Hybrid Cultivars for Jalapeño Production

ORT CIENCE H S 40(6):1679–1681. 2005. having inexpensive F2 hybrid cultivar seed available that produces acceptable fruit qual- Second Generation (F ) Hybrid ity and yield. 2 To test the feasibility of using F2 hybrid cultivars to produce an acceptable jalapeño crop, Cultivars for Jalapeño Production four commercially available F hybrid cultivars 1 of jalapeño were self-pollinated to produce F2 Paul W. Bosland progeny. The original F hybrid cultivar was Department of Agronomy and Horticulture, New Mexico State University, Las 1 then compared to its F2 progeny for yield, and Cruces, NM 88003 plant and fruit characteristics. Additional index words. F hybrid, F hybrid, aji, pepper, chile, yield, seed, fruit 1 2 Materials and Methods Abstract. Chile pepper (Capsicum spp.) hybrids are normally produced by hand-emascu- Seed of the F hybrid jalapeño cultivars lating the female parent and then pollinating the emasculated fl ower by hand. Increased 1 yield has occurred with F hybrid seed, but the seed is considered too expensive by growers ‘Grande’, ‘Mitla’, ‘Perfecto’, and ‘Tula’ were 1 acquired from a commercial seed source. The F to be direct-seeded, a common production practice in the southwestern U.S. chile pepper 1 hybrid cultivars were grown under insect-proof industry. In ornamental fl owers, when F2 hybrid seed is available, it is cheaper than F1 net cages to produce the F2 generation seed hybrid seed. If F2 hybrid chile pepper cultivars could manifest heterosis, and produce fruit quality acceptable to the chile pepper industry, then a less-costly alternative would (Bosland, 1993). The comparison experiments were conducted for 2 years at the Leyendecker be available to growers. A series of fi eld trials with jalapeños was conducted to test F1 hybrid cultivars to their F progeny for yield and fruit quality. The results indicated Plant Science Research Center (LPSRC), 2.5 2 km south of Las Cruces, N.M., and at the Fabian that in some instances the F2 progeny can yield as well as the F1 hybrid parent. There- fore, F hybrid cultivars can be used in a commercial production system. However, if a Garcia Science Center (FGSC), Las Cruces. 2 The soil type at the LPSRC is a Brazito sandy male-sterility system is used to produce the F1 hybrid cultivar, the F2 progeny will have signifi cantly lower yield than the F hybrid parent, as was the case in one accession in loam (mixed thermic typic torripsamment) and 1 a Glendale clay-loam (fi ne-silty, mixed (calcare- this trial. Nevertheless, F2 hybrid cultivars are an additional way to supply high yielding hybrid cultivars to growers. ous), thermic typic torrifl uvent) at the FGSC. The original F1 hybrid cultivar seed along The introduction of F hybrid cultivars 2004). The retail seed cost of these F hybrid 1 2 with its F2 progeny were planted in a randomized has dramatically infl uenced crop production cultivars are about less than one-half the price complete block design with fi ve replications.

(Coors and Pandy, 1999). Heterosis or hybrid of a comparative F1 hybrid cultivar. Each replication had 36 plants. A single line of vigor produced by F1 hybrid cultivars can sig- In vegetable crops, few F2 hybrid cultivars plants was spaced 25 cm apart within the row nifi cantly increase yield and crop uniformity are sold. There are reports that F2 hybrid cultivar and 1 m between rows. The plants were grown for maturity and quality. In addition, F1 hybrid vegetable populations can yield as much or using standard cultural practices for growing ja- cultivars allow the plant breeder to quickly nearly as well as the F1 hybrid population for lapeños in southern New Mexico (Bosland et al., combine dominantly inherited disease and pest some crops. Curtis (1941) observed that the F2 1994). Plots were furrow irrigated throughout resistance in a single generation. However, the generation of a Cucurbita pepo L. hybridization the season to maintain optimal plant growth.

cost of producing F1 hybrid cultivars in some did not differ from the F1 generation in early or For the fi rst year, the data collected included crops can restrict their use because the seed is total fruit yields. Both the F1 and F2 populations plant height, plant width, single fruit weight, fruit too expensive. The high-priced seed of F1 hybrid were signifi cantly earlier than either parent. He length, fruit width, wall thickness, pungency, cultivars limits their use for some direct-seeded proposed that F2 generation seed could be used and marketable yield (Tables 1 and 2). Two days vegetable crops. For example, in chile peppers for commercial planting. In addition, Schuster et before the fi rst harvest, six randomly chosen (Capsicum annuum L.) only 2% of the United al. (1974) reported the hybrid vigor of C. pepo plants in each replication were measured for

