Modelling the demography of crenate broomrape (Orobanche crenata) as affected by broad bean (Vicia faba) cropping frequency and planting date

Weed Science ◽  
1997 ◽  
Vol 45 (2) ◽  
pp. 261-268 ◽  
Author(s):  
Francisca López-Granados ◽  
Luis García-Torres
Keyword(s):  
Broad Bean ◽  
Management Strategies ◽  
Field Studies ◽  
Planting Date ◽  
Planting Dates ◽  
Cropping Frequency ◽  
Seed Loss ◽  
Model Predictions ◽  
Reported Data

A mathematical model of crenate broomrape populations in broad bean as affected by cropping frequency and planting dates in the absence of crenate broomrape control practices was constructed using previously reported data. In consecutive broad bean cropping, broomrape populations reached a maximum infection severity (D) of 62, 47, and 30 emerged broomrape m−2for early (mid-October), intermediate (mid-November), and late (mid-December) planting dates, respectively. The maximumDvalues were reached earlier as planting dates were brought forward, taking from 4 to 6 yr, starting from very low initial infections (D ≤0.2 emerged broomrape m−2). If broad bean was cropped every 3 yr, 15, 21, and 27 yr were needed, respectively, according to the model, to reach the maximumDfor the three planting dates considered. A sensitivity analysis was conducted to determine the effect of changing the values of the main demographic parameters in broomrape life cycle (germination, attachment, and seed loss) on the output of the model under different management strategies (planting dates and cropping frequency). Generally, an increase in seed attachment and a decrease in seed loss affected broomrape population dynamics. Between the two processes evaluated, the time taken to reach the maximum infection severity (D) was less sensitive than the maximum broomrape population values. Model predictions were validated using results from long-term field studies at the late planting date sown every year. Simulated values generated good predictions (R2= 0.82).

scholarly journals Effect of Genotype, Planting Date, and Spacing on Zoysiagrass Establishment from Vegetative Plugs

HortScience ◽  
2011 ◽  
Vol 46 (8) ◽  
pp. 1194-1197 ◽  
Author(s):  
Bradley S. Sladek ◽  
Gerald M. Henry ◽  
Dick L. Auld
Keyword(s):  
Field Experiments ◽  
Slow Growth ◽  
Field Studies ◽  
Early Summer ◽  
Planting Date ◽  
Growing Degree Days ◽  
Degree Days ◽  
Planting Dates ◽  
Establishment Rate

Slow growth and establishment rate has become a major limitation to the increased use of zoysiagrass (Zoysia spp.) as a turfgrass surface. Two separate field studies were conducted to evaluate the effect of genotype, planting date, and plug spacing on zoysiagrass establishment. Field experiments were conducted in 2007 and 2008 to quantify the establishment rate of six zoysiagrass genotypes from vegetative plugs. ‘Meyer’ exhibited the largest plug diameter (22 cm) 6 weeks after planting (WAP). In contrast, ‘Diamond’ exhibited the smallest plug diameter (13 cm) 6 WAP. A similar trend was observed 12 WAP. ‘Meyer’, ‘Zorro’, and ‘Shadow Turf’ exhibited the largest plug diameters (60, 58, and 57 cm, respectively) 12 WAP. In contrast, ‘Emerald’ and ‘Diamond’ exhibited the smallest plug diameters (41 and 40 cm, respectively) 12 WAP. Although statistically different, all zoysiagrass genotypes reached similar establishment 18 WAP indicating that plugging these genotypes in a comparable environment and using techniques described in this research may result in analogous long-term (18 weeks) establishment. Field experiments were conducted in 2006 and 2007 to determine the optimum planting date and plug spacing of ‘Shadow Turf’ zoysiagrass. ‘Shadow Turf’ zoysiagrass plugs planted on 28 July 2006 (11% to 65% cover) and 14 June 2007 (5% to 39% cover) exhibited the greatest increase in turfgrass cover 6 WAP, except for plugs planted 15.2 cm apart on 26 May 2006 (74% cover). Zoysiagrass cover was greatest for plugs planted on 26 May 2006 (63% to 100%) and 17 May 2007 (46% to 97%) 16 WAP regardless of plug spacing. These planting dates corresponded to the highest accumulative growing degree-days (GDD) experienced by all planting dates in both years. Plugs planted on 15.2-cm centers exhibited the greatest zoysiagrass cover 6 and 16 WAP regardless of planting date. Using late spring/early summer planting dates and 15.2- to 30.5-cm plug spacings may result in the quickest turfgrass cover when establishing ‘Shadow Turf’ zoysiagrass from plugs.

