lathyrus_long

6 ms·

1.
by lathyrus_long 3y ago
Tissue culture is also used without genetic engineering. Orchid flasking is the classic example, since the seedlings require an external source of energy. A symbiotic fungus provides that in nature, but it's easier to replace that with
2.
by lathyrus_long 4y ago
It's not fundamentally incompatible, but non-proprietary hybrids are extremely rare. The effort to maintain the two parents and do the cross is much greater than that of saving seed from an open-pollinated variety, so very few growers
3.
by lathyrus_long 4y ago
You could say that a log scale is useful only when the variable can be usefully regarded as the exponential of something, and I think you'd be tautologically right. That exponential structure just shows up very often, whether from huma
4.
by lathyrus_long 4y ago
Log scales are also widely used for physical quantities that humans can't directly perceive, like radio-frequency electric fields. The logarithmic nature of human perception provides an additional benefit in some cases, but it's n
5.
by lathyrus_long 4y ago
That's a question of why Fourier transforms are important though, not just how they're defined and computed. The next-level answer is presumably that sinusoids (or complex exponentials in general) are the eigenfunctions of general
6.
by lathyrus_long 4y ago
As others note, it's exactly a change in basis. In particular, it's an orthonormal basis, meaning that the dot product (correlation) between a basis function and itself is one, and between any two different basis functions is zero
7.
by lathyrus_long 4y ago
This article doesn't say, but vertical farms almost always grow hydroponically, using sterilized inert media (like coir) or inherently sterile inert media (like rockwool). The water and fertilizer are delivered together by drip irrigat
8.
by lathyrus_long 4y ago
It's more complicated than that, since the wavelength distribution matters--we can effectively transform green photons that the plant would have reflected into red or blue photons that it will absorb. (The plant still benefits from som
9.
by lathyrus_long 4y ago
The objections are to vertical farms for grain, not vertical farms in general. Leafy greens are ideal candidates for indoor growing by artificial light, since they need relatively little light and are quickly perishable. The savings in tran
10.
by lathyrus_long 4y ago
Tomatoes, peppers, lettuce, culinary herbs, and many other plant species are grown profitably under hydroponic conditions. This is especially common in colder climates, to maximize the yield per square foot in expensive greenhouses. It&#x27
11.
by lathyrus_long 4y ago
I'm not sure that's how I perceive capsaicin myself; but the guy who bred the Carolina Reaper is a recovering addict (in the usual sense, street drugs and alcohol), and he certainly describes his creations in similar terms: https
12.
by lathyrus_long 4y ago
I think that's seed potato production, where the consistency and lack of pathogens justifies the extra cost. Here's a manual: https://cipotato.org/wp-content/uploads/2014/08/005447.pdf It would
13.
by lathyrus_long 4y ago
What do you mean by "sludge"? Typical hydroponic solution just looks like water, thus the name. The fertilizers used are higher purity ("greenhouse grade", "ultra-soluble", etc.) than those applied to soil, sin
14.
by lathyrus_long 4y ago
> High calorie and/or high fiber foods require complex rhizospheres which is currently only found in healthy soil. What is your source for this claim? Major grains (wheat, corn, rice, etc.) grow fine hydroponically--I've actual
15.
by lathyrus_long 4y ago
Surely this relationship is noteworthy only to the extent it's potentially a causality? The authors are careful not to make explicit claims, but most discussion here is about that possibility. The title of this HN submission is too (&q
16.
by lathyrus_long 4y ago
> Conventional vs organic is not clear cut. Certainly agreed. Note that the guidelines I linked above do permit certain synthetic pesticides, despite their somewhat confusing use of the word "conventional" in the text that I qu
17.
by lathyrus_long 4y ago
A matter of degree, maybe. Certainly there's a degree of understanding that's cheaper than just blind heavy spraying, and that any grower would thus be foolish not to obtain. I've often seen "IPM" used to refer to s
18.
by lathyrus_long 4y ago
Many American cities have "community gardens" equivalent to the European allotments. Mine will provide a few hundred square feet to any resident for a nominal fee, for the exclusive use of that resident with some basic restriction
19.
by lathyrus_long 4y ago
I've seen fruit marked as "IPM" in my local grocery store. That refers to integrated pest management, a general philosophy of controlling pests through understanding of their physiology, behavior, and interaction with the art
20.
by lathyrus_long 4y ago
I've heard of facilities with short crop cycles (greens, herbs, etc.) running totally bug-free with zero pesticides, with air showers at the entrance and careful segregation so that one introduction doesn't ruin their whole crop,
21.
by lathyrus_long 4y ago
The p values are small enough that the correlation seems likely to be real, even after lots of dredging through that dataset. I'm less sure about the causality, though. It's also possible they've just discovered that richer p
22.
by lathyrus_long 4y ago
Other kinds of fruit have higher sugar content; jujube is reportedly highest, reaching thirties or even forties. For a strawberry 13-14 is quite good, though. Here's a sophisticated amateur who managed to hit 14.5 (with lower average):
23.
by lathyrus_long 4y ago
They applied "nutrient solution of 0.125× strength MS nutrient solution, pH 5.7 (Murashige and Skoog)". The salts in that make a typical complete hydroponic fertilizer. https://en.wikipedia.org/wiki/Murashige_
24.
by lathyrus_long 5y ago
Huh, quoting: > While they're easily cultivated from seed and grown in nurseries both in the United States and in Asia, the large, old, wild-harvested Dudleya are considered luxury items by collectors overseas and command high price
25.
by lathyrus_long 5y ago
Maybe, but I've never heard of anyone buying a wild-collected orchid from a species where commercially tissue-cultured specimens were available. Beyond the ethical question, greenhouse specimens tend to be more perfect, to carry fewer
26.
by lathyrus_long 5y ago
The usual cheap RO systems operate from household water pressure only. They fill a pressure tank at the output, allowing the purified water to be dispensed from a faucet. The pressure across the membrane is that input pressure minus the tan
27.
by lathyrus_long 5y ago
"Soilless Culture: Theory and Practice" is a pretty good textbook. I also recommend the USDA's https://www.fs.usda.gov/treesearch/pubs/46345 That's not about hydroponics, but the theory behind
28.
by lathyrus_long 5y ago
I grow mostly by sunlight on my balcony. I've also got some white LM301B lights, which seem very popular among those growing by artificial light only. Greenhouse growers supplementing sunlight still seem to prefer red-blue. You could t
29.
by lathyrus_long 5y ago
Sophisticated growers routinely get lab tests that provide a breakdown by element of the leaves, fruit, or other parts of the plant. This is mostly to assess plant health, but also gives an indication of the nutritional value to humans. It&
30.
by lathyrus_long 5y ago
Nothing exciting--the plants drain into a 1020 tray, and a pump sucks up the leachate. The pump feeds into a waste bucket, through a sample cup that contains pH and EC electrodes. (It would be more common for the leachate just to drain by g

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