COMPETITIVE INTERACTIONS OF ALFALFA AND ANNUAL WEEDS AS AFFECTED BY ALFALFA WEEVIL (COLEOPTERA: CURCULIONIDAE) STUBBLE DEFOLIATION

1989 ◽  
Vol 24 (1) ◽  
pp. 78-83 ◽  
Author(s):  
G. David Buntin
Keyword(s):  
Dry Matter ◽  
Chenopodium Album ◽  
Dry Weight ◽  
Amaranthus Retroflexus ◽  
Dry Matter Accumulation ◽  
Weed Species ◽  
Alfalfa Weevil ◽  
Matter Production ◽  
Annual Weeds ◽  
The Impact

The impact of stubble defoliation by alfalfa weevil, Hypera postica (Gyllenhal), larvae on the establishment and growth of selected annual weeds in alfalfa was examined under controlled conditions in the greenhouse. Weed species were large crabgrass, Digitaria sanguinalis (L.) Scop., yellow foxtail grass, Setaria lutescens (Weig.) Hubb., redroot pigweed, Amaranthus retroflexus L. and common lambsquarters, Chenopodium album L. Stubble defoliation increased the survival of all weed species except foxtail grass. Dry matter production of aerial portions of crabgrass, foxtail grass, pigweed and lambsquarters was 28.4, 7.2, 23.7, and 7.3 times greater, respectively, when growing with defoliated than undefoliated alfalfa. Stubble defoliation also enhanced plant height and leaf number of most weed species. Stubble defoliation reduced dry matter accumulation and delayed development of alfalfa regrowth. Alfalfa root dry weight was more adversely affected than top dry weight by stubble defoliation. The presence of weeds did not significantly (P > 0.05) affect the growth and development of defoliated and undefoliated alfalfa. This result suggests that stubble defoliation by alfalfa weevil larvae reduced the competitive ability of alfalfa which allowed weeds to grow and occupy gaps within the alfalfa canopy.

Response of Dwarf Wheat (Triticum aestivum) and Four Weed Species to Herbicides

Weed Science ◽  
1981 ◽  
Vol 29 (5) ◽  
pp. 521-524 ◽  
Author(s):  
O. P. Kataria ◽  
Vijay Kumar
Keyword(s):  
Triticum Aestivum ◽  
Dry Matter ◽  
Chenopodium Album ◽  
Wheat Crop ◽  
Weed Species ◽  
Convolvulus Arvensis ◽  
Matter Production ◽  
Dwarf Wheat ◽  
Hand Weeding ◽  
High Degree

Control of littleseed canarygrass (Phalaris minor Retz.), wild oat (Avena fatua L.), common lambsquarters (Chenopodium album L.), and field bindweed (Convolvulus arvensis L.) in dwarf wheat (Triticum aestivum L.) fields was studied with five herbicides and hand weeding. Terbutryn [2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine] and 1-benzthiazol-2-yl-1,3-dimethylurea controlled the weeds more effectively than did two hand weedings. Diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], nitrofen (2,4-dichlorophenyl p-nitrophenyl ether), and dichlormate (3,4-dichlorobenzyl methylcarbamate), proved only partially effective against weeds, and were therefore significantly inferior to two hand weedings. Spikes per meter of row length and test weight of wheat were increased significantly by 1-benzthiazol-2-yl-1,3-dimethylurea (1.5 to 2 kg/ha), terbutryn (0.5 kg/ha), and two hand weedings over the yields of the weedy check. The 1-benzthiazol-2-yl-1,3-dimethylurea showed a high degree of selectivity in the wheat crop at 2 kg/ha and increased yields to those of weed-free plots. Terbutryn was almost as effective as 1-benzthiazol-2-yl-1,3-dimethylurea, which increased the wheat yields over those of the weedy check by 19.8 and 42.4% during the 1974/75 and 1975/76 seasons, respectively. Tolerance of dwarf wheat to terbutryn at 0.75 kg/ha was variable, resulting in significant decreases in yield components and grain yield. Dry-matter yield of wheat was negatively correlated with the dry matter production of weeds.

