An Improved Method of BA Application for the Promotion for the Promotion of Fruit Set in Muskmelon

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Cucurbit Genetics Cooperative Report 6:51 (article 26) 1983

Henry M. Munger and David P. Lane
Cornell University, Ithaca, NY 14853

The artificial cytokinin N6-benzyladenine (BA) greatly improves the percentage of fruit set in hand-pollinated muskmelon (1). This effect is probably even more pronounced in situations where emasculation is involved or where pollinations are made by inexperienced persons. It has been standard procedure here and, as far as we know, elsewhere to apply 1% BA in lanolin to the base of the ovary after pollination. This mixture is difficult to apply, being very thick at Ithaca temperatures, and ovaries are sometimes damaged mechanically in the process.

In 1982 we tried applying BA in a lanolin emulsion and found this a great improvement. To maintain about 1% BA in the lanolin after the emulsion dried, we dissolved 0.5 g BA in 10 ml of 70% ETOH and added it to the hot mixture of 9 g stearic acid, 3.18 ml morpholine, 120 ml distilled water and 48 g lanolin, the formula of Warmke and Blakeslee (2) for applying colchicine. (See their paper for details of preparing the emulsion.) The consistency of the emulsion did not vary greatly over the usual range of temperatures and could be stored and applied easily with a plastic squeeze bottle having a small tip. We used bottles that originally contained nasal sprays. There was much less wastage of the emulsion, and it was possible to apply a thinner and more uniform coating than with the paste. It was also faster to use, less messy, and less damaging to the ovaries.

Shortly after starting to use BA in lanolin emulsion we observed that nearly all pollinations made with it were setting fruit and promptly abandoned other methods. We have, therefore, no data to show that it gives a higher percentage of fruit set than BA in lanolin paste, but even if set were no better, ease of usage in itself justifies the emulsion method.

Literature Cited

  1. Jones, C. M. 1965. Effects of benzyladenine on fruit set in muskmelon. Proc. Amer. Soc. Hort. Sci. 87:335–340.
  2. Warmke, H. E. and A. F. Blakeslee. 1939. Induction of simple and multiple polyploidy in Nicotiana by colchicine treatment. Jour. Hered. 30:419–432.