MEASUREMENT OF EVAPORATION FROM SOIL BENEATH CROP CANOPIES

1983 ◽  
Vol 63 (1) ◽  
pp. 137-141 ◽  
Author(s):  
G. K. WALKER
Keyword(s):  
Zea Mays ◽  
Key Words ◽  
Leaf Area ◽  
Energy Supply ◽  
Zea Mays L ◽  
Growing Season ◽  
Soil Core ◽  
Crop Cover ◽  
Intact Soil Core ◽  
Intact Soil

Evaporation rates beneath maize canopies were measured using an intact soil core technique. Early in the growing season evaporation rates were periodically high (4.0 mm∙day−1) following rain, but declined rapidly. At full crop cover, when energy supply normally limits evaporation, significant differences in evaporation were detected between canopies with leaf area indices of 3.0 and 4.0. Key words: Evaporation measurement, energy supply, Zea mays L., leaf area, soil evaporimeter, lysimeter

Effects of Routine Handling on Maize Growth

1977 ◽  
Vol 4 (6) ◽  
pp. 857 ◽  
Author(s):  
MF Beardsell
Keyword(s):  
Zea Mays ◽  
Leaf Area ◽  
Zea Mays L ◽  
Dry Weight ◽  
Controlled Environment ◽  
Short Term ◽  
Total Leaf Area ◽  
Reduced Height ◽  
Plant Characteristics ◽  
Routine Handling

Maize (Zea mays L. cv. XL45) plants were grown from seed in controlled-environment rooms. Twice-daily weighings of the plants and containers for 7 days reduced height, and removing plants from the rooms for two 20-min periods daily for 7 days gave significant reductions in stem and leaf dry weights and total leaf area. Transpiration rates were not affected by either of these treatments. Short-term removal from the rooms (up to 10 min daily) produced no significant reductions in plant characteristics. Measuring leaf lengths daily for 10 days resulted in significant reductions in stem dry weight and plant height. It is suggested that control plants should always be subjected to the same degree of handling as treated plants.

Postemergence control of quackgrass [Elytrigia repens (L) Nevski] with DPX-79406 in corn (Zea mays L)

1994 ◽  
Vol 74 (2) ◽  
pp. 375-381 ◽  
Author(s):  
M. E. Reidy ◽  
C. J. Swanton
Keyword(s):  
Zea Mays ◽  
Key Words ◽  
Significant Interaction ◽  
Growth Stage ◽  
Field Experiments ◽  
Zea Mays L ◽  
Optimum Dose ◽  
Corn Yield ◽  
Leaf Stage ◽  
Elytrigia Repens

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

RESPOSTAS MORFOAGRONÔMICAS DE MILHO SUBMETIDO A DESFOLHA ARTIFICIAL

2017 ◽  
Vol 16 (3) ◽  
pp. 460
Author(s):  
EMERSON TROGELLO ◽  
LUAN FERREIRA BORGES ◽  
FÁBIO ARAÚJO DE OLIVEIRA ◽  
QUÉZIA SANCHES MUTAGUTI ◽  
INGRID GOMIDES BARROS ◽  
...  
Keyword(s):  
Zea Mays ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Analysis Of Variance ◽  
Zea Mays L ◽  
Grain Weight ◽  
Area Index ◽  
Plant Removal ◽  
And Control ◽  
Different Levels

