HORTSCIENCE, VOL. 31(2), APRIL 1996 198 CROP PRODUCTION HORTSCIENCE 31(2):198–200. 1996. important. Optimum plant population or in- row plant spacing studies have been conducted on bell (Batal and Smittle, 1981; Everett and Subramanya, 1983; Locascio and Stall, 1994; Russo, 1991; Stoffella and Bryan, 1988), cherry (Orzolek, 1981), pimento (Johnson et al., 1973), cayenne (Decoteau and Graham, 1994), and Tabasco peppers (Sundstrum et al., 1984). Little research has been conducted on pepperoncini pepper (Saamin, 1978). Our ob- jective was to investigate the influence of in- row plant spacing on pepperoncini pepper growth and yield. Materials and Methods Five in-row plant spacings were evaluated: 7.5, 15, 22.5, 30, and 45 cm on raised beds, 0.85 m wide and 15 cm high. Field studies were conducted at the Dept. of Horticulture Hill Farm in 1992 and the Burden Research Station in 1993 (Baton Rouge, La.). The soils at both locations were an Olivier silt loam (Typic Paleudults). On 27 May 1992 and 4 June 1993, pepperoncini pepper seeds (‘Golden Greek’, Petoseed Co, Saticoy, Calif.) were sown into 72-cell trays (cell length, 5.7 cm; 4.8 cm 3 ) filled with commercial soilless mix (Metromix 350; W.R. Grace & Co., Cam- bridge, Mass.) and placed in a greenhouse. Four-week-old transplants were hand- transplanted into 3.7-m-long plots on 1.1-m centers. Individual plots consisted of three rows, with all data obtained from the middle row. Plots received 650 kg preplant fertilizer (8N–10.4P–20K)/ha banded in the row and N (NH 4 NO 3 ; 56 kg N/ha) sidedressed on the bed shoulder at first harvest. Recommended pep- per plant establishment and pest management practices were followed (Boudreaux, 1992). Overhead irrigation was applied as needed throughout the season. Immature fruit within the prescribed com- mercial size requirements (3.5 to 6 cm long) were removed by hand twice a week for a total of eight harvests. Marketable fruit were har- vested manually, counted, and weighed for each plot. The first harvests were 4 Aug. 1992 and 17 Aug. 1993. Marketable fruit yields, summed for early (first three harvests) and total yield, were expressed on a per-plant and per-hectare basis. Fruit length, width, and weight were measured from five fruit per plot randomly selected at each harvest. Plant characteristics were measured at last harvest. Stem length, leaf area (LA) [deter- mined with an area meter (Delta-T Devices, Cambridge, England)], fresh and dry weights (70C for 48 h) of stem and leaf fractions, and leaf : stem ratio (dry-weight basis) were deter- mined from one plant in each plot. The follow- ing growth characteristics were calculated according to Hunt (1990): specific LA (SLA) (LA ÷ leaf dry weight), LA ratio (LAR) (LA ÷ total plant weight), and LA index (LAI) (LA ÷ ground area per plant). In addition, stem diam- eter (measured with a caliper at the soil sur- face) was determined from three plants in each plot. In 1993, canopy height (from the soil to top of the canopy) was measured. The study was a randomized complete-block design, with four replications both years. Data were sub- jected to analysis of variance, and orthogonal contrasts were used to analyze significant trends. Results and Discussion Vegetative characteristics. In-row plant spacing influenced pepperoncini pepper plant growth in 1992 (Table 1). As in-row plant spacing increased from 7.5 to 45 cm, whole- plant, stem, and leaf dry weights and stem diameter increased linearly. Stem length, how- ever, was unaffected by in-row plant spacing. LA also increased linearly with wider in-row plant spacing. There were no statistical differ- ences in the leaf : stem ratio and SLA. In-row spacing influenced the LAR and LAI cubi- cally. The highest plant, stem, and leaf dry weights and LA and the largest stem diameter were from plants produced at the widest spac- ing (45 cm). The lowest plant, stem, and leaf dry weights, the smallest stem diameter, and the highest LAR were from plants at the 15-cm spacing. All plant characteristics, other than SLA, were influenced by in-row spacing in 1993 (Table 2). As in-row plant spacing increased from 7.5 to 45 cm, plant and stem dry weight increased linearly, while canopy height and stem length decreased linearly. Stem diameter and leaf dry weight were affected quadrati- cally by spacing. LA and the leaf : stem ratio increased linearly with wider row spacing, but row spacing had no affect on SLA. LA ratio increased linearly with wider spacings, while the LAI was influenced quadratically. The highest plant and leaf dry weights, LA, leaf : stem ratio, and LAR and the lowest LAI were from plants produced at the widest (45 cm) plant spacing. The lowest whole-plant, stem, and leaf weights; LA; leaf : stem ratio; and In-row Plant Spacing Affects Growth and Yield of Pepperoncini Pepper Carl E. Motsenbocker Department of Horticulture, Louisiana State University Agricultural Center, Baton Rouge, LA 70803 Additional index words. Capsicum annuum, plant parameters, early yield, total yield, plant spacing Abstract. Pepperoncini pepper (Capsicum annuum var. annuum L. ‘Golden Greek’) was grown at in-row spacings of 7.5, 15, 22.5, 30, and 45 cm to determine the effect of plant population on growth and fruit yield in a 2-year field study. In 1992, pepper plants grown at the 15-cm in-row spacing had the lowest plant, stem, and leaf dry weights, while plants at the lowest density (45-cm spacing) had the highest plant, leaf, and stem dry weights and the largest leaf area (LA). Of plants grown at the 7.5-cm spacing, the total yield and fruit count per hectare were higher than at the other spacings; however, fruit yield per plant was lowest. In 1993, the lowest plant and leaf dry weights and LA and highest LA index (LAI) were from plants at the 7.5-cm in-row spacing. Plants at the 45-cm spacing had the highest plant and leaf dry weight and LA and the lowest LAI. Pepper plants grown at the narrowest spacing produced the lowest early and total fruit yield per plant but the most fruit per hectare. In general, plants grown at the narrowest spacings produced the smallest plant, leaf, and stem biomass but resulted in the highest fruit yields and counts per hectare and the lowest fruit yields per plant. Received for publication 1 June 1995. Accepted for publication 21 Nov. 1995. Louisiana Expt. Station manuscript no. 95-28-9277. We gratefully acknowl- edge the technical assistance of Alan W. Fennel and Yuehe Huang and the assistance with statistical analysis of Raul Macchiaveli. The cost of publish- ing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact. Pepper (Capsicum species) has consider- able biodiversity, including several species of commercial importance in the United States (Bosland, 1992). Capsicum annuum (L.) var- ies in plant growth habit, fruit pigmentation and size, pungency, and market characteris- tics. Within this species, there are numerous types, and each type and cultivar often have specific cultural and market requirements. Fresh and processed production of nonbell pepper types in the southern United States is expanding. There is limited research reported on the effect of environmental characteristics and cultural practices on yield and quality characteristics of these nonbell pepper types (e.g., Saamin, 1978). Pepperoncini pepper is a processing type grown in the southern United States in limited quantities. Immature fruit of mildly pungent and nonpungent pepperoncini pepper are used as a pickled condiment. Demand is increasing due to the popularity of salad bars in the retail and food service industries. Most pepperoncini pepper in the U.S. market is imported from production areas in the Mediterranean. An estimated 9 million kilograms were imported into the United States in 1992 (Jim Lusk, personal communication). In general, produc- tion and harvesting costs are high and the returns relatively low in peppers grown for processing. Managing production inputs and minimizing production costs are increasingly