Jumbo Cranium
Texas where else
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BCSnob wrote:Jumbo Cranium wrote:I'd venture a guess that warming is usually more beneficial from a crop standpoint than cooling. Wouldn't that depend upon the "normal" crop for that region? Cool weather crops would not benefit from prolonged warming. There are more crops that do well in warmer climates than those that do well in cool climates; however, famine can stem from loosing crops that are suited to one climate when that climate changes (warming, cooling, increased precipitation, decreased precipitation).
In my experience a few degrees of lower temperature that causes frost is much more damaging than several degrees warmer. True, some crops are more cold tolerant, but you spoke of Africa in a previous post and again, I would hazard a aguess and say frost would be much more damaging to the local crops.
Roger
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BCSnob
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A few degrees colder than normal will only more the first frost a few weeks earlier.
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Jumbo Cranium
Texas where else
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LOL Always??? Are you sure about that. Cooling temps would have the effect of a longer winter no? That means earlier frosts in the fall and later frosts in the spring. Late frosts are probably one of the most damaging weather phenomenom there are.
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Deb and Ed M
SW MI, USA
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All I know that as one drives across the border into Alaska, there's a trial section of highway where they are trying (successfully it appears)to stop the Permafrost from melting - by sticking large vent pipes into the roadbed so that ground heat can dissipate.
We ARE living on a ball of molten rock, after all.....LOL!
Deb
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tommyznr
NR, WI
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I have been in some of the discussions with Jumbo, the same people that poo-pooed him have had a few drinks to celebrate the victory over my lack of knowledge and understanding of the scientific method. I am not sure how I missed the chapter on scientific method in my many years.
Anyway, let’s assume all the models that suggest catastrophic climate change are wrong and we have come to the end of global warming. My fear is that it will take so long for the world to get educated about the facts that a large number of people will get full credit for ending global warming. It will look like all the policies put in place (they are coming) will have been a huge success. This, in turn, will make the next super crisis that much easier to shove down our throats.
I am not saying the debate is over, but it certainly should open back up again.
Tom
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BCSnob
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Genotypic and temperature effects on whe........d quality in a hot irrigated environment
High temperature influences both grain yield and end-use quality of wheat. The objectives of this study were to evaluate the performance of selected wheat genotypes under heat stress and to examine the effects of high temperatures during grain filling on grain yield and end-use quality parameters. Fifteen bread wheat genotypes in 2000/2001 and 18 genotypes in 2002/2003 were evaluated under the optimum and late-sowing conditions of the irrigated hot environment of the Gezira Research Farm, Wad Medani, Sudan. The genotypes comprised released varieties and elite lines from the Sudanese wheat improvement programme. Data collected included grain yield, grain weight and grain end-use quality including protein content, protein composition, SDS sedimentation values (SDSS) and gluten strength as determined by mixograph analyses. High temperatures significantly decreased grain yield by decreasing grain weight. Although genotypes exhibited variation in magnitude of response, results indicated that high temperature during grain filling increased both soluble and insoluble protein contents, SDSS, mixograph peak height (MPH) and the descending slope at 2 min past peak (MDS). In contrast, mixograph peak time (MPT) and the curve width at 2 min past peak (MCW) were significantly decreased. Flour protein correlated positively with SDSS, MPH and MDS and negatively with MCW. MPT correlated negatively with MDS and positively with MCW. Results indicate that high temperature increased both soluble and insoluble protein contents. SDSS and MPH, and hence the gluten strength, but decreased flour mixing time and tolerance and hence the dough elasticity. Variation observed among genotypes suggests that grain end-use quality could be improved under high temperature conditions utilizing the available variability; however, it might require evaluation under various growing conditions.
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BCSnob
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Effect of increasing temperature on yiel........ of some winter crops in northwest India
The effect of increase in temperature on grain yield of some winter crops (wheat, mustard, barley and chickpea) in northwest India was evaluated on the basis of historic records and through a dynamic crop growth model, WTGROWS.
The model output indicates that increase in temperature by 1–3°C is likely to advance the optimal sowing dates by 5–8 days per degree rise in temperature. However, this advancement is less in relatively cool regions.
Attainable yield of wheat is also subject to decrease with similar degree of increase in temperature. Yield–temperature response curves show that there is a decrease in grain yield of wheat in all the four states studied (Figure 1), with maximum decrease in Haryana (4.29 q per ha) followed by Rajasthan (2.49 q per ha) per degree rise in seasonal temperature.
* This post was
edited 10/14/08 01:27pm by BCSnob *
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BCSnob
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I've supported my argument (warmer temps can lower crop yields) with published studies (peer review).
I've not argued lower temps will have no effect on crop yields; only that increasing temps can also have a negative impact on crop yields. The impact be highly dependent upon the region of interest and the crops planted in that region.
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Jumbo Cranium
Texas where else
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Ok, thats 2 studies showing wheat yields may go down due to higher temps. The first one states "Variation observed among genotypes suggests that grain end-use quality could be improved under high temperature conditions utilizing the available variability; however, it might require evaluation under various growing conditions." so it may be inconclusive since they acknowledge they need to study it more. It also said the seeds were planted under optimum AND LATE sowing conditions, but did not differentiate the yields in the 2 samples. If you are planting late you can expect higher temps.
However, a late frost usually destroys the entire crop, not just reduce its yeild. I'm not talking about wheat here. I talking fruits and vegetables and some other grains.
Thanks at least for not saying I am too uneducated to even discuss the matter and I must bow in your superior presence. Thats the typical response from one of our resident PhD's
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Jumbo Cranium
Texas where else
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One of my main arguments is that the Earths climate has NEVER been stable and how can we expect it to conform to it's present conditions without knowing what caused the changes in the past. I see these shows on TV where they are experimenting with ways to reverse warming, that appears to have stopped all by itself 10 years ago, even though C02 levels have continued to rise.
What happens if they find a way to cool the planet? They won't undertsand completely how it works, they won't know when to stop it, they wont know how it will effect the planet, yet they keep muddling along trying ever so hard to reverse an effect that has happened hundreds of times before with absolutely no influence by man.
Thats scary.
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