Wikipedia:Reference desk/Archives/Science/2024 March 6

= March 6 =

Pathogens that increase crop yields
Is there any plant virus/bacterium/whatever that has been associated with increased crop yields? I remember seeing a paper a long time ago that a few plant pathogens (I think it was viruses) increase the fruit/seed yield of their hosts, along with the usual disease symptoms, and discussed reasons why this might be so. Note that I am asking about "pathogens"; symbiotic or commensal relationships or endophytes and mycorrhiza are not what I am asking about. Jo-Jo Eumerus (talk) 08:14, 6 March 2024 (UTC)
 * There's this possible example; Ustilago esculenta on Zizania latifolia. Abductive  (reasoning) 20:44, 7 March 2024 (UTC)
 * So, active symbiosis? If so, a widely known symbiosis is the one legumes and rhizobia bacteria formed. Zarnivop (talk) 21:58, 8 March 2024 (UTC)
 * Not symbiosis, precisely not symbiosis. Pathogens, viruses and diseases. I saw years ago a paper discussing that sometimes, plants produce more/bigger fruits/seeds after an infection with viruses or phytoplasms, but I can't find it again. Jo-Jo Eumerus (talk) 10:00, 9 March 2024 (UTC)
 * Perhaps some sort of last-ditch reproduction? If so, the crop quality will suffer, and be lower in nutrient value, maybe by adding too much endosperm or by making more smaller seeds or fewer larger ones. Or the plant may switch from perennial to annual. Its overall reproductive success will be impaired. Abductive  (reasoning) 11:52, 10 March 2024 (UTC)
 * "Symbiosis" merely means a systematic interaction between species, which can be mutualistic, commensalistic, or parasitic. The rhizobia–legume symbiosis is mutualistic. If you exclude all forms of symbiosis you exclude parasitic symbiosis and thereby all tolerated (non-lethal) infections by pathogens. The Ustilago esculenta wild rice smut destroys the flowering structures of the infected plant, which therefore cannot make seed. It is not to the natural reproductive advantage of the host, but is artificially advantageous through human cultivation, which makes it difficult to assess its placement in the categorization mutualism—commensalism—parasitism. --Lambiam 12:26, 9 March 2024 (UTC)
 * Correct, the only reason Ustilago esculenta increases the crop yield of Zizania latifolia is because it prevent the plant from making high-protein seeds. The plant then sequesters carbon—that it would otherwise consume to produce those seeds—in its stems. This process increases the mass of the crop. Abductive  (reasoning) 11:44, 10 March 2024 (UTC)
 * Thing is, "symbiosis" is ofteb restricted to examples of mutually beneficial interactions. I wss specifically not asking about these. JoJo Eumerus mobile (main talk) 12:00, 10 March 2024 (UTC)
 * Words have no biological reality. You asked for a pathogen that increased crop yield, and I gave one. Abductive  (reasoning) 23:25, 10 March 2024 (UTC)

Has the cubic correction to redshift versus luminosity been tested, or is it likely to be?
A 2017 paper mentions this (details are in the draft article under the heading An alternative to Dark Energy) but the value did not seem to be available then. This is for the draft article: Draft:Shockwave Cosmology Hewer7 (talk) 16:49, 6 March 2024 (UTC)


 * All I could find were posts of people asking whether this cubic correction had been measured. --Lambiam 21:17, 6 March 2024 (UTC)
 * I just tried the copilot ai but got nothing useful towards answering this question. Hewer7 (talk) 14:24, 16 March 2024 (UTC)