A FIELD COMPARISON STUDY OF AMMONIUM PHOSPHATES AND SUPERPHOSPHATE–UREA OR AMMONIUM NITRATE ON CORN (ZEA MAYS L.) GROWTH IN FIVE QUEBEC SOILS

1978 ◽  
Vol 58 (2) ◽  
pp. 221-228 ◽  
Author(s):  
J. R. OKALEBO ◽  
A. F. MacKENZIE

Effects of mono-, diammonium, and superphosphate with added urea or ammonium nitrate on corn (Zea mays L.) growth were studied in the field in 1971 and 1972. At the rate of 100 kg P2O5/ha, none of the carriers affected emergence of seedlings in five Quebec soils. Leaf P content at silking time was of little benefit in predicting P status of the plants, or in differentiating among the carriers. Phosphorous applications gave significant corn yield increases, with carriers performing alike when averaged over all sites. However, some yield differences among carriers occurred on some soil types and seasons. These carrier differences were not consistent and remain to be clarified. The ammonium phosphates compared with the check generally hastened maturity but reduced potassium levels in leaf tissue of corn.

Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 226-234 ◽  
Author(s):  
Frank L. Young ◽  
Donald L. Wyse ◽  
Robert J. Jones

Field studies were conducted to evaluate the effect of quackgrass [Agropyron repens(L.) Beauv. ♯ AGRRE] density and soil moisture on corn (Zea maysL.) growth and yield. Quackgrass densities ranging from 65 to 390 shoots/m2reduced corn yield 12 to 16%. A quackgrass density of 745 shoots/m2reduced corn yields an average of 37% and significantly reduced corn height, ear length, ear-fill length, kernels/row, rows/ear, and seed weight. In the soil moisture study, quackgrass was shorter than corn throughout the growing season, and analyses of corn leaf tissue indicated that quackgrass did not interfere with the nutrient status of the corn. In 1979, soil moisture was not limiting and corn yields were similar in all treatments regardless of irrigation or the presence of quackgrass. In 1980, soil moisture was limited and irrigation increased the yield of quackgrass-free corn. Irrigation also increased the yield of quackgrass-infested corn to a level similar to irrigated corn. When light and nutrients are not limiting factors, an adequate supply of soil moisture can eliminate the effects of quackgrass interference on the growth, development, and yield of corn.


2009 ◽  
Vol 89 (5) ◽  
pp. 969-975
Author(s):  
Nader Soltani ◽  
Richard J Vyn ◽  
Laura L Van Eerd ◽  
Christy Shropshire ◽  
Peter H Sikkema

A study was conducted over a 3-yr period (2003, 2004, and 2005) to evaluate the effect of reduced herbicide rates - 20, 40, 60, 80, and 100% of the manufacturer’s recommended rate (MRR) - on weed biomass reduction, environmental impact (EI), yield, and profitability of corn (Zea mays L.) in Ontario. The herbicide rate required to provide 95% biomass reduction of velvetleaf (Abutilon theophrasti Medic.), redroot pigweed (Amaranthus retroflexus L.), common ragweed (Ambrosia artemisiifolia L.), common lambsquarters (Chenopodium album L.), and annual grasses was 92, 30, 41, 28, and 83% of the MRR for isoxaflutole plus atrazine, >200, 119, 23, 23, and 117% of the MRR for dimethenamid plus dicamba/atrazine, 141, 72, 46, 45, and >200% of the MRR for glufosinate plus atrazine, and 81, 29, 18, 24, and 88% of the MRR for nicosulfuron/rimsulfuron plus dicamba/diflufenzopyr, respectively. The herbicide rate required to provide 95% of weed-free corn yield was 61, 22, 130, and 11% of the MRR for isoxaflutole plus atrazine, dimethenamid plus dicamba/atrazine, glufosinate plus atrazine, and nicosulfuron/rimsulfuron plus dicamba/diflufenzopyr, respectively. Nicosulfuron/rimsulfuron plus dicamba/diflufenzopyr had the lowest EI. The results of profitability analysis suggested that the MRR rates do not tend to maximize profit margins. In most cases, there were no significant differences in profit margins for treatments with 40, 60, 80, and 100% of the MRR. Key words: Atrazine, dicamba, diflufenzopyr, dimethenamid, glufosinate, nicosulfuron, rimsulfuron, Zea mays L.