The Interaction of Soybean (Glycine max) and Five Weed Species in the Greenhouse

Weed Science ◽  
1985 ◽  
Vol 33 (5) ◽  
pp. 669-672 ◽  
Author(s):  
Janet L. Shurtleff ◽  
Harold D. Coble
Keyword(s):  
Glycine Max ◽  
Dry Matter ◽  
Dry Weight ◽  
Amaranthus Retroflexus ◽  
Matter Content ◽  
Dry Matter Content ◽  
Weed Species ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Redroot Pigweed

The influence of relative planting date on the growth of common cocklebur (Xanthium pensylvanicumWallr. ♯ XANST), common ragweed (Ambrosia artemesiifoliaL. ♯ AMBEL), sicklepod (Cassia obtusifoliaL. ♯ CASOB), and redroot pigweed (Amaranthus retroflexusL. ♯ AMARE) grown in competition with soybean [Glycine max(L.) Merr. ‘Bragg’] was studied in the greenhouse. Increases in dry matter and height were slower for the five weed species than for soybean throughout the period of the study. The root: shoot ratio of soybean was the highest of any plant in the study, while common ragweed, common cocklebur, common lambsquarters, and sicklepod were intermediate, and redroot pigweed was the lowest. Soybean dry weight was always reduced when grown in competition with a weed. Soybean dry-matter production was reduced most when weeds were planted 2 weeks before soybean, especially with common cocklebur and common lambsquarters. Weed dry-matter content was severely reduced when the weed seed were planted simultaneously with or following soybean. Soybean height was usually reduced by competition with the weeds. The height of common ragweed was increased, however, when planted simultaneously with soybean. Common lambsquarters, redroot pigweed, and common ragweed heights were increased when planted 2 weeks prior to soybean.

Dry matter accumulation by Piceasitchensis seedlings during winter

1978 ◽  
Vol 8 (2) ◽  
pp. 207-213 ◽  
Author(s):  
Ian K. Bradbury ◽  
D. C. Malcolm
Keyword(s):  
Soil Temperature ◽  
Dry Matter ◽  
Dry Weight ◽  
Relative Increase ◽  
Weight Increase ◽  
Dry Matter Accumulation ◽  
Weight Changes ◽  
Incoming Radiation ◽  
Matter Production ◽  
Harvest Intervals

Dry matter production by Sitka spruce seedlings (Piceasitchensis (Bong.) Carr) outside the period of shoot extension was determined in southern Scotland by harvesting plants from a nursery on 13 occasions between late September and mid-May. Air and soil temperature and incoming radiation were measured in an attempt to relate weight changes to climatic variables. Dry weight of the plants apparently doubled between late September and mid-April but subsequently changed little. Most dry weight increase occurred during October, late March, and April but there was also a slight increase in weight in midwinter. The relative increase in weight was similar in roots and shoots until mid-January but thereafter was proportionally much greater in shoots than in roots and was associated with a marked increase in needle weight. Lack of weight increase in late spring was attributed to the respiratory demands of bud expansion. Dry matter changes in the 12 harvest intervals was not related to mean daily temperature, incoming radiation, or photoperiod, but when averaged over periods of 1 month a much closer relationship was evident.

Dry matter accumulation into zygotic seed; a model and its application to artificial seeds

1994 ◽  
Vol 4 (2) ◽  
pp. 89-96 ◽  
Author(s):  
Yvon Le Deunff ◽  
Jacques Loiseau
Keyword(s):  
Water Content ◽  
Dry Matter ◽  
Zygotic Embryo ◽  
Dry Weight ◽  
Cell Number ◽  
Dry Matter Accumulation ◽  
Weed Species ◽  
Elementary Model ◽  
Pea Seed

