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

HortScience ◽  
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.

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

2009 ◽  
Vol 89 (3) ◽  
pp. 455-464 ◽  
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

Advances in Chinese research on Azolla

1985 ◽  
Vol 86 ◽  
pp. 161-167 ◽  
Author(s):  
Thomas A. Lumpkin
Keyword(s):  
Green Manure ◽  
Field Application ◽  
Symbiotic Relationship ◽  
Aquatic Fern ◽  
Communication Problems ◽  
The Impact

SynopsisThe aquatic fern Azolla has a symbiotic relationship with an N2-fixing cyanobacterium. Fanners in China and Vietnam have used Azolla for centuries as a green manure for rice and as fodder for pigs, ducks and fish. Chinese researchers have been studying Azolla since the early 1950's but many of their achievements are unknown outside China because of language and other communication problems. This article reviews current Chinese Azolla research and focuses on the impact of newly introduced Azolla species in the areas of field application, use of spores, and isolation of the N2-fixing symbiont.

scholarly journals Compost enriched with ZnO and Zn-solubilising bacteria improves yield and Zn-fortification in flooded rice

2018 ◽  
pp. 310-316 ◽  
Author(s):  
Hassan Zeb ◽  
Azhar Hussain ◽  
Muhammad Naveed ◽  
Allah Ditta ◽  
Shakeel Ahmad ◽  
...  
Keyword(s):  
Grain Quality ◽  
Management Practices ◽  
Essential Element ◽  
Growth Yield ◽  
Dry Weight ◽  
Carbonic Anhydrase Activity ◽  
Maximum Increase ◽  
Chlorophyll Contents ◽  
Growth Physiology ◽  
Flooded Rice

Zinc (Zn) is an essential element for humans, animals and plants, however, its deficiency has been widely reported around the world especially in flooded rice. Adequate amount of Zn is considered essential for optimum growth and development of rice. We hypothesised that management practices like Zn-mineral fertiliser, -compost, and -solubilising bacteria would improve Zn availability and uptake in flooded rice. A series of studies were conducted to find out the comparative efficacy of Zn-enriched composts (Zn-ECs) with Zn solubilising bacteria (ZnSB) vs. ZnSO4 for improved growth, yield and Zn accumulation in rice. There were six treatments viz. control, ZnSB, ZnO (80% Zn), ZnSO4 (33% Zn), Zn-EC80:20 and Zn-EC60:40. In all the treatments, Zn was applied at the rate of 5 kg ha–1 except the control. The treatment Zn-EC60:40 resulted in the maximum Zn release in soil as compared to ZnSO4 and all other treatments during incubation study. The treatment Zn-EC60:40 significantly improved root dry weight, grain yield and 100-grain weight of rice by 15, 22 and 28%, respectively as compared to ZnSO4. The same treatment resulted in the maximum increase in photosynthetic rate (11%), transpiration rate (21%), stomatal conductance (17%), chlorophyll contents (8%) and carbonic anhydrase activity (10%) while a decrease of 27% in electrolyte leakage was observed in comparison with ZnSO4 application. Moreover, the maximum increase in grain quality parameters and Zn bioaccumulation was observed with the application of Zn-EC60:40 in comparison with ZnSO4 application and all other treatments. We conclude that Zn-EC60:40 are not only an effective strategy to improve growth, physiology and yield parameters of rice, but also to improve the grain quality and Zn-bioaccumulation in rice compared to ZnSO4.

Row Spacing and Seeding Rate Effects on Eastern Black Nightshade (Solanum Ptycanthum) and Soybean

2007 ◽  
Vol 21 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Adrienne M. Rich ◽  
Karen A. Renner
Keyword(s):  
Dry Weight ◽  
Field Studies ◽  
Production Costs ◽  
Row Spacing ◽  
Seeding Rate ◽  
Soybean Yield ◽  
Eastern Black Nightshade ◽  
Solanum Ptycanthum ◽  
Black Nightshade ◽  
Rate Effects

Reducing seeding rates in 19- or 76-cm row soybean below the optimum rate may reduce soybean competitiveness with weeds, and indirectly increase production costs to the grower. Field studies in 2001 and 2002 evaluated the effect of soybean seeding rate and row spacing on the emergence, growth, and competitiveness of eastern black nightshade (EBN) in soybean. EBN emergence ceased within 45 d after planting (DAP), and was similar across soybean seeding rates and row spacing. EBN control by glyphosate was not affected by soybean population or row spacing. Soybean planted in 19-cm rows was more competitive with EBN, regardless of seeding rate. Increasing the soybean seeding rate in 76-cm rows from 185,000 seeds/ha to 432,000 seeds/ha reduced EBN dry weight threefold at East Lansing and nearly twofold at Clarksville in 2002. There was no increase in EBN density or dry weight in 19-cm row soybean planted at 308,000 seeds/ha compared with 556,000 seeds/ha, whereas a seeding rate of 432,000 seeds/ha in 76-cm row soybean did not suppress EBN dry weight or increase soybean yield in the presence of EBN compared with a seeding rate of 308,000 seeds/ha.

