Calculation to Estimate Weight for Tomato Hybrid?

Sicilianu · June 21, 2015

I remember someone on this forum or another one had a formula to estimate the weight of the F1 cross based on the weight of the parents. Does someone know what I am talking about? It was like the square root of the addition of the weights divided by something. haha

I wanted to test on data from my 1st F1 hybrid last year, Fiaschetto di Manduria x Cherokee Chocolate.

Fiaschetto is usually about 15-20 grams and Cherokee Chocolate is about 283 grams. The hybrid was measured to be 73 grams.

maf · June 21, 2015

Lol, unfortunately I have no formula involving square roots and such. In my experience it is intermediate between the two parents but closer to the smaller parent, which is pretty much what you describe in yours. With so many genes affecting fruit size and weight I doubt there could be a formula that would be accurate in all cases, but if there is I would love to hear it!

joseph · June 21, 2015

Depends on the combining ability of the parents... Might be better, might be worse.

**carolyn137** · June 21, 2015

All I know, which isn't much, is that in a cross small fruit size is dominant to large fruit size and I have no idea which genes are involved.

But when I look at the human kids born from a tall dad and a short mom, what I usually see, if they have enough kids to be able to draw some conclusions, ahem, is that shorter kids are in the majority. The reverse works as well.

Yes, I've grown Fiaschetto and Cherokee Chocolate but I'm not one who deliberately crosses varieties. When I was much younger growing many hundreds of plants and varieties each year, I can't think of anyone who did it, say, as a hobby, that is, not for money.

Carolyn

Minnesota Mato · June 25, 2015

I read it here also. I can't find where it was but I do have it in my notes. The square root of a x b = f1 size. 3-4 ounces x 8-12 ounces, square root of 24-48=5-7 ounces. Some smart person here deserves the credit.

Sicilianu · June 26, 2015

Thanks Minnesota Mato! I think that was it!

Sicilianu · June 27, 2015

Quote:

Originally Posted by Minnesota Mato

I read it here also. I can't find where it was but I do have it in my notes. The square root of a x b = f1 size. 3-4 ounces x 8-12 ounces, square root of 24-48=5-7 ounces. Some smart person here deserves the credit.

Quote:

Originally Posted by Sicilianu

I remember someone on this forum or another one had a formula to estimate the weight of the F1 cross based on the weight of the parents. Does someone know what I am talking about? It was like the square root of the addition of the weights divided by something. haha

I wanted to test on data from my 1st F1 hybrid last year, Fiaschetto di Manduria x Cherokee Chocolate.

Fiaschetto is usually about 15-20 grams and Cherokee Chocolate is about 283 grams. The hybrid was measured to be 73 grams.

65 to 75 grams would be predicted for the F1 using the numbers above and it was actually 73!

travis · June 28, 2015

This method of estimating the projected fruit size (actually weight) of an F1 hybrid using its parental inputs's weights comes from Keith Mueller, a student of Dr. Randy Gardner at NCSU. Whether the method was used by Dr. Gardner or others at NCSU, I do not know.

I have used the formula with many of my own custom crosses and gotten fairly on point results, but not consistently ... possibly due to growing conditions year to year relative to soil moisture, ambient heat, rainfall, plant spacing, fertilizer regimens, etc.

The one time the formula hit it on the nose was Green Giant x Yellow Submarine. Other times not as accurate, for what it's worth.

June 21, 2015	#1
Sicilianu Tomatovillian™ Join Date: Jan 2014 Location: Pasadena, CA Posts: 33	Calculation to Estimate Weight for Tomato Hybrid? I remember someone on this forum or another one had a formula to estimate the weight of the F1 cross based on the weight of the parents. Does someone know what I am talking about? It was like the square root of the addition of the weights divided by something. haha I wanted to test on data from my 1st F1 hybrid last year, Fiaschetto di Manduria x Cherokee Chocolate. Fiaschetto is usually about 15-20 grams and Cherokee Chocolate is about 283 grams. The hybrid was measured to be 73 grams.

June 21, 2015	#4
carolyn137 Moderator Emeritus Join Date: Jan 2006 Location: Upstate NY, zone 4b/5a Posts: 21,169	All I know, which isn't much, is that in a cross small fruit size is dominant to large fruit size and I have no idea which genes are involved. But when I look at the human kids born from a tall dad and a short mom, what I usually see, if they have enough kids to be able to draw some conclusions, ahem, is that shorter kids are in the majority. The reverse works as well. Yes, I've grown Fiaschetto and Cherokee Chocolate but I'm not one who deliberately crosses varieties. When I was much younger growing many hundreds of plants and varieties each year, I can't think of anyone who did it, say, as a hobby, that is, not for money. Carolyn __________________ Carolyn

June 21, 2015	#2
maf Tomatovillian™ Join Date: Jun 2010 Location: England Posts: 512	Lol, unfortunately I have no formula involving square roots and such. In my experience it is intermediate between the two parents but closer to the smaller parent, which is pretty much what you describe in yours. With so many genes affecting fruit size and weight I doubt there could be a formula that would be accurate in all cases, but if there is I would love to hear it!

June 21, 2015	#3
joseph Tomatovillian™ Join Date: May 2013 Location: Cache Valley, N/E of The Great Salt Lake Posts: 1,244	Depends on the combining ability of the parents... Might be better, might be worse.

June 25, 2015	#5
Minnesota Mato Tomatovillian™ Join Date: Aug 2011 Location: minnesota Posts: 175	I read it here also. I can't find where it was but I do have it in my notes. The square root of a x b = f1 size. 3-4 ounces x 8-12 ounces, square root of 24-48=5-7 ounces. Some smart person here deserves the credit.

June 26, 2015	#6
Sicilianu Tomatovillian™ Join Date: Jan 2014 Location: Pasadena, CA Posts: 33	Thanks Minnesota Mato! I think that was it!

June 28, 2015	#8
travis Tomatovillian™ Join Date: Jan 2006 Location: Evansville, IN Posts: 2,984	This method of estimating the projected fruit size (actually weight) of an F1 hybrid using its parental inputs's weights comes from Keith Mueller, a student of Dr. Randy Gardner at NCSU. Whether the method was used by Dr. Gardner or others at NCSU, I do not know. I have used the formula with many of my own custom crosses and gotten fairly on point results, but not consistently ... possibly due to growing conditions year to year relative to soil moisture, ambient heat, rainfall, plant spacing, fertilizer regimens, etc. The one time the formula hit it on the nose was Green Giant x Yellow Submarine. Other times not as accurate, for what it's worth.