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

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.

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Foliar and Root Absorption of Atrazine Applied Postemergence to Giant Foxtail

Weed Science ◽

10.1017/s0043174500031441 ◽

1969 ◽

Vol 17 (2) ◽

pp. 251-256 ◽

Cited By ~ 17

Author(s):

Lafayette Thompson ◽

F. W. Slife

Keyword(s):

Field Experiments ◽

Soil Surface ◽

Dry Weight ◽

Field Studies ◽

Simulated Rainfall ◽

Root Absorption ◽

Giant Foxtail ◽

Setaria Faberii ◽

Chamber Studies ◽

Growth Chamber Studies

In growth chamber studies, high relative humidity and rewetting crystalline spray deposits of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) increased absorption by and phytotoxicity to giant foxtail (Setaria faberii Herrm.), but phytotoxicity was restricted to expanded (unrolled) leaves unless some atrazine was absorbed by the roots. Though phytotoxicity was increased by simulated rainfall when root absorption was prevented, an appreciable number of the plants were killed only when atrazine residues were washed into the soil. In field studies, atrazine applied to a wet soil surface was as effective as the same rate of atrazine foliarly applied. In other field experiments, atrazine applied to giant foxtail on a wet soil and followed by simulated rainfall reduced stand and dry weight, but on a dry soil and not followed by simulated rainfall, atrazine reduced dry weight less and did not reduce stand. These results are due to root absorption of atrazine from wet soil. Spray additives increased phytotoxicity.

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Response of soya beans to planting date in south-eastern Queensland. II.* Vegetative and reproductive development

Australian Journal of Agricultural Research ◽

10.1071/ar9740723 ◽

1974 ◽

Vol 25 (5) ◽

pp. 723 ◽

Cited By ~ 12

Author(s):

RJ Lawn ◽

DE Byth

Keyword(s):

Seed Yield ◽

Vegetative Growth ◽

Growth Period ◽

Reproductive Development ◽

Planting Date ◽

Biological Efficiency ◽

Vegetative Development ◽

Planting Dates ◽

Growing Period ◽

Seed Yields

Vegetative and reproductive development of a range of soya bean cultivars was studied over a series of planting dates in both hill plots and row culture at Redland Bay, Qld. Responses in the extent of vegetative and reproductive development were related to changes in the phasic developmental patterns. The duration and extent of vegetative development for the various cultivar-planting date combinations were closely associated with the length of the period from planting to the cessation of flowering. Thus, vegetative growth was greatest for those planting dates which resulted in a delay in flowering and/or extended the flowering phase. Similarly, genetic lateness of maturity among cultivars was associated with more extensive vegetative development. Seed yield per unit area increased within each cultivar as the length of the growing period was extended until sufficient vegetative growth occurred to allow the formation of closed canopies under the particular agronomic conditions imposed. Further increases in the length of the period of vegetative growth failed to increase seed yield, and in some cases seed yields were actually reduced. Biological efficiency of seed production (BE) was negatively correlated with the length of the vegetative growth period. Differences in BE among cultivar-planting date combinations were large. It is suggested that maximization of seed yield will necessitate an optimum compromise between the degree of vegetative development and BE. Optimum plant arrangement will therefore vary, depending on the particular cultivar-planting date combination. ___________________ \*Part I, Aust. J. Agric. Res., 24: 67 (1973).

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

Weed Science ◽

10.1017/s004317450009281x ◽

1997 ◽

Vol 45 (2) ◽

pp. 261-268 ◽

Cited By ~ 12

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).

