Response of Weeds to Soil pH

Weed Science ◽  
1975 ◽  
Vol 23 (6) ◽  
pp. 473-477 ◽  
Author(s):  
G. A. Buchanan ◽  
C. S. Hoveland ◽  
M. C. Harris

Ten warm-season and six cool-season weed species were grown in the glasshouse on Hartsells fine sandy loam soil and Lucedale sandy loam soil at pH levels from 4.7 to 6.3. Growth of species varied widely in response to soil pH as measured by herbage yield. Showy crotalaria (Crotalaria spectabilis Roth), coffee senna (Cassia occidentalis L.), and large crabgrass (Digitaria sanguinalis (L.) Scop.] were highly tolerant to low pH soils. Sicklepod (Cassia obtusifolia L.), annual bluegrass (Poa annua L.), Carolina geranium (Geranium carolinianum L.), and buckhorn plantain (Plantago lanceolata L.), were medium to high in tolerance. Jimsonweed (Datura stramonium L.), tall morningglory [Ipomoea purpurea (L.) Roth], crowfootgrass [Dactyloctenium aegyptium (L.) Richter], and prickly sida (Sida spinosa L.) were medium to low in tolerance to low soil pH. Growth of Florida beggarweed [Desmodium tortuosum (Sw.) DC], redroot pigweed (Amaranthus retroflexus L.), chickweed [Stellaria media (L.) Cyrillo], common dandelion (Taraxacum officinale (Weber), and wild mustard [Brassica kaber (DC.) L.C. Wheeler var. pinnatifida (Stokes) L.C. Wheeler] was severely reduced in soils with low pH.

Weed Science ◽  
1976 ◽  
Vol 24 (2) ◽  
pp. 194-201 ◽  
Author(s):  
C. S. Hoveland ◽  
G. A. Buchanan ◽  
M. C. Harris

Ten warm-season and seven cool-season weed species were grown in the glasshouse on Hartsells fine sandy loam taken from field plots that had been in long-term fertility studies. The soil pH was 5.9 and phosphorus (P) levels ranged from 8 to 95 kg/ha and the potassium (K) levels from 40 to 213 kg/ha. Growth response to P and K levels was measured by dry herbage yield. Redroot pigweed (Amaranthus retroflexus L.), jimsonweed (Datura stramonium L.), and Florida beggarweed [Desmodium tortuosum (Sw.) DC] were the most responsive warm-season weed species to P, whereas chickweed [Stellaria media (L.) Cyrillo] was the most responsive cool-season weed to P. Extreme P deficiency symptoms were evident on species giving a high response to P. P-deficient plants were severely stunted and exhibited a characteristic reddish-purple color. Showy crotalaria (Crotalaria spectabilis Roth), tall morningglory [Ipomoea purpurea (L.) Roth], sicklepod (Cassia obtusifolia L.), Carolina geranium (Geranium carolinianum L.), and coffee senna (Cassia occidentalis L.) were the most tolerant to low soil P. Redroot pigweed, jimsonweed, and Florida beggarweed were the most responsive warm-season weeds to K. Wild mustard [Brassica kaber (DC.) L.C. Wheeler var. Pinnatifida (Stokes) L.C. Wheeler] and annual bluegrass (Poa annua L.) were the most responsive cool-season weeds to K. Potassium deficiency symptoms were characterized primarily by severe stunting. Buckhorn plantain (Plantago lanceolata L.), Carolina geranium, and curly dock (Rumex crispus L.) were the most tolerant cool-season weeds to low soil K. Generally, weeds were more sensitive to low soil-test P than K.


age ◽  
2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Dinesh Panday ◽  
Maysoon M. Mikha ◽  
Bijesh Maharjan

Weed Science ◽  
1971 ◽  
Vol 19 (5) ◽  
pp. 580-582 ◽  
Author(s):  
Gale A. Buchanan ◽  
Earl R. Burns

Competitive effects of cocklebur (Xanthium pensylvanicumWallr.) and redroot pigweed (Amaranthus retroflexusL.) on cotton (Gossypium hirsutumL.) were evaluated in four experiments at two locations in Alabama during the period 1966 to 1968. Cocklebur was more competitive with cotton than was pigweed on Norfolk sandy loam soil. A density of eight cocklebur plants per 7.31 m of row reduced cotton yields 20 to 40%. Higher densities of cocklebur resulted in greater yield reductions. Forty-eight cocklebur plants per 7.31 m of row caused cotton yields to be reduced more than 80%. Pigweed at a density of 48 weeds per 7.31 m of row reduced cotton yields less than 50% on the Norfolk soil. On Lucedale sandy clay loam, cocklebur and pigweed were equally competitive and both species were more competitive than on Norfolk soil. A density of eight cocklebur or pigweed plants per 7.31 m of row resulted in 60 to 70% cotton yield reductions. The highest density of pigweed studied, 48 plants per 7.31 m of row, reduced cotton yields 90% on the Lucedale soil. Vegetative growth, boll, and seed size were not affected as much as cotton yields by either weed species. Percentage lint and fiber properties were unaffected by plant competition.