Repeseed adaptation in Northern New South Wales. II.* Predicting plant development of Brassica campestris L. and Brassica napus L. and its implications for planting time, designed to avoid water deficit and frost

1978 ◽  
Vol 29 (4) ◽  
pp. 711 ◽  
Author(s):  
AS Hodgson
Keyword(s):  
Daily Rainfall ◽  
Planting Date ◽  
Intermediate Region ◽  
Brassica Napus L ◽  
Planting Dates ◽  
Linear Temperature ◽  
North West ◽  
The North ◽  
Moisture Deficit

Two experiments were conducted to determine the growing degree-day (D°) requirements of annual B. campestris and B. napus cultivars, and to evaluate their use in planning crop development strategies to avoid frost and moisture deficit at three locations. In the first experiment, base temperatures and D° requirements were calculated for four phases from planting to grain-filling, on the basis of linear temperature-development rate responses measured in the field at Tamworth, N.S.W. The phenological pattern of each species was predicted for several planting dates at locations representing the north-west slopes, northern tablelands and an intermediate region, by using long-term mean daily temperatures and calculated Do requirements. From these predictions and long-term mean daily rainfall and pan evaporation rates, the available soil moisture depletion was estimated for each planting date. For each location, planting date strategies for both species were evaluated for avoidance of frost and moisture deficit. The predicted optimum planting dates for B. napus and B. campestris were, respectively, 20 June and 5 August for the north-west slopes, 20 August and 1 October for the northern tablelands, and 30 June and 18 August for the intermediate region. In the second experiment, the influence of planting date on the grain yield of B. campestris and B. napus was studied in several seasons at each of the locations studied in the first experiment. The planting date that gave the highest yield varied between species and locations. B. campestris was favoured by later dates than B. napus. For both species these dates were earliest on the north-west slopes and latest on the northern tablelands. Yields of B. napus were higher than those of B. campestris at all locations when each species was planted at a favourable time. Predicted optimum planting dates from experiment 1 are discussed in relation to the field results from experiment 2. _____________________ *Part I, Aust. J. Agric. Res., 29: 693 (1978).

Within-Season Changes in the Residual Weed Community and Crop Tolerance to Interference over the Long Planting Season of Sweet Corn

Weed Science ◽  
2009 ◽  
Vol 57 (3) ◽  
pp. 319-325 ◽  
Author(s):  
Martin M. Williams
Keyword(s):  
Sweet Corn ◽  
Growth Period ◽  
Field Studies ◽  
Planting Date ◽  
Growth And Yield ◽  
Planting Dates ◽  
Crop Tolerance ◽  
Weed Interference ◽  
Control Failure ◽  
Planting Season

Sweet corn is planted over a long season to temporally extend the perishable supply of ears for fresh and processing markets. Most growers' fields have weeds persisting to harvest (hereafter called residual weeds), and evidence suggests the crop's ability to endure competitive stress from residual weeds (i.e., crop tolerance) is not constant over the planting season. Field studies were conducted to characterize changes in the residual weed community over the long planting season and determine the extent to which planting date influences crop tolerance to weed interference in growth and yield traits. Total weed density at harvest was similar across five planting dates from mid-April to early-July; however, some changes in composition of species common to the midwestern United States were observed. Production of viable weed seed within the relatively short growth period of individual sweet corn plantings showed weed seedbank additions are influenced by species and planting date. Crop tolerances in growth and yield were variable in the mid-April and both May plantings, and the crop was least affected by weed interference in the mid-June and early-July planting dates. As the planting season progressed from late-May to early-July, sweet corn accounted for a great proportion of the total crop–weed biomass. Based on results from Illinois, a risk management perspective to weeds should recognize the significance of planting date on sweet corn competitive ability. This work suggests risk of yield loss from weed control failure is lower in late-season sweet corn plantings (June and July) than earlier plantings (April and May).