RESUMO - O objetivo deste estudo foi avaliar as características morfoagronômicas do híbrido simples de milho em função da aplicação de diferentes intensidades de desfolha artificial, realizadas no estádio R1 de desenvolvimento. O experimento foi conduzido na área experimental do Instituto Federal Goiano,em Morrinhos-GO, na safra 2015/2016. Foi aplicado o delineamento de blocos completamente casualizados, com oito tratamentos e quatro repetições, sendo eles: remoção de uma folha acima e uma abaixo da espiga; remoção de duas folhas acima e abaixo da espiga; remoção de três folhas acima e abaixo da espiga; remoção de todas as folhas da planta; remoção de todas as folhas acima da espiga; remoção de todas as folhas abaixo da espiga; remoção da folha da espiga; e testemunha sem desfolha. Os caracteres avaliados foram: estande de plantas, número de plantas acamadas, prolificidade, densidade de colmo, comprimento e diâmetro de espiga, comprimento de grão, massa de mil grãos, massa de grãos espiga-1 e produtividade. Os dados foram submetidos à análise de variância pelo teste F a 5% de probabilidade, observando que todas as variáveis avaliadas foram influenciadas quanto aos efeitos dos tratamentos empregados. O enchimento dos grãos esteve intimamente relacionado à fotossíntese. Sem as folhas, esta fase ficou plenamente comprometida.Palavras-chave: Zea mays, fotoassimilados, translocação, índice de área foliar, rendimento. MORPHOAGRONOMIC CHARACTERISTICS OF MAIZE AS A FUNCTION OF DIFFERENT LEVELS OF ARTIFICIAL DEFOLIATION  ABSTRACT - The objective of this study was to evaluate of morphoagronomic characteristics of simple hybrids of maize, depending on the application of different intensities of artificial defoliation, carried out in R1, when the style-stigma were fertilized. The experiment was conducted in an experimental area of the Instituto Federal Goiano, Campus Morrinhos, State of Goiás, Brazil, during the agricultural year 2015/2016. We applied the design of completely randomized block with eight treatments, in four replications: removal of a leaf above and one below the ear; removal of two leaves above and below the ear; removal of three leaves above and below the ear; removal of all leaves of the plant; removal of all leaves above the ear; removal of all leaves below the ear; removal of the leaf of the ear; and control without defoliation. The traits evaluated were stand of plants, number of plant lodging, prolificacy, density, length and diameter of the cob, length of a grain, weight of a thousand grains, grain mass cob-1 and productivity. The data obtained were subjected to analysis of variance by F test at 5% probability, noting that all variables were influenced as to the effects of the treatments used. The filling of grains is closely related to photosynthesis. Without the leaves, this phase was fully damaged.Keywords: Zea mays L., photoassimilates, translocation, leaf area index, yield.

Intact soil-core microcosms compared with multi-site field releases for pre-release testing of microbes in diverse soils and climates

2001 ◽  
Vol 47 (3) ◽  
pp. 237-252 ◽  
Author(s):  
Joel V Gagliardi ◽  
J Scott Angle ◽  
James J Germida ◽  
R Campbell Wyndham ◽  
Christopher P Chanway ◽  
...  
Keyword(s):  
Low Cost ◽  
Soil Microbiology ◽  
Soil Core ◽  
Wheat Roots ◽  
Fallow Soil ◽  
Site Field ◽  
Intact Soil Core ◽  
Regression Slopes ◽  
Field Plots ◽  
Intact Soil

Intact soil-core microcosms were used to compare persistence of Pseudomonas chlororaphis 3732RN-L11 in fallow soil and on wheat roots with field releases at diverse sites. Parallel field and microcosm releases at four sites in 1996 were repeated with addition of one site in 1997. Microcosms were obtained fresh and maintained at 60% soil water holding capacity in a growth chamber at 70% relative humidity, a 12-hour photoperiod, and constant temperature. Persistence of 3732RN-L11 was measured at each site in field plots and microcosms at 7–21 day intervals, and in duplicate microcosms sampled at an independent laboratory. Linear regression slopes of field plot and microcosm persistence were compared for each site, and between identical microcosms sampled at different sites, using log10transformed plate counts. Microcosm persistence closely matched field plots for wheat roots, but persistence in fallow soil differed significantly in several instances where persistence in field plots was lower than in microcosms. Analysis of weather variations at each site indicated that rainfall events of 30–40 mm caused decreased persistence in fallow soil. Cooler temperatures enhanced persistence in field plots at later time points. Inter-laboratory comparison of regression slopes showed good agreement for data generated at different sites, though in two instances, longer sampling periods at one site caused significant differences between the sites. Soil characteristics were compared and it was found that fertility, namely the carbon to nitrogen ratio, and the presence of expanding clays, were related to persistence. These microcosm protocols produced reliable data at low cost, and were useable for pre-release risk analyses for microorganisms.Key words: microcosm, soil, microbiology, risk assessment, 3732RN-L11.

