Effect of Transplant Size on Yields and Returns of Bell Peppers. Nathan Howard, Brent Rowell, and John C. Snyder Department of Horticulture

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1 Effect of Trnsplnt Size on Yields nd Returns of Bell Peppers Nthn Howrd, Brent Rowell, nd John C. Snyder Deprtment of Horticulture Introduction Bell peppers hve een mjor vegetle crop for frmers in western Kentucky for the pst five yers. Growers hve successfully mrketed fresh mrket green ell peppers through wholesle uyers nd the West Kentucky Grower Coopertive in Owensoro. In 2005, over 150 cres ell peppers were sold on the fresh wholesle mrket in northwestern Kentucky. Growers re using intense mngement techniques including drip irrigtion nd lck plstic mulch. Yields in the re hve consistently exceeded 1000 oxes per cre. Growers continue to djust fertility, disese mngement, nd cultivr selection to ttin yields closer to 2000 oxes/cre. The est ell pepper producers in centrl Kentucky round the Georgetown coopertive re using similr mngement techniques nd re producing on similr soil types ut consistently otin closer to 1800 oxes/cre. The only ovious difference in their production prctices is the size of their trnsplnts. Centrl Kentucky growers re using 128-cell Styrofom trys for trnsplnts while western Kentucky growers re using 242-cell trys. Lrger cell sizes result in lrger trnsplnts which should etter withstnd stresses t plnting nd should susequently produce erlier peppers. The purpose of this reserch ws to determine if lrger cell/trnsplnt size results in yield increse nd/or higher erly yields (usully ssocited with higher mrket prices). Secondly, we wnted to know if these yield differences justified the higher cost of trnsplnt production ssocited with using lrger cell size. Mterils nd Methods The tril ws conducted in coopertion with ell pepper grower in Henderson County. Four cell sizes were used for trnsplnt production: 72-, 128-, 200-, nd the stndrd 242-cell try. The vriety used ws Allince donted y Rupp Seed Compny. Ech tretment ws seeded in the greenhouse on 7 Mrch. The plnts were tken outside the greenhouse on 2 My nd hrdened off for three dys. On 5 My the plnts were trnsplnted into rised eds with lck plstic mulch with drip irrigtion (Figure 1). Ech tretment hd 20 plnts in doule rows tht were 18 in. prt on the ed with 15 in. etween plnts in the rows. Beds were spced 66 inches prt from center to center resulting in plnt popultion of 12,672 plnts per cre. The grower mnged the tril plot in the sme mnner s the rest of his field. Phosphorus nd potssium were pplied pre-plnt ccording to soil test results nd current University of Kentucky recommendtions. Nitrogen ws pplied t the rte of 60 l/cre prior to plnting with nd dditionl 140 l/cre sidedressed (fertigted) through the irrigtion system. Fungicides (mne nd copper) were pplied on weekly sis for disese prevention. Mustng Mx nd Orthene insecticides were pplied s needed when insect popultions reched uncceptle thresholds. The tril ws rrnged in rndomized complete lock design with four replictions.

