Longspine Sandbur (Cenchrus longispinus) Ecology and Interference in Irrigated Corn (Zea mays)

1997 ◽  
Vol 11 (4) ◽  
pp. 667-671 ◽  
Author(s):  
Randy L. Anderson
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Great Plains ◽  
Plant Development ◽  
Production Systems ◽  
Growing Degree Days ◽  
Degree Days ◽  
Boot Stage ◽  
Plant Seedlings ◽  
Corn Grain

Longspine sandbur is a troublesome weed infesting corn in the Great Plains. However, herbicides are now available to control this species. This study characterized longspine sandbur ecology in irrigated corn to aid producers in integrating herbicides into their production systems. Longspine sandbur began emerging May 25, and by June 15, 84% of the seasonal emergence had occurred. Plant development was related to cumulative growing degree days. Seeds were viable early in longspine sandbur's development, with 20% of seeds viable by heading. Producers can minimize seed production of longspine sandbur in field borders by mowing plants at the boot stage. Bur production per plant was related to time of emergence, with seedlings emerging in late May producing 1,120 burs per plant. Seedlings emerging 4 wk later produced 84% fewer burs. Controlling longspine sandbur before 4 wk of interference prevented loss of corn grain yield.

GRAIN YIELD COMPARISON OF PURE STANDS AND MIXTURES OF DIFFERENT PROPORTIONS FOR TWO HYBRIDS OF MAIZE

1985 ◽  
Vol 65 (3) ◽  
pp. 481-485 ◽  
Author(s):  
G. J. HOEKSTRA ◽  
L. W. KANNENBERG ◽  
B. R. CHRISTIE
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Zea Mays L ◽  
Pure Stand ◽  
Higher Plant ◽  
Data Support ◽  
Plant Densities ◽  
The Difference ◽  
Corn Grain ◽  
Corn Grain Yield

The objective of this study was to determine the effects on grain yield of growing cultivars in mixtures of different proportions. Two maize (Zea mays L.) hybrids, Pride 116 and United 106, were grown for 2 yr in pure stand and in seven mixtures of different proportions (7:1, 6:2, 5:3, 4:4, 3:5, 2:6, 1:7) at plant densities of 61 500, 99 400, and 136 000 plants per hectare. The total number of mixture combinations was 42, i.e. 2 years × three densities × seven proportions. All but one mixture yielded as expected based on the yield of component hybrids in pure stand. The higher yielding hybrid (United 106) yielded significantly less grain per plant in mixtures than in pure stand. The lower yielding hybrid (Pride 116) yielded more in mixtures than in pure stand, although the difference was not significant. These data support previous observations that the ability of a hybrid to yield in pure stands is not necessarily related to its ability to yield in mixtures. High plant densities appear to enhance the likelihood of interactions occurring among hybrids. For United 106, the number of proportions yielding less grain per plant than in pure stand was highly significant at the two higher plant densities. For Pride 116, the number of proportions yielding more than in pure stand was highly significant at the highest plant density.Key words: Corn, grain yield, mixtures of different proportions, high plant densities, Zea mays

The Critical Period of Johnsongrass (Sorghum halepense) Control in Field Corn (Zea mays)

Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 944-947 ◽  
Author(s):  
Hani Z. Ghosheh ◽  
David L. Holshouser ◽  
James M. Chandler
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Critical Period ◽  
Sorghum Halepense ◽  
Control Methods ◽  
Field Corn ◽  
Hand Weeding ◽  
Corn Grain ◽  
Corn Grain Yield

Experiments were conducted from 1989 to 1991 to determine the critical period of johnsongrass control in field corn. Maximum weed-infested and weed-free periods of 0 to 20 wk after corn emergence were maintained by either hand weeding or nicosulfuron application. Interference duration effects on corn grain yield were not affected by johnsongrass control methods. The critical period for johnsongrass control was determined to be between 3 and 6.5 wk after corn emergence to avoid losses above 5% of yield produced by full-season weed-free corn.

Application Timing for Weed Control in Corn (Zea mays) with Dicamba Tank Mixtures

1997 ◽  
Vol 11 (3) ◽  
pp. 602-607 ◽  
Author(s):  
Eric Spandl ◽  
Thomas L. Rabaey ◽  
James J. Kells ◽  
R. Gordon Harvey
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Weed Control ◽  
Field Studies ◽  
Corn Yield ◽  
Application Timing ◽  
Common Lambsquarters ◽  
Giant Foxtail ◽  
Corn Grain ◽  
Corn Grain Yield

