Weed suppression in Vigna unguiculata with a spring-seeded brassicaceae green manure

The effect of phosphorus rate on plant height, biomass yield and nodulation of green manure crops was investigated. Seven green manure species viz. Sesbania rostrata, Sesbania aculeata, Crotalaria juncea, Vigna unguiculata, Phaseolus mungo, Vigna radiata and Glycine max and three phosphorus rates viz. 18, 27 and 36 kg P ha-1 were used. Plant height was different for each green manure crops during the growth period though phosphorus fertilization had no significant effect on plant height and biomass yield. On the other hand, phosphorus fertilization had significant effect on nodulation of green manure crops. The number of nodules plant-1 increased significantly with the age of the plants up to 60 days after sowing (DAS) and thereafter declined sharply at 75 DAS. The highest number of nodules plant-1 was produced at 36 kg P ha-1 followed by 27 kg P ha-1. The lowest number of nodules plant-1 was produced at 18 kg P ha-1. Keywords: Green manure crops; Phosphorus; Growth; Nodulation; Biomass yield DOI: 10.3329/jbau.v7i1.4793 J. Bangladesh Agril. Univ. 7(1): 23-28, 2009

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Clover green manure productivity and weed suppression in an organic grain rotation

Renewable Agriculture and Food Systems ◽

10.1017/s1742170516000430 ◽

2016 ◽

Vol 32 (5) ◽

pp. 474-483 ◽

Cited By ~ 5

Author(s):

Katja Koehler-Cole ◽

James R. Brandle ◽

Charles A. Francis ◽

Charles A. Shapiro ◽

Erin E. Blankenship ◽

...

Keyword(s):

Winter Wheat ◽

White Clover ◽

Green Manure ◽

Red Clover ◽

Late Summer ◽

Weed Suppression ◽

Grain Protein ◽

Above Ground Biomass ◽

Ground Biomass ◽

Sampling Times

AbstractGreen manure crops must produce high biomass to supply biological N, increase organic matter and control weeds. The objectives of our study were to assess above-ground biomass productivity and weed suppression of clover (Trifolium spp.) green manures in an organic soybean [Glycine max (L.) Merr.]-winter wheat (Triticum aestivum L.)-corn (Zea mays L.) rotation in eastern Nebraska in three cycles (2011–12, 2012–13, 2013–14). Treatments were green manure species [red clover (T. pratense L.) and white clover (T. repens L.)] undersown into winter wheat in March and green manure mowing regime (one late summer mowing or no mowing). We measured wheat productivity and grain protein at wheat harvest, and clover and weed above-ground biomass as dry matter (DM) at wheat harvest, 35 days after wheat harvest, in October and in April before clover termination. Winter wheat grain yields and grain protein were not affected by undersown clovers. DM was higher for red than for white clover at most sampling times. Red clover produced between 0.4 and 5.5 Mg ha−1 in the fall and 0.4–5.2 Mg ha−1 in the spring. White clover produced between 0.1 and 2.5 Mg ha−1 in the fall and 0.2–3.1 Mg ha−1 in the spring. Weed DM was lower under red clover than under white clover at most sampling times. In the spring, weed DM ranged from 0.0 to 0.6 Mg ha−1 under red clover and from 0.0 to 3.1 Mg ha−1 under white clover. Mowing did not consistently affect clover or weed DM. For organic growers in eastern Nebraska, red clover undersown into winter wheat can be a productive green manure with good weed suppression potential.

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Response of Wetland Taro Yield and Weeds to Preplant Establishment of Azolla in Hawaii

HortScience ◽

10.21273/hortsci.30.4.912f ◽

1995 ◽

Vol 30 (4) ◽

pp. 912F-912

Author(s):

Joseph DeFrank

Keyword(s):

Phosphoric Acid ◽

Green Manure ◽

Dry Weight ◽

Weed Suppression ◽

Symbiotic Relationship ◽

Seeding Rate ◽

Azolla Filiculoides ◽

Blue Green Algae ◽

Nursery Pond ◽

Flooded Rice

Azolla (Azolla filiculoides) is a floating fern that maintains a symbiotic relationship with an N-fixing blue-green algae. In many parts of Asia, azolla is used as a green manure in flooded rice cultivation. Taro (Colocasia esculenta) grown under flooded conditions is used to produce a traditional Hawaiian staple, poi. Azolla has been present in Hawaii for many years, but is not used in a controlled way for either nutrient augmentation of production sites or weed suppression. In this experiment, azolla was removed from a stream on the island of Kauai and multiplied in a nursery pond. Phosphoric acid was added to the nursery pond as a nutrient (P = 5 ppm) at 5-day intervals to accelerate azolla growth. Azolla was moved from the nursery pond and added to taro production plots at a seeding rate of 488 kg·m–2. Phosphoric acid was used in production plots to hasten coverage of the water surface by azolla. Ten days after azolla inoculation, production plots were covered and taro seed pieces were planted. Weed dry weights from conventional and azolla covered plots were recorded 91 days after taro planting. Taro corms were harvested 315 days after planting. Weed dry weight in azolla plots was 86% less than conventional plots. Azolla delayed taro maturity, causing a 41% reduction in marketable corm yield.

