SPROUTING AND DEVELOPMENT OF YELLOW NUT SEDGE TUBERS

1977 ◽  
Vol 57 (2) ◽  
pp. 509-514 ◽  
Author(s):  
G. H. FRIESEN ◽  
A. S. HAMILL

Tubers of yellow nut sedge (Cyperus esculentus L.) were collected from four farm fields representing three soil types in southern Ontario in November of 1974 or 1975. These fields contained from 760 to 8,484 tubers/m2 in the top 40 cm of soil. Tubers extracted from these soils failed to sprout following 6 wk of storage under dry conditions, but sprouting approached 100% if previously stored under cool, moist conditions. Cool temperatures during dry storage for 90 wk reduced subsequent sprouting. Tubers sprouted as well in the greenhouse as in petri plates in a germination chamber. Root growth averaged 2 cm/day in glass-lined root boxes and tuber initiation commenced 90 days after planting. Tuber production was greatest under a short day length of 12 h or less, while shoot and root growth was stimulated by a long photoperiod.

1973 ◽  
Vol 80 (3) ◽  
pp. 369-373 ◽  
Author(s):  
K. Simpson ◽  
P. Crooks ◽  
S. McIntosh

SummaryThirteen field experiments were made during 6 years on seed-potato growing farms in south-east Scotland, comparing three rates, 70, 140 and 280 kg K/ha as potassium chloride and four rates of 0–54 kg Mg/ha as kieserite in 3 × 4 factorial experiments.More than 70 kg/ha of potassium increased total yield only at one site, which had a recent history of low K application and very low available K. Yields were decreased by more than 70 kg/ha of potassium at three sites in a season with abnormally dry conditions just after planting. Applied magnesium had little effect on total yield.Extra potassium increased ware yield but decreased seed yield, both consistently, probably because the fertilizer damaged some stolons at or before tuber initiation and fewer tubers developed. The ware/seed ratio was generally increased by extra K, but after the dry spring this ratio was unaltered or reduced. Applied magnesium had little effect on the ratio.Our results suggest that the present rates of K fertilizer, used for commercial seed-potato crops (114–138 kg K/ha) in south-east Scotland are excessive, and a much lower rate of approximately 70 kg K/ha would be adequate except on very low K sites.


2006 ◽  
Vol 20 (2) ◽  
pp. 326-333 ◽  
Author(s):  
Glenn Wehtje ◽  
Charles H. Gilliam ◽  
Michael E. Miller ◽  
James E. Altland

It has been previously reported that POST-applied isoxaben can effectively control established hairy bittercress. Experiments were conducted to determine the relative importance of root vs. foliar entry of POST-applied isoxaben. At a common isoxaben rate of 0.56 kg/ha, foliar-only and foliar plus soil applications provided 10.5 and 23.3% control, respectively, as determined by fresh weight reduction. In contrast, soil-only application provided 47.0% control. Hairy bittercress foliar absorption of14C–isoxaben did not exceed 15% of the amount applied after 72 h. Therefore, the comparatively less effectiveness of foliar-only applications may be attributed primarily to limited absorption. Minimal isoxaben concentration required to inhibit root growth of hydroponically grown hairy bittercress was 0.0025 mg/L. Higher concentrations were required to produce a response in the foliage. Sorption of isoxaben by pine bark rooting substrate, typical of what is used in container nursery production, exceeded 99% of amount applied after 36 h. Even with 99% sorption, the probable concentration within the aqueous phase remains sufficient to inhibit hairy bittercress root growth. Additional studies with14C–isoxaben established that approximately 35% of the root-absorbed isoxaben was translocated into the foliage. Translocation from the roots into the foliage was reduced to 16% when the experiment was repeated during environmental conditions less favorable for vegetative growth (i.e., longer day length and higher temperature). Results indicate that the control of hairy bittercress with POST-applied isoxaben is likely the result of root absorption and root-growth inhibition. Expression of phytotoxicity within the foliage is also a component, but is dependent upon the root-absorbed isoxaben being translocated into the foliage. Extent of this translocation is dependent upon plant maturity and prevalent environmental conditions.