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Growth, Reproductive Potential, and Control Strategies for Deeproot Sedge (Cyperus entrerianus)

Weed Technology ◽

10.1614/wt-d-10-00130.1 ◽

2012 ◽

Vol 26 (1) ◽

pp. 122-129 ◽

Cited By ~ 1

Author(s):

Charles T. Bryson ◽

Richard Carter

Keyword(s):

Growth Rate ◽

Field Study ◽

Control Strategies ◽

Reproductive Potential ◽

Field Studies ◽

Growth Chamber ◽

Chamber Studies ◽

Growth Chamber Studies ◽

And Control ◽

Achene Production

Greenhouse, growth chamber, and field studies were conducted at Stoneville, MS, in 2000 to 2008, to determine the growth rate, reproductive and overwintering potential, and control of deeproot sedge. In growth chamber studies, deeproot sedge growth rate (ht) and plant dry wt were greatest at 25/35 C (night/day temperatures), when compared with regimes of 5/15, 15/25, and 20/30 C. Based on the average number of scales (fruiting sites per spikelet), spikelets per inflorescence, and culms per plant, deeproot sedge reproductive potential was 2.6-, 6.2-, and 17.4-fold greater than Surinam, green, and knob sedges, respectively. A single deeproot sedge plant produced an average of 85,500 achenes annually. Mowing at 15-cm ht weekly prevented achene production but did not kill deeproot sedge plants. The average number of inflorescences produced on mowed plants was 1.2 to 4 times greater in 2- and 1-yr-old deeproot sedge plants, respectively, when compared with unmowed plants. Mature deeproot sedge achenes were produced between monthly mowings. In a 3-yr field study, glyphosate, glufosinate, hexazinone, and MSMA provided more than 85% control of deeproot sedge, and above the soil, live deeproot sedge plant dry wt was reduced by 50, 64, 68, 72, 86, and 93% by dicamba, halosulfuron-methyl, MSMA, hexazinone, glufosinate, and glyphosate, respectively. All (100%) deeproot sedge plants 1 yr old or older overwintered at Stoneville, MS, at 33°N latitude.

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

Weed Science ◽

10.1614/ws-08-164.1 ◽

2009 ◽

Vol 57 (3) ◽

pp. 319-325 ◽

Cited By ~ 9

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).

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PIGEON PEA YIELDS AS INFLUENCED BY PLANTING DATE AND PRUNING

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v68i2.7275 ◽

1969 ◽

Vol 68 (2) ◽

pp. 173-177

Author(s):

Edmundo Rivera ◽

Héber Irizarry

Keyword(s):

Total Yield ◽

Pigeon Pea ◽

Planting Date ◽

Planting Dates ◽

Proper Management ◽

Tropical Conditions

This research determined the effect of planting date and pruning on the productivity of five pigeon pea cultivars planted under humid tropical conditions at Corozal and under wet-dry tropical conditions at Santa Isabel (under irrigation). With proper management, two successful heavy crops of pigeon peas were obtained from December to May from plots planted March, June and September, with average total yield of 10,800 kg of mature pods/ha. At Corozal, highest yields were obtained from the September planting with the 2-B-Bushy cultivar, 12,900 kg of mature-green pods/ha. At Santa Isabel, with irrigation, pigeon peas yielded about 25% more than at Corozal, and determinate line 147 produced the highest yields, 16,195 kg of mature-green pods/ha. Pruning the pigeon pea bushes after harvesting the first crop decreased yields of the following crop at both locations, at all planting dates and in all cultivars.

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Enhanced Growth and Seed Properties in Introduced vs. Native Populations of Yellow Starthistle (Centaurea solstitialis)

Weed Science ◽

10.1614/ws-06-211r.1 ◽

2007 ◽

Vol 55 (5) ◽

pp. 465-473 ◽

Cited By ~ 30

Author(s):

Timothy L. Widmer ◽

Fatiha Guermache ◽

Margarita Yu Dolgovskaia ◽

Sergey Ya. Reznik

Keyword(s):