scholarly journals Mustard Cover Crop Growth and Weed Suppression in Organic, Strawberry Furrows in California

HortScience ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 432-440 ◽  
Author(s):  
Eric B. Brennan ◽  
Richard F. Smith
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Sinapis Alba ◽  
Weed Suppression ◽  
Shoot Biomass ◽  
Plastic Mulch ◽  
Seeding Rate ◽  
Crop Cover ◽  
Cover Cropping ◽  
Growing Seasons

Strawberry (Fragaria ×ananassa Duch.) production in California uses plastic mulch–covered beds that provide many benefits such as moisture conservation and weed control. Unfortunately, the mulch can also cause environmental problems by increasing runoff and soil erosion and reducing groundwater recharge. Planting cover crops in bare furrows between the plastic cover beds can help minimize these problems. Furrow cover cropping was evaluated during two growing seasons in organic strawberries in Salinas, CA, using a mustard (Sinapis alba L.) cover crop planted at two seeding rates (1× and 3×). Mustard was planted in November or December after strawberry transplanting and it resulted in average densities per meter of furrow of 54 and 162 mustard plants for the 1× and 3× rates, respectively. The mustard was mowed in February before it shaded the strawberry plants. Increasing the seeding rate increased mustard shoot biomass and height, and reduced the concentration of P in the mustard shoots. Compared with furrows with no cover crop, cover-cropped furrows reduced weed biomass by 29% and 40% in the 1× and 3× seeding rates, respectively, although weeds still accounted for at least 28% of the furrow biomass in the cover-cropped furrows. These results show that growing mustard cover crops in furrows without irrigating the furrows worked well even during years with relatively minimal precipitation. We conclude that 1) mustard densities of ≈150 plants/m furrow will likely provide the most benefits due to greater biomass production, N scavenging, and weed suppression; 2) mowing was an effective way to kill the mustard; and 3) high seeding rates of mustard alone are insufficient to provide adequate weed suppression in strawberry furrows.

scholarly journals Effect of green manure along with nitrogenous fertilizer on the growth and yield of turmeric (curcuma longa l.) of Bangladesh

2018 ◽  
Vol 6 (1) ◽  
pp. 140
Author(s):  
Mahbuba Ferdous ◽  
Mohammad Kabirul Islam ◽  
Md. Monirul Islam ◽  
Md Isfatuzzaman Bhuyan ◽  
Md Sazedul Islam ◽  
...  
Keyword(s):  
Green Manure ◽  
Curcuma Longa ◽  
Maximum Yield ◽  
Coastal Region ◽  
Dry Weight ◽  
Leaf Length ◽  
Growth And Yield ◽  
Fresh Weight ◽  
Nitrogenous Fertilizer ◽  
Combined Application

Turmeric is an important spice crop of Bangladesh. A field experiment was conducted at farmer’s field of North Jhatibunia, Mirzagonj, Patuakhali during April, 2015 to February, 2016. The study was performed to find out the effect of green manure and nitrogenous fertilizer on the growth and yield of turmeric (BARI Halud-2), in coastal region of Bangladesh. In this study different combinations of green manure along with nitrogenous fertilizer were used. There was eight treatment combinations (viz. 7 ton biomass/ha + 100 kg N/ha, 7 ton biomass/ha + 80 kg N/ha, 7 ton biomass/ha + 60 kg N/ha, 7 ton biomass/ha + 40 kg N/ha, 7 ton biomass/ha + 20 kg N/ha, 7 ton biomass/ha, 100 kg N/ha and control). The highest number of leaves per plant (11.67) were recorded by the combined application of 7 ton biomass/ha along with 100 kg N/ha. The highest plant height (80.70 cm) and the longest leaf length (47.33 cm) were recorded by the application of 100 kg N/ha. The highest number of tillers per plant (7.67), maximum number of primary rhizomes per plant (9.00), maximum fresh weight of clump (189.67 g), highest fresh weight of roots (48.01 g), maximum fresh weight of rhizomes (277.70 g), maximum dry weight of clump (20.01 g), highest dry weight of roots (9.25 g), maximum dry weight of rhizomes (67.50 g) and maximum yield of fresh rhizome per hectare (6.64 tons) were recorded by the combined application of 7 ton /ha biomass+ 40 kg N/ha. Highest number of secondary rhizomes per plant (17.00) and maximum number of tertiary rhizomes per plant (7.00) were recorded by the application of 7 ton biomass/ha + 60 kg N/ha. With a few exception, the best performance in terms of growth and yield of turmeric were found from the combination of 7 ton biomass /ha + 40 kg N/ha.  

