Weeds & plant development?
 

This is for a dove field.

Last year, on May 9th, I broadcast fertilizer per soil test and about 35 lbs of peredovik sunflower seeds for planting on several acres, then disked it up a bit. There was a good rain 3 days later. Everything started growing.

I picked May 9th, because it is 110 days before dove season starts, and the sunflowers were supposed to mature in 100 days. The soil temp was around 68 degs or warmer.

The problem was that there were 25+ pigweed/waterhemp weeds for every sunflower plant once everything came up. Also, on Sept 1, the sunflowers were NOT mature. They were still green and the heads were moist. Some state managed land that I dove hunt on plants sunflowers. On Sept 1, it's been bush hogged and any standing sunflowers have dry heads that shatter and spread seeds if you knock them.

For this year, I am applying treflan to control the pigweed, and am planting the same variety of sunflower. I'm using a 2 row planter, broadcasting N, row banding P, there's enough K in the soil already.

Questions...should I plant the sunflowers sooner than May 9th this year since they weren't mature by Sept 1? Right now, soil temp is around 55+ degs. Last year with 110 days of growing with competing weeds, they weren't mature by opening day.

But...since I'm controlling the weeds this year, will the sunflowers mature sooner than they did last year since there will be no competition? If this is the case, I would plant them in early May.

Plant now with 140 days of growing or plant in May with 110 days of growing? Both plantings will not have competing weeds. That is the question.

RE: Weeds & plant development?
 

Can you find a varity with a 100 or 90 day maturity date?

I am not an agronimist, but the maturity date and shattering date you described are probablly two different dates. Controlling weeds will help the plant's growth and production, but my guess is that it will do little for maturity. Sunflowers are a warm season type of plant, so planting too early (and I have no clue what too early is) may not help and even hurt the stand. I don't think sunflowers are very frost or cool weather tolerant.


Therefore, if you can't plant them earlier, then try to get an earlier maturing variety if possible.