Weed Science ◽  
1983 ◽  
Vol 31 (4) ◽  
pp. 572-575 ◽  
Author(s):  
Zain Ghafar ◽  
Alan K. Watson

Major differences in above- ground biomass and tuber production of yellow nutsedge (Cyperus esculentusL. # CYPES) were not observed when corn (Zea maysL. “CO-OP S265”) was seeded on different dates (1st, 2nd, 3rd and 4th week of May; and 1st week of June). The final seedbed was prepared just prior to each seeding date and this cultivation stimulated dormant tubers to sprout. As a result, a large population of yellow nutsedge emerged with the corn at all seeding dates. Because fertilizer was banded near the corn row, yellow nutsedge biomass, tuber dry weight and number of tubers were higher within corn rows than between rows. Tuber size was affected by seeding date and shifted toward smaller tubers within corn rows and larger tubers between the rows as the corn was sown late. The optimum seeding date of corn was in the 3rd week of May when the highest corn yield was obtained and yellow nutsedge growth was generally reduced.


1987 ◽  
Vol 38 (4) ◽  
pp. 655 ◽  
Author(s):  
KG Rickert ◽  
RH Sedgley ◽  
WR Stern

The performance of the spring wheat cultivar Gamenya, the leading cultivar in Western Australia since 1968, was studied to identify key aspects of its response to the environment under typically dry conditions on two contrasting soil types: a heavy clay loam and a light loamy sand overlying clay in the Merredin region.In the rain-fed treatments the total water use was similar on both soils and was of the order of 240 mm. On the heavy-textured soil at high nitrogen, the foliage canopy developed more rapidly than on the light soil, resulting in earlier soil water depletion and haying off. Water use efficiencies of about 10 kg grain ha-1 per mm of water were similar to those reported for winter rainfall areas in south-eastern Australia. This suggests a greater degree of buffering against spring drought than is indicated by the high ratio of pre-anthesis to post-anthesis water use (3-4.7:l) relative to values of 2-2.7:l in other parts of the Australian wheatbelt. Data on the partitioning of dry matter indicated that this buffering of the harsh spring conditions at Merredin may be due to a greater contribution of assimilates from pre-anthesis storage, to grain filling. In dry environments, further critical evaluation is needed of the role of stored assimilates in grain formation.Faster canopy closure on the heavy soil resulted from a higher density of shoots and possibly larger leaves. This led to the suggestion that on heavier, more fertile soils, an ideotype with restricted tillering, may be higher yielding. By the end of the season ear bearing shoot densities and total water use were the same on both soil types, thus masking earlier important differences.


1979 ◽  
Vol 93 (3) ◽  
pp. 719-726 ◽  
Author(s):  
S. Kar ◽  
S. B. Varade ◽  
B. P. Ghildyal

SUMMARYRoot growth of rice (Oryza saliva L.) is frequentlyinhibited by an adverse physical environment resulting from high moisture stress and strength of soilunder upland conditions, and the effects are often reflected in poor performance of the crop. This necessitates a critical understanding of rice root growth under varying soil physical conditions.The growth responses of the rice root system to the interaction between moisture regime and bulk density of soil as well as to the induced soil physical characteristics were assessed under controlled glasshouse conditions. Four moisture regimes: 0 (M1), 0–20 (M2), 0–350(M3), and 350–10000 (M4) mb, were superimposed on low, medium and high bulk density treatments in clay, loam and sandy loam soils. The soil physical environment was characterized by measurements of moisture distribution, penetrationenergy and oxygen diffusion rate in soils as functions of depth.A low moisture stress of 20 mb in low density soils favoured rice root growth. In low density soils, even though the number of roots at the base (proximal end) was maximum under M1, the depth of penetration, volume and dry weight of root were significantly more underM2 than under M1; M3 and M4. Irrespective of bulk density, even though oxygen diffusion rates in soils under M3 and M4 were greater than those under M1 and M2, the number of roots at the base, volume and dry weight of the root system decreased under M3 and M4 owing to low moisture content and high penetration energy in the surface layer (0–5 cm) of all the soil types. Lower moisture content and higher penetration energy at higher bulk densities of the soil types significantly reduced the root growth and especially the depth of penetration.


