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Made available in DSpace on 2014-06-11T19:26:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-24Bitstream added on 2014-06-13T20:34:24Z : No. of bitstreams: 1 takata_whs_me_botfca.pdf: 422211 bytes, checksum: 5af12fb97f188348230baf5f4a2c8a89 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O mercado de frutas exóticas no Brasil tem ganhado prestígio e o cultivo da pitaya apresenta-se promissor. Porém, o seu ciclo é limitado ao longo do ano, principalmente, pela influência do fotoperíodo no seu florescimento. A utilização de regulador vegetal, sobretudo a giberelina (GA), pode substituir a necessidade de dias longos. Nesse sentido se estudou diferentes épocas de aplicação e várias concentrações de GA3 no período não indutivo com o objetivo de induzir e antecipar o florescimento. O delineamento experimental utilizado foi blocos ao acaso em esquema fatorial 3x5, sendo três épocas de aplicação e cinco concentrações do regulador vegetal. As épocas de aplicação iniciaram em maio, junho e julho, sendo realizadas três aplicações a cada 30 dias. As concentrações estudadas foram 0, 100, 200, 300 e 400 mg L-1 de GA3. A época de aplicação de GA3 não influenciou em nenhuma das características estudadas, por outro lado o fator concentração, apesar de não ter antecipado o florescimento, proporcionou aumento na fixação de frutos, número de frutos, massa média de frutos e produtividade. Com base nos resultados obtidos é possível concluir que a aplicação de GA3 foi benéfica às características agronômicas da pitaya / The exotic fruit market in Brazil has gained prestige and cultivation of pitaya presents promising. But the cycle is limited throughout the year, and its flowering by photoperiod. The use of plant growth regulator, especially gibberellins, can replace the need for long days, in this sense, we studied different application periods and some concentrations of GA in non-inductive period in order to anticipate flowering. The experimental design was randomized blocks in factorial scheme 3x5, being three times of application and five concentrations of the GA3. The application periods began in May, June and July, and three times application, one every 30 days. The concentrations studied were 0, 100, 200, 300 and 400 mg L-1 GA3 application timing did not influence any of the traits on the other hand the concentration factor, despite not having anticipated the flowering could provide increased fruit set, fruit number, mean fruit mass and productivity. Based on the results, we concluded that the GA3 application was beneficial to the agronomic characteristics of pitaya

Studies were conducted to evaluate the effects of trinexapac-ethyl (TE) on height reduction, tillering, chlorophyll content, color, flowering, and root development of three ornamental grasses: Calamagrostis ×acutiflora 'Karl Foerster', Miscanthus sinensis 'Variegatus', and Pennisetum ×advena 'Rubrum'. Two applications of TE reduced height in all grasses and improved chlorophyll content in C. 'Karl Foerster' while delaying flowering in M. 'Variegatus' and P. 'Rubrum'. Tillering was slightly increased in M. 'Variegatus' with two TE applications. Shoot dry weight (SDW) and root dry weight (RDW) were reduced in C. 'Karl Foerster', SDW was reduced in P. 'Rubrum' and SDW and RDW were unaffected by applications of TE in M. 'Variegatus'. TE is effective for growth control in ornamental grass production systems; however, the results are species specific and should be tested further before widespread use on other ornamental grass species.

Flower forcing to meet holiday market can increase the value of potted flowering plants. This study was to investigate the effects of chilling and post-chilling photoperiod treatments on flowering of banana shrub and the effects of water stress, daminozide, chlormequat, and ethephon on flowering of bougainvillea. Experiments were conducted at R.R. Foil Plant Science Research Center and MSU Dorman Greenhouse at Mississippi State University (MSU), Mississippi State, MS. Results from banana shrub experiment indicated that 8-week chilling at 8 ºC was necessary for banana shrub to break bud dormancy and a tank mix of daminozide and chlormequat was able to increase the number of flower buds on banana shrub. Results from bougainvillea experiment indicated that water stress, daminozide, and chlormequat enhanced flowering. In conclusion, this study provided fundamental information to future research on flower forcing of banana shrub and bougainvillea.

Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Dale J. Bremer / Jack D. Fry / Irrigation management may influence nitrate leaching under tall fescue (Festuca arundinacea) and also affect its mowing requirements. Two experiments were conducted on tall fescue growing on a Chase silt loam soil near Manhattan, Kansas. Each experiment was arranged in a split-plot design, with irrigation treatments applied to whole plots: 1) frequency-based irrigation, water was applied three times weekly to deliver a total of 19 mm water wk⁻¹ regardless of weather conditions; and 2) soil moisture sensor (SMS)--based irrigation, 34 mm of water was applied when soil dried to a predetermined threshold. In the first experiment, sub-plots consisted of unfertilized turf, and N applied as urea or polymer-coated urea at 122 and 244 kg ha⁻¹ yr⁻¹. Suction lysimeters at a 0.76 m depth were used to extract nitrate leachate bi-monthly. Turf quality was rated weekly. In the second experiment, subplots were mown at 5.1 cm or 8.9 cm, based upon the 1/3 rule, with or without monthly applications of the growth regulator trinexapac-ethyl (TE). Data were collected on total mowings and visual turf quality. Soil moisture sensor-based irrigation resulted in water savings of 32 to 70% compared to frequency-based irrigation. Leaching levels did not exceed 0.6 mg L⁻¹ and no differences in leaching were observed between irrigation treatments or among N sources. All fertilized turf had acceptable quality throughout the study. In the second experiment, irrigation strategy did not influence total number of mowings. In the first year, TE application reduced total mowings by 3 in tall fescue mowed at 5.1 cm, but only by 1.5 when mowed at 8.9 cm. In the second year, mowing at 8.9 vs. 5.1 cm or using TE vs. not resulted in a 9% reduction in total mowings each. The SMS-based irrigation saved significant amounts of water applied compared to frequency-based irrigation, while maintaining acceptable quality, but irrigation treatments did not affect nitrate leaching or mowing frequency in tall fescue on fine silt-loam soil. Nitrate leaching, regardless of amount, was well below the standards set for human health (10 mg L⁻¹). Applications of TE are more beneficial for turfgrass mowed at lower cutting heights.