scholarly journals Planting Date and Romaine Lettuce Cultivar Affect Quality and Productivity

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 640-645 ◽  
Author(s):  
Robert J. Dufault ◽  
Brian Ward ◽  
Richard L. Hassell
Keyword(s):  
Interaction Effect ◽  
Planting Date ◽  
Freezing Damage ◽  
Romaine Lettuce ◽  
Planting Dates ◽  
Yield And Quality ◽  
October 17 ◽  
Harvest Maturity ◽  
Lettuce Cultivar

The objective of this study was to determine the best combination of planting dates (PDs) and cultivars on yield and quality for long-term production of romaine lettuce. `Green Forest' (GF), `Apache' (AP), `Darkland' (DK), `Green Tower' (GT), `Ideal Cos' (IC), and `Tall Guzmaine' (TG) were successfully grown to harvest maturity on 19 PDs from September 1998 to April 2001. Lettuce planted in September and April PDs (pooled over cultivars and year), required as little as 47 and 49 days, respectively, to reach harvest (all cultivars harvested on the same day). Lettuce planted in October, November, February, and March PDs (pooled over cultivars and year), required on average 64, 66, 75, and 67 days to reach harvest, respectively, but in the coldest PDs of December and January, 90 and 98 days, respectively, were needed to reach maturity. Of the eight PDs evaluated, marketable numbers/plot (pooled over cultivars and years) were greatest in the September PD, followed by April (–8% decrease from September PD) > March (–13%) > October (–17%) > November (–21%) > December = January = February (about –30%) and heads weighed the most in September > January = February (–7% decrease from September PD) > March = April (–14%) > October (–21%) > December (–25%) > November (–31%). Cull heads/plot (pooled over cultivars and years) were greatest in April > December (–5% decrease from April PD) > January = February (–16%) > November (–27%) > October (–34%) > March (–44%) > September (–49%). Two out of three November PDs were lost to freezing damage and this PD should be avoided. Significant bolting occurred primarily in the September and October PDs (in 1 of 3 years) with negligible bolting in the November, December, and January PDs, but bolting recurred again in the February, March and April PDs. Marketable numbers/plot (pooled over all PDs and years) were greatest for GF > GT (–7% decrease from GF) > AP (–8%) > IC (–9%) > DK (–11%) > TG (–21%). The interaction effect of cultivar × PD indicated that GF yielded the most marketable heads in 6 out of 8 PDs. The best performing cultivars by PD (pooled over years) were September and February = GF and IC; October = TG; November = AP; December, January, March, and April = GF.

scholarly journals Effect of Planting Date on Vegetable Amaranth Leaf Yield, Plant Height, and Gas Exchange

HortScience ◽  
2002 ◽  
Vol 37 (5) ◽  
pp. 773-777 ◽  
Author(s):  
W.F. Whitehead ◽  
J. Carter ◽  
B.P. Singh
Keyword(s):  
Gas Exchange ◽  
Plant Height ◽  
Vegetative Growth ◽  
Field Studies ◽  
Planting Date ◽  
Day Length ◽  
Leaf Biomass ◽  
Amaranthus Tricolor ◽  
Planting Dates ◽  
Cubic Equation