AbstractPea seed development on the mother plant consists of three phases, all limited by water concentration (WC). The first (P1) or embryogenesis sensu stricto takes place at constant WC (stable at 80%). During the phase P2, cotyledon filling or maturation, WC decreases linearly from 80 to 55% (physiological desiccation) but the water content stays constant while the dry weight increases until it stops abruptly (at 55% WC), at this time, the seed has almost reached its final dry weight, its maturity mass or physiological maturity. The third phase, P3, consists of a fast desiccation which leads to a WC of 18–14%, where the seed is mature and ready to harvest. Similar events occur in other grain legumes, in cereals where mass maturity is attained at a lower WC (close to 40%) and in other species including crop or weed species. An elementary model of pea seed dry-matter accumulation, based on the constancy of water content (P1) and the linear decrease of WC from 80 to 55% (P2), allows us to define a coefficient α linked to WC and to calculate dry matter changes versus α. This model, taking account of WC in other species, can be generalized easily. Maturation of the somatic embryo, occurring under conditions very close to those present in vivo around the zygotic embryo, follows a pattern of decrease of WC similar to that of the zygotic embryo. We expect that if cell number is similar in the somatic and the zygotic embryo, synseeds will be ready for trade in the near future since control of all the processes that lead to zygotic-like embryoids is now available.

scholarly journals Influence of Rate, Timing, and Method of Nitrogen Fertilizer Application on Uptake and Use of Fertilizer Nitrogen, Growth, and Yield of June-bearing Strawberry

2004 ◽  
Vol 129 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Bernadine Strik ◽  
Timothy Righetti ◽  
Gil Buller
Keyword(s):  
Ammonium Nitrate ◽  
Dry Matter ◽  
Dry Weight ◽  
Dry Matter Accumulation ◽  
Fertilizer N ◽  
Fertilizer Nitrogen ◽  
The Third ◽  
Reproductive Tissues ◽  
Total Plant ◽  
The Impact

Fertilizer nitrogen (FN) recovery, and changes in nitrogen (N) and dry weight partitioning were studied over three fruiting seasons in June-bearing strawberry (Fragaria ×ananassa Duch. `Totem') grown in a matted row system. Fertilizer nitrogen treatments were initiated in 1999, the year after planting. The standard ammonium nitrate N application at renovation (55 kg·ha-1 of N) was compared to treatments where additional N was applied. Supplemental treatments included both ground-applied granular ammonium nitrate (28 kg·ha-1 of N) applied early in the season and foliar urea [5% (weight/volume); 16 kg·ha-1 of N] applied early in the season and after renovation. When labeled N was applied (eight of nine treatments) it was applied only once. The impact of no FN from the second through the third fruiting season was also evaluated. Fertilizer nitrogen treatment had no impact on total plant dry weight, total plant N, yield or fruit quality from the first through the third fruiting seasons. Net dry matter accumulation in the first fruiting season was 2 t·ha-1 not including the 4 t·ha-1 of dry matter removed when leaves were mowed during the renovation process. Seasonal plant dry weight and N accumulation decreased as the planting aged. Net nitrogen accumulation was estimated at 40 kg·ha-1 from spring growth to dormancy in the first fruiting season (including 30 kg·ha-1 in harvested fruit, but not including the 52 kg·ha-1 of N lost at renovation). Recovery of fertilizer N ranged from 42% to 63% for the broadcast granular applications and 15% to 52% for the foliar FN applications, depending on rate and timing. Fertilizer N from spring applications (granular or foliar) was predominantly partitioned to leaves and reproductive tissues. A large portion of the spring applied FN was lost when plants were mowed at renovation. Maximum fertilizer use efficiency was 42% for a granular 55 kg·ha-1 application at renovation, but declined to 42% just before plant growth the following spring, likely a result of FN loss in leaves that senesced. In June, ≈30% of the N in strawberry plants was derived from FN that was applied at renovation the previous season, depending on year. This stored FN was reallocated to reproductive tissues (22% to 35%) and leaves (43% to 53%), depending on year. Applying fertilizer after renovation increased the amount of remobilized N to new growth the following spring. The following June, 15% of plant nitrogen was derived from fertilizer applied at renovation 2 years prior.

scholarly journals Changes in weed infestation of common bean (Phaseolus vulgaris L.) under conditions of strip intercropping and different weed control methods

2012 ◽  
Vol 63 (2) ◽  
pp. 171-178 ◽  
Author(s):  
Aleksandra Głowacka
Keyword(s):  
Common Bean ◽  
Weed Control ◽  
Chenopodium Album ◽  
Floristic Composition ◽  
Dry Weight ◽  
Amaranthus Retroflexus ◽  
Weed Species ◽  
Aerial Parts ◽  
Weed Infestation ◽  
Strip Intercropping

