Microwave radar response to canopy moisture, leaf-area index, and dry weight of wheat, corn, and sorghum

1981 ◽  
Vol 11 ◽  
pp. 207-220 ◽  
Author(s):  
Thomas W. Brakke ◽  
Edward T. Kanemasu ◽  
Jean L. Steiner ◽  
Fawwaz T. Ulaby ◽  
Ed Wilson
1958 ◽  
Vol 51 (3) ◽  
pp. 347-352 ◽  
Author(s):  
R. H. M. Langer

1. Swards of S. 48 timothy and S. 215 meadow fescue growing alone or together were sampled at intervals of 3 weeks throughout the season. The number and weight of leaves, stems and ears were determined, and leaf area was estimated.2. Despite high rainfall, the total number of tillers in both species declined from the beginning of the experiment until early July, but increased again from then onwards until the original complement had been approximately restored. The number of leaves failed to show a corresponding increase in the autumn because each tiller carried fewer leaves than earlier in the year.3. In the spring total dry weight increased more rapidly in meadow fescue than in timothy which in turn out-yielded meadow fescue later in the season. Both species attained their greatest dry weight soon after ear emergence, a period which was marked by considerable crop growth and relative growth rates.4. Leaf area index reached a maximum before total dry weight had increased to its highest level, but then declined in both species. Meadow fescue differed from timothy by producing a second crop of foliage after the summer with a leaf area index of about 7. This second rise appeared to be due mainly to increased leaf size in contrast to timothy whose leaves became progressively smaller towards the end of the season.5. The differences in growth between the species discussed with reference to their dates of ear emergence which in this experiment differed by about 6 weeks.


2021 ◽  
Vol 30 (2) ◽  
pp. 159-168
Author(s):  
Shabnur Chowdhury ◽  
MK Rahman

Effects of organic manures on growth and yield of lettuce (Lactuca sativa L.) and nutrient accumulation in its leaves was examined. The experiment was conducted in a completely randomized design (CRD) replicated thrice with ten treatments involving nine organic manures and a control treatment. Growth parameters viz. plant height, leaf number, leaf length, leaf area, leaf area index and fresh and dry weight of leaf, stem and root were assessed. The highest height (23.69 cm), longest leaf (32.18cm), leaf area (5883.43cm2), leaf area index (6.434), fresh weight (85.41 g) and dry weight (42.73 g) were found in Payel organic manure. The maximum leaf number (27) was recorded in Approshika organic manure. The maximum content of nitrogen (6.12%), phosphorus (1.83%), potassium (4.11%) and Sulphur (1.69%) were observed in Payel organic manure. The best growth performance and nutrient accumulation was observed in Payel organic manure. Dhaka Univ. J. Biol. Sci. 30(2): 159-168, 2021 (July)


Weed Science ◽  
1984 ◽  
Vol 32 (3) ◽  
pp. 364-370 ◽  
Author(s):  
Ronald C. Cordes ◽  
Thomas T. Bauman

Detrimental effects on growth and yield of soybeans [Glycine max(L.) Merr. ‘Amsoy 77′] from density and duration of competition by ivyleaf morningglory [Ipomea hederacea(L.) Jacq. ♯3IPOHE] was evaluated in 1981 and 1982 near West Lafayette, IN. Ivyleaf morningglory was planted at densities of 1 plant per 90, 60, 30, and 15 cm of row in 1981 and 1 plant per 60, 30, 15, and 7.5 cm of row in 1982. Each density of ivyleaf morningglory competed for 22 to 46 days after emergence and the full season in 1981, and for 29 to 60 days after emergence and the full season in 1982. The best indicators of competition effects were leaf area index, plant dry weight, and yield of soybeans. Ivyleaf morningglory was more competitive during the reproductive stage of soybean growth. Photosynthetic irradiance and soil moisture measurements indicated that ivyleaf morningglory does not effectively compete for light or soil moisture. All densities of ivyleaf morningglory could compete with soybeans for 46 and 60 days after emergence in 1981 and 1982, respectively, without reducing soybean yield. Full-season competition from densities of 1 ivyleaf morningglory plant per 15 cm of row significantly reduced soybean yield by 36% in 1981 and 13% in 1982. The magnitude of soybean growth and yield reduction caused by a given density of ivyleaf morningglory was greater when warm, early season temperatures favored rapid weed development.


