Sales of containerized roses have increased dramatically in recent years and producing flowering plants in containers in a timely manner is important to the nursery industry. An experiment was conducted to determine whether forcing containerized roses will be faster in a retractable roof greenhouse compared to outdoors. Results suggest that forcing roses in a retractable roof greenhouse can shorten the production time and increase quality of finished plants, however, cultivar, time of harvesting, and time in cold storage also affect these parameters.

The objective of this study was to determine whether mesquite (Prosopis velutina) and jojoba (Simmondsia chinensis) seedlings have a preference for the ammonia or nitrate form of nitrogen (N) to maximize growth and minimize N leaching when seedlings were grown in sand culture. Seedlings were fertigated with different ratios of NH₄⁺:NO₃⁻ to determine effects on shoot and root growth and N leaching. Nutrient solution containing 67 % NH₄⁺: 33 % NO₃⁻ resulted in greatest biomass of mesquite seedlings after 120 days of fertigation. N tissue concentrations of mesquite seedlings were highest for plants supplied with 100% ammonium. N leachate remained stable until 12 weeks after the onset of treatment, but increased significantly by week 16. Dry weight of jojoba seedlings did not differ throughout the experiment regardless of the nutrient solution provided, however N tissue concentration in jojoba seedlings fertigated with 100% ammonium was twice as high as that of plants fertigated with 100% nitrate.

The objective of this project was to determine whether the size of planting holes and the addition of organic material in the backfill is beneficial for plant establishment and growth during the early years. Acacia farnesiana were transplanted from containers into a permanent landscape using four methods: large planting hole with or without amendments or a small planting hole with or without amendments. The study was repeated on two sites. Three years following transplanting, plant growth such as height and caliper were not affected by the planting hole size or amendments, but differed significantly between sites. Plants that received more irrigation and were planted in a less rocky soil had greater caliper and were taller than those supplied with less irrigation and planted on a more rocky soil. Visual observations one and three years after transplanting indicate that trees that were amended with compost in the backfill had the highest incidence of leaning trunks and sinking crowns (20% of trees in study or 37% of those receiving amendments) while of those trees that were not amended only one tree (3%) was leaning three years after transplanting. Hole size at transplanting had no significant effect on leaning or sinking three years after transplanting. These results confirm earlier research across the country that 33% to 50% organic amendment in backfill compared to native soil at transplanting is not beneficial for native trees, but increases the risk of leaning or sinking.

The efficacy of six ALS herbicides for controlling purple nutsedge in bermudagrass turf was demonstrated in five field experiments during the summer of 2004. The highest degree of nutsedge control at 95% at the end of the summer was observed after three monthly applications of trifloxysulfuron at 0.026 lb a.i./A.. Three monthly applications of halosulfuron at 0.062 lb a.i./A controlled nutsedge 88 to 90% at the end of September to early October. Imazaquin at 0.5 lb a.i./A plus MSMA at 3.0 lb a.i./A gave 91% control of nutsedge with three applications. The most rapid and efficacious nutsedge control was observed with flazasulfuron giving 91% control at 15 days after a single application. The highest degree of nutsedge control with a single application of sulfosulfuron was 91 to 96% control at 28 days after treatment. In general, ALS herbicides applied as a single application or multiple applications provided one month of effective control following a first application. After one month, the degree of control declined unless repeated applications at monthly intervals or as needed were applied for extended control. Penoxsulam at 0.12 lb a.i./A in one test gave only 70% control. MSMA at 3.0 lb a.i./A was applied four times and nutsedge control at the end of the season was 63 to 66%.

Higher SU herbicide rates provided more effective ryegrass removal that resulted in improved establishment of the seeded bermudagrass. In most instances in this study, the percent bermudagrass coverage increased as herbicide rates increased. Glyphosate was very effective in completely removing ryegrass non-selectively. Flazasulfuron at 0.018 lb ai/A eliminated 88% of the ryegrass. Observations also showed that foramsulfuron, rimsulfuron,and chlorsulfuron were effective in removing ryegrass. In plots where ryegrass had been eliminated, faster bermudagrass coverage in a greater area of the plot was achieved. The least amount of bermudagrass coverage occurred in the untreated plots. It appeared that most of the herbicides evaluated in this study were relatively safe on seeded Princess 77 bermudagrass since emergence and establishment occurred in all plots. The speed and degree of coverage in the plots increased due to efficacy of the herbicides in eliminating ryegrass prior to seeding.

Velocity, (bis pyrobac-sodium) was applied at different ai/a rates in multiple application series to evaluate treatments for post emergence seed head and vegetative control of Poa annua var. annua. Velocity herbicide, when applied to perennial ryegrass overseed turf with heavy PA infestations, caused periodic discoloration of the ryegrass and yellowing/bronzing of the PA. The leaf yellowing of PA caused by Velocity is in contrast to color enhancement of PA from Proxy/Primo tank mixes. Seed head suppression of PA from Velocity was slightly greater in early April, than in early March. As cumulative treatment amounts of active ingredient of Velocity increased, the seed head suppression increased for treatments beyond the 30 + 30 gm ai/a rate. Above this rate, seed head suppression was increased, but not consistently with the applied active ingredient rate. Seed head suppression of PA on March 5 from Velocity ranged from 35% to 75% among Velocity treatments applied at 30, 45 and 60 grams ai/a. Embark alone had fair seed head suppression from early to mid-March, but decreased dramatically afterwards. There was no benefit of the 30 + 60 gm ai/a treatment, over the 60 + 60 gm ai/a treatment for seed head suppression of PA. Biological response in terms of absolute rate of ai/a applied and response to cumulative amounts of total Velocity were not consistent for PA seed head suppression or vegetative control. No product affectively reduced vegetative control of PA in a highly infested stand of PA which was 40-50% PA. If Velocity is to be competitive against other PA seed head reducing products, rate structures and timings may have to be amended for more multiple applications.