The experiment was conducted in the years 2004-2006 in a private farm in the village of Frankamionka in Zamość district. There were two experimental factors: I. Cultivation methods - sole cropping and strip intercropping; and II. Tending methods - mechanical, mechanical-chemical, and chemical weed control. The subject of the study was weed infestation of the Mela variety of common bean. Beans were sown between 30 April and 5 May. Weed infestation was assessed in the last week before harvesting by determining its floristic composition and the frequency of occurrence of particular weed species, as well as the air-dry weight of weeds. The dominant weed species were <i>Galinsoga parviflora</i>, <i>Echinochloa crus-galli</i>, <i>Chenopodium album</i>, and <i>Amaranthus retroflexus</i>, which comprised 84.7% of the total number of weeds. Strip intercropping markedly reduced the number of weeds per unit area (by 50%), as well as the dry weight of their aerial parts. The most effective method of weed control was the mechanical-chemical method, which resulted in the lowest occurrence of weeds. It also significantly reduced the weight of weeds.

Effects of Temperature and CO2Concentration on the Growth of Cotton (Gossypium hirsutum), Spurred Anoda (Anoda cristata), and Velvetleaf (Abutilon theophrasti)

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 751-757 ◽  
Author(s):  
David T. Patterson ◽  
Maxine T. Highsmith ◽  
Elizabeth P. Flint
Keyword(s):  
Dry Matter ◽  
Dry Weight ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Short Term ◽  
Leaf Weight ◽  
Matter Production ◽  
Total Plant ◽  
Net Assimilation ◽  
Total Dry Weight

Cotton, spurred anoda, and velvetleaf were grown in controlled-environment chambers at day/night temperatures of 32/23 or 26/17 C and CO2concentrations of 350 or 700 ppm. After 5 weeks, CO2enrichment to 700 ppm increased dry matter accumulation by 38, 26, and 29% in cotton, spurred anoda, and velvetleaf, respectively, at 26/17 C and by 61, 41, and 29% at 32/23 C. Increases in leaf weight accounted for over 80% of the increase in total plant weight in cotton and spurred anoda in both temperature regimes. Leaf area was not increased by CO2enrichment. The observed increases in dry matter production with CO2enrichment were caused by increased net assimilation rate. In a second experiment, plants were grown at 350 ppm CO2and 29/23 C day/night for 17 days before exposure to 700 ppm CO2at 26/17 C for 1 week. Short-term exposure to high CO2significantly increased net assimilation rate, dry matter production, total dry weight, leaf dry weight, and specific leaf weight in comparison with plants maintained at 350 ppm CO2at 26/17 C. Increases in leaf weight in response to short-term CO2enrichment accounted for 100, 87, and 68% of the observed increase in total plant dry weight of cotton, spurred anoda, and velvetleaf, respectively. Comparisons among the species showed that CO2enrichment decreased the weed/crop ratio for total dry weight, possibly indicating a potential competitive advantage for cotton under elevated CO2, even at suboptimum temperatures.

EFFECTS OF TEMPERATURE ON RATE AND DURATION OF KERNEL DRY MATTER ACCUMULATION OF MAIZE

1988 ◽  
Vol 68 (4) ◽  
pp. 935-940 ◽  
Author(s):  
M. TOLLENAAR ◽  
T. W. BRUULSEMA
Keyword(s):  
Growth Rate ◽  
Zea Mays ◽  
Dry Matter ◽  
Zea Mays L ◽  
Dry Weight ◽  
Controlled Environment ◽  
Dry Matter Accumulation ◽  
Linear Kernel ◽  
Effects Of Temperature ◽  
Kernel Growth

