Texas Panicum (Panicum texanum) Growth as Affected by Irrigation Management and Planting Date

Weed Science ◽  
1990 ◽  
Vol 38 (4-5) ◽  
pp. 374-378 ◽  
Author(s):  
Jill Schroeder ◽  
Clyde C. Dowler ◽  
James R. Stansell
Keyword(s):  
Seed Production ◽  
Irrigation Management ◽  
Dry Weight ◽  
Planting Date ◽  
Soil Matric Potential ◽  
Seed Number ◽  
Matric Potential ◽  
Total Seed

The effect of soil matric potential from −0.02 to <–1.5 MPa on Texas panicum growth in drainage lysimeters covered by an automatic rainfall shelter was measured in 1984, 1985, and 1986. Rate of tiller production was faster for plants established in April than June in 1984 and 1985, but not 1986. In 1985 and 1986, dry weight was greater, but total seed production was less for plants established in April than June. Irrigation when the soil matric potential was −0.02, −0.075, or −1.5 MPa did not affect rate of tiller production in 1984. Irrigation when the soil matric potential was −1.5 MPa decreased dry weight of plants but increased seed number per panicle compared to irrigation when the soil matric potential was −0.02 MPa in 1985 and 1986. Plants grown in lysimeters irrigated at soil matric potential <–1.5 MPa in 1985 and 1986 did not wilt at 8:00 a.m.; therefore, they were not watered after establishment. These nonirrigated plants averaged 0.9 and 0.4 kg dry weight and produced 92 200 and 16 100 seeds in 1985 and 1986, respectively.

The beneficial effect of ants on the reproductive success of Dyckia floribunda (Bromeliaceae), an extrafloral nectary plant

2003 ◽  
Vol 81 (1) ◽  
pp. 24-27 ◽  
Author(s):  
José L Vesprini ◽  
Leonardo Galetto ◽  
Gabriel Bernardello
Keyword(s):  
Seed Production ◽  
Reproductive Output ◽  
Fruit Set ◽  
Seed Set ◽  
Reproductive Organs ◽  
Extrafloral Nectaries ◽  
Perennial Herb ◽  
Seed Number ◽  
Total Seed ◽  
Mutualistic Association

Dyckia floribunda is a perennial herb from the Argentinian Chaco with extrafloral nectaries. Ants visited these nectaries while patrolling inflorescences and infructescences. We anticipated that ants attracted to extrafloral nectaries might protect the reproductive organs, increasing plant reproductive output. To evaluate the possibility of mutualism between D. floribunda and ant visitors, we determined whether ant-accessible plants showed a higher seed production than ant-excluded plants. Experimental fieldwork suggested a decrease in fruit set of ant-excluded plants compared with ant-accessible plants but the seed number per fruit was not affected by ant exclusion. Thus, total seed number per plant was highly reduced in treated spikes. Analyses of covariance confirmed these trends, indicating that total seed production per plant was strongly affected by ant exclusion. This study marks the first experimental report of this mutualistic association in Bromeliaceae.Key words: ant–plant interaction, Bromeliaceae, Chaco, Dyckia floribunda, fruit set, seed set, mutualism.

Determination of irrigation set points for cranberries from soil- and plant-based measurements

2016 ◽  
Vol 96 (1) ◽  
pp. 37-50 ◽  
Author(s):  
Jean Caron ◽  
Simon Bonin ◽  
Steeve Pepin ◽  
Leroy Kummer ◽  
Clay Vanderleest ◽  
...  
Keyword(s):  
Physical Properties ◽  
Irrigation Management ◽  
Maximum Yield ◽  
Soil Physical Properties ◽  
Yield Response ◽  
Soil Matric Potential ◽  
Response Curves ◽  
Matric Potential ◽  
Set Point ◽  
Point Estimates

Cranberry production requires accurate irrigation management to optimize crop yield and reduce water use. However, irrigation guidelines for that crop are scarce and empirical. The objective of this study was to identify appropriate soil matric potential (ψ) irrigation set points for cranberry production. A three-step process was used to evaluate the set points. Crop water requirements were first evaluated in the field and, second, combined to soil physical properties with a hydrological model to estimate irrigation set points. Third, experimental measurements were carried out in a growth cabinet and in the field to validate the set point estimates from independent observations. Irrigation set point estimates obtained from yield response curves, photosynthesis and transpiration measurements, and soil physical properties were all consistent and suggest that soil matric potential be maintained between −4.0 and −7.0 kPa to ensure an adequate water supply to the crop and optimal fruit yield. Yield responses suggest that cranberries are highly sensitive to small changes in soil matric potential, showing differences of about 20 000 kg ha−1 when outside of the −4.0 to −7.0 range, with a maximum yield between 35 000 and 40 000 kg ha−1, depending on the site.