Author(s):  
Giovani Apolari Ghirardello ◽  
Lucas da Silva Araújo ◽  
Luisa Carolina Baccin ◽  
Mateus Augusto Dotta ◽  
Raphael Oliveira Souza ◽  
...  

Selectivity index is a way of assessing the discrimination of herbicide to a given crop by observing its effects on the crop and the weeds. The aim was to obtain the selectivity index of indaziflam herbicide to sugarcane cultivar IACSP95-5000 as a function of five weed species in two soils textures. The experiment was carried out in a greenhouse at Piracicaba, São Paulo, Brazil. The treatments consisted of indaziflam doses (0; 12.5; 25; 50; 100; 200; 400; 800 and 1,600 g of the active ingredient (ai) ha-1), applied in pre-emergence of the sugarcane and of the weeds Urochloa decumbens, Urochloa plantaginea, Digitaria horizontalis, Panicum maximum and Rottboellia cochinchinensis. In sandy loam soil, a 100% control for all weeds was provided at 25 g ai ha-1. In clay soil, for D. horizontalis the 90% reduction in total dry mass (ED90) was obtained at 25 g ai ha-1, for R. cochinchinensis at 193 g ai ha-1, for U. plantaginea at 152 g ai ha-1, for P. maximum at 124 g ai ha-1, and for U. decumbens at 94 g ai ha-1. Indaziflam was selective to IACSP95-5000 in both soils, with 10% of reduction in dry mass (ED10) at 137 g ai ha-1 for soil with a sandy loam texture and 353 g ai ha-1 for clay soil. The selectivity index was higher than 1 for all weeds in clay soil. It was not possible to obtain the selectivity index for sandy loam soil due to species susceptibility to the herbicide.


1999 ◽  
Vol 13 (2) ◽  
pp. 425-428 ◽  
Author(s):  
Mark J. Vangessel

Herbicides from several chemical families were evaluated in the greenhouse for preemergence control of perennial weed species emerging from seeds. Weed species were bermudagrass, johnsongrass, Canada thistle, common milkweed, common pokeweed, hemp dogbane, and horsenettle. Atrazine, cloransulam, chlorimuron, clomazone, flumetsulam, imazaquin, linuron, metolachlor, metribuzin, pendimethalin, and sulfentrazone were used representing common preemergence herbicide families used in the mid-Atlantic region for corn and soybean in a sandy loam soil. Hemp dogbane and common pokeweed were controlled (greater than 85%) by eight of the 11 herbicides in this study, indicating they may be the two most susceptible species in the trial. Metolachlor and pendimethalin provided control of only bermudagrass, and linuron controlled only Canada thistle. Cloransulam controlled all species except bermudagrass. Clomazone provided greater than 80% control of all species except horsenettle. Metribuzin alone or in combination with chlorimuron provided the broadest spectrum and highest level of control. Metribuzin provided greater than 85% control of all species except johnsongrass. Soil-applied herbicides can limit the establishment of perennial species from seeds.


Agronomie ◽  
2002 ◽  
Vol 22 (7-8) ◽  
pp. 731-738 ◽  
Author(s):  
Roland Harrison ◽  
Sharon Ellis ◽  
Roy Cross ◽  
James Harrison Hodgson

2020 ◽  
Vol 18 (4) ◽  
pp. 84-87
Author(s):  
Yu.V. Leonova ◽  
◽  
T.A. Spasskaya ◽  

The change in the microbiological activity of sod-podzolic sandy loam soil when using coffee waste and sewage sludge as a fertilizer for oats in comparison with traditional fertilizers is considered. During the study, it was determined that the predominant groups were bacteria and actinomycetes. Bacilli and fungi are few in number. The introduction of sewage sludge and coffee waste into the sod-podzolic sandy loam soil at a dose of 10 t / ha increases the activity of the microflora of the sod-podzolic sandy loam soil, which increases the effective and potential fertility.


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