1994 ◽  
Vol 74 (2) ◽  
pp. 375-381 ◽  
Author(s):  
M. E. Reidy ◽  
C. J. Swanton

Laboratory and field experiments were established to determine the optimum dose and timing of postemergence applications of DPX-79406 for quackgrass control. Four node quackgrass rhizome fragments from each biotype were grown under controlled conditions. At the three-to-four-leaf stage, quackgrass plants were sprayed with DPX-79406 and evaluated for control. A significant response of quackgrass biotypes to DPX-79406 was evident only at lower doses. In the field, quackgrass was effectively controlled by all doses of DPX-79406. Significant growth-stage effects were observed for quackgrass shoot and rhizome dry weights in the year of application and in the year following application. There was a significant interaction between year and growth stage. In 1990, quackgrass biomass was greater when DPX-79406 was applied at the two-to-three-leaf stage of quackgrass than at the four-to-five-leaf stage. In 1991, however, the opposite occurred. Within a growth stage, the 6.25 g ha−1 dose was as effective for controlling quackgrass as 18.5 g ha−1, in both years of the study. In 1991, significant decreases in corn yield were observed for DPX-79406 doses of > 12.5 g ha−1 applied at the four-to-five-leaf stage of quackgrass. For all the variables studied, DPX-79406 doses of 6.25–12.5 g ha−1 resulted in consistent control of quackgrass. Key words: DPX-79406, nicosulfuron, rimsulfuron, quackgrass, Elytrigia repens, corn, Zea mays


Mycorrhiza ◽  
2013 ◽  
Vol 23 (6) ◽  
pp. 497-505 ◽  
Author(s):  
Qun Chu ◽  
Xinxin Wang ◽  
Yang Yang ◽  
Fanjun Chen ◽  
Fusuo Zhang ◽  
...  

2018 ◽  
Vol 9 (1) ◽  
pp. 25-32
Author(s):  
Sergio Iglesias ◽  
Julio Alegre ◽  
Carlos Salas ◽  
José Egüez
Keyword(s):  
Zea Mays ◽  

2013 ◽  
Vol 1 ◽  
pp. 23-27
Author(s):  
MN Paudel

Improved open pollinated maize (Zea mays L.) varieties exhibit different emergence reaction as a result of either inferior seed quality or affected by agronomic practices of maize planting. To address problem of low emergence percentage of maize varieties, an experiment was laid out in factorial design under two types of soil (red clay and sandy loam), three level of depth of sowing (7, 14 and 21 cm) for Rampur Composite, Manakamana-1 and Arun-2 maize varieties in Rampur, Chitwan for representing main season (May-August). The result of the experiment revealed that emergence count was highly significant for soil types and depth of sowing among the maize varieties tested. Manakamana-1 expressed lowest percentage (20 and 29%) followed by Arun-2 (22 and 33%) and Rampur Composite (24 and 39%) of emergence under red clay and sandy loam soils, respectively. Likewise, emergence count at 10 days after sowing was recorded highly significant for depth of showing indicating that irrespective of varieties higher the planting depth lower the emergence count.. There was a positive relation between depth of planting and length of mesocotyle resulting loss of seed vigor which furnished low emergence of the maize varieties. It is suggested that depth of sowing affect emergence percentage which consequently have effects on plant population maintenance. Hence, it was concluded that sowing below 7cm deep is not feasible for the tested varieties under red clay and sandy loam soils. DOI: http://dx.doi.org/10.3126/ajn.v1i0.7539 Agronomy Journal of Nepal (Agron JN) Vol. 1: 2010 pp.23-27


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