1976 ◽  
Vol 56 (2) ◽  
pp. 339-350 ◽  
Author(s):  
GERALD A. MULLIGAN ◽  
BONNY E. JUNKINS

This account of Cyperus esculentus L. (yellow nut sedge) summarizes biological information on this species as part of a series of contributions on plants that are weedy in Canada. Yellow nut sedge is weedy in cultivated fields of Nova Scotia, New Brunswick, southern Quebec and southern Ontario and has only become a prominent weed in Canada during the last two decades.


Weed Science ◽  
2008 ◽  
Vol 56 (5) ◽  
pp. 735-742 ◽  
Author(s):  
Theodore M. Webster ◽  
Timothy L. Grey ◽  
Jerry W. Davis ◽  
A Stanley Culpepper

The phase-out of methyl bromide requires alternative nutsedge management options in vegetable systems. Options that target tuber production, the primary means of reproduction, will be most beneficial. A study was conducted to evaluate the response of purple nutsedge and yellow nutsedge foliar growth and tuber production to a range of glyphosate rates. Glyphosate was applied at six rates between 0.41 and 2.57 kg ae ha−1to 5-wk-old nutsedge plants with multiple shoots. The rate of glyphosate needed to reduce growth 50% (I50) was similar for purple nutsedge foliar growth (0.58 kg ha−1) and tuber biomass (0.55 kg ha−1). In contrast,I50for yellow nutsedge foliar growth was 0.73 kg ha−1, which was greater than theI50for tuber biomass (0.41 kg ha−1). First-order tubers, those directly attached to the initial tuber, had anI50of 0.70 and 0.44 kg ha−1of glyphosate for purple nutsedge and yellow nutsedge tuber biomass, respectively. For all higher-order tubers,I50values ranged from 0.29 to 0.60 and 0.14 to 0.30 kg ha−1of glyphosate for purple nutsedge and yellow nutsedge tuber biomass, respectively. Glyphosate at 0.74 kg ha−1prevented fourth-order purple nutsedge and third-order yellow nutsedge tuber production (terminal tubers for yellow nutsedge). Fifth- and sixth-order purple nutsedge tuber production was eliminated by the lowest tested rate of glyphosate (0.41 kg ha−1). Effective nutsedge management options will require consistent control between spring and autumn crops. Glyphosate is economical, poses no herbicide carryover issues to vegetables, and minimizes nutsedge tuber production; therefore, it is a suitable candidate to manage nutsedges.


Weed Science ◽  
1983 ◽  
Vol 31 (3) ◽  
pp. 419-422 ◽  
Author(s):  
Philip A. Banks

Nine soil-applied herbicides were evaluated in the field in cotton (Gossypium hirsutumL.) and soybeans [Glycine max(L.) Merr.] and in the greenhouse without crops to determine their effects on the control, regrowth, and tuber production of yellow nutsedge (Cyperus esculentusL.). Fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl) phenyl]-4(1H)-pyridinone} and norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone] provided the best (100%) control in the greenhouse. Tubers exposed to herbicide-treated soil in the greenhouse for 4 or 8 weeks produced fewer new tubers when transplanted into nontreated soil than nontreated tubers did. Yellow nutsedge shoot and tuber populations in the field were significantly reduced by all herbicides, except for alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], after 2 yr of treatment in cotton and soybeans.


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