Optimal application timing for dicamba–acetamide tank mixes was examined in field studies conducted in Michigan and Wisconsin from 1993 to 1995. Dicamba was tank mixed with alachlor, metolachlor, or SAN 582H and applied at planting, 7 d after planting, and 14 d after planting. Additional dicamba plus alachlor tank mixes applied at all three timings were followed by nicosulfuron postemergence to determine the effects of noncontrolled grass weeds on corn yield. Delaying application of dicamba–acetamide tank mixes until 14 d after planting often resulted in lower and less consistent giant foxtail control compared with applications at planting or 7 d after planting. Corn grain yield was reduced at one site where giant foxtail control was lower when application was delayed until 14 d after planting. Common lambsquarters control was excellent with 7 or 14 d after planting applications. At one site, common lambsquarters control and corn yield was reduced by application at planting. Dicamba–alachlor tank mixes applied 7 d after planting provided similar weed control or corn yield, while at planting and 14 d after planting applications provided less consistent weed control or corn yield than a sequential alachlor plus dicamba treatment or an atrazine-based program.

Influence of Density on Johnsongrass (Sorghum halepense) Interference in Field Corn (Zea mays)

Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 879-883 ◽  
Author(s):  
Hani Z. Ghosheh ◽  
David L. Holshouser ◽  
James M. Chandler
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Maximum Density ◽  
Sorghum Halepense ◽  
Constant Density ◽  
Yield Losses ◽  
Density Dependent ◽  
Field Corn ◽  
Corn Grain ◽  
Corn Grain Yield

Experiments were conducted from 1990 to 1994 to investigate the density-dependent effects of rhizome and seedling johnsongrass on the magnitude of full-season interference in field corn. Corn grain yield was decreased as rhizome johnsongrass density increased. A maximum density of 3 rhizome johnsongrass plants 9.8 m−1of row was considered critical to avoid yield losses above 5% of full-season weed-free corn. Interference of johnsongrass plants originating from seed and growing at densities up to 128 plants 9.8 m−1of row did not affect grain yield. Seedling johnsongrass plants growing at a constant density of 9.8 plants m−1of row did not affect yield from corn planted at five densities.

scholarly journals Phenology and degree days of rice cultivars under organic culture

1970 ◽  
Vol 40 (2) ◽  
pp. 149-153 ◽  
Author(s):  
MR Islam ◽  
S Sikder
Keyword(s):  
Grain Yield ◽  
Life Span ◽  
Growing Degree Days ◽  
Rice Cultivars ◽  
Degree Days ◽  
Phenological Stages ◽  
Cultural Conditions ◽  
Use Efficiency ◽  
Organic Culture ◽  
Plot Design

Variations in the phenology and degree days of five fine rice cultivars viz., Rajshahi swarna, Silkumul, Kataribhog, Lal pajam and Sanla under organic and inorganic cultural conditions were studied following a split plot design. The requirement of days to attain various phenological stages was highest in Rajshahi swarna, medium in Silkumul, Kataribhog and Lal pajam and the lowest in Sanla for both the cultural conditions. The growing degree days (GDD) and heat use efficiency (HUE) were slightly higher under inorganic than organic culture because of higher life span of rice cultivars in inorganic culture. The highest GDD and HUE were found in Rajshahi swarna, whereas the lowest in Sanla. Results also showed that the requirement of days and GDD were initially higher up to maximum tillering stage under organic culture but thereafter these requirements were greater under inorganic culture for all the cultivars. The grain yield was somewhat lower in organic compared to inorganic culture. In Rajshahi highest grain yield of swarna was 2.90 and 2.74 t/ha under inorganic and organic culture, respectively. Key words: Phenology; Growing degree days; Heat use efficiency; Fine rice DOI: http://dx.doi.org/10.3329/bjb.v40i2.9770   Bangladesh J. Bot. 40(2): 149-153, 2011 (December)  

scholarly journals Effect of temperature and sunshine on the productivity of rice crop

MAUSAM ◽  
2021 ◽  
Vol 47 (1) ◽  
pp. 85-90
Author(s):  
A. S. R. A. S. SASTRI ◽  
S. K. RAI ◽  
A. K. SRIVASTAVA ◽  
J. L. CHAUDHARY
Keyword(s):  
Grain Yield ◽  
Minimum Temperature ◽  
Rice Crop ◽  
Effect Of Temperature ◽  
Maximum Temperature ◽  
Multiple Regression Equation ◽  
Growing Degree Days ◽  
Degree Days ◽  
Maturity Stages ◽  
Sunshine Hours

