In 1999, two studies were conducted using bell pepper (Capsicum annuum L.) Study one evaluated the effect of three different mulch systems and bare soil (BS) on day and night temperatures encountered during the early growth, flowering, and fruit set period. Mulch systems were black plastic (BP), black plastic over white plastic (BOW), and minimum tilled rye (MTR). Study two evaluated the use of a 30% shade fabric on black plastic produced bell pepper. In study one, maximum daytime temperatures during the pre-flowering phase was significantly higher for MTR, 35.9 °C, compared to, 33.3, 32.5, and 32.1 °C for BOW, BP, and BS respectively. During early fruit set and fruit development, MTR was 36.9 °C, compared to 35.6, 34.9, 34.9 °C for BWP, BS, and BP respectively. Minimum nighttime temperatures were not significantly different between treatments. Bloom numbers and fruit set were adversely affected by MRT and were significantly lower than other treatments 23 and 15 days prior to harvest. Marketable weight and number of fruit per plot were significantly lower at harvest for MRT, 2.5 kg compared to 15.7, 14.5, and 11.6 kg for BWP, BP, and BS respectively. In study two, 30% shading 15 days prior to harvest resulted in 40% increase in number, 101 and 72, and weight, 21 and 15 kg, of marketable fruit for shaded area compared to nonshaded area respectively. Numbers of culls per plot, predominately sunburned fruit in non-shaded area, were reduced 72% by shading. The potential for developing systems to improve bell pepper production in Alabama are feasible based on these studies.
Robert Boozer, Eric Simonne, and Jim Pitts
Robert Boozer, Eric Simonne, and Jim Pitts
A clear polyester plastic was evaluated to determine if its physical properties were suitable for vegetable plasticulture. Integrity of the clear plastic was greatly reduced if edges were damaged or torn, resulting in ripping during the mulch lading process. All six punching devices evaluated for planting holes performed well on the black plastic. Flame burner rated highest for the clear plastic and the lowest rating was achieved with the standard transplanter wheel punch. Clear plastic deteriorated quickly and by 78 days after laying was brittle. Where paint treatments provided adequate coverage, deterioration was greatly reduced. Weed growth under clear plastic was a problem early, but weeds soon died due to heat accumulation under the clear plastic. Despite a lower cost, limited agricultural use could be made of this material.
Arlie A. Powell, James Pitts, and Robert Boozer
Early flowering of peach in the southeastern U.S. often results in some annual crop loss as a result of late winter–early spring freezes. It has been shown in peach and other prunus that a fall application of ethephon delays flowering 4 to 7 days and possibly affords increased bud hardiness. However, delayed harvest and smaller fruit size of certain varieties may occur. Hydrogen cyanamide replaces lack of chilling in peach, but can also advance harvest date and possibly enhance or maintain fruit size. A randomized complete-block experimental design was used to evaluate whether hydrogen cyanamide could offset the delayed harvest and smaller fruit size disadvantages of using ethephon without advancing bloom dates over a 3-year period. Treatment combinations of ethephon (at 20%, 50%, and 90% of required chilling) and hydrogen cyanamide (at 90% to 100% of required chilling) were applied as whole-tree foliar sprays to near point of drip. Results exhibited a possible trend toward hydrogen cyanamide overcoming smaller fruit size and delayed harvest.
Eric Simonne, Robert Boozer, and Amarat Simonne
White sweet corn (Zea mays L.) is widely grown in the southeastern United States. Although `Silver Queen' has been a popular variety in that region for over 20 years, many other varieties are now available. Selecting a variety for commercial or home production is a complex decision because varieties vary considerably with regard to field performance, ear characteristics, and eating quality. Because limited information is available on overall evaluation of sweet corn varieties, the objectives of this study were to 1) evaluate field performance, ear characteristics and eating quality of selected white sweet corn varieties, 2) globally compare varieties using an overall rank-sum index (ORSI), and 3) determine if `Silver Queen' is still the best variety or if it benefits from name recognition. Significant differences among varieties were found for most of the attributes evaluated. When a variety needs to be selected on the basis of a single group of attributes, our results suggest that the best varieties for field performance, ear characteristics and eating quality were `Even Sweeter' and `Treasure', `Silver Queen' and `Rising Star', and `Silverado', respectively. When ranks for all attributes were pooled together, the ORSI for all varieties fell within the 40 to 60 median range for ORSI. These results suggest that while marked differences between varieties can be found for a selected attribute, overall all selected varieties showed similar potential for commercial production. Panel response on sweet corn variety names and the rate of correct blind identification of `Silver Queen' suggested that while it is still among the best varieties, `Silver Queen' did benefit from name recognition.
Robert T. Boozer, Robert C. Ebel, and James A. Pitts
A Phil Brown Corporation, hydraulic operated rope thinner was evaluated in 1995 and 1997 to determine performance for bloom thinning under Alabama peach growing conditions. Using detailed pruned trees in 1995, the rope thinner removed 55% and 57% of the blooms from two double pass treatments and 42% from single pass. Thinning was 9% to 31% higher in the upper one-half of the fruiting zone. In 1997, nondetail pruned trees were used and ground speed was evaluated. Percent blooms removed by single pass were 28, 23, and 22 for 1.6, 3.2, and 4.8 km·h-1, respectively. Double pass clockwise removed 38% of the blooms at 3.2 km·h-1. Greatest time saving for follow-up hand thinning was 15 minutes per tree with double pass over hand-thinned only.
