Abstract
The nature of the competition between barley and the twitch grass, Holcus mollis , has been studied. H. mollis has overrun much of the light, semi‐acid arable land near Woburn on Lower Greensand soils; about 2 1/2 tons of dry rhizomes and roots per acre were dug up on land where it had grown for 10 months. All this rhizome growth occurred within the top 8 in. of the soil. H. mollis commonly increases until the roots occupy from 0.11 to 0.141. root space per 1 g. dried roots and rhizomes. It is slightly superior to barley in ability to utilize available nitrogen. When barley and this Holcus are grown together with abundance of food and water for both plants, the effect of the weed on the yield of barley depends on whether the barley or the weed first becomes established and on the rate of sowing of the barley. If barley growth begins before that of Holcus , it may smother the weed completely and sustain no loss of yield provided the barley is planted thickly enough. If the two competing plants start at the same time, thickness of planting is still able to limit the extent to which the weed can reduce the yield of barley, though even with the thickest planting the Holcus can reduce barley yield by one‐third. Where Holcus is already established in the ground from the previous year and the crop is thinly planted, the weed is able to eliminate the barley completely, but where barley is sown thickly it is still able to give a 50% yield. With a sparse crop of barley, an increase in the number of weed units makes no difference to the growth of the barley provided the crop becomes well established. Where the crop and the weed start together and so compete on equal terms, any increase of Holcus growth is obtained at the cost of an almost equal falling off in the yield of barley, showing that the respective plant growths are almost complementary. Once the weed has fully occupied the soil, it is able to suppress the growth of the barley almost entirely. The barley and the Holcus reduce the growth of each other even when the root space and supply of plant food are ample for both.
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Claims 14
Claim · model-written summary
H. mollis produced about 2 1/2 tons of dry rhizomes and roots per acre after 10 months near Woburn.
- Taxon
- barley
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Hordeum vulgaret0 - Interactor
- H. mollis
Holcus mollise0weed - Outcome
- dry rhizomes and roots per acree0
- Value
- 2 1/2 tonse0
- Setting
- Woburne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“H. mollis has overrun much of the light, semi‐acid arable land near Woburn on Lower Greensand soils; about 2 1/2 tons of dry rhizomes and roots per acre were dug up on land where it had grown for 10 months.”
t0“BARLEY”
Claim · model-written summary
The H. mollis rhizome growth was confined to the upper 8 inches of soil.
- Taxon
- barleyHordeum vulgaret0
- Outcome
- rhizome growthe0
- Value
- 8 in.e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All this rhizome growth occurred within the top 8 in. of the soil.”
t0“BARLEY AND CERTAIN WEEDS UNDER CONTROLLED CONDITIONS: II. COMPETITION WITH HOLCUS MOLLIS”
Claim · model-written summary
H. mollis commonly increased to the stated root occupancy range.
- Taxon
- barleyHordeum vulgaret0
- Interactor
- H. mollisHolcus mollise0weed
- Outcome
- root space per 1 g. dried roots and rhizomese0
- Direction
- increasese0
- Value
- 0.11 to 0.141.e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“H. mollis commonly increases until the roots occupy from 0.11 to 0.141. root space per 1 g. dried roots and rhizomes.”
t0“BARLEY”
Claim · model-written summary
H. mollis was slightly superior to barley in use of available nitrogen.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- ability to utilize available nitrogene0
- Direction
- superiore0
- Comparator
- barleye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It is slightly superior to barley in ability to utilize available nitrogen.”
t0“HOLCUS MOLLIS”
Claim · model-written summary
Early, dense barley could completely smother Holcus.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- smother the weed completelye0
- Qualifier
- barley is planted thickly enoughe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“If barley growth begins before that of Holcus , it may smother the weed completely and sustain no loss of yield provided the barley is planted thickly enough.”
Claim · model-written summary
Early, dense barley sustained no yield loss from Holcus.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- no loss of yielde0
- Direction
- no losse0
- Qualifier
- barley is planted thickly enoughe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“If barley growth begins before that of Holcus , it may smother the weed completely and sustain no loss of yield provided the barley is planted thickly enough.”
Claim · model-written summary
Denser barley sowing limited the yield reduction from Holcus when both started together.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- yield of barleye0
- Direction
- limite0
- Qualifier
- start at the same timee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“If the two competing plants start at the same time, thickness of planting is still able to limit the extent to which the weed can reduce the yield of barley, though even with the thickest planting the Holcus can reduce barley yield by one‐third.”
Claim · model-written summary
Even with the thickest simultaneous sowing, Holcus reduced barley yield by one third.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- barley yielde0
- Direction
- reducee0
- Value
- one‐thirde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“If the two competing plants start at the same time, thickness of planting is still able to limit the extent to which the weed can reduce the yield of barley, though even with the thickest planting the Holcus can reduce barley yield by one‐third.”
Claim · model-written summary
Previously established Holcus eliminated thinly planted barley.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- eliminate the barley completelye0
- Qualifier
- crop is thinly plantede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Where Holcus is already established in the ground from the previous year and the crop is thinly planted, the weed is able to eliminate the barley completely, but where barley is sown thickly it is still able to give a 50% yield.”
Claim · model-written summary
Densely planted barley retained 50% yield against established Holcus.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- yielde0
- Value
- 50%e0
- Qualifier
- barley is sown thicklye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Where Holcus is already established in the ground from the previous year and the crop is thinly planted, the weed is able to eliminate the barley completely, but where barley is sown thickly it is still able to give a 50% yield.”
Claim · model-written summary
Additional weed units did not change growth of well established sparse barley.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- growth of the barleye0
- Direction
- makes no differencee0
- Qualifier
- crop becomes well establishede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With a sparse crop of barley, an increase in the number of weed units makes no difference to the growth of the barley provided the crop becomes well established.”
t0“HOLCUS MOLLIS”
Claim · model-written summary
When established together, more Holcus growth accompanied an almost equal decrease in barley yield.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- yield of barleye0
- Direction
- falling offe0
- Qualifier
- start togethere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Where the crop and the weed start together and so compete on equal terms, any increase of Holcus growth is obtained at the cost of an almost equal falling off in the yield of barley, showing that the respective plant growths are almost complementary.”
Claim · model-written summary
Full soil occupation by Holcus nearly completely suppressed barley growth.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- growth of the barleye0
- Direction
- suppresse0
- Qualifier
- fully occupied the soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Once the weed has fully occupied the soil, it is able to suppress the growth of the barley almost entirely.”
t0“HOLCUS MOLLIS”
Claim · model-written summary
Barley and Holcus mutually reduced growth even with ample root space and nutrients.
- Taxon
- barleyHordeum vulgaree0
- Outcome
- growth of each othere0
- Direction
- reducee0
- Qualifier
- root space and supply of plant food are amplee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The barley and the Holcus reduce the growth of each other even when the root space and supply of plant food are ample for both.”