Just finished planting some corn, and have been a bit concerned at the time it is taking to germinate (up to 2weeks). Dug some seeds up and am finding a lot that have swollen but not germinated and have gone a bit dark and soft (pythium?) and quite a few that have germinated but seem to have brown discoloration around the lower shoot near the seed, with limited or no roots also (seed pics). Other plants are pushing out three leaves.

Planter runs that were sown two days earlier seem to be emerged and quite good. I know this would suggest soil temp, but I just didn't think it got that cold.

We had a warm start but was followed by three frosts in a row. Soil temp at 9.00am got down to 10 deg C for a couple of days, moisture is good. Could the cold snap knock the germinating seed? or could it be fert. burn.

I have never had fert problems in the past using the same system all on 26" rows (soild stand), even on skip row with the same fertiliser rates ( 12-13-12 @ 125kg/Ha + 46-0-0 (urea) @ 120kg/Ha)  using cross-slot seeder that places it about 1" to the side of seed. Maybe in the past I've been lucky? Anyway I think it will be a replant, which i'm not really excited about, but if anyone has some suggestions it would be much appreciated.

Thanks 

Jim

Oh yeah, there wernt that many emerged plants that showed these symptoms (like in the pics) my main concern were the large amounts of ones that had only swollen and hadn't germinated at all, I just thought these could have been ones that had  been injured and not killed off totally and may give you some clues to the underlying problem.

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Thanks Ed,

I may be jumping the gun, we've got warm weather so I'll wait another week and check it out again. I'ts just if i'm going to re-plant then I only have a couple of weeks left to do so before it's getting late.
It's a tough decision.

Thanks

Jim

Was there a hint of sarcasm in there Ed? You've got to remember that this is Australia, we get the varieties you guys probably had several years ago. In Australia, this variety is about as short crm and drought tolerant as we get (which is what I need) I'm in winter crop wheat, Canola and Chickpeas country. The whole Australian corn crop at a guess would be only a few hundred thousand acres (mostly irrigated), so we rely on your non -GM mid west varieties.  

By the way here is another shot of a seed, does cold make the actual root stunted and black? 

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The soil mosture is what I would call ideal for germination, nice and moist but far from wet.

I guess the one thing that puzzles me is that we've had a 10 deg c soil temp before and never had a problem. 

My concern is how do you manage the ones that come up three weeks later in my replant. We are in a marginal yield area for corn (60bu/acre avg.) I guess I just take out the emerged ones at the end of the week and put up with the extra's later (mind you there isn't a lot of them that are going to come up).

Thanks for your replies guys.

Jim

  Have been planting 36bo8 for many a year. In this area in most years it still will rank in the top three or four across the plot.. Cold tolerance has been good along with early growth.  That said it has been around quite awhile. Maybe the seed you got has lost some vigor. I heard that it is unavailable this year.  Ours was froze off four times this year. Planted in cold wet conditions as most corn was.

  Would think it was fertilizer damage but the ones that didn't germinate shouldn't have been burnt.  as far as getting them all the same. a good frost will even them out.