The effects of bud self-pollination and open flower self-pollination on the field characteristics of broccoli (Brassica oleracea var. Italica)

Summary

Broccoli (Brassica oleracea L. var. italica) progenies grown from seed obtained by greenhouse budpollination (BP), open-flower self-pollination (OS), open-flower self-pollination with ether treatment of the stigma (OSE), and cross.pollination (CP) were compared in the field. For plant height, plant weight, head diameter, and head weight, BP resulted in the lowest values, OS and OSE were intermediate, and CP gave highest values. BP was highest, OS and OSE intermediate, and CP lowest for days to head emergence and days to harvest. Differences between OS and OSE were slight and all were non-significant for the 7 lines with complete data, but were significant for plant weight and head diameter when 20 lines were analyzed by the unweighted means method. The comparison BP versus OS-OSE was non-significant for plant height in both analyses and for head weight in the 7-line analysis only. In a second experiment using only BP and OS, and omitting days to head emergence, trends were similar but only the effects on head diameter were statistically significant. In the greenhouse, BP produced much more seed than either OS or OSE, and CP produced more than BP. Treatment of the stigma of open flowers with ether to overcome self-incompatibility did not result in greater seed production. Weight/100 seeds was higher in CP but did not differ among the three self-pollination methods.