Predicting Yellow Nutsedge (Cyperus esculentus) Emergence Using Degree-day Models

Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 821-829 ◽  
Author(s):  
Cheryl A. Wilen ◽  
Jodie S. Holt ◽  
William B. McCloskey
Keyword(s):  
United States ◽  
Predictive Models ◽  
Field Experiments ◽  
Temperature Data ◽  
Cyperus Esculentus ◽  
Degree Days ◽  
Model Accuracy ◽  
Yellow Nutsedge ◽  
Degree Day ◽  
The Relationship

We examined the relationship between temperature and emergence of yellow nutsedge tubers to generate predictive models for the arid southwestern United States. Field experiments were conducted in California and Arizona to obtain phenological and temperature data needed to generate degree-day models. The effect of air temperature on emergence was tested with available programs using four methods to calculate degree-days (single sine, double sine, single triangle, and double triangle). Separate models were tested for each genotype examined (Arizona source and California source) as no one model was a good predictor of emergence when data were pooled. Results indicate that there is year to year variation in model accuracy but predictions of date of emergence can be made to within 2 d of actual emergence. This information can be used to schedule cultivations to reduce early yellow nutsedge competition in the field.

scholarly journals Interactions Between Chill-Hours and Degree-Days Affect Carpogenic Germination in Monilinia vaccinii-corymbosi

2001 ◽  
Vol 91 (1) ◽  
pp. 77-83 ◽  
Author(s):  
H. Scherm ◽  
A. T. Savelle ◽  
P. L. Pusey
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Degree Days ◽  
Carpogenic Germination ◽  
Conditioning Period ◽  
Low Degree ◽  
Heating Degree Days ◽  
Relationship Of ◽  
High Degree ◽  
The Relationship

The relationship of cumulative chill-hours (hours with a mean temperature <7.2°C) and heating degree-days (base 7.2°C) to carpogenic germination of pseudosclerotia of Monilinia vaccinii-corymbosi, which causes mummy berry disease of blueberry, was investigated. In two laboratory experiments, pseudosclerotia collected from rabbiteye blueberry in Georgia were conditioned at 5 to 6°C for 26 to 1,378 h prior to placement in conditions favorable for germination and apothecium development. The number of chill-hours accumulated during the conditioning period affected the subsequent proportion of pseudosclerotia that germinated and produced apothecia, with the greatest incidence of carpogenic germination occurring after intermediate levels of chilling (≈700 chill-hours). The minimum chilling requirement for germination and apothecium production was considerably lower than that reported previously for pseudo-sclerotia from highbush blueberry in northern production regions. The rate of carpogenic germination was strongly affected by interactions between the accumulation of chill-hours and degree-days during the conditioning and germination periods; pseudosclerotia exposed to prolonged chilling periods, once transferred to suitable conditions, germinated and produced apothecia more rapidly (after fewer degree-days had accumulated) than those exposed to shorter chilling periods. Thus, pseudosclerotia of M. vaccinii-corymbosi are adapted to germinate carpogenically following cold winters (high chill-hours, low degree-days) as well as warm winters (low chill-hours, high degree-days). Results were validated in a combined field-laboratory experiment in which pseudosclerotia that had received various levels of natural chilling were allowed to germinate in controlled conditions in the laboratory, and in two field experiments in which pseudosclerotia were exposed to natural chilling and germination conditions. A simple model describing the timing of apothecium emergence in relation to cumulative chill-hours and degree-days was developed based on the experiments. The model should be useful for better timing of field scouting programs for apothecia to aid in management of primary infection by M. vaccinii-corymbosi.

Effect of weather station logging interval on the precision of degree-day estimates

1995 ◽  
Vol 35 (6) ◽  
pp. 795 ◽  
Author(s):  
DM Watson ◽  
GAC Beattie
Keyword(s):  
Weather Station ◽  
Data Logging ◽  
Degree Days ◽  
Degree Day ◽  
The Relationship

The relationship between data-logging intervals and degree-day estimates was examined to determine the longest interval giving equivalent information to estimates based on 12-min intervals and, so, the most efficient interval for estimation of degree-days

Yellow Nutsedge and Cotton Response to Several Herbicides

Weed Science ◽  
1973 ◽  
Vol 21 (4) ◽  
pp. 327-329 ◽  
Author(s):  
P. E. Keeley ◽  
C. H. Carter ◽  
J. H. Miller
Keyword(s):  
Gossypium Hirsutum ◽  
Field Experiments ◽  
Cyperus Esculentus ◽  
Yellow Nutsedge