Field studies were conducted during 1992 and 1993 to determine the effect of six monthly planting dates from April to September on gas exchange, plant height, and leafy fresh and dry yields of vegetable amaranth (Amaranthus tricolor L.). Vegetative growth was satisfactory for May to August planting. Seeds planted in April failed to germinate due to low soil temperatures. Plant growth was significantly reduced in the September planting possibly due to low fall temperatures and shortened day length. Soil and air temperatures 25 °C or higher promoted optimal stand establishment and growth. The vegetative growth of June seeded amaranth took place during the warmest part of the summer and as a result had maximum CO2 exchange rate (CER), plant height, and leafy fresh and dry yields. The relationship between planting date and CER, transpiration rate (E), stomatal conductance (gs), plant height, and leafy fresh and dry yields was quadratic, while a cubic equation provided best fit between the planting date and internal leaf CO2 concentration (Ci). The results suggest that it is possible to stagger the planting of Amaranthus tricolor in the southeastern United States to assure availability of fresh leafy greens throughout the summer. However, the crop produces maximum leaf biomass when grown during the warmest part of the summer.

Effect of Weed Management Strategy and Planting Date on Herbicide Use in Peanuts (Arachis hypogaea)

1990 ◽  
Vol 4 (1) ◽  
pp. 20-25 ◽  
Author(s):  
H. Michael Linker ◽  
Harold D. Coble
Keyword(s):  
Weed Management ◽  
Management Strategy ◽  
Management Strategies ◽  
Planting Date ◽  
Integrated Weed Management ◽  
Preventive Strategy ◽  
Weed Species ◽  
Planting Dates ◽  
The Cost ◽  
Herbicide Use

Experiments were conducted in 1987 and 1988 at two locations each year to determine how two weed management strategies and three planting dates affected the cost and amount of herbicide needed to control weeds in peanuts. Weed management strategies used for each planting date included preventive, which duplicated a standard grower program, or an integrated weed management system. The least expensive strategy depended upon weed species composition, weed populations and planting date. In all cases, the integrated weed management strategy required less herbicide (acid equivalent or active ingredient) than the preventive strategy.

Seasonal Emergence and Growth ofSorghum almum

1988 ◽  
Vol 2 (3) ◽  
pp. 275-281
Author(s):  
Charlotte V. Eberlein ◽  
Timothy L. Miller ◽  
Edith L. Lurvey
Keyword(s):  
Seed Production ◽  
Dry Weight ◽  
Field Studies ◽  
Planting Date ◽  
Corn Yield ◽  
Seed Plant ◽  
Planting Dates ◽  
Shoot Dry Weight ◽  
Two Peaks ◽  
Growth And Reproduction

Field studies on time of emergence, influence of planting date on growth and reproduction, and winter survival of rhizomes were conducted on sorghum-almum grown in corn and crop-free environments. In 1985, peak emergence of sorghum-almum occurred during early May in crop-free plots and mid-May in corn. In 1986, two peaks of emergence, one in early June and one in late June, were noted in both crop-free and corn plots. Emergence after mid-July was 4% or less of the total emerged in 1985, and no sorghum-almum emerged after mid-July in 1986. In planting date studies, sorghum-almum was seeded alone or in corn at 2-week intervals. Corn competition reduced sorghum-almum shoot, rhizome, and root growth at all planting dates. Maximum sorghum-almum seed production was 43 110 seed/plant when grown without competition but only 1050 seed/plant when grown with corn competition. When grown with corn competition, no seed developed on sorghum-almum seeded 6 or more weeks (mid-June or later) after corn planting. Shoot dry weight of sorghum-almum grown with corn competition was 3 g/plant or less for plants seeded 4 or more weeks (early June or later) after corn planting. Therefore, controlling sorghum-almum in corn through mid-June should prevent seed production and corn yield losses due to sorghum-almum competition. Rhizomes produced by sorghum-almum grown alone or with corn competition did not survive the winter; therefore, in Minnesota, sorghum-almum survival from one growing season to the next depends on seed production.

scholarly journals The captive population of the Lion-tailed Macaque Macaca silenus (Linnaeus, 1758). The future of an endangered primate under human care