The response of rate and duration of kernel dry matter accumulation to temperatures in the range 10–25 °C was studied for two maize (Zea mays L.) hybrids grown under controlled-environment conditions. Kernel growth rates during the period of linear kernel growth increased linearly with temperature (b = 0.3 mg kernel−1 d−1 °C−1). Kernel dry weight at physiological maturity varied little among temperature treatments because the increase in kernel growth rate with increase in temperature was associated with a decline in the duration of kernel growth proportional to the increase in kernel growth rate.Key words: Zea mays L, period of linear kernel dry matter accumulation, controlled-environment conditions, kernel growth rate

scholarly journals Weed Interference Affects Dry Bean Yield and Growth

2012 ◽  
Vol 4 (3) ◽  
pp. 70-75 ◽  
Author(s):  
Hossein GHAMARI ◽  
Goudarz AHMADVAND
Keyword(s):  
Chenopodium Album ◽  
Growing Season ◽  
Amaranthus Retroflexus ◽  
Growth And Yield ◽  
Weed Competition ◽  
Weed Species ◽  
Dry Bean ◽  
Logistic Equations ◽  
Weed Interference ◽  
Minimum Number

Dry bean is one of the most important pulse crops in Iran. Field study was conducted in 2011 to evaluate effects of weed competition from a natural flora on growth and yield of dry bean (Phaseolus vulgaris L.). The treatments consisted of weed infestation and weed removal periods (10, 20, 30, 40 and 50 days) after crop emergence. Control plots kept weed-infested and weed-free throughout growing season. To assess the weed competition effect on crop characteristics, Richards, Gompertz and logistic equations were fitted to the data. The most abundant weed species were Chenopodium album and Amaranthus retroflexus. Increase in duration of weed interference decreased the stem height of dry bean. At the end of the growing season, dry bean was 20 cm taller in season-long weed-free treatment compared to the season-long weed-infested treatment. As the number of days of weed interference increased, a declining trend of LAI and number of pods was observed. The minimum number of pods was obtained in season-long weed-infested treatment (5.01 pods/plant). Weed interference during the whole growing season, caused a 60% reduction in yield. Considering 5% and 10% acceptable yield lost, the critical period of weed competition was determined from 20 to 68 and 23 to 55 days after planting (DAE), respectively.

scholarly journals Seasonal Partitioning of Leaf and Fruit Potassium and Fruit Dry Matter in French Prune Trees at Various Potassium Levels

1991 ◽  
Vol 116 (6) ◽  
pp. 981-986 ◽  
Author(s):  
F.J.A. Niederholzer ◽  
R.M. Carlson ◽  
K. Uriu ◽  
N.H. Willits ◽  
J.P. Pearson
Keyword(s):  
Dry Matter ◽  
Dry Weight ◽  
Fruit Growth ◽  
Growth Stages ◽  
Dry Matter Accumulation ◽  
Accumulation Rates ◽  
Mature Trees ◽  
Linear Relationships ◽  
Weight Yield ◽  
High K

A study was undertaken to determine the seasonal dynamics of leaf and fruit K content and the influence of tree K status and fruit growth on leaf and fruit K accumulation rates in French prune (Prunus domestics L. cv. d'Agen). Mature trees in a commercial orchard were treated with various rates of K2 SO4. (O to ≈20 kg/tree) in the fall. Fruit dry weight yield per tree at harvest and fruit K content were higher for high-K trees, but fruit percent K (by dry weight) was ≈1.0% for all trees. Leaf scorch and subsequent abscission severely reduced the canopy of K-deficient trees. Significant positive linear relationships between leaf and fruit K accumulation rates existed for the periods of 28 Apr.-28 May (May) and 28 May-7 July (June). A significant negative linear relationship existed between these two criteria from 7 July-3 Aug. (July). May (0.237 mg K per fruit-day) and July (0.267 mg K per fruit-day) mean fruit K accumulation rates were similar, but both were significantly higher (P = 0.001) than those for June (0.140 mg K per fruit-day). Mean leaf K accumulation rates for May (- 0.007 mg K per leaf-day) and July (-0.010 mg K per leaf-day) were similar, but both were significantly (P = 0.001) less than for June (0.005 mg K per leaf-day). Potassium per fruit accumulation was highest in trees with highest K status. Periods of net leaf K efflux and influx did not precisely correlate with fruit growth stages measured by fruit dry weight. The period of lowest fruit K accumulation (28 May-7 July) coincided with the period of maximum dry matter accumulation by the kernel. After 7 July, all increases in fruit dry weight and K content were due to mesocarp growth.

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