Seven herbicides were evaluated for the control of yellow nutsedge (Cyperus esculentusL.) in cotton (Gossypium hirsutumL. ‘Acala SJ-1’) in three field experiments during 1970 and 1971. The herbicides, 2-chloro-2′,6′-diethyl-N-(methoxymethyl) acetanilide (alachlor); 2-chloro-2′,6′-diethyl-N-(butoxymethyl) acetanilide (CP-53619); 2,4-bis(isopropylamino)-6-methylthio)-s-triazine (prometryne); 2-(α-naphthoxy)-N, N-diethylpropionamide (R-7465);S-isopropyl 5-ethyl-2-methylpiperidine-1-carbothioate (R-12001); 4-chloro-5-(dimethylamino)-2-(α,α,α-trifluoro-m-tolyl)-3-(2H)-pyridazinone (San-6706); and 2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione (methazole), were applied broadcast and incorporated 10 cm deep into the soil before the preplanting irrigation. All herbicides controlled nutsedge for at least 1 month in two or more experiments. Cotton was most tolerant to applications of 2.24 and 4.48 kg/ha of CP-53619, 3.36 and 6.72 kg/ha of prometryne, 1.12 kg/ha of San-6706, and 2.24 kg/ha of methazole. Higher rates of San-6706 and methazole and all rates of alachlor, R-7465, and R-12001 reduced the yield of cotton in one or more experiments.

Control of Yellow Nutsedge (Cyperus esculentus) and Smooth Pigweed (Amaranthus hybridus) in Summer Squash with Halosulfuron

2008 ◽  
Vol 22 (4) ◽  
pp. 660-665 ◽  
Author(s):  
Brian W. Trader ◽  
Henry P. Wilson ◽  
Thomas E. Hines
Keyword(s):  
Field Study ◽  
Field Experiments ◽  
Cyperus Esculentus ◽  
Weed Species ◽  
Amaranthus Hybridus ◽  
Yellow Nutsedge ◽  
Application Method ◽  
Summer Squash ◽  
Smooth Pigweed

Field experiments were conducted in 1999, 2000, and 2001 to investigate PRE and POST applications of halosulfuron-methyl in combination with clomazone plus ethalfluralin for control of sedge and smooth pigweed in summer squash. Halosulfuron was applied PRE or POST to summer squash at 9, 18, or 27 g ai/ha in combination with a PRE application of clomazone at 175 g ai/ha plus ethalfluralin at 630 g ai/ha. Smooth pigweed control by addition of halosulfuron at 18 and 27 g/ha in combination with clomazone plus ethalfluralin PRE was greater than 89% independent of application method. Yellow nutsedge control was greater than 83% with POST applications of halosulfuron at 18 and 27 g/ha in combination with clomazone plus ethalfluralin PRE. Yellow nutsedge control was greater than 60% from all POST halosulfuron applications at 9, 18, or 27 g/ha in the greenhouse. In a separate field study without ethalfluralin PRE, rice flatsedge control was more than 85% from halosulfuron applied POST at 18 and 27 g/ha. Yellow summer squash and zucchini squash were injured as much as 52 and 47%, respectively, from inclusion of halosulfuron PRE or POST at 27 g/ha in treatments. Summer squash yields were generally not affected by halosulfuron rate, and were comparable to or higher than summer squash treated by only the mixture of clomazone plus ethalfluralin. In these studies, summer squash were injured by halosulfuron applied at 9 to 27 g/ha PRE or POST, yet rapidly recovered, making this herbicide acceptable for use in combination with clomazone and ethalfluralin for controlling several common weed species.

scholarly journals A Comparison of Instruments and Contract Services Used to Calculate Degree-days

2005 ◽  
Vol 15 (3) ◽  
pp. 572-576
Author(s):  
Matthew L. Richardson ◽  
Dewey M. Caron
Keyword(s):  
Sampling Interval ◽  
Temperature Data ◽  
Ease Of Use ◽  
Weather Data ◽  
Degree Days ◽  
Data Logger ◽  
Degree Day ◽  
Temperature Data Logger ◽  
Time Required ◽  
Service Data