Robert C. Ebel, Arnold Caylor, Jim Pitts, and Bobby Boozer
Ethrel [(2-chloroethyl)phosphonic acid] was applied at 0, 100 or 200 ppm (mg·L-1) for 3 years to the early maturing `Empress' peach [Prunus persica (L.) Batsch] to determine if bloom delay by Ethrel reduces fruit weight at harvest. Trees were hand thinned at 0 or 3 weeks after full bloom to equalize cropload across Ethrel treatments and to determine if any reduction in fruit weight by Ethrel can be compensated by harvest with earlier thinning. Ethrel at 200 ppm (mg·L-1) delayed bloom by 3, 0, and 7 days in 1994, 1996 and 1997, respectively. Despite bloom delay, Ethrel did not delay harvest or reduce fruit weight. Thus, earlier hand thinning was not necessary. Ethrel did not affect blossom density and was not phytotoxic to vegetative or reproductive organs. These results indicate that even with the shorter fruit growth period of early maturing peach cultivars such as `Empress', there is sufficient time for fruit growth to recover on Ethrel treated trees so that fruit weight at harvest is not reduced.
Arlie A. Powell, Robert T. Boozer, and James A. Pitts
Phenological studies were conducted over a 3-year period beginning in Winter 1993–94 to relate flowering and fruiting stages of peach to heat accumulation [growing degree hours (GDH)]. Mature trees of `Loring' and `Redhaven' peach in the same orchard were used annually. Some variation from year to year was apparent in GDH levels related to 50% flower and other stages of development. Major sources for this variation appear to be timing and severity of pruning, tree vigor, and shoot diameter. Temperature predict models were used successfully to properly forecast GDH accumulation and and various flowering and fruiting stages once rest was satisfied.
Esmaeil Fallahi, Bahar Fallahi, James R. McFerson, Ross E. Byers, Robert C. Ebel, Robert T. Boozer, Jim Pitts, and Bryan S. Wilkins
Effects of Tergitol-TMN-6 surfactant on blossom thinning (fruit set), fruit quality, and yield were studied in different cultivars of peach (Prunus persica [L.] Batsch) during 2003 to 2005, and in one cultivar of nectarine Prunus persica [L.] in one orchard and one cultivar of plum (Prunus domestica [L.]) in two orchards in 2004. In addition to Tergitol-TMN-6, effects of Crocker's fish oil (CFO) alone in three peach cultivars or in combination with lime sulfur in a nectarine cultivar were studied on fruit set, quality, and yield. Tergitol-TMN-6 at 5 mL·L–1 or higher rates, applied at about 75% to 85% bloom, reduced fruit set without russeting peach fruit. Peach fruit size was often increased by Tergitol-TMN-6 treatment. Applications of Tergitol at 20 mL·L–1 or 30 mL·L–1 excessively thinned peaches. Tergitol-TMN-6 at all rates burned foliage, but the symptoms disappeared after a few weeks without any adverse effects on tree productivity. Tergitol-TMN-6 at 7.5 mL·L–1 or 10 mL·L–1, applied either once at about 80% to 85% bloom or twice at 35% bloom and again at 80% to 85% bloom, reduced fruit set without any fruit russeting in nectarine. Tergitol-TMN-6 at 7.5 mL·L–1 to 12.5 mL·L–1 reduced fruit set in `Empress' plum. CFO at 30 mL·L–1 was effective in blossom thinning of some peach cultivars. A combination of lime sulfur and CFO was not effective in blossom thinning of nectarine. Considering results from several orchards in different locations in the Pacific Northwest over 3 years, Tergitol-TMN-6 is an excellent blossom thinner for peach, nectarine, and plum at rates of 7.5 to 12.5 mL·L–1, sprayed at a spray volume of 1870.8 L·ha–1 when about 75% to 85% blooms are open.
Wheeler G. Foshee III, Brad E. Reeder, Raymond J. Kessler Jr., Larry W. Wells, Joseph M. Kemble, Edgar L. Vinson, Robert T. Boozer, and William A Dozier Jr
Production of high tunnel tomatoes and snapdragons was evaluated over a 2-year period at the Wiregrass Experiment Station, in southeastern Alabama. `BHN 640', `Florida 91', `Sunleaper', and `Carolina Gold', were evaluated in early Spring 2004. Results indicated that `BHN 640' outperformed `Florida 91' and `Carolina Gold' in early production of high tunnel grown tomatoes. A late Fall 2005 study examined `BHN 640' and `Florida 91'. Results indicated that `BHN 640' was superior to `Florida 91' in total marketable fruit. Season extension of both spring and fall tomato production were accomplished. A planting date study was completed in the early Spring 2005. The following four planting dates were evaluated: 31 Jan., 17 Feb., 4 Mar., and 25. Mar 2005. Wind damage to the high tunnel caused some mortality; however, the two earliest planting dates (31 Jan. and 17 Feb. 2005) produced over 10 lbs. of marketable tomatoes per plant. These were both superior to the last planting date of 25 Mar 2005. Cut snapdragons were evaluated for suitable colored mulch (red, white, or blue) and varieties for summer (`Opus Yellow', `Opus Rose', `Monaco Red', and `Potomac Early White') and fall (`Apollo Purple', `Apollo Yellow', `Monaco Red', `Monaco Rose', and `Potomac Early Orange') production. Results indicated that inflorescence length was affected by the color of mulch. The red mulch had increased inflorescence length compared to the white in Summer 2005. The Fall 2005 study revealed that white mulch had longer inflorescence length than the red or blue mulch. Some varietal differences were observed. The `Apollo Purple' had longer stem lengths than all other varieties for the fall study. The summer study revealed that `Opus Yellow' had longer inflorescence lengths than all others but stem lengths were all similar.