated for increasing the duration and extent of Fraser fir [Abies fraseri (Pursh.) Poir.] seedling growth. Aqueous solutions of 0, 222, or 444 μm BA (0, 50, or 100 ppm) were sprayed on the shoots of Fraser fir seedlings biweekly from 18 until 38 weeks after planting. Foliar sprays of 444 μm BA increased seedling height 19%, increased shoot weight 57%, reduced root weight 22%, and increased total weight 27%. Apical meristem activity was stimulated and the long periods of dormancy typical of Fraser fir seedlings were avoided. Chemical name used: 6-benzylaminopurine (BA).
208 ORAL SESSION 55 (Abstr. 483–490) Floriculture: Growth and Development
Abbreviations: DW, dry weight; FW, fresh weight; HPS, high pressure sodium; IR, infrared; PPF, photosynthetic photon flux; RGR, relative growth rate. 1 Currently Assistant Professor, Dept. of Horticulture, Forestry, Landscape and Parks, South Dakota
regulators occurs at the PPJ indicating that these compounds accelerate the progression of abscission ( Malladi et al., 2012 ; Vashisth and Malladi, 2013 ). However, it is unclear if the PPJ perceives and responds to these growth regulator applications or
them for 5 to 10 years, and make selections based on tree performance and fruit quality of these HLB-affected trees. Based on promising reports of accelerated citrus growth when grown in an MRM system ( Adair, 2018 ), we tested the hypothesis that such
( Petropoullou and Alston, 1998 ) indicates that pollen tube growth can be accelerated under the appropriate high-temperature range, resulting in a reduced travel time of the pollen tube to the ovules. In this study, increased temperature could accelerate pollen
lighting accelerated plant growth significantly compared with simultaneous red and blue, especially from 22 to 31 DAS ( Figs. 2 – 5 ). Thus, the effect of alternate irradiation appears to make a significant difference to plant growth at a later stage of