States acreage is planted to F1 hybrid cultivars hybridizations diminished only slightly in the plant height and plant width. The experiment (Janick, 1998). F2 generation, but decreased signifi cantly in the was harvested three times throughout the sea- The second-generation hybrid (F2 hybrid next generation (F3). They suggested that F1 son. From the middle of each replication, 10 cultivar) has not received as much attention hybrid seed produced by hand pollination could randomly chosen plants were harvested and

as a means of providing cost-effective hybrid be multiplied by open pollination to produce F2 the fruit bulked. After harvesting, the fruit were vegetable cultivars. This may be attributed to hybrid seed for commercial sale. sorted with any fruit deemed unacceptable for

the fact that F2 hybrid cultivars have a reputation Jalapeño chile pepper is an important crop the market, i.e., red, diseased, deformed, small, of lower yield and unacceptable uniformity of in the southwestern U.S. and Mexico. In 2002 etc., being discarded and only the marketable

fruit quality. Nevertheless, the cost of F2 hybrid in New Mexico, jalapeños were worth $3 mil- yield recorded. A random subsample of 10 fruit cultivar seed should be considerably less than lion at farm-gate alone and with processing, from each replication was taken from the fi rst

that of an F1 hybrid cultivar, because it can more than $20 million (NMDA, 2002). The harvest and the fruit quality traits measured and be produced by open-pollination without the current F1 hybrid cultivars of jalapeño available recorded (Tables 1 and 2). In the second year, precaution against selfi ng or sibbing that is to the growers are uniform and high yielding, the plots were harvested in a similar manner

required for producing F1 hybrid cultivar seed. but relatively expensive as compared to com- with the exception that only marketable yield Several ornamental fl ower cultivars are sold as mercially available open-pollinated cultivars of data were collected (Tables 1 and 2). As in the

F2 hybrids rather than F1 hybrids to reduce seed jalapeño. Presently, popular F1 hybrid cultivars fi rst year, the plots were harvested three times cost. For example, ‘Speckles Mixed’ geranium of jalapeño are priced at 25 times the cost of throughout the season. The data of the yield and (Pelargonium × hortorum L.H. Bailey), ‘Padpar- open-pollinated jalapeño cultivar seed (personal fruit characteristics of the F1 hybrid cultivars and adja’ and ‘Jolly Joker’ pansy (Viola wittrockiana observation). This is due in part to the hand labor the F2 hybrid populations were compared using Gams.), ‘Fuseedia’ Fuchsia hybrida hort. Ex costs in producing F1 hybrid cultivars. Manual Student’s t test with probability set at 5%. Sieb and Voss, and ‘Kariba Mixed’ portulaca emasculation and hand-pollination of fl owers (Portulaca grandifl ora Hook.), are all sold as adds considerable costs to producing F hybrid 1 Results F2 hybrid cultivars (Thompson and Morgan, cultivars of jalapeño. Most jalapeño growers in the southwestern In both years, at the two research sites Received for publication 20 Apr. 2005. Accepted U.S. direct-seed the crop, therefore, the cost (LPSRC and FGSC), the growing seasons for publication 28 May 2005. A contribution of the of F1 hybrid cultivar seed has been prohibi- were favorable for the production of jalapeños. New Mexico Agriculture Experiment Station, New tive. Consequently, jalapeño production in the The marketable yields at LPSRC and FGSC Mexico State University, Las Cruces. southwestern United States could benefi t from differed between the years. Overall, the yields

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OOctober.indbctober.indb 11679679 88/11/05/11/05 88:59:47:59:47 AAMM at the FGSC were reduced in the second year as of ‘Grande’ and ‘Tula’ were the same as their mercial production. The results further support

compared to the fi rst year. No obvious factors F2 hybrid population at the LPSRC, and at the that fruit quality characteristics important to can be accorded for the reduction in yield. Of FGSC, ‘Mitla’, ‘Perfecto’, and ‘Tula’ had the the jalapeño processing industry can be met

course, cultivar by year interactions are common same fruit length as their F2 hybrid population, with F2 hybrid jalapeño cultivars. In fact, the in cultivar trials, and most of the time the exact respectively. ‘Mitla’ and ‘Perfecto’ differed from F2 hybrid populations producing similar yield factors causing the signifi cant change in yields their F2 hybrid population at the LPSRC, and with acceptable fruit quality characteristics cannot be deduced. ‘Grande’ differed from its F2 hybrid population at as the F1 hybrid parent validates the use of F2 With most comparisons, the F2 hybrid popu- FGSC. Overall, these differences in fruit lengths hybrid cultivars of jalapeño for commercial lations’ plant and fruit characteristics were not are insignifi cant in commercial production. production.