Various instruments and contract services can be used to calculate degree-days. This study compared instruments and services to the Wescor Biophenometer, an instrument used by cooperators of the Southeast Pennsylvania IPM Research Group (SE PA IPM RG) throughout Delaware and southeastern Pennsylvania for 10 years. Instruments evaluated in the study were the Wescor Biophenometer Datalogger, Avatel HarvestGuard, Avatel Datascribe Junior, Davis Weather Monitor II, Accu-Trax, and the HOBO H8 Pro Temperature Data Logger. The services were SkyBit and national weather data. Different combinations of instruments and services were used at three locations in Pennsylvania and four locations in Delaware over a 2-year period. We checked the degree-day accumulation of each instrument and service weekly and made statistical comparisons among the instruments and services at each site. To further construct a comparison of the instruments, we noted distinctive qualities of each instrument, interviewed the manufacturers, and received feedback from SE PA IPM RG members who used the instruments. We evaluated the instruments' algorithms, durability, cost, temperature sampling interval, ease of use, time input required by the user, and other distinctive factors. Statistically, there were no significant differences in degree-day accumulations between the Biophenometer, Harvest-Guard, Datascribe, Weather Monitor II, Skybit, or weather service data. However, cost and time required to access/interpret data and personal preference should be major considerations in choosing an instrument or service to measure degree-days.

THE EFFECT OF TEMPERATURE, MOISTURE AND NITROGEN ON THE RATE OF DEVELOPMENT OF SPRING WHEAT AS MEASURED BY DEGREE DAYS

1983 ◽  
Vol 63 (4) ◽  
pp. 833-846 ◽  
Author(s):  
H. R. DAVIDSON ◽  
C. A. CAMPBELL
Keyword(s):  
Spring Wheat ◽  
Standard Error ◽  
Time Scale ◽  
Field Experiments ◽  
Effect Of Temperature ◽  
Degree Days ◽  
Rate Of Development ◽  
Degree Day ◽  
Developmental Parameters ◽  
Growth Room

A phenological index based on meteorological parameters that accurately describes the development of wheat is urgently needed by agricultural researchers. In this study, a biometeorological time scale was proposed. It was developed from data obtained in a growth chamber study in which the effect of temperature, N fertility and soil moisture on spring wheat (Triticum aestivum L.) development were assessed. The model was then proofed using data from two field experiments. A normalized time scale was derived relating phenological development to percent SD, defined as ((number of days to a selected phenological stage)/(number of days to soft dough)) × 100. The degree day equation was modified to incorporate this time scale as:[Formula: see text]where K1 is a rate constant having units % SD∙°C−1∙day−1; bo is a base temperature below which no development occurs with units °C; and Tm is the mean daily temperature between growth stages S1 and S2. This equation was used to derive values for the developmental parameters. In the growth room K = 0.0875 (standard error 0.0045) and bo = 4.6 (standard error 0.99). Under fie d conditions K1 = 0.0935 (standard error 0.0123) and bo = 2.4 (standard error 2.213). The growth room and field parameters were not significantly different at the 5% probability level. Temperature was the only environmental parameter which influenced the rate of development under the conditions of this experiment. The number of days to the various developmental stages was inversely and linearly related to mean daily temperature over the 15–25 °C range. The degree day equation was shown to be a good index of development. Under fie d conditions the number of degree days to progress a crop to the flowering stage was 703 (standard error 9.4) and to the soft dough stage 1086 (standard error 15.4). The small variability in the values of the developmental parameters obtained in the growth room and field experiments were attributed to errors in the determination of phenological dates, and differences between temperature in the crop microclimate and measured temperatures from the standard meteorological site. A further modification to the degree day equation was postulated to account for the influence of daylength on wheat development.Key words: Temperature and development, moisture and development, degree days, development of wheat

Yellow Nutsedge Sprouting and Resprouting Potential

Weed Science ◽  
1975 ◽  
Vol 23 (4) ◽  
pp. 333-337 ◽  
Author(s):  
R. J. Thullen ◽  
P. E. Keeley
Keyword(s):  
Time Interval ◽  
Refrigerated Storage ◽  
Cyperus Esculentus ◽  
Tuber Weight ◽  
Short Life ◽  
Physical Character ◽  
Yellow Nutsedge ◽  
The Third ◽  
The Relationship