Based on the experimental work with 8 different thermal and light environments, the effect of temperature and sunshine on rice crop (var : IR-36) was studied. It was found that the rice crop grown during winter/summer season experience, extremes of minimum temperature at seedling and vegetative stages and extemes of maximum temperature at reproductive and maturity stages.  Correlation coeffcients between the grain yield and maximum and minimum temperature growing degree days and total number of sunshine hours at each of the growth stages.viz:. seedling.  vegetative. reproductive and maturity stages were worked out.                             Multiple regression equation was worked out with 5 parameters upto vegetative stage to  predict the  grain yield of rice

Effects of Sublethal Concentrations of Bentazon, Fluazifop, Haloxyfop, and Sethoxydim on Corn (Zea mays)

Weed Science ◽  
1986 ◽  
Vol 34 (2) ◽  
pp. 171-174 ◽  
Author(s):  
Jon P. Chernicky ◽  
Fred W. Slife
Keyword(s):  
Zea Mays ◽  
Seed Germination ◽  
Grain Yield ◽  
Seed Weight ◽  
Growth Stage ◽  
Field Studies ◽  
Propanoic Acid ◽  
Sublethal Concentrations ◽  
Corn Grain ◽  
Corn Grain Yield

Field studies were conducted to measure the response of corn (Zea maysL. var. ‘Pioneer 3377’) to foliar applications of sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one}, fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy] propanoic acid}, and haloxyfop {2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy] propanoic acid} as influenced by corn growth stage and the addition of 7.7, 15,4, 77.7, 140, 280, and 840 g/ai/ha of bentazon [3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide]. Applications of sethoxydim (16.8, 33.6, 67.2, 100, and 134 g ai/ha), fluazifop, or haloxyfop (1.0, 2.0, 4.0, 8.0, 10.0, and 13.4 g ai/ha) to four- to five-leaf corn did not reduce seed weight, but significant reductions resulted when sethoxydim (100 g/ha) or fluazifop (13.4 g/ha) was applied to 70- to 80-cm (six-leaf) corn with or without bentazon. Corn grain yield was significantly reduced by sethoxydim (>67.2 g/ha) treatment at either growth stage of corn. In contrast, corn injury induced by fluazifop (>8.0 g/ha) and haloxyfop (13.4 g/ha) resulted in reductions in yield only when applications were made to 70- to 80-cm corn. Significant reductions in seed germination also resulted from foliar applications of the graminicides, but these reductions were inconsistent across corn growth stage.

Effect of Preplant Tillage, Post-Plant Cultivation, and Herbicides on Weed Density in Corn (Zea mays)

1993 ◽  
Vol 7 (3) ◽  
pp. 728-734 ◽  
Author(s):  
Robert G. Wilson
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Weed Control ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Weed Density ◽  
Proso Millet ◽  
Plant Cultivation ◽  
Herbicide Treatments ◽  
Corn Grain

A four-year experiment was conducted near Scottsbluff, NE to evaluate the effect of different methods of preplant tillage, post-plant cultivation, and herbicides on weed density and grain yield. Ridge-till enhanced the development of kochia and reduced the density of wild proso millet and common lambsquarters. Tandem disking increased longspine sandbur and redroot pigweed density whereas moldboard plowing increased common sunflower density. Cultivation reduced weed density 86% but weeds that remained after cultivation reduced corn grain yield by 40% as compared with a hand-weeded control. Weed control treatments that integrated cultivation and herbicides controlled a broader spectrum of weed species than cultivation or herbicide treatments alone.

Modeling vegetative development of berseem clover (Trifolium alexandrinum L.) as a function of growing degree days using linear regression and neural networks

2004 ◽  
Vol 84 (2) ◽  
pp. 511-517 ◽  
Author(s):  
W. M. Clapham ◽  
J. M. Fedders
Keyword(s):  
Neural Networks ◽  
Linear Regression ◽  
Plant Development ◽  
Predictive Ability ◽  
Growing Degree Days ◽  
Trifolium Alexandrinum ◽  
Neural Models ◽  
Degree Days ◽  
Threshold Temperatures ◽  
Berseem Clover

Accurate models of berseem clover (Trifolium alexandrinum L.) development in relation to growing degree-days (GDD) would be useful to both producers and researchers. Predictive ability of linear regression models of plant development may be limited by choice of threshold temperature and the non-linear nature of plant development. Neural networks provide a robust approach to dealing with non-linearity, and may therefore be useful for modeling plant development. In exp.1, a numerical scale of plant development was created and used to describe growth of four cultivars of berseem clover (Bigbee, Joe Burton, Saidi and Tabor) under controlled environmental conditions (constant temperature of 12, 18 or 24°C per 12-h photoperiod) for up to 18 wk of vegetative growth. Simple linear regression and neural networks were used to model plant development in relation to GDD using a range of threshold temperatures. Predictive ability of the models was compared with the results from a second controlled environment study (exp. 2). The r2 of the linear and neural models produced in exp. 1 were maximized at GDD threshold temperatures of 0 to 2°C. Results from exp. 2 indicated that the predictive ability of neural models matched or exceeded that of the linear models for all threshold temperatures evaluated. Results of the current study suggests that neural network models are relatively insensitive to base temperatures across the range tested and may therefore be preferable when a priori knowledge of temperature thresholds is not available. Key words: Berseem clover, plant development, phenology modeling, growing degree days, base temperature, neural network modeling