different from their F1 hybrid parent (Tables 1 Marketable yield, which is the most impor- The results also indicate that plant height, and 2). For the characteristics, fruit width, fruit tant characteristic for commercial production, plant width, single fruit weight, fruit length,

wall thickness, and pungency, none of the F2 was the same for ‘Grande’ and ‘Tula’ and their fruit width, wall thickness, pungency, and hybrid populations differed from their F1 hybrid F2 hybrid population for both locations and for marketable yield may or may not differ between parent. At the LPSRC, the F1 hybrid ‘Grande’ both years. In the fi rst year at the LPSRC, ‘Mitla’ the F1 hybrid parent and their F2 populations did not differ from its F2 hybrid population for had about 30% greater yield than its F2 hybrid depending on year and location. This implies any of the eight characteristics examined. At population, however in the second year, the that multiple year and location studies are nec-

the FGSC, ‘Grande’ and its progeny differed marketable yield was the same for both popula- essary before an F2 hybrid cultivar of jalapeño only in fruit length (0.92 cm) and in fruit tions. For ‘Perfecto’ the fi rst year’s yield was could be released, just as would be expected

weight (4.7 g), however, this did not affect the equivalent to its F2 population, but the second of an F1 hybrid cultivar. marketable yield. year produced a signifi cant yield reduction in the Disease resistance could be another limita-

When plant height and plant width were F2 population. In the fi rst year at FGSC, ’Mitla’ tion to the use of the F2 hybrid cultivars. If the F2 examined at both locations, only ‘Tula’ differed and ‘Perfecto’ had yield reductions as compared hybrid cultivar is derived from an hybridization

from its F2 hybrid population. At the LPSRC, to their F2 hybrid population. While in the second between a resistant parent and a susceptible it was for plant height and at FGSC it was for year, ‘Mitla’ had the same yield as its F2 hybrid parent, the F2 hybrid cultivar would segregate both plant height and plant width. The F2 hybrid population, and ‘Perfecto’ had a yield reduction for resistance. Depending on the inheritance population was taller than the F1 hybrid cultivar with its F2 hybrid population. of the disease resistance trait, 25% or more of parent, and was wider at the FGSC. However, Some of the yield reduction in ‘Perfecto’ can the individuals would be susceptible and given

these differences would be insignifi cant for be traced to male-sterile plants in the F2 progeny. a conducive environment for disease develop- production of the crop. At each location and in each year, the F2 hybrid ment, a signifi cant yield loss could occur. When the fruit characteristics are exam- population of ‘Perfecto’ had male-sterile plants. Hybrid seed production in chile peppers is ined, the single fruit weight was the same for These male-sterile plants did not set fruit, and labor intensive, particularly emasculation of

‘Mitla’, ‘Grande’, and ‘Tula’ and their F2 hybrid when they did, the fruit were too small to be fl owers on the female parent. The use of male- populations, respectively, at the LPSRC. Only commercially acceptable. sterility facilitates the production of F1 hybrid ‘Perfecto’ differed from its F2 hybrid population cultivars. If emasculation is eliminated, the at LPSRC. At the FGSC, ‘Mitla’, ‘Perfecto’, Discussion cost of seed production should also be reduced. and ‘Tula’ had the same single fruit weight as In this study, the F1 hybrid ‘Perfecto’ seems their F2 hybrid population, respectively, but it The results demonstrate that F2 hybrid to be produced using a male-sterility system. was ‘Grande’ that differed from its F2 hybrid cultivars of jalapeño have the potential for Male sterility is a recessive trait allowing the population in single fruit weight. The fruit length providing acceptable marketable yield for com- F1 hybrid cultivar to be fully fertile, while in

Table 1. Comparison of plant and fruit characteristics, and marketable yield among four commercial jalapeño fi rst generation (F1) hybrids and their second generation (F2) progeny at the Leyendecker Plant Science Research Center, Las Cruces, N.M. Plant Fruit Marketable yield Htz Widthz Wt Length Width Wall thickness Pungency (kg·ha–1) (cm) (cm) (g) (cm) (cm) (cm) (SHU) Year 1 Year 2

Grande F1 41.8 39.0 21.72 6.96 2.82 0.52 37,240 10,867 11,989 Grande F2 40.4 39.1 20.34 6.64 2.78 0.52 57,675 10,673 9,663 * * Mitla F1 35.0 36.8 19.66 6.62 2.74 0.58 51,755 10,461 8,123 * * Mitla F2 37.0 36.4 16.94 6.00 2.56 0.54 41,845 7,355 6,432 * * * Perfecto F1 36.8 36.9 21.40 6.90 2.86 0.52 45,375 10,991 12,806 * * * Perfecto F2 38.5 37.8 16.50 6.20 2.68 0.50 61,320 9,107 6,297 * Tula F1 37.6 35.4 23.72 7.18 3.08 0.46 73,379 12,671 9,367 * Tula F2 43.7 34.5 21.14 6.80 2.98 0.52 72,096 10,930 10,027 zPlant height and width was averaged from six plants each of fi ve replications. * Signifi cant difference at P < 0.05 in value between the F1 parent and the F2 progeny using Student’s t test.