1983 ◽  
Vol 34 (1) ◽  
pp. 39 ◽  
Author(s):  
RG Rees ◽  
GJ Platz

Effects of yellow spot (Pyrenophoua tuitici-repentis) on two cultivars (Banks and Olympic) of wheat have been examined in a field experiment where distinctly different epidemics were produced in various treatments. Severe yellow spot before jointing reduced production of both tillers and dry matter, and substantially lowered leaf area index at jointing. Severe disease after jointing reduced leaf area index at flowering, dry weight of plants at maturity and harvest index. Crop phenology was also modified, with flowering being delayed by early disease and crop maturity hastened by late disease. Where yellow spot was severe throughout, the grain-filling period was greatly reduced. Grain yield of Banks was reduced by c. 13 % by early disease, c. 35 % by late disease, and c. 48 % by disease throughout the crop season. Most of the loss was in reduced grain size. Although yield loss in Olympic was less than in Banks, the resistance of Olympic was shown to be inadequate.


2021 ◽  
Vol 4 (1) ◽  
pp. 6-13
Author(s):  
Baha Eldin. M. Idris ◽  
Wael. A. Marajan ◽  
Abubaker Haroun Mohamed Adam

Despite the existing several Sugar manufacturing companies in Sudan, there is an acute shortage in sugar supply, therefore the government imports Sugar to bridge the gap. One of the strategies to be followed is the introduction of Sugar beet (Beta vulgaris) crop, mainly for sugar production. This crop has several advantages over Sugarcane such as short duration, less water requirement, in addition to other uses like animal feed. Therefore it became necessary to have good understanding of agricultural operations, cultural practices and adaptation. However, the main objective of this study was to assess the effect of Nitrogen fertilizer and plant spacing on vegetative growth of Sugar beet. This study was conducted at the farm of the College of Agriculture, University of Bahri, Alkadro, Khartoum State-Sudan; during the season 2016/2017. The experiment was arranged in Split plot in Randomized Complete Block Design with six treatments and four replications. Two plant spacing (15 and 20 cm.) were used as main plot, referred as (S1, S2) along with three levels of Nitrogen fertilizer (40, 80 and 120 kg/ha.), as subplot; referred as (N1, N2 and N3) and the control (0). Data regarding leaf number, leaf area index (LAI), leaf dry weight (g) (LDW), root diameter (mm.) and root fresh weight were recorded and statistically analyzed. The results showed S2 (20 cm) increased all the studied plant characters, namely the leaf number (29.139), leaf area index by (7.54), leaf dry weight (g) to (89.870), root diameter (mm) (94,992), root fresh weight (g) (695.80) compared to S1(1015 cm). On the other hand; the application of N3 (120 kg/ha.) increased the lead number (30.956), leaf Area Index (8.841), Leaf dry weight (102.47), root diameter (97.955) and root fresh weight (851.77) compared to S2 and S1 as presented in (table 4, table 5 and table 6).


HortScience ◽  
2006 ◽  
Vol 41 (2) ◽  
pp. 361-366 ◽  
Author(s):  
Laurie Hodges ◽  
Entin Daningsih ◽  
James R. Brandle

Field experiments were conducted over 4 years to evaluate the effects of antitranspirant (Folicote, Aquatrol Inc., Paulsboro, N.J.) and polyacrylamide gel (SuperSorb, Aquatrol Inc., Paulsboro, N.J.) on early growth of transplanted muskmelon grown either protected by tree windbreaks or exposed to seasonal winds. A randomized complete block design (RCBD) with split plot arrangement was used with wind protection (sheltered and exposed) areas as the main treatment and use of an antitranspirant spray or gel dip as subtreatments. Based on destructive harvests in the field, treatments and subtreatments did not affect dry weight or leaf area index in the first 2 years. Specific contrasts, however, showed that gel application significantly increased fresh weight, dry weight, and leaf area index over that of the untreated transplants whereas the spray application tended to reduce these factors during the first 3 weeks after transplanting. Significant differences between gel and spray subtreatments disappeared by 5 weeks after transplanting. Shelterbelts ameliorated crop microclimate thereby enhancing plant growth. Significantly, wind velocity at canopy height was reduced 40% on average and soil temperatures were about 4% warmer in the sheltered plots compared to the exposed plots during the first 5 weeks post-transplant. Muskmelon plants in the sheltered areas grew significantly faster than the plants in the exposed areas in 2 of the 3 years reported, with the 3-year average fresh weight increased by 168% due to wind protection. Overall transplanting success and early growth were enhanced the most by wind protection, followed by the polyacrylamide gel root dip, and least by the antitranspirant foliar spray. We conclude that microclimate modification by wind speed reduction can increase early muskmelon plant growth more consistently than the use of polyacrylamide gel as a root dip at transplanting or the use of an antitranspirant spray. A polyacrylamide gel root dip generally will provide more benefit during early muskmelon growth than the use of an antitranspirant spray.