An experimental site was selected at Yuma Agricultural Research Center, University of Arizona, to evaluate the effect of Messenger on melon plant growth and yield. Four treatments in completely randomized block design replicated four times were applied to melon planted on 84- inch beds. High Mark open pollinated melon variety was planted on 3-20-2001 using a commercial planter. Treatments included Messenger applied at 3-leaf stage on 5-4-2001 Messenger applied every 14 days starting on 5-15, 5-29, 6-13, 6-27-2001, standard management practices and control. Observations collected included plant mapping and yield. Results were variable, showed no significant effect of Messenger on plant growth and yield. However, there was indication that Messenger may have an effect on plant growth pattern and yield. Messenger applied at 3-leaf stage and repeated applications seemed to induce an early melon formation, increased number of nodes and yield. It was not possible to make recommendation based on one-year results. Further investigation is needed to verify the results obtained from this experiment.

Messenger applied at three timely applications at early runner, bloom, and fruiting stages of watermelon versus bi-weekly applications, showed no significant statistical differences for vine length, number of blooms, or harvestable yields. Visual observations for the watermelon plant health at the end of the season tended to indicate that the three timely applications resulted in slightly more vigorous plants than the bi-weekly treated watermelon plants. Cantaloupe vine growth, number of fruit set, yield weight, and fruit size were not different between Messenger treatments and were not enhanced compared to the untreated check.

Processing onions were treated with AuxiGro in spring 2001. Applications were applied at four and 7.5 weeks prior to harvest. A single application of 4 oz. product/acre at either four or 7.5 weeks prior to harvest increased yield by approximately 0.7 tons/acre. Two applications resulted in a 1.3 tons/acre yield increase. Differences noted were not statistically different, but the two application treatment provided an increased net return of approximately $95/acre.

Dry Seed+, a fertilizer/plant growth regulator, was applied to processing onions at planting in the fall of 1998 to evaluate the effect on yields. Yield data obtained June 1999 indicated no effect in this experiment, although this was dissimilar to other trial results. Salt content at the field was thought to have limited yields, and have stressed growing plants, which may have contributed to lack of yield differences noted. Further testing is necessary to further evaluate this product.

In 2011, Poa annua L. (Poa) biotypes were collected from greens of two golf courses in Lexington, Kentucky: 1.) The Lexington Country Club (LCC) and 2.) The University Club (UC). The samples were collected based on exhibiting one of two appearances while on the same green: 1.) dark green, with few to no flower heads (dark biotype) or 2.) light green, with numerous flower heads (light biotype). Two PGRs, paclobutrazol and flurprimidol, and two herbicides, bispyribac-sodium and amicarbazone, were applied to the plants both in the field and the greenhouse. Quality ratings were recorded weekly in both the field and greenhouse and grass clippings were collected and measured weekly in the greenhouse. Flurprimidol controlled the dark biotypes and paclobutrazol controlled the light biotypes in the field in 2011. However, only location by treatment interactions were in 2012; flurprimidol, bispyribac-sodium, and amicarbazone controlled the biotypes from the LCC while paclobutrazol controlled the biotypes from UC. In the greenhouse study there was a significant three way interaction between color, location, and treatment for quality. PGRs controlled the light biotypes from LCC and the dark biotypes from UC. Herbicides controlled the light biotypes more than the dark, however, the light biotypes recovered after amicarbazone treatments. PGRs reduced clipping weights of the dark biotypes more than the light and herbicides reduced clipping weights of the light biotypes more than the dark. Both PGRs and herbicides reduced clipping weights of the Poa collected from the LCC more than UC. These results demonstrate both the potential for differential responses between Poa biotypes to PGRs and herbicides and that these differences, like all things about Poa, may be complex. A laboratory experiment was also designed to examine the absorption and potential metabolism of 14C-labeled flurprimidol in creeping bentgrass (Agrostis stolonifera (L.)), bermudagrass (Cynodon dactylon (L.)), Kentucky bluegrass (Poa pratensis (L.)), perennial ryegrass (Lolium perenne (L.)), tall fescue (Festuca arundinacea (Schreb.)), and zoysiagrass (Zoysia japonica (Steud.)) and light and dark Poa biotypes collected from golf greens. Flurprimidol absorption and translocation was greater for warm season grasses than cool season grasses. Only parent flurprimidol was detected in all turf species.