2 The 2005 growing seson ws very good for peppers in Kentucky. Wrm wether nd low disese nd insect pressure persisted throughout. The tril plot ws hrvested four times etween 29 June nd 20 July. Peppers were hrvested ccording to coopertive stndrds, mking sure ech pepper hd solid wll regrdless of size. Hrvested peppers were grded ccording to USDA stndrds, counted, nd weighed. Grdes for peppers included jumo, extr lrge, lrge, medium, nd chopper (misshpen fruit). Dt were then nlyzed for sttisticl differences. Results nd Discussion Only the 72-cell tretment hd fruits redy for hrvest 29 June (first hrvest); fruits in the rest of the tretments were not mture enough for hrvest on tht dte (Figure 2). We expected n erlier pepper with lrger cell/trnsplnt size nd this proved to e the cse. The price for peppers the lst week of June ws well ove verge (Tle 1); higher prices re typicl for peppers hrvested in Kentucky efore the fourth of July. The 72-cell plnts lso yielded significntly more thn the other three tretments during the second week of hrvest (Figure 2). There were no significnt differences in totl yields mong tretments for the lst two hrvests (Figure 2). The totl yields were somewht surprising (Figure 3). As expected the lrger cell size produced erlier peppers nd higher yield tht ws significntly different from the yield produced y the smller trnsplnts. The 72-cell tretment out-yielded the stndrd 242-cell tretment y 421 oxes n cre (Tle 2). Although we hd expected tht the 128-cell tretment would e the next highest yielding, this ws not the cse s this tretment ws the lowest yielding tretment overll (Figure 3). This ws unexpected nd is difficult to explin. The other two tretments yielded s expected, etween 1300 nd 1450 oxes per cre. Trnsplnt production costs were determined y the locl vegetle trnsplnt producer nd re listed in Tle 2. To py for the lrgest cell size (72-cell trys), the net return to the grower would hve to e $1330/cre. After net income ws clculted, the grower could hve pid for the lrger cell size nd would hve mde n dditionl $2024/cre. This ws lso surprise ecuse we hd thought tht the lrgest cell size wouldn t py for itself. Switching grower from 242 to 128 cell size ws thought to e esier to justify ecuse the grower only needed to mke n extr $750/cre to py for it; however, the results indicted tht growers would lose $707/cre y switching to this cell size (Tle 2). The 200 cell size generted nother 120 oxes n cre nd the grower needed to ern $167/cre to py for tht switch; this ws elieved to e ttinle nd does py for itself, generting nother $473/cre. In conclusion, the results of this study were surprising. It ws expected tht there would e significnt difference in yield per cre from the 72-cell size, ut it ws questioned whether the grower could py for this. The results proved tht it could. It ws expected tht there would e n opportunity for growers to switch to128-cell trys, ut yields were inexplicly lower with tht tretment. It ws predicted tht the 200-cell tretment would yield more thn the 242 nd py for itself which proved to e the cse. This study clerly shows the dvntge of tking lrger trnsplnt to the field in ell pepper production. Similr studies with crops such s tomtoes nd eggplnt my yield similr results. The enefit of hving lrger root ll (Figure 1) nd lrger, stronger trnsplnt will hve direct positive impct on yields. This tril will e repeted in 2006.

3 Figure 1. Photogrph of trnsplnts when tken to the field: from left to right, plnts from 72-, 128-, 200-, nd 242-cell trys. Notice difference in size of the plnts.

4 Tle 1. Averge weekly wholesle prices (per 32-l ox) for ell peppers from June 29 th to July 20 th, 2005 t West Kentucky Grower Coopertive. Hrvest Dte Jumo X-Lrge Lrge Medium Chopper June 29 $13.39 $12.05 $10.25 $5.51 $6.65 July July July Tle 2. Costs per cre, sed on plnt popultion of 12672/A, per cre yield differences, rek even point, nd per cre income for four trnsplnt cell sizes. Cell Size Cost per cre Yield difference from 242 cell Income needed to rek even Income difference from 242 cell 72 $ oxes $ $ $ oxes $ $ $ oxes $167 + $ $

5 Figure 2. Effects of trnsplnt cell size (no. cells/try) on erly nd lte ell pepper yields t four hrvest dtes, 2005; dt re mens of four replictions. Columns for hrvest, leled with the sme letter re not significntly different s determined y the Duncn-Wller LSD (P=0.05) Cells/try Yield (oxes/cre) st 2nd 3rd 4th Hrvest

6 Figure 3. Effects of trnsplnt cell size (no. cells/try) on totl mrketle yields of ell peppers in Dt re mens of 4 replictions; mens followed y the sme letter re not significntly different s determined y Wller-Duncn LSD (P = 0.05) Totl yield (oxes/cre) c c No. of cells per try