Tuesday, June 12, 2007

watching for the first tomato

I've had nice tomato flowers for a couple of weeks now - but no baby tomatoes. I though maybe it was because we had no bees around (which concerns me too). But in checking into this I see that bees are not an important pollinator of tomatoes. It seems more like the wet weather may be the culprit (maybe affecting our bee population too?). We've had perfect temperatures for tomato fruit set, but our rainfall has been higher than usual, with a lot of drizzly damp days without much sun to dry things out.

Tomato pollination info (from WSU): Tomato flowers come complete with both male and female organs and are self-fertilizing. Pollen is shed with great abundance between 10:00 a.m. and 4:00 p.m. on dry, sunny days. Normally, the wind will pollinate the flower sufficiently. To ensure better pollination, gently shake or vibrate the entire tomato plant. The best time to do this is midday when it's warm, and the humidity is low. Optimum fruit set occurs within a very narrow night temperature range of between 60° F and 70° F. When tomato plants experience night temperatures lower than 55° F or above 75° F, interference with the growth of pollen tubes prevents normal fertilization. The pollen may even become sterile, thus causing the blossoms to drop. High daytime temperatures, rain, or prolonged humid conditions also hamper good fruit set. If the humidity is too low, the pollen will be too dry and will not adhere to the stigma. If the humidity is too high, the pollen will not shed readily. Pollen grains may then stick together, resulting in poor or nonexistent pollination.

I guess I'll go out and shake the tomato plants! Gently. And I think I'll put in some bee-attracting annuals, too, even if that's not what's wrong with the tomatoes.

Solanum lycopersicum
garden bees


Ottawa Gardener said...

Man... a wonder that I ever get tomatoes with such requirements. Thankfully I do!

Leslie said...

Kathy ... thanks for the great info