Adjacent II segregation products in B–A translocations of maize

Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 595-602 ◽  
Author(s):  
B. Kindiger ◽  
C. Curtis ◽  
J. B. Beckett
Keyword(s):  
Zea Mays ◽  
Key Words ◽  
Zea Mays L ◽  
Genetic Data ◽  
B Chromosomes ◽  
Cytological Data ◽  
Opposite Pole

In maize (Zea mays L.), meiotic events in B–A translocations that cause the A chromosome to move to one pole and the A–B and B–A chromosomes to move to the opposite pole result in the production of balanced, functional microspores and megaspores. Meiotic events that allow other combinations of chromosomes to proceed to the two poles (A A–B and A B–A) lead to the production of both duplicate (A A–B) and deficient (B–A) spores. Microspores and often megaspores that are deficient for a segment of the A chromosome are expected to abort. Duplication-bearing gametes usually function through the egg but are less able to compete with the normal gametes in the pollen. Cytological data, and genetic data from pollen, kernel, and seedling counts, were used to identify the production of A A–B gametes by B–A translocation heterozygotes and hyperploids. Adjacent II segregation of the A and A–B chromosomes of B–A heterozygotes and hyperploids has been detected in stocks of several different B–A translocations. Some B–A translocations exhibited a frequency of adjacent II segregation as high as 23%.Key words: Zea mays, adjacent segregation, B chromosomes, translocation.

scholarly journals Application of the Richards function to the description of leaf area growth in maize (Zea mays L.)

2014 ◽  
Vol 63 (1) ◽  
pp. 5-7 ◽  
Author(s):  
Andrzej Grzegorczyk
Keyword(s):  
Zea Mays ◽  
Leaf Area ◽  
Nonlinear Regression ◽  
Growth Process ◽  
Zea Mays L ◽  
Logistic Function ◽  
Area Growth ◽  
Richards Function ◽  
Constant Coefficients ◽  
Leaf Area Growth

The leaf area growth in maize was approximated basing on the Richards function in the form of: y=A[l+b exp(-kt)]<sup>1/(1-m)</sup> . The constant coefficients of the Richards function were found by means of the Marquardt's method. The initial values of parameters were given basing on results of the preliminary approximation of the growth process by means of logistic function y = A[l+b exp(-kt)]<sup>-1</sup>. The procedure of nonlinear regression was found to be useful (curvilinear determination coefficient R<sup>2</sup> = 0.995). The Richards curve precisely describes the course of changes of the leaf area in maize since sprouting to a tassel flowering phase.

scholarly journals Aplikasi Biochar dan Kompos Terhadap Peningkatan Hasil Tanaman Jagung (Zea Mays L.)

GEMA AGRO ◽  
2018 ◽  
Vol 23 (1) ◽  
pp. 24 ◽  
Author(s):  
Petrus Kaliang Lelu ◽  
Yohanes Parlindungan Situmeang ◽  
Made Suarta
Keyword(s):  
Zea Mays ◽  
Leaf Area ◽  
Harvest Index ◽  
Zea Mays L ◽  
Block Design ◽  
Growth And Yield ◽  
Randomized Block Design ◽  
Compost Treatment

This study aims to determine the effect of biochar dosage and compost fertilizer and its interaction on the growth and yield of corn crops. This experiment used a randomized block design (RBD) with a factorial pattern consisting of 2 factors. The first factor was the dose of biochar (B) consisting of 4 levels, namely: 0 ton ha-1 (B0), 5 ton ha-1 (B1), 10 ton ha-1 (B2), 15 ton ha-1 (B3). The second factor is the dosage of compost fertilizer (K) consisting of 2 levels: 0 ton ha-1 (K0), and 20 ton ha-1 (K1). The results showed that the interaction between the treatment of biochar dose and compost fertilizer had no significant effect on all observed variables. Biochar and compost treatment have significant effect to most observed variables, except on leaf area and harvest index have no significant effect. Treatment of biochar with a dose of 10 ton ha-1 gave the highest dry kiln seedlings weight of 7.83 tons increased by 35.60% compared to the lowest dose without biochar of 5.77 tons. Treatment of compost doses of 20 ton ha-1 gave the highest dry seed oven per hectare weight of 7.42 tons increased by 16.60% when compared with the lowest yield on treatment without compost dose as much as 6.37 tons.

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