Seedling Growth ◽

Starch Content ◽

Field Studies ◽

The United States ◽

Native Range ◽

Yellow Starthistle ◽

Invasive Range ◽

Native Populations ◽

Chamber Studies ◽

Growth Chamber Studies

There is much discussion as to why a plant becomes invasive in a new location but is not problematic in its native range. One example is yellow starthistle, which originates in Eurasia and is considered a noxious weed in the United States. We grew yellow starthistle originating from native and introduced regions in a common environment to test whether differences in growth would be observed. In growth chamber studies, seedlings originating from the invasive range were larger than seedlings from the native range after 2 wk. Seed starch content is an important component of initial seedling growth. The starch content of seeds from introduced populations was higher than that of seeds from native populations. Regression analysis showed a relationship between the amount of starch in the seeds and the weight of yellow starthistle seedlings after 2 wk growth. There was no difference in chromosome number, except in accessions originating from Sicily and Sardinia. Field studies conducted in France and Russia revealed that rosettes and mature plants grown under natural conditions were larger when grown from seeds originating from the invasive range than from seeds originating from the native range. The number of capitula per plant and stem diameters were not significant among all populations, but differences were noted. The F1 progeny of plants originating from U.S. seed, but grown and pollinated in France, showed no differences in seedling growth, mature plant characteristics, and seed starch content from the plants grown from field-collected U.S. seed. The changes in seed starch resource allocation and its relation to plant growth is useful in understanding factors that contribute to yellow starthistle's invasibility.

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Morphology, Turf Quality, and Heat Tolerance of Intermediate Ryegrass

HortScience ◽

10.21273/hortsci.39.1.170 ◽

2004 ◽

Vol 39 (1) ◽

pp. 170-173 ◽

Cited By ~ 15

Author(s):

M.D. Richardson

Keyword(s):

Heat Tolerance ◽

Perennial Ryegrass ◽

Field Studies ◽

High Temperature Stress ◽

Growth Chamber ◽

Annual Ryegrass ◽

Greenhouse Study ◽

Chamber Study ◽

Chamber Studies ◽

Growth Chamber Studies

Bermudagrass (Cynodon spp.) turf is often overseeded with a cool-season species such as perennial ryegrass (Lolium perenne L.) to provide an improved winter surface for activities such as golf or athletic events. Perennial ryegrass can become a persistent weed in overseeded turf due to the heat and disease tolerance of improved cultivars. Intermediate ryegrass is a relatively new turfgrass that is a hybrid between perennial and annual ryegrass (L. multiflorum Lam.). Very little information is available on intermediate ryegrass as an overseeding turf. Greenhouse, field, and growth chamber studies were designed to compare two cultivars of intermediate ryegrass (`Transist' and `Froghair') with three cultivars of perennial ryegrass (`Jiffie', `Racer', and `Calypso II') and two cultivars of annual ryegrass (`Gulf' and `TAM-90'). In a greenhouse study, the perennial ryegrass cultivars had finer leaf texture (2.9-3.2 mm), shorter collar height (24.7-57.0 mm), and lower weight/tiller (29-39 mg) than the intermediate and annual cultivars. In the field studies, the intermediate cultivar Transist exhibited improved turfgrass quality (6.1-7.1) over the annual cultivars (4.5-5.8) and the other intermediate cultivar Froghair (5.4-5.7). However, neither of the intermediate cultivars had quality equal to the perennial ryegrass cultivars (7.0-7.9). The perennial ryegrass cultivars exhibited slow transition back to the bermudagrass compared to the annual and intermediate ryegrass cultivars. In the growth chamber study, the annual and intermediate cultivars all showed increased high-temperature stress under increasing temperatures compared to the perennial cultivars, which did not show stress until air temperature exceeded 40 °C. Collectively, these studies indicate that the intermediate ryegrass cultivar Transist may have promise as an overseeding turfgrass due to its improved quality compared to annual types and a lack of heat tolerance relative to perennial cultivars, but with transition qualities similar to perennial ryegrass.

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

HortScience ◽

10.21273/hortsci.37.5.773 ◽

2002 ◽

Vol 37 (5) ◽

pp. 773-777 ◽

Cited By ~ 4

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.

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Seasonal Emergence and Growth ofSorghum almum

Weed Technology ◽

10.1017/s0890037x0003058x ◽

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.

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