Comparative Analysis of 5 Wrinkled-Skin Linear Pepper Varieties

In order to screen and breed superior local varieties of wrinkled-skin linear pepper and promote the development of the traditional wrinkled-skin linear pepper industry in Duyun City, the Duyun City Vegetable Station, with the support of the Qiannan Prefecture Director's Fund, conducted a comparative screening trial of wrinkled-skin linear pepper varieties from March to November 2006 in Shazhai Township, known as the "Home of Peppers."

1 Materials and Methods

1.1 Test Varieties Five test varieties were used, all local varieties. Namely: 1) Sandu Zhouqin linear pepper; 2) Guiding Houchang linear pepper; 3) Dushan Mawei linear pepper; 4) Duyun Machang linear pepper; 5) Duyun Shazhai linear pepper (CK).

1.2 Overview of the Test Site The test site was located in Jijing Group, Shazhai Village, Shazhai Township, Duyun City, at an altitude of 850m, with an average annual temperature of 16.2°C and annual rainfall of 1226mm, and a warm and humid climate. The test field was dry sloping land with yellow sandy loam soil, slightly acidic soil, and medium fertility, with rapeseed as the previous crop.

1.3 Experimental Design The experiment used a randomized block arrangement, with 5 varieties, 3 replications, and a total of 15 plots, each plot with an area of 16.5 sq m, plant spacing of 40cm x 50cm, and 72 hills and 144 plants planted per plot. The distance between plots was 70cm, with protective rows around the perimeter.

1.4 Field Management The seeds were soaked on March 7, 2006; after 12h they were washed and drained, then placed in a constant-temperature incubator for germination. Sowing was on March 14, temporary planting on April 11, and field transplanting on May 15. Before transplanting, 19,500 kg of farmyard manure and 900 kg of Western compound fertilizer (13:17:15) were applied per hectare as base fertilizer. Fertilizer was applied 3 times in the field: on May 31, 22,500 kg of diluted manure water was applied per hectare; on June 21, 1,500 kg of ammonium nitrate was applied per hectare; and on July 3, 4,500 kg of oil cake was applied per hectare. Cultivation and hilling were carried out once each on May 3, June 11, and July 3. During the seedling stage, Decis + agricultural streptomycin and Yakkesi + Yiduxing were used to prevent and control pests and diseases twice each. During the field stage, on May 16, May 21, May 30, June 4, June 17, June 25, July 2, July 7, July 11, July 16, July 23, and July 29, pesticides such as metalaxyl-copper, chlorothalonil, zineb, agricultural streptomycin, fenpropathrin, Qikeman, and abamectin were used to prevent and control pests and diseases 12 times.

1.5 Yield Measurement and Agronomic Trait Investigation After the wrinkled-skin linear peppers turned red, fresh fruits were harvested, weighed, and recorded as plot yield. Five plants were randomly selected from each plot for plant trait measurement. At the peak harvest stage, 15 pepper fruits were randomly selected from each variety for determination of product economic traits.

2 Results and Analysis

2.1 Growth Period As can be seen from Table 1:

2.1.1 Growth period. Variety 1 was the same as CK, at 265d; the growth period of varieties 2, 3, and 4 was 276d, 11d longer than CK.

2.1.2 Emergence period. Variety 1 was the same as CK; variety 3 was 2d later than CK; variety 4 was 4d later than CK.

2.1.3 Initial flowering period. Variety 1 was the same as CK; the initial flowering period of varieties 2 and 3 was 3d later than CK; variety 4 was 7d later than CK.

2.1.4 Initial harvest period. Variety 1 was the same as CK; varieties 2, 3, and 4 were 4d later than CK.

2.2 Plant Traits

2.2.1 Plant type. The order of plant type from compact to loose was 1 > 2 > 3 > 4 > CK.

2.2.2 Number of pods per plant. The order of number of pods per plant from high to low was 4 > 3 > 1 > CK > 2.

2.2.3 Fresh pepper weight per pod. The order of fresh pepper weight per pod from high to low was CK > 4 > 2 > 1, 3.

2.2.4 Fruit wall thickness. The order of fruit wall thickness from thick to thin was CK > 2 > 4 > 3 > 1.

2.2.5 Pepper fruit length. The order of pepper fruit length from long to short was 4 > CK > 3 > 2 > 1.

2.2.6 Fruit diameter. The order of pepper fruit from thick to thin was CK > 4 > 2 > 1 > 3.

2.3 Yield As can be seen from Table 3: Variety 1 had a plot yield of 40.8kg, equivalent to a unit yield of 8242.4kg/hm2, a reduction of 16364kg per hectare compared with CK; variety 2 had a plot yield of 40.5kg, equivalent to a unit yield of 8181.8kg/hm2, a reduction of 1697.0kg per hectare compared with CK; variety 3 had a plot yield of 24.7kg, equivalent to a unit yield of 4989.9kg/hm2, a reduction of 4888.9kg per hectare compared with CK; variety 4 had a plot yield of 49.7kg, equivalent to a unit yield of 10040.4kg/hm2, an increase of 161.6kg per hectare compared with CK. The order of yield of the 5 test varieties from high to low was 4 > CK > 1 > 3 > 2.

3 Summary

Among the 5 test varieties, the pepper fruits ranged in color from bright red to deep red, and they were relatively disease-resistant; no bacterial wilt or root rot occurred during the trial. Based on comprehensive trait comparison, variety 4, namely Duyun Machang linear pepper, had relatively high yield, increasing by 161.6kg per hectare compared with the control, and also had many pods per plant, long pepper fruits, relatively thick fruit walls, and relatively good commercial traits, but its plant type was relatively loose, making it suitable for planting under the climate and soil fertility conditions of Shazhai Township. Variety 5, namely Duyun Shazhai linear pepper, had relatively high yield, thick pepper fruit walls, and deep red color, and was suitable for planting under the climate and soil fertility conditions of Shazhai Township. Duyun Machang linear pepper and Duyun Shazhai linear pepper can serve as superior local linear pepper varieties for further purification and rejuvenation, and in the purification and rejuvenation work in the coming year, emphasis should be placed on selecting and retaining individual plants with compact plant type and many pods as seed plants. Varieties 1, 2, and 3, namely Sandu Zhouqin linear pepper, Guiding Houchang linear pepper, and Dushan Mawei linear pepper, when planted under the climate and soil fertility conditions of Shazhai Township, had short pepper fruits, thin pepper flesh, and relatively low yield, and should be eliminated.