Potato (Solanum tuberosum L.) production best management practices (BMPs) are under development for the Tri-County Agricultural Area (TCAA; St. Johns, Putnam, and Flagler counties) near Hastings, Fla. BMPs are designed to reduce nitrate non-point pollution in the St. Johns River from the |8000 ha in potato production in the TCAA. Research to develop a controlled release fertilizer (CRF) program to help growers meet the current nitrogen rate BMPs was conducted during the 2003 season. A randomized complete block experiment with four replications was conducted at the Plant Science Research and Education Unit in Hastings, Fla. The treatments were no nitrogen control, ammonium nitrate (168 and 212 kg N/ha) and three CRF products blended at different ratios (168 kg N/ha). Total tuber yields for `Atlantic' for the no nitrogen, and 168 and 212 kg N/ha ammonium nitrate treatments were 11.5, 23.4, and 36.4 MT/ha. The best combination of the three CRF products were a ratio of 33:33:33 with a 40 day, 75 day, 120 day release period, respectively. Total yield for this blend was 42.2 MT/ha. Specific gravities for tubers in all four treatments were 1.060, 1.072, 1.078, and 1.082, respectively. Percent of tubers with hollow heart four all four treatment were 8.1, 18.2, 20.0, and 6.4% respectively. Percent of tubers with internal heat necrosis four all four treatments were 20.6, 8.1, 20.6, and 6.3%, respectively. The CRF treatment produced significantly more tubers than the ammonium nitrate treatment at the same nitrogen rate. Quality of the tubers in the CRF treatment was higher than tubers from the no nitrogen control and ammonium nitrate treatments. Research will continue to optimize the CRF program for potato production in Florida.
Chad Hutchinson* and Eric Simonne
Jason Osborne and Eric Simonne
The challenges encountered and discussions generated during the review process of the manuscripts submitted to the Variety Trials category of HortTechnology have revealed the need to review issues encountered during manuscript preparation and to provide flexible guidelines for authors and reviewers. Using a question/answer format, this manuscript discusses issues related to data collection and statistical methods available to compare varieties. Clear objectives and conclusions, adequate plot size, careful selection of entries, and sound statistical procedures are considered essential. Several additional factors (following standard production practices, using multiple seed sources, reporting analysis of variance table and mean square error, reporting multiyear/multilocation trials) are regarded as desirable, with different degrees of desirability, depending on the crop. These flexible guidelines should be viewed as recommendations for authors and reviewers rather than requirements. While defining the state-of-the-art in variety trialing is of interest to all those involved, it may be difficult to achieve when resources are limiting. It is ultimately the prerogative and responsibility of the author(s) to ensure that the work is scientifically sound.
Carolyn DeMoranville and Eric Simonne
Eric Simonne and John Owen
Because deer pressure in Alabama is high, the efficacy of Garlic Barrier™ (GB) in controlling deer damage was evaluated with sweetpotato (SWP), southernpea (STP), sweet corn (SC), and zucchini squash (ZSQH). GB was applied on or around the plots at 10× the recommended rate. Damage was rated three times weekly on a 0 (0% damage) to 5 (100%) scale between 15 June and 18 Sept. All damage observed was unambiguously attributed to deer. GB on the plot significantly (P < 0.02) reduced grazing damage to SWP and STP, but not enough to prevent economical losses. Protection from GB around the plots was similar to the unsprayed control. Damage to SWP began 3 days after establishment. Damage to STP was limited to the developing pods. No damage was observed to SC and ZSQH (P > 0.37) during vegetative and reproductive stages. These results document scientifically the deer-repellent property of GB under natural conditions when applied directly on the plants. However, in its present formulation and under severe deer pressure, GB alone may not provide economical protection.
Eric Simonne and Ronald Shumack
Vegetable variety trials (VVT) are of interest to the entire vegetable industry from breeders, seed companies, growers, consultants, researchers, to Extension personnel. However, despite their importance VVT have always been given little-to-no scientific merit. In a period where resources are limited, regional VVT may provide a way for Land Grant institutions to include VTT as an entire part of their effort. This presentation will discuss the advantages (better use of resources, increased service to industry), challenges (credit given to VTT authors during tenure, timeliness of publication, uniformity of methods), and opportunities (publications in Hort Technology, regional publication, VTT web page, SR-IEG) associated with VVT. Participants will be given an opportunity to express their opinion through a questionnaire. Together with industry response, results will be used to inform the administration and work toward a regional VTT for the Southeast.
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.