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Optimal seeding rate for organic production of field pea in the northern Great Plains

Canadian Journal of Plant Science ◽

10.4141/cjps08113 ◽

2009 ◽

Vol 89 (3) ◽

pp. 455-464 ◽

Cited By ~ 10

Author(s):

J. M. Baird ◽

F. L. Walley ◽

S. J. Shirtliffe

Keyword(s):

Great Plains ◽

Green Manure ◽

Inorganic Nitrogen ◽

Block Design ◽

Organic Production ◽

Weed Suppression ◽

Field Pea ◽

Northern Great Plains ◽

Seeding Rate ◽

Post Harvest

Seeding rates have not been established for organic production of field pea in the northern Great Plains and producers must rely upon a recommended target stand of 88 plants m-2 for conventional production of this crop. This seeding rate may not be suitable as the two systems differ in the use of inputs and in pest management. The objective of this study was to determine an optimal seeding rate for organic production of field pea considering a number of agronomic factors and profitability. Field sites were established using a randomized complete block design with increasing seeding rates, summerfallow and green manure treatments. Seed yield increased up to 1725 kg ha-1 with increasing seeding rate. Weed biomass decreased with increasing seeding rate by up to 68%. Post-harvest soil phosphorus levels and soil water storage did not change consistently between treatments. Post-harvest soil inorganic nitrogen (N), however, was higher for the summerfallow and green manure treatments than for the seeding rate treatments. Field pea reached a maximum economic return at a seeding rate of 200 seeds m-2 and an actual plant density of 120 plants m-2. Organic farmers should increase the seeding rate of field pea to increase returns and provide better weed suppression. Key words: Pea (field), organic, seeding rate, weed suppression, profit, soil N

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Cowpea (Vigna unguiculata L. Walp.) as a green manure to improve the productivity of a menthol mint (Mentha arvensis L.) intercropping system

Industrial Crops and Products ◽

10.1016/j.indcrop.2009.11.004 ◽

2010 ◽

Vol 31 (2) ◽

pp. 289-293 ◽

Cited By ~ 12

Author(s):

Man Singh ◽

A. Singh ◽

S. Singh ◽

R.S. Tripathi ◽

A.K. Singh ◽

...

Keyword(s):

Vigna Unguiculata ◽

Green Manure ◽

Mentha Arvensis

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Weed supression by smother crops and selective herbicides

Scientia Agricola ◽

10.1590/s0103-90162004000100004 ◽

2004 ◽

Vol 61 (1) ◽

pp. 21-26 ◽

Cited By ~ 7

Author(s):

Francisco José Severino ◽

Pedro Jacob Christoffoleti

Keyword(s):

Field Experiment ◽

Weed Management ◽

Green Manure ◽

Residual Effect ◽

Cropping System ◽

Pigeon Pea ◽

Weed Suppression ◽

Integrated Weed Management ◽

Weed Species ◽

Arachis Pintoi

Using a smother crop is thought to suppress weed density and to add other beneficial effects in sustainable agricultural systems. Weed suppression ought to be considered an essential component of integrated weed management. However, very little is known about the effects of green manure plants on weeds. This study evaluated the influence of three green manure species on weed suppression and selectivity of herbicides. A field experiment was designed to determine the effect of the green manure species Crotalaria juncea, Arachis pintoi and pigeon pea on the weeds Brachiaria decumbens, guineagrass and hairy beggarticks, and on the natural weed infestation in the inter rows area of an avocado orchard. The weed species were suppressed differently by each green manure species. Soil samples collected from the field experiment presented a residual effect, of at least 30 d, in suppressing weed seed bank recruitment; this residual effect was caused by the residues of the green manure present in the soil. When the green manure was incorporated into the top 5 cm of soil or left on the surface, in a greenhouse experiment, the emergence of weed seeds was significantly inhibited, depending on the species, and on the amount and depth of green manure incorporation. Greenhouse experiments indicate that pre-emergence herbicides cause lower phytotoxicity than post-emergence Arachis pintoi. Smother crops using green manure species, when well established in an area, provide additional weed control to the cropping system and are effective and valuable tools in integrated weed management.

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Weed suppression withBrassicagreen manure crops in green pea

Weed Science ◽

10.1017/s0043174500093139 ◽

1997 ◽

Vol 45 (3) ◽

pp. 439-445 ◽

Cited By ~ 76

Author(s):

Kassim Al-Khatib ◽

Carl Libbey ◽

Rick Boydston

Keyword(s):

Green Manure ◽

Weed Suppression ◽

White Mustard ◽

Weed Population ◽

Weed Density ◽

Mount Vernon ◽

Green Foxtail ◽

Green Pea ◽

Dry Soil ◽

Green Manure Crops

Weed suppression in green pea was evaluated when green pea was planted after a fall planting of rapeseed, white mustard, rye, or wheat had been incorporated into the soil in spring. Tests were conducted at Mount Vernon, WA, in 1994 and 1995. Weed suppression in peas varied between different green manure crops. One month after planting, the highest weed population was in green pea following wheat, whereas the lowest was in green pea following rapeseed. Rye and white mustard suppressed early weeds relative to wheat by 25 and 30%, respectively. However, at harvest, weed density was similar in green pea planted after all green manure crops. Weed suppression improved when cultivation or metribuzin at 0.14 kg ha−1was used in combination with white mustard, rapeseed, or rye. Pea population was not affected by green manure crops, except for rapeseed, which reduced pea population. In greenhouse experiments, white mustard added to the soil at 20 g per 400 g air dry soil reduced emergence of shepherd's-purse, kochia, and green foxtail by 97, 54, and 49%, respectively. Rapeseed suppressed emergence of shepherd's-purse, kochia, and green foxtail by 76, 25, and 25%, respectively.

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