2021 ◽  
Vol 13 (9) ◽  
pp. 19352-19357
Author(s):  
Nilofer Begum ◽  
Werner Kaumanns ◽  
Alexander Sliwa ◽  
Mewa Singh
Keyword(s):  
Birth Control ◽  
Management Strategies ◽  
Field Studies ◽  
Control Measures ◽  
Term Survival ◽  
Human Care ◽  
Captive Propagation ◽  
Conservation Breeding ◽  
Term Management

For conservation breeding, the endangered Lion-tailed Macaques have been maintained in North America under SSP since 1983 and in Europe under EEP since 1989. Based on a growing interest to support the species long-term survival, the SSP population increased considerably during the first few years of the programme but due to space problems and resulting birth control measures, it has drastically declined to small numbers and a non- breeding status at present. The EEP population continually increased till 2012, but due to the lack of spaces and birth control practises, it has gradually declined since then. It is emphasised that the knowledge gained from field studies on Lion-tailed Macaques in India and its incorporation for captive management under EEP has helped develop appropriate management strategies. Captive propagation of the Lion-tailed Macaque in India, the habitat country, can profit from the successes and drawbacks of the long-term management experiences of SSP and EEP.

scholarly journals Growth, maturity and flowering of pigeon peas, Cajanus cajan L. Millsp., at high latitudes

1969 ◽  
Vol 73 (3) ◽  
pp. 223-229 ◽  
Author(s):  
Rubén Vélez-Colón ◽  
Stephen A. Garrison
Keyword(s):  
Field Studies ◽  
Pigeon Pea ◽  
Germination Percentage ◽  
Planting Date ◽  
Mechanical Equipment ◽  
Vegetative Development ◽  
Planting Dates ◽  
Early Maturity ◽  
Chamber Studies ◽  
Growth Chamber Studies

The effects of temperature and planting dates on germination, emergence, growth, vegetative development, and time to flowering and maturity of the pods of pigeon pea were evaluated. Growth chamber studies were conducted to determine the effects of 12.5°, 15°, and 20° C on the germination of pigeon pea cultivar 2B-Bushy. Germination percentage was low (1.0 and 2.0%) at 15° and 12.5° C, respectively. At 17.5°, germination increased to 18% (average) and required 4 to 9 days. At 20° C, germination was 48° (average) and required 2 to 5 days. The vigor of the seed lot appeared to be low. Replicated field studies were conducted with large plant populations to determine the effect of planting date on emergence, growth, flowering and maturity of the pods of the commercial cultivar 2B-Bushy and two lines (PR2 7/13 and PR2 7/16) for early maturity in New Jersey (40° N fat,). Pigeon peas seeded May 19 emerged in 12 days at a mean soil temperature of 19° C at 2.5-crn depth. At later planting dates (2 June, 16 June, 1 July and 14 July) pigeon peas emerged in 6 or 7 days. Plant height and height to the first branch at flowering decreased in all three genotypes at the later planting dates. Pigeon peas planted at all sowing dates were tall but could be harvested with mechanical equipment. Planting date had a significant effect on the earliness of flowering and the percentage of plants that flowered. All plants of the PR2 selections flowered at all planting dates. The 2B-Bushy cultivar flowered only the first three planting dates; and not all the plants flowered. The 2B-Bushy flowered in the upper one-third of the plant, whereas the PR2 lines flowered in the upper two thirds. None of the plants of the 2B-Bushy genotype produced pods by the termination of the experiment, 15 October, just before frost. The PR2 lines seeded May 19 and June 2 produced 12% of the plants with mature green pods, and 6% of the plants with some dry pods, respectively, by 15 October. About 3% of these PR2 plants had 90% of their pods dry by 15 October. Thus, the PR2 lines were highly variable for maturity at 40° N lat. Therefore, pigeon peas could be selected for adaptation to this location and even more northerly areas.

Sign in / Sign up

Export Citation Format

Share Document