Table 2. Comparison of plant and fruit characteristics, and marketable yield among four commercial jalapeno fi rst generation (F1) hybrids and their second generation (F2) progeny at the Fabian Garcia Science Center, Las Cruces, N.M. Plant Fruit Marketable yield Htz Widthz Wt Length Width Wall thickness Pungency (kg·ha–1) (cm) (cm) (g) (cm) (cm) (cm) (SHU) Year 1 Year 2 * * Grande F1 35.1 36.8 21.88 6.80 2.70 0.49 81,925 10,507 7,170 * * Grande F2 35.5 36.9 17.18 5.88 2.54 0.47 79,497 9,096 7,118 * Mitla F1 33.0 28.0 17.14 6.22 2.40 0.51 75,844 12,513 5,530 * Mitla F2 34.2 29.1 14.38 5.62 2.38 0.47 79,169 9,539 5,132 * * Perfecto F1 35.0 28.1 19.58 6.46 2.58 0.50 56,655 11,399 7,990 * * Perfecto F2 36.6 28.8 17.06 5.94 2.50 0.49 59,919 4,459 4,603 * * Tula F1 35.0 34.1 20.48 6.28 2.66 0.47 88,431 11,246 8,335 * * Tula F2 40.6 39.3 20.12 6.32 2.66 0.49 81,082 9,271 7,540 zPlant height and width is the mean of six plants from each of fi ve replications. * Signifi cant difference at P < 0.05 in value between the F1 parent and the F2 progeny using Student’s t test.

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OOctober.indbctober.indb 11680680 88/11/05/11/05 88:59:51:59:51 AAMM Curtis, L.C. 1941. Comparative earliness and the F2 generation, and subsequent later gen- addition to F1 hybrids, that will provide good productiveness of fi rst and second generation erations, male-sterility manifests itself. The yielding cultivars for growers. The F2 hybrid use of male sterility would limit the utility of cultivar seed of jalapeño could be exploited summer squash (Cucurbita pepo) and the pos- sibilities of using the second generation for F2 hybrid cultivars. Theoretically, 25% of the by seed companies as a hybrid that produces a plants would be male-sterile, and with a self- uniform and high yielding crop, but at a lower commercial planting. Proc. Amer. Soc. Hort. Sci. 38:596–598. pollinating crop, pollen would be unavailable seed cost to the grower. Janick, J. 1998. Hybrids in horticultural crops, p. to pollinate fl owers and allow for fruit set, thus 45–56. In: K.R. Lamkey and J.E. Staub (eds.). contributing to a 25% reduction in yield. On Literature Cited Concepts and breeding of heterosis in crop plants. the other hand, a satisfactory male-sterility Bosland, P.W. 1993. An effective plant fi eld-cage CSSA (Madison,Wis.) Spec. Publ. 25. Schuster, W., M.R. Haghdadi, and J. Michael. 1974. system could help reduce the cost of F1 hybrid to increase the production of genetically pure seed. This would allow growers access to less chile (Capsicum spp.) seed. HortScience Inbreeding and heterosis in pumpkins (Cucurbita expensive F hybrid seed. 28(10):1053. pepo L.) II. Bastardwuchsigketi. Z. Pfl anzen- 1 züchtg. 73:233–248 (in German). In conclusion, it is clear that F2 hybrid Bosland, P.W., A.L. Bailey, and D.J. Cotter. 1994. cultivars can have an important role not only Growing chiles in New Mexico. N.M. State Univ. Thompson and Morgan. 2004. The seed catalogue 2003. Thompson and Morgan, Jackson, N.J. in hybrid fl owers, but also in jalapeño produc- (Las Cruces) Coop. Ext. Serv. Guide H-230. Coors, J.G. and S. Pandey. 1999. The genetics and New Mexico Department of Agriculture. 2002. tion. Based on the results of this study, seed 2002 New Mexico agricultural statistics; Chile, producers now have another seed class, in exploitation of heterosis in crops. Amer.Soc. Agron.–Crop Sci. Soc. Amer., Madison, Wis. acreage, yield, and production by county. p. 61. N.M. Dept. Agr.

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