Yellow nutsedge (Cyperus esculentusL.) was studied to determine the relationship between physical character of tubers and sprouting habits. All tuber lots studied, which averaged from 157 to 662 mg per tuber, sprouted and grew well under greenhouse conditions. Longevity (the time between initial planting and death) increased with tuber weight. Weight of the third and fourth sprouts equalled that of the first and second sprouts for heavy tubers, but sprout weight decreased for light tubers. Detaching the plants at 2-week intervals from the tubers which produced them allowed all buds present to sprout. However, when the plants were detached at 4-week intervals, a reduction in the number of sprouts and a decrease in longevity were observed. Allowing plants to grow for 8 weeks before detaching did not cause any further decrease. Number of buds, number of sprouts, number of multiple sprouts, the time interval between first planting and first sprout, and the time interval between successive sprouts did not vary with initial tuber weight. Prolonged refrigerated storage of tubers caused an increased number of multiple sprouts, a decreased initial and subsequent sprouting interval, and a short life.

Influence of Yellow Nutsedge Competition on Furrow-Irrigated Cotton

Weed Science ◽  
1975 ◽  
Vol 23 (3) ◽  
pp. 171-175 ◽  
Author(s):  
P. E. Keeley ◽  
R. J. Thullen
Keyword(s):  
Gossypium Hirsutum ◽  
Field Experiments ◽  
Cyperus Esculentus ◽  
Seed Cotton ◽  
Fourfold Increase ◽  
Yellow Nutsedge ◽  
Fiber Properties ◽  
Tenfold Increase ◽  
Reduced Height ◽  
Cotton Plants

In five field experiments conducted during 1972 and 1973, yellow nutsedge (Cyperus esculentusL.) was either undisturbed or removed from planting beds by hoeing 0, 2, 4, 6, and 8 weeks after cotton (Gossypium hirsutumL. ‘Acala SJ-1’) emergence. Yellow nutsedge undisturbed in beds increased from 23 plants/m of row at cotton emergence to 100 plants/m at harvest. Nutsedge competing with cotton for more than 4 weeks reduced yield of seed cotton. Nutsedge that competed all season reduced yields 34%, as compared with 20% when it competed for 6 and 8 weeks. Nutsedge that competed with cotton for more than 4 weeks reduced height and number of cotton plants and delayed maturity. Although nutsedge competition reduced yields and delayed maturity, it generally did not alter fiber properties. When nutsedge was removed at cotton emergence and was followed by 14 weekly hoeings, the final tuber population was reduced to 24% of the beginning population. When nutsedge removal was delayed for 6 weeks and was followed by nine weekly hoeings, a fourfold increase in tubers resulted. A further tenfold increase resulted when nutsedge was not removed.

Response of Yellow Nutsedge and Soybeans to Bentazon, Glyphosate, and Perfluidone

Weed Science ◽  
1975 ◽  
Vol 23 (3) ◽  
pp. 215-221 ◽  
Author(s):  
E. W. Stoller ◽  
L. M. Wax ◽  
R. L. Matthiesen
Keyword(s):  
Glycine Max ◽  
Field Experiments ◽  
Foliar Application ◽  
Cyperus Esculentus ◽  
Leaf Stage ◽  
Yellow Nutsedge ◽  
Foliar Sprays ◽  
Good Coverage

Laboratory, greenhouse, and field experiments were conducted in 1972 and 1973 on the efficacy of controlling yellow nutsedge (Cyperus esculentusL.) in soybeans [Glycine max(L.) Merr.] with bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4)3H-one 2,2-dioxide], glyphosate [N-(phosphonomethyl)glycine], and perfluidone [1,1,1-trifluoro-N-[2-methyl-4-(phenylsulfonyl)phenyl] methanesulfonamide]. Young nutsedge plants (four- to six-leaf stage) were more susceptible to foliar sprays of the three herbicides than were older (six- to eight-leaf stage) plants. Foliar application of bentazon resulted in slow acropetal translocation of the herbicide, but killed the parent tubers. Good coverage of the foliage by bentazon sprays is essential, because the bentazon frequently kills only the foliage contacted by the spray. Applied as a postemergence broadcast spray, glyphosate injured soybeans severely at rates higher than 0.3 kg/ha, but did not satisfactorily control yellow nutsedge at rates less than 2.2 kg/ha. Perfluidone was active on yellow nutsedge when applied to either soil or foliage; yellow nutsedge was controlled best with preplant incorporated treatments at 4.5 kg/ha. Applications of 4.5 kg/ha perfluidone in the field significantly injured soybeans and reduced yields.

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