Timing and Measurement of Weed Seed Shed in Corn (Zea mays)

1996 ◽  
Vol 10 (3) ◽  
pp. 535-543 ◽  
Author(s):  
Frank Forcella ◽  
Dean H. Peterson ◽  
James C. Barbour
Keyword(s):  
Seed Production ◽  
Dry Weight ◽  
Weed Seed ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Seed Processing ◽  
Wild Mustard ◽  
Green Foxtail ◽  
Viable Seeds ◽  
Total Seed

In west central Minnesota the extent and duration of weed seed shed was measured for two years in corn that received cultivation but no herbicides. Percentage of seed production represented by viable (filled) seeds was about 79% for green foxtail, 68% for wild mustard, 49% for Pennsylvania smartweed, 48% for common lambsquarters, and 35% for redroot pigweed. Percentage viable seeds varied from 11% in 1993 to 59% in 1994 for redroot pigweed, but was more stable for other species. Seed shed commenced in late August in a cool year (1993) and early August in a warm year (1994). Average growing degree days (base 10 C) from corn planting until 25% seed shed was 983 for common lambsquarters, 984 for wild mustard, 1004 for Pennsylvania smartweed, and 1034 for both green foxtail and redroot pigweed. Brief weather events, such as wind storms, dispersed large percentages of total seed production within a single day. More than one-fifth of all viable seeds of green foxtail, redroot pigweed, and common lambsquarters were retained by the seedheads and dispersed by combines at harvest. In contrast, seeds of early-maturing species, such as wild mustard, were completely dispersed before corn harvest in the warmer year, but one-third of seeds were retained by seedheads at harvest in the cooler year. Measurement of seed shed was compared using five seed trap designs. The preferred design consisted of a 10-cm-diam plastic cup, whose bottom was replaced by a brass screen, and the entire unit attached to a small wooden stake for support. This design provided, on average, the highest estimates of seed production, least among-replication variability, highest correlation with weed population density and aboveground dry-weight, lowest assembly cost, and greatest ease for sample access and seed processing.

Influence of Planting Date on Growth of Palmer Amaranth (Amaranthus palmeri)

Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 199-204 ◽  
Author(s):  
Paul E. Keeley ◽  
Charles H. Carter ◽  
Robert J. Thullen
Keyword(s):  
Seed Production ◽  
Dry Matter ◽  
Planting Date ◽  
Palmer Amaranth ◽  
Amaranthus Palmeri ◽  
Seed Plant ◽  
Viable Seed ◽  
Soil Temperatures ◽  
Total Seed

Palmer amaranth (Amaranthus palmeriS. Wats. # AMAPA) planted in a field at monthly intervals from March through October at Shafter, CA, began to emerge in March when soil temperatures at a depth of 5 cm reached 18 C. With the exception of March and April plantings, at least 50% of the seed of later plantings produced seedlings within 2 weeks after planting. Although growth of plants was initially slower for early plantings, plantings from March to July reached 2 m or greater in height by fall. Due to longer growing times, plantings from March to June eventually produced more dry matter and a greater number of inflorescences than later plantings. Plants began flowering 5 to 9 weeks after planting in March through June and 3 to 4 weeks after planting in July through October. Some viable seed was produced as early as 2 to 3 weeks after flowering began. Total seed production in the fall ranged from 200 000 to 600 000 seed/plant for the March through June plantings, and 115 to 80 000 seed/plant for the July through September plantings. Killing frosts in November prevented Palmer amaranth planted in October from producing seed.

Flowering Patterns, Seed Production, and Somatic Polymorphism of Three Weed Species

Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 418-425 ◽  
Author(s):  
Scott A. Senseman ◽  
Lawrence R. Oliver
Keyword(s):  
Seed Germination ◽  
Seed Production ◽  
Dry Weight ◽  
Field Studies ◽  
Seed Number ◽  
Weed Species ◽  
Flowering Pattern ◽  
Pitted Morningglory ◽  
Temperature Responses

Field studies determined flowering pattern, seed production, and somatic polymorphism of pitted morningglory, common cocklebur, and sicklepod under interspecific and no interference with soybean. Flowering patterns differed between years but were similar under both interferences. Interspecific interference reduced flower and seed numbers 85 to 99%. Rainfall had little effect on flowering, but photoperiod and temperature responses were evident for all weed species. The production equations for seed number per plant from dry weight were quadratic for pitted morningglory and common cocklebur but linear for sicklepod. All species showed somatic polymorphism; however, differences in seed germination and viability were not consistent between years.

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.

Effect of planting date and density on calendula and peppermint herbs

2014 ◽  
Vol 1 (1) ◽  
pp. 25-29
Author(s):  
Rahim Mohammadian ◽  
Behnam Tahmasebpour ◽  
Peyvand Samimifar
Keyword(s):  
Mutual Effect ◽  
Dry Weight ◽  
Planting Date ◽  
Mass Reduction ◽  
Flower Number ◽  
Planting Dates ◽  
Randomized Design ◽  
Significant Difference ◽  
Completely Randomized Design ◽  
Total Maximum

A factorial experiment was conducted with a completely randomized design to evaluate the effects of planting date and density on calendula herbs and peppermint. It had 3 replicates and was done in Khosroshahr research farm, Tabriz in 2006. Under studied factors were: 3 planting dates (10 May, 25 May and 10 June) in 4 densities (25, 35, 45, 55) of the plant in square meters. The results of variance a nalysis showed that there was 1% probability significant difference between the effects of planting date and bush density on the leave number, bush height and the bush dry weight. But the mutual effect of the plant date in mentioned traits density was insignificant. Regarding the traits mean comparison, the total maximum dry weight was about the 55 bush density in mm. Also, the bush high density in mm causes the bush growth and its mass reduction. When there is the density grain, the flower number will increase due to bush grain in surface unit. Overall, we can conclude that 10 June planting and 45 bush density in mm is the most suitable items and results in favored production with high essence for these crops.

Sign in / Sign up

Export Citation Format

Share Document