Several items need consideration when products are evaluated for use as transition agents. These are (1) efficacy of ryegrass removal [rate of ryegrass decline and appearance of turf during transition], (2) tolerance and performance of incoming bermudagrass and (3) application safety for next season’s repeat overseed operations. This test was designed to evaluate application safety for the next overseeding which occurs in the early fall. Therefore, AEF was applied in the summer to bermudagrass turf prior to overseed operations. Most responses of the perennial ryegrass (overseed) turf to previous treatments of AEF 130360 occurred immediately after overseeding, from mid-October to early November. AEF 130360 applied 2 weeks before overseeding caused a significant decrease in seedling vigor, percent plot ryegrass cover, and percent bermudagrass plot straw present. Both AEF treatments applied closest to overseeding (2 weeks prior) had the least amount of initial ryegrass, the greatest amount of green bermudagrass, and later in the season, the most amount of straw (dormant) bermudagrass. Differences in turfgrass quality were not significant due to treatments at any time throughout the test, and most treatments ranked higher than the control in overall quality. Under the conditions of this test, application of AEF 130360 at either 0.64 or 1.28 ounces/product/M made one month before actual oversseding did not cause detrimental effects to ryegrass emergence, ryegrass cover, turfgrass color or overall quality.

Proxy (ethephon) was applied to 100% pure stands of Poa annua as either a single or repeat application 24 days apart at both a five and ten-ounce product rate per 1000 square feet. Percent plot seed heads were decreased significantly on three of five evaluation dates before either the loss of treatment effect and/or environmental conditions triggered profuse flowering (by 20 April, 2000). The five-ounce rate produced moderate seed head suppression at 16 and 25 days after the first treatments by which afterwards, control was minimal. By April, the five-ounce repeat applications were no better in suppression of seed heads than either of the single applications, regardless of application timing (March 3 or 29). The ten-ounce rates generally produced 40% - 80% greater seed heads suppression than the five-ounce rate treatments. Maximum seed head control was achieved by the repeat applications (March 3 and 29) of the ten-ounce rate, which consistently produced between 8% and 19%, seed head cover up until the first ten days of April 2000. Proxy, when applied at the five-ounce/M rate had the greatest effect in seed head suppression early in the test (10 March). Perhaps earlier season applications at the five-ounce rate may be necessary to manifest greater suppression initially, and perhaps in a cumulative fashion for season long control.

Several new sulfonylurea products have (or are being) brought to market for use in turf. One use of these products is for removing ryegrass from overseeded bermudagrass, since perennial ryegrass has become too persistent due to improvements in heat, drought, and close mowing tolerance. The soil half life of sulfonylurea is greatly increased in high pH soils, which are typical in the southwest. Superintendents may need to re-establish seeded bermudagrass after use of a S.U. transition agent if the underlying bermudagrass is sparse. With this in mind, a replicated field trial was conducted in summer 2004 to evaluate three rates of foramsulfuron (0.4, 0.8, 1.2 ounce /product/1000 ft2) herbicide at 0, 7, 14, and 28 days after seeding. Foramsulfuron is sold as Revolver. Revolver applied at time of seeding (0DAS) and 1 week after seeding (7 DAS) caused the greatest amounts of bermudagrass suppression in terms of bermudagrass plot cover and visible seedling vigor. When applied (7 DAS), bermuda cover (averaged over all three applied rates of Revolver) at 21, 28, and 36 DAS was 8%, 22% and 32% bermuda cover, respectfully, versus NTC mean values of 22, 49 and 54% cover, respectively. The second greatest degree of Bermuda suppression occurred from Revolver applied at the day of seeding (0 DAS). The effects lasted up until and included the end of the test on 29 Sept (36 DAS). When averaged over all 3 applied rates of Revolver, percent plot bermudagrass cover at 21, 28, and 36 DAS was 10%, 30% and 40% respectively for the 0 DAS treatments. The NTC cover for these same dates was 22%, 50% and 53% respectively. Vigor visual scores were minimal as well for all rates applied at (0 DAS) and at (7 DAS). Plots remained stunted up to 36 DAS for Revolver turfs applied at (7 DAS) and (0 DAS). Application at the time of seeding (0 DAS) resulted in more bermudagrass plot cover than if applied at (7 DAS). Rate reduction responses were realized only for Revolver application timings made at 0 DAS and 7 DAS (Table 1, 5, Figs. 1-4). No rate responses resulted for Revolver when applied at 14 DAS, 28 DAS. In conclusion, Revolver was safest when applied 14 DAS or later, with little rate effects.

Khakiweed (Alternanthera pungens) was treated late in the season with select herbicides for initial screening of herbicides for post emergence control. Treatments were applied on October 7, 2004 and evaluated five weeks after treatment on Nov 16, 2004. The F ratio for the treatment main affect was highly significant for percent weed control. All rate affect contrasts were not significant for those treatments applied at two or more active ingredient levels. The "S.U. herbicides" vs. "all others" contrast was significant at P=0.05, as the S.U.. chemicals as a whole provided better coverage than the 2-4, D type and Penoxsulam. Percent weed control ranged from 7% to 99% late season control of Khakiweed. There were noticeable differences between S.U. products, as Revolver provided minimal weed control (7%) while Manor and Monument provided very good to excellent control (94% to 99%). Both Manor rates resulted in 99% control, while the three rates of Monument produced 94%-98% mean percent weed control values. Penoxsulam was intermediate, providing 56% and 70% control for the SC and G formulations, respectively. Banvel, 2-4, D and Buctril produced 22%-24% Khakiweed control. Tranxit had minimal affect (12%), as did Revolver at 6%.