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- Author or Editor: J.C. Rodriguez x
Abstract
2,3,5-triiodobenzoic acid (TIBA), (2-chloroethyl) phosphonic acid (ethephon), 6-(benzylamino) - 9 - (2-tetrahydropyran-yl) - 9 H-purine (PBA), and N6 benzyl adenine (N6BA) were applied to greenhouse rose cvs. Red American Beauty, Forever Yours, Mary DeVor and Jack Frost as sprays, lanolin paste, and in solutions in floral foam. Axillary shoot development was significantly increased when PBA and N6BA were applied as sprays, in paste or in solutions in floral foam. The most significant response was obtained when the chemical solutions were absorbed from floral foam cubes attached to a cutback rose cane. Most of the axillary buds broke dormancy when the growth regulating chemicals were applied by this method, however, many of the developing buds stopped growth before becoming shoots. Chemicals PBA and N6BA significantly increased the development of flowering and blind shoots for all rose clones. Plant growth regulating chemicals, methods of application, and concentrations favorable for the development of axillary shoots had no comparable effect on basal shoots developing from the rose bud union.
Abstract
Geraniums (Pelargonium hortorum Bailey) grown under constant supplemental lighting using 105 watt Wide Spectrum Gro-Lux fluorescent lamps at 14 lamp watts/ft2 for periods of 0 to 4 weeks flowered in approximately the same no. of days from seeding and the terminal stems had similar no. of nodes. Plants lighted 6 to 10 weeks also flowered uniformly but 24-55 days (21-33%) earlier and with 2-6 fewer nodes than those receiving no supplement light or lighted for less time.
Abstract
Supplemental lighting nightly during late spring and early summer with Wide Spectrum Gro-Lux fluorescent lamps at 29 lamp watts/ft2 has been found to improve the development of newly planted dormant and cut-back rose plants. Lighted plants of cvs Electra, Red American Beauty and Forever Yours produced a higher percentage of flowering stems than unlighted plants. Plants receiving supplemental lighting had significant increases in the no. of flowering stems developing after a hard pinch, and generally significant increases in bottom breaks. Cut flower production was increased 18-41% after plant development had been completed, but for ‘Electra’ this increase was in flower stem lengths less than 15 inches.
The beneficial effects of early mycorrhizal inoculation with two arbuscular fungi, Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe and Glomus intraradices Schenck and Smith, were evaluated on Myrobalan 29 C (Prunus cerasifera × Prunus munsoniana Wight and Edr.) plum rootstock in soil infested or noninfested with the root lesion nematode Pratylenchus vulnus Allen and Jensen under microplot conditions. During this two year study, mycorrhizal colonization did not affect the number of nematodes per gram of root in plants infected with P. vulnus. In contrast, P. vulnus significantly decreased the percentage of mycorrhizal root colonization. Most elements were within sufficiency levels for plum by foliar analysis, although low P and deficient Fe and Cu levels were detected in P. vulnus treatments. Early mycorrhizal inoculation with G. mosseae favored plant growth after 20 months, but in soils infested by P. vulnus, only G. intraradices increased the tolerance of Myrobalan 29 C plum rootstock to damaging nematode levels by stimulating plant nutrition and vegetative growth.
Abstract
Backcrosses and outcrosses of mite resistant strawberry selections and combinations of resistant selfed lines were made. Backcrosses to the resistant parents resulted in intermediate progeny means but they were closer to that of the less resistant parent. Backcrosses to the susceptible parent also resulted in intermediate progeny means but they were close to that of the more resistant parent. Outcrosses gave progenies similar to those of backcrosses but with less spread in resistance. Crosses of certain resistant selfed selections showed almost complete dominance for mite resistance.
Abstract
Four greenhouse rose cultivars were grown under 9, 12, and 16-hr daylengths from September to May during 1969-70 and 1970-71. Flower production was generally increased significantly under the 16-hr daylength, particularly during January and February. At this day length, rose stems flowered again more quickly, but with the same number of nodes present as in the other treatments. The internode between the 2 uppermost 5-leaflet leaves was significantly longer on plants grown at 16 and 12 hr than the 9-hr daylengths. Flower fresh and dry wt increased as the daylengths increased from 9 to 16 hr and the percentages of blind stems were found to decrease. Rose leaf and flower petal size were unchanged by the daylength.
Galia-type muskmelon (Cucumis melo cv. Gal-152) was grown as a fall and spring crop to determine the effect of plant density (1.7, 2.5, 3.3, and 4.1 plants/m2) on yield, fruit quality, plant growth, and economic feasibility for producing the crop in a greenhouse. Plant density had no influence on the early or total number of fruit produced per plant. Marketable yields increased linearly from 11.0 to 20.0 kg·m−2 in fall and from 21.9 to 48.3 kg·m−2 in spring with increasing plant density. Mean fruit size was unaffected by plant density during fall (mean weight, 1.0 kg), but was reduced linearly during spring from 1.8 kg at 1.7 plants/m2 to 1.5 kg at 4.1 plants/m2. Soluble solids content was unaffected by plant density in either fall or spring and averaged 10.1% in both seasons. Number of leaves per plant was unaffected by plant density, but internode length was increased at 4.1 plants/m2 compared with plants from the other densities. Increasing the plant density of ‘Gal-152’ muskmelon grown under protected cultivation led to increased yields in both fall and spring without negatively impacting fruit quality. When the market price is $1.44/kg, increased yields at 3.3 plants/m2 can potentially increase net returns over yields of plants spaced at 2.5 plants/m2 by 25% and nearly double net returns from plants grown at 1.7 plants/m2.
Abstract
Foliar sprays of 6-(benzylamino)-9-(2-tetrahydropyranyl)-9H-purine (PBA) at 200 or 300 ppm and 6-benzylamino purine (BA) at 500 or 1000 ppm, caused the development of 90% or more of the lateral branches of ‘Annette Hegg’ and ‘Dark Red Annette Hegg’ poinsettia (Euphorbia pulcherrima Willd.) while 2 to 4 lateral branches developed from terminal stems of “Eckespoint C-l Red” near the position of the apical meristem. (2-Chloroethyl)phosphonic acid (ethephon) sprays increased lateral branch development significantly above the control treatment but less than PBA or BA while 2, 3, 5-triiodobenzoic acid (TIBA) produced only slightly more branches than the control.
In the spring of 2001 and 2002, different combinations of media (coarse perlite, medium perlite, and pine bark) and containers (polyethylene bags and plastic pots) were used for hydroponic production of `Galia' muskmelons (Cucumis melo L.) to determine their effect on fruit yield and quality, and their influence on costs of production. Marketable yields obtained for `Gal-152' in the spring 2001 and 2002 were 25.5 kg·m–2 and 39.0 kg·m–2 respectively. When data were combined for 2001 and 2002, fruit yield and fruit quality were unaffected by any combination of media and container. Average soluble solids content was generally greater than 10° Brix. It was determined that the use of pine bark media and plastic pots instead of perlite and bags would save $18,200 per year (two crops)—a feasible option for reducing costs of producing `Galia' muskmelons in greenhouses using soilless culture without loss of yield and fruit quality.