Screening screw pepper varieties suitable for substrate bag culturing based on fuzzy Borda combination evaluation method.

[Objective] This study screened high-yielding and high-quality screw pepper varieties suitable for substrate bag cultivation in Northern Shaanxi to provide basis for the development of soilless cultivation of pepper. [Method] Twenty screw pepper varieties including Silk Road New Star, Silk Road Star, Lou Lan Star, Extra Early One-foot Long, Zhongnong Qingluo Prince, Longxuan 339, Biosow 019, HP29017, HP29037, HP29047, HP29082, Western Long Dragon, Kubota Conch Pepper King, Golden Pepper No.6, Golden Pepper No.8, Golden Pepper No.9, Golden Pepper No.12, Bolon (37 - 94) > Stem Hair 802 and Vols Tenro were chosen for substrate bag cultivation in this study. The weight of single fruit, pericarp thickness, fruit length, contents of vitamin C, soluble protein, free amino acid, reducing sugar, total soluble sugar, nitrate nitrogen as well as yield were measured and compared. The correlations of indexes were analyzed by Pearson analysis. The yield and quality indexes of each variety were evaluated by principal component analysis, technique for order preference by similarity to ideal solution, membership function analysis and grey relational degree analysis. The results of three single comprehensive evaluations by extant consistency test (Kendall-W) were evaluated in combination and the fuzzy Borda evaluation method was used to select varieties suitable for substrate bag culturing in Northern Shaanxi. [Result] The weight of ingle fruit was 25.62 - 52.83 g, with the heaviest in Longxuan 339. The pericarp thickness was 1.58 - 2.17 mm, with Vols Tenro the thickest. The fruit length was 19.42 - 30.55 cm, with the longest in HP29082. The content of vitamin C was 276.37 - 1 058.09 mg/hg, and Golden Pepper No.8 was the highest. The content of soluble protein was 0.97 - 1.61 mg/g, and Golden Pepper No.12 was the highest. The content of free amino acid was 393.78 - 969.69 µg/g, with the highest in Vols Tenro. Contents of reducing ugar and total soluble sugar were 3.82% -6.65% and 9.87% -13.91%, and Biosow 019 had the highest ontents. There was no significant difference in nitrate content among varieties. The yield was 9 625.98 - 84 600.00 kg/hm², and Silk Road New Star had the highest value. The results of single comprehensive evaluation methods were different, and the results of principal component analysis method had weak correlations with those of other methods. The correlations among other single evaluation methods passed the Kendall-W test and they were compatible for combined evaluation. The fuzzy Borda combination evaluation method passed tests with good credibility. The obtained top 5 varieties were Silk Road New Star, HP29047, Silk Road Star, Longxuan 339 and Biosow 01 9. [Conclusion] Silk Road New Star, HP29047, Silk Road Star, Longxuan 339 and Biosow 019 were suitable for substrate cultivation in Northern Shaanxi. [ABSTRACT FROM AUTHOR]