Evaluation of Bell Pepper (Capsicum annuum) Cultivars Grown Under an Open Shaded Structure University of Florida IFAS Extension - County Faculty Fenneman, D.K., A. Gazula, R.C. Hochmuth, S.R. McCoy, and W.L. Laughlin. Florida produces nearly 20,000 acres of green bell peppers in the field annually. Field grown Florida bell peppers are not available in large supply during the late summer and early fall (July- September) due to high temperature, high humidity and frequent rainfall during that time. The marketplace prefers that growers consistently supply high quality product for as long as possible. This entices large wholesale growers to produce in multiple field locations to extend their season. Small, direct market farmers extend the season through the adoption of season-extending cultural practices rather than changing locations. Most of the season extension practices lengthen the season into the cooler part of the year. Yet, few practices are used to extend the season into the hottest part of the year. This research trial was conducted to continue the initial work with bell peppers under shade production and to evaluate several bell pepper cultivars for their performance in this system. Background & Objective Materials & Methods The trials were conducted under an open 40x40 ft commercial shade structure (Atlas, Alapaha, GA) (Figure a). Peppers were grown in 3- gallon plastic pots filled with a soilless media. Pots were arranged in single rows with 4 foot spacing between the centers of the rows. Plants were spaced 12 inches apart in the row (Figure b). The bell pepper crop was established on April 3, 2012 using transplants. The trial was established with one transplant per pot. Pepper cultivars were selected because of their performance as a vigorous field cultivar and likelihood to perform well over a long production period of 7 to 8 months with mature green fruit as the target maturity for harvest. The crop was irrigated and fertilized using standard hydroponic production practices. Plants were trellised with string and plastic plant clips supporting each plant to an overhead cable trellis system. Three weeks after transplanting, the pepper plants were pruned to form a double stem system over each row. Plant height measurements were taken on 20 June, 5 July and 15 Aug, and mature green fruit were harvested every two to three weeks from 11 June through 19 Nov 2012. Fruit were graded into USDA grades and each grade was counted and weighed. The yield for the peppers grown under shade was converted to yield per acre. Cultivar Fruit Length (in) Plant Height (in) 4288A 3.69 bcd 52.8 8302 3.70 abcd 52.5 9325 3.79 abcd 69.5 2815 3.86 abc 56.3 Aristotle 4.09 ab 46.8 Godzilla 3.90 abc 55.3 Vanguard 3.77 abcd 54.5 Heritage 3.75 abcd 61.0 20896 3.61 cd 58.5 50169 3.77 abcd 60.8 Olympus 4.17 a 58.0 20854 3.35 d 62.3 Tomcat 3.79 abcd 54.0 Crusader 3.50 cd 49.8 Cutlass 3.80 abcd 49.0 Phoenix 3.34 d 62.5 Colossal 3.52 cd 63.8 Significance p<0.002 NS Cultivar Early Season Yield (Boxes/A) Mid Season Yield (Boxes/A) 4288A 682 c 1,011 abcd 8302 735 bcd 966 bcd 9325 740 bcd 1,422 ab 2815 784 abcd 980 bcd Aristotle 757 bcd 956 bcd Godzilla 949 ab 1,323 abc Vanguard 788 abcd 980 bcd Heritage 680 cd 1,327 abc 20896 662 d 1,102 abcd 50169 811 abcd 1,330 abc Olympus 807 abcd 883 cd 20854 898 abc 1,481 a Tomcat 796 abcd 818 d Crusader 998 a 1,093 abcd Cutlass 995 a 879 cd Phoenix 822 abcd 1,125 abcd Colossal 837 abcd 1,396 ab Significance p<0.02 p<0.02 Cultivar Total Yield (Boxes/A) Total Fancy Yield (Boxes/A) 4288A 2,637 1,651 bcd 8302 2,426 2,111 abc 9325 3,094 2,273 abc 2815 2,611 2,092 abc Aristotle 2,385 1,599 cd Godzilla 3,127 2,553 a Vanguard 2,299 1,884 abcd Heritage 2,829 2,246 abc 20896 2,667 1,836 bcd 50169 2,899 2,330 ab Olympus 2,255 1,830 bcd 20854 3,315 2,271 abc Tomcat 1,967 1,332 d Crusader 2,659 1,896 abcd Cutlass 2,394 1,722 bcd Phoenix 2,475 1,833 bcd Colossal 3,300 2,250 abc Significance NS p<0.01 Production of bell peppers in an open shade structure resulted in mostly US Fancy fruit, especially during the early and mid-season harvests, but much less during late season harvests. Fruit length was significantly different among cultivars and varied from 3.35 inches in ‘Phoenix’ to 4.17 inches in ‘Olympus’ (Table 1). Several cultivars had fruit length similar to ‘Olympus’. Total season marketable yields ranged from 1967 to 3315 boxes per acre (28-lb boxes), but yield differences were not significant (Table 2). The total season marketable fruit were mainly in the Fancy category. Total season Fancy yields varied from 1332 boxes per acre with ‘Tomcat’ to 2553 boxes per acre with ‘Godzilla’ (Table 2). Nine cultivars had similar total season Fancy yields to ‘Godzilla’. Yields reported here were lower than in a 2006 trial due to increased number of days with extended cloudy and rainy weather, especially during June and July, including tropical storm Debby. Differences in early and mid-season yields among cultivars were significant, however, late season yields were similar among cultivars (Table 3). Overall fruit size decreased in the late summer and early fall harvests. The percentage of the total fruit graded as Fancy was typically over 95% among all cultivars during early season harvests, but decreased to 80% during mid-season harvests, and was about 35% or less during late season harvests. During the long growing season another important factor in selecting a cultivar is plant height. In this trial, the plant heights did not show significant differences. There was a trend in plant height among cultivars, but a high degree of variability within cultivars, largely due to stem breakage during storms, led to no significant differences (Table 1). Overall top performers are listed in Table 4. The results from this trial were presented at educational field days (Figure c). Shade structures allow small farmers to extend the growing season of not only peppers (Figure d) but with other crops as well (Figure e). Results & Discussion Table 1: Effect of cultivar on fruit height & fruit width. Table 2: Effect of cultivar on Total & USDA Fancy fruit yield. Table 3: Effect of cultivar on early & mid season yield. Top Total Season Fancy Yielding Largest Fruit (L and W) 8302 8302 9325 9325 2815 2815 Vanguard Vanguard 50169 50169 Heritage Aristotle Godzilla Tomcat 20854 Crusader Colossal Table 4: Top performing pepper cultivars. Figure a: Commercial shade structure used in trial. Figure b: Pepper plant setup in shade structure. Figure e: Small farmer growing mixed vegetables under a shade structure. Figure d: Small farmer growing green peppers under a shade structure. Figure c: UF/IFAS Extension field days demonstrating shade production systems.