2021 ◽  
Vol 4 (1) ◽  
pp. 14-22
Author(s):  
Wael. A. Marajan ◽  
Baha Eldin. M. Idris ◽  
Abubaker Haroun Mohamed Adam

Sugar beet is one of the sugar crops which widely grown in different regions of the world due to its advantages over Sugarcane. Several studies were conducted in Sudan to assess its adaptation and economic value. However, the aim of this experiment was to study the effect of application of compost and different levels of phosphorus fertilizer and their combination on Sugar beet (Beta vulgaris) growth attributes, yield and yield components. The study was conducted during the winter season 2018 –2019 at the farm of the College of Agriculture, University of Bahri, Alkadaro-Khartoum State, Sudan. The experiment was arranged in Randomized Complete Block Design (RCBD) with three replications and six treatments, namely the Compost (5t./ha.), Phosphorous (P2O5) (88kg./ha.), P2O5 (176 kg./ha.), Compost (5t./ha.)+P2O5 (88kg./ha.), Compost (5t./ha.)+ P2O5 (176Kg./ha.) and the Control (C) respectively. All cultural practices were carried out timely according to the recommendations of the Agricultural Research Centre in Sudan. Then the data pertaining the following agronomic traits were recorded, the leaf number; leaf dry weight (g), leaf area index (LAI) (cm), root diameter (RD) (cm) and root fresh weight (RFW) (g). The results of statistical analysis revealed the application of compost in combination with phosphorus displayed significant increase at 5% level for the leaf number (22.75), leaf area index (5.23), leaf dry weight(36.78), root diameter(69.67) and root fresh weight (422.68), followed by the application of compost alone compared to the control and other treatments. The study concludes that the combination of compost and mineral fertilizer (P2O5) proved to increase all Sugar beet growth and yield parameters.


Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 609-615 ◽  
Author(s):  
Michael S. Defelice ◽  
William W. Witt ◽  
Michael Barrett

Monoculture velvetleaf had greater dry weight, growth rate, leaf area index, and height than velvetleaf grown in association with conventional or no-tillage corn. Velvetleaf planted 5 weeks after corn had significantly lower dry weight, leaf area index, and height compared to velvedeaf planted at the same time as corn. The combination of interference from corn and delayed planting caused a significant reduction in velvetleaf population at the end of the season, delayed the date of 50% velvetleaf flowering, increased the number of days required for 50% flowering, and reduced the number of capsules per plant. Velvetleaf dry weight/hectare and leaf area index increased as plant population increased. Velvetleaf dry weight, leaf area, capsules, and seed/plant decreased as plant density increased. There were no differences in vegetative or reproductive growth between velvetleaf grown in conventional or no-tillage areas.


1991 ◽  
Vol 18 (1) ◽  
pp. 30-37 ◽  
Author(s):  
David P. Davis ◽  
Timothy P. Mack

Abstract Growth characteristics of three commonly planted peanut cultivars were measured during the 1988 and 1989 growing seasons at the Wiregrass Substation in Headland, Ala., to develop equations for predicting leaf area index (LAI) from other growth varibales. These equations were needed to allow rapid estimation of leaf area loss from foliar-feeding insects or foliar-fungal pathogens. Conventionally planted and tilled fields of Florunner, Sunrunner and Southern Runner peanut (Arachis hypogaea L.) were sampled for plant vegetative stage, reproductive stage, height, number of leaves, leaf area, leaf dry weight, number of pods, pod dry weight, stem dry weight, and stand density. Most growth characteristics increased linearly (p<0.05) with time in both years. LAI was significantly correlated (P<0.05) with most growth variables for each cultivar. Linear regression was used to create equations for prediction of LAI from leaf dry weight (range of R2 = 0.93 to 0.97) and number of leaves (range of R2 = 0.74 to 0.95) for each cultivar, and all cultivars combined. Equations were also developed to predict LAI from plant height (range of R2 = 0.85 to 0.96) and plant vegetative stage (range of R2 = 0.81 to 0.83). These equations should be useful to those who wish to estimate LAI from other growth variables.


1971 ◽  
Vol 22 (1) ◽  
pp. 1 ◽  
Author(s):  
DW Puckridge

Photosynthesis of two wheat cultivars grown in the field was examined during three seasons by use of a portable field assimilation chamber. There were large differences in dry weight, leaf area, and carbon dioxide uptake between seasons. Variations in carbon dioxide uptake by the community were related mainly to changes in leaf area index (LAI). There were changes in carbon dioxide uptake per unit LAI with time, and between the two cultivars in the first season, but the effects of these changes were small compared with the effects of LAI. Differences in grain yield were correlated with LAI and carbon dioxide uptake in the period after anthesis.


Sign in / Sign up

Export Citation Format

Share Document