Impact of Spring Wheat Planting Density, Row Spacing, and Mechanical Weed Control on Yield, Grain Protein, and Economic Return in Maine

Weed Science ◽  
2012 ◽  
Vol 60 (2) ◽  
pp. 244-253 ◽  
Author(s):  
Lauren N. Kolb ◽  
Eric R. Gallandt ◽  
Ellen B. Mallory
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Weed Suppression ◽  
Planting Density ◽  
Grain Protein ◽  
Seeding Rate ◽  
Management Options ◽  
Weed Density ◽  
Net Returns ◽  
Farmer Practices

Effective in-season weed management options are limited for organic cereal farmers. Two alternatives to current farmer practices are improving efficacy of physical weed control through use of interrow cultivation or increasing the competitive ability of the crop through elevated seeding rates and more uniform spatial planting patterns. It is unknown how these two methods affect yield, quality, and economic returns. Field experiments were conducted in the northeast United States to determine whether the yield gain from increased weed control from these contrasting weed management strategies resulted in increased net returns and how these different systems affected grain quality. Wheat was planted at two seeding rates (400 and 600 plants m−2), in three row spacings (11, 18, and 23 cm). A fourth crop arrangement that approaches a more uniform spatial distribution through a combination of drilling and broadcasting seed was included. For weed control, treatments received tine harrowing. Wheat sown in wide rows also received interrow cultivation. Each system was sown in the presence and absence of condiment mustard, which was sown as a surrogate weed. Increased seeding rate reduced weed density 64% compared to a crop-free check and 30% compared to regional farmers' practices of 18-cm rows and 400 plants m−2. Increased seeding rates lowered grain protein 5% compared to standard seeding rates. Wide rows, in combination with interrow cultivation, reduced weed density 62%, increased yield 16%, and net returns 19% compared to regional organic practices. Significant increases in grain N were limited to weed-free plots. While increased seeding rates improved weed suppression, the high input cost of organic seed make this an unsatisfactory alternative to interrow cultivation and current farmer practices, as yield would need to be. 15 t ha−1higher at elevated density to offset the extra cost of seed.

Effect of tillage practices and fertilizer management on the growth and nitrogen efficiency in soybean

2018 ◽  
Author(s):  
Swapan Kumar Roy ◽  
Seong Woo Cho ◽  
Soo Jeong Kwon ◽  
Jong Ho Yang ◽  
Yeong Ju Bae ◽  
...  
Keyword(s):  
Plant Height ◽  
Green Manure ◽  
Nitrate Concentration ◽  
Dry Weight ◽  
Conventional Tillage ◽  
Fertilizer Application ◽  
Nitrogen Efficiency ◽  
Soybean Seeds ◽  
Fertilizer Management ◽  
Tillage Practices

A field experiment was performed to evaluate the effects of tillage systems and fertilizer management on the growth and nutrient uptake in soybean. The plant height, fresh weight and dry weight of conventional tillage (CT) were much higher those observed for no-tillage (NT). The highest plant height (128.47 cm) was observed in CT with chemical fertilizer. The plant nitrate concentration was higher (2.29%) in NT with green manure than chemical fertilization. However, nitrogen increased steadily in all treatments, and the highest quantity of total nitrogen (476.7 Kg/ha) was observed in NT with green manure. The NO3-N content in the soil decreased gradually just after the vegetative stage. Tillage practices and additional fertilizer application was less effective on the uptake of N, P and K in soybean seeds as compared to NT with green manure. The results postulated that NT strategies with fertilizers might influence the growth characteristics and mineral uptake in soybean.

scholarly journals The Development of the Grain of Wheat

1909 ◽  
Vol 3 (2) ◽  
pp. 195-217 ◽  
Author(s):  
W. E. Brenchley ◽  
A. D. Hall
Keyword(s):  
Phosphoric Acid ◽  
Dry Weight ◽  
Prominent Feature ◽  
Chemical Changes ◽  
Ripening Process ◽  
Loss Of Weight ◽  
Whole Plant ◽  
Main Period ◽  
Three Stages

A study during 1907 and 1908 of various plots of wheat cut at three-day intervals leads to the following general conclusions:(1) The whole plant, and with it the nitrogen, ash, and phosphoric acid it contains, increases in weight until about a week before it would be regarded as ready to cut. Some decrease of dry weight takes place during the last week.(2) In the formation of the grain three stages may be distinguished:(a) a period during which the pericarp is the most prominent feature,(b) the main period during which the endosperm is filled,(c) the ripening period characterised by the desiccation of the grain.(3) For the filling of the endosperm each plant possesses as it were a special mould, and continually moves into the grain uniform material cast in that mould, possessing always the same ratio of nitrogenous to non-nitrogenous materials and ash. The character of the mould possessed by each plant is determined by variety, soil, season, &c.(4) The main feature of the ripening process is desiccation rather than the setting in of such chemical changes as the conversion of sugars into starch, non-protein into protein, though the latter change also takes place.(5) The maximum dry weight of grain is attained a day or two before the grain would be regarded as ripe by the farmer. Allowing for the fact that the tillered shoots are a little behind the central shoots, no loss of weight in the crop will be incurred by cutting before the corn appears quite ripe, while a number of accidental mechanical losses due to birds, shedding, weather, may thus be avoided. Other experiments have shown that, though there may be no gain, there will be no loss in the quality of the wheat due to such early cutting.

Sign in / Sign up

Export Citation Format

Share Document