scholarly journals DESEMPENHO DA SOJA EM SUCESSÃO AO CONSÓRCIO DE MILHO SEGUNDA SAFRA COM DIFERENTES DENSIDADES DE Crotalaria spectabilis

Nativa ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 649
Author(s):  
Edison Ulisses Ramos Junior ◽  
Eduardo Megier de Ramos ◽  
Luana Manoela Konzen ◽  
Alexandre Ferreira da Silva ◽  
Flávio Dessaune Tardin ◽  
...  
Keyword(s):  
Zea Mays ◽  
Glycine Max ◽  
Grain Yield ◽  
Environmental Preservation ◽  
Input Use ◽  
Grain Productivity ◽  
Glycine Max L ◽  
The City ◽  
Crotalaria Spectabilis ◽  
Corn Grain

A demanda crescente por alimentos, associada à necessidade de preservação ambiental, e a disponibilidade limitada de terras para a expansão da área cultivada, tem demandado desenvolvimento contínuo de tecnologias que resultem no aumento da produtividade de grãos, na racionalização do uso de insumos, dos recursos ambientais e dos meios de produção. O presente trabalho teve como objetivo avaliar o desempenho da soja (Glycine max (L.) Merrill) semeada em sucessão ao consórcio de milho (Zea mays L.) segunda safra com diferentes densidades de Crotalaria spectabilis. O experimento foi semeado em 15 de fevereiro de 2016, em uma área experimental da Embrapa Agrossilvipastoril, na cidade de Sinop/MT. O delineamento utilizado foi de blocos ao acaso, com quatro repetições. Cada parcela apresentava 11 linhas com 0,45 cm de espaçamento entre si e 10 metros de comprimento, sendo considerada, como área útil, as três linhas centrais. Os tratamentos foram constituídos de 4 densidades da C. spectabilis, sendo 10, 20, 30 e 40 kg de sementes por ha, além da testemunha, com milho solteiro. A semeadura da soja foi realizada em outubro de 2016, sob as parcelas colhidas do consórcio de milho com crotalária. Ao final do ciclo, coletou-se 10 plantas da área útil de cada parcela, para que fossem avaliados os componentes de produção e produtividade da cultura. Observou-se que a crotalária não causou redução na produtividade de grãos do milho, porém em apenas um ciclo de consórcio, não permitiu que se obtivessem incrementos na produtividade de grãos da soja.Palavras-chave: diversificação de culturas; consórcio milho-crotalária; produtividade de grãos. PERFORMANCE OF SOYBEAN IN SUCCESSION TO MAIZE SECOND CROP INTERCROPPED WITH DIFFERENT SOWING DENSITY WITH Crotalaria spectabilis ABSTRACT: The growing demand for food, associated with the need for environmental preservation, and the limited availability of land for the expansion of cultivated area, has demanded continuous development of technologies that result in increased grain productivity, rationalization of input use, environment resources and the means of production. The objective of this work was to evaluate the performance of soybean (Glycine max (L.) Merrill) in succession to the intercropped of maize (Zea mays) second crop with different densities of Crotalaria spectabilis. The experiment was sowing on February 15, 2016, in an experimental area of Embrapa Agrossilvopastoral, in the city of Sinop/MT. The experimental design was a randomized complete block, with four replications. Each plot had 11 lines with 0.45 cm of spacing and 10 meters of length, being considered as useful area, the three central plots. The treatments consisted of 4 densities of C. spectabilis, being 10, 20, 30 and 40kg of seeds per hectare, besides the control with the single maize. The sowing of the soybean was carried out in October 2016, under the plots harvested from the maize intercropped with the Crotalaria, where the cultivar M 8210IPRO was used and at the end of the cycle 10 plants of the useful area of each plot were collected, so that Production components. With the results obtained, it was possible to observe that the crotalaria did not cause a reduction in corn grain yield, but in only one consortium cycle, it did not allow the increase of grain yield of the soybean. Therefore, the continuity of the work must be carried out in order to be able to obtain increases in soybean production in succession, and also to evaluate the best C. spectabilis density to be used in intercropping.Keywords: crop diversification; maize-crotalaria intercrop; grain yield.

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