Eric Simonne and Doyle A. Smittle
An irrigation scheduling model for turnip greens (Brassica rapa L.) was developed and validated.. The irrigation scheduling model is represented by the equation: 12.7 (i-3) * 0.5 ASW = 0i-1 + Ei(0.365+0.00154i+0.00011i2) - R - I where crop age is i; effective root depth is 12.7 * (i-3) with a maximum of 300 mm; usable water (cm/cm of soil) is 0.5 ASW; deficit on the previous day is Di-1 evapotranspiration; is pan evaporation (Ei) times 0.365+0.0154i+0.00011i2; rainfall (R) and irrigation (I) are in millimeters. Yield measured as leaf weight, and quality analyzed in terms of color (Gardner XL20 cronameter L, a, b), leaf blade and blade: stem weight ratio were determined. Leaf yield and quality responses were affected by both irrigation and fertilizer rates. Yield increased quadratically as irrigation rates increased from 0 to 190% of the model rate. Maximum leaf yields were produced by irrigations at 100% of the model rate. Leaf quality parameters also tended to change quadratically with irrigation rates. Leaf yield and quality changed quadratically as nitrogen fertilizer rates increased from 80 to 120% of the median recommended N rate for Georgia.
Amy Simonne, Eric Simonne, Ronald Eitenmiller and Christine Harris Coker
Lettuce (Lactuca sativa) production historically has been limited in the southeastern United States because of the risk of early bolting and unacceptable bitterness. Small-scale vegetable growers may be able to include lettuce in their production through selection of bolt tolerant and nonbitter varieties. The objectives of this research were to evaluate earliness, bitterness, vitamin E, ascorbic acid, folate, β-carotene, and lutein content in 17 lettuce varieties. Significant difference were found among varieties for days to harvest (DTH) (47 DTH for `Epic' to 37 DTH for `Big Curly'). Observed DTH in this study was consistently 7 to 10 days less than commercial descriptions of the lettuce varieties, due to the use of transplants. Only `Slobolt' and `Greengo' bolted before reaching marketable size. Panelists found that the bitterness was acceptable for most varieties, but not for `Nancy,' `Big Curly,' and `Slobolt'. Significant differences among varieties were also found in vitamin E, ascorbic acid, folate, β-carotene, and lutein. `Redprize' and `Nevada' were the best varieties overall, while `Salinas 88 Supreme,' `Epic,' `Legacy,' `Big Curly,' `Slobolt,' and `Greengo' were unacceptable.
Chris Frank, Eric Simonne, Robert Nelson, Amarat Simonne and Bridget Behe
Most bell peppers produced and consumed in the United States are green in color. However, red, yellow, orange, brown, white, black, and purple bell pepper are also available. While bell pepper consumption has been increasing in the past 10 years, limited information is available on how color, retail price, and vitamin C influence consumer behavior. A conjoint analysis of 436 consumer responses showed that color (75%) and retail price (23%) were more important than vitamin C (3%) in shaping consumer purchase decision. Six consumer segments were identified. Segments II to V preferred green bell pepper, while segments I and VI favored the orange and brown color, respectively. Demographic variables were not good predictors of segment membership. However, previous purchases of bell pepper significantly affected the probability of membership in at least one segment. These results suggest that while green is the preferred color, a market exists for orange, red, and yellow peppers. Results on price sensitivity suggest that profits at the retail level are likely to increase by increasing the price of green peppers, and decresing that of the colored ones.
Eric Simonne, Amarat Simonne, Nancy Green and Jim Pitts
Field performance, ear characteristics and sensory ratings were determined for `Even Sweeter,' `Fantasia', `Silver Queen', `Silverado', `Snow Belle', `Snow White', `Starshine', and `Treasure' sweet corn varieties. Yield (P = 0.60), ears per hectare (P = 0.77), and ear fill (P = 0.22) were not significantly affected by variety, whereas ear set height (P < 0.01), ear length (P < 0.01) and diameter (P < 0.01), tip cover (P < 0.01), eye appeal (P < 0.01), as well as sensory ratings of appearance (P < 0.01), sweetness (P < 0.01), and flavor (P < 0.01) after cooking were. None of the selected varieties was rated unacceptable. However, because mean separation tests at the 5% and 10% levels did not provide clear groupings and because all attributes have to be considered together in variety evaluation, a global performance index (GPI) was developed by adding the ranks of each variety for each attribute. GPI ranged between 28 for `Treasure' and 59 for `Snow White' on a 10 (best) to 80 (worse) scale. `Treasure', `Silver Queen', and `Even Sweeter' were above average. These varieties may be considered best performers for white sweet corn production in central Alabama.