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Midway, UT

For the last week I've been studying a post that both of you participated in back in 2004 about source-sinks. I've found the subject fascinating. I've been reading some of the scientific journalsand trying to find anything that is definitive that removal of flowers will increase the source-sink relationship with the pumpkin. There are some studies that I've found that hint that is true, have you tried this in the real world and have a good article that supports it? I did it last year for different reasons and got a good pumpkin and the theory makes sense to me.

Also, outside of seaweed are their other fertilizers/additives other than seaweed that you have found that increase the growth hormones in the plant? I read one old study that suggested coconut milk might have some of the same properties.

7/18/2008 11:54:58 AM

Ohio

Arvadaboy, this doesnt have much to do with your sink question, but Todd Skinner gave me this hint about male flowers that worked perfect for me this year. He just leaves male flowers on his first two secondaries and cuts the rest off as he trains his vines, and it works out that you have more then enough males to pollinte with through out the season. Plus you dont have to be crawling into the middle of your plant to cut all the soggy ones you dont use off.

7/18/2008 5:40:21 PM

Ontario, Canada.

Sink source relationship...Over the years we've had a few good discussion about this topic and much has been debated in the banter here back and forth.

A review for those who don't understand the topic.

A Sink is any part of the plant that requires photosynthate by products in order enlarge or grow. A pumpkin plant may have numerous sinks from flowers to roots and shoots.

A general rule here at BP is basically to have as few sinks as possible by the time the chosen fruit gets to its maximum growth potential at about day 30. Many like to get this point earlier than others at somewhere near day 10. This reduces competition from other sinks which consume the daily output of the plant. Therefore any actively growing part of the plant is a sink and should be removed as soon as possible after fruit set.

7/19/2008 7:21:18 AM

Ontario, Canada.

The sink-source transition in leaves

http://www.scri.ac.uk/scri/file/individualreports/1999/08SINKSO.PDF

"All leaves on a plant undergo a transition from a
sink (a net carbon importer) to a source (a net
carbon exporter) during their development. The early
growth of a leaf is supported by carbohydrate
imported from other sources in the plant. These
sources are usually other mature leaves or photosynthetic
organs on the plant, or in the case of a seedling,
the cotyledons. As the lamina expands and the leaf
matures, levels of photosynthesis increase until the leaf
can support itself. When the amount of carbon accumulated
by photosynthesis is greater than the requirement
of respiration and growth, a positive carbon
balance is achieved by that leaf. The leaf then
becomes an exporter of carbon. In dicotyledonous
plants, the conversion from sink to source begins
shortly after the leaf begins to unfold, and is known as
the sink-source transition."

7/19/2008 7:40:07 AM

Ontario, Canada.

Other interesting topics for those willing to learn the biology of the plant include.

Phleom loading

Xylem peduncle resistance

Assimilate Transport in Cucurbits

7/19/2008 8:19:05 AM