Effects of yellow spot on wheat: comparison of epidemics at different stages of crop 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.

1981 ◽  
Vol 96 (1) ◽  
pp. 167-186 ◽  
Author(s):  
D. W. Lawlor ◽  
W. Day ◽  
A. E. Johnston ◽  
B. J. Legg ◽  
K. J. Parkinson

SUMMARYThe effects of water deficit on growth of spring barley were analysed under five irrigation treatments. One crop was irrigated at weekly intervals from emergence throughout the growing season, and one was not irrigated at all after emergence. Soil water deficits in the other treatments were allowed to develop early, intermediate or late in the crop's development.Weekly irrigation produced a crop with a large leaf area index (maximum value 4) and maintained green leaf and awns throughout the grain-filling period. Early drought decreased leaf area index (maximum value 2) by slowing expansion of main-stem leaves and decreasing the number and growth of tiller leaves. Leaf senescence was also increased with drought. Drought late in the development of ears and leaves and during the grain-filling period caused leaves and awns to senesce so that the total photosynthetic areas decreased faster than with irrigation. Photosynthetic rate per unit leaf area was little affected by drought so total dry-matter production was most affected by differences in leaf area.Early drought gave fewer tillers (550/m2) and fewer grains per ear (18) than did irrigation (760 tillers/m2 and 21 grains per ear). Late irrigation after drought increased the number of grains per ear slightly but not the number of ears/m2. Thus at the start of the grain-filling period crops which had suffered drought early had fewer grains than irrigated (9·5 and 18·8 × 103/m2 respectively) or crops which suffered drought later in development (14 × 103/m2).During the first 2 weeks of filling, grains grew at almost the same rate in all treatments. Current assimilate supply was probably insufficient to provide this growth in crops which had suffered drought, and stem reserves were mobilized, as shown by the decrease in stem mass during the period. Grains filled for 8 days longer with irrigation and were heavier (36–38 mg) than without irrigation (29–30 mg). Drought throughout the grainfilling period after irrigation earlier in the season resulted in the smallest grains (29 mg).Grain yield depended on the number of ears, the number of grains per ear and mass per grain. Early drought decreased tillering and tiller ear production and the number of grains that filled in each ear. Late drought affected grain size via the effects on photosynthetic surface area.Drought decreased the concentrations of phosphorus, potassium and magnesium in the dry matter of crops, and irrigation after drought increased them. Concentration of nitrogen was little affected by treatment. Possible mechanisms by which water deficits and nutrient supply affect crop growth and yield are discussed.


1975 ◽  
Vol 26 (3) ◽  
pp. 497 ◽  
Author(s):  
EAN Greenwood ◽  
P Farrington ◽  
JD Beresford

The time course of development of a lupin crop was studied at Bakers Hill, Western Australia. The aim was to gain insight into the crop factors influencing yield. Weekly measurements were made of numbers and weights of plant parts, and profiles of roots, leaf area and light interception. A profile of carbon dioxide in the crop atmosphere was taken at the time of maximum leaf area, and the net carbon dioxide exchange (NCE) of pods was estimated for three successive weeks. The crop took 10 weeks to attain a leaf area index (LAI) of 1 and a further 9 weeks to reach a maximum LAI of 3.75, at which time only 33% of daylight reached the pods on the main axis. Once the maximum LAI was attained at week 19, leaf fall accelerated and rapid grain filling commenced almost simultaneously on all of the three orders of axes which had formed pods. Measurements of NCE between pods on the main axis and the air suggest that the assimilation of external carbon dioxide by the pods contributed little to grain filling. Grain dry weight was 2100 kg ha-1 of which 30%, 60% and 10% came from the main axis, first and second order apical axes respectively. Only 23% of the flowers set pods and this constitutes an important physiological limitation to grain yield.


2017 ◽  
Vol 14 (2) ◽  
pp. 147-154 ◽  
Author(s):  
MM Kamrozzaman ◽  
MAH Khan ◽  
S Ahmed ◽  
N Sultana

An experiment was conducted at Sadipur charland under Farming System Research and Development Site, Hatgobindapur, Faridpur, during rabi season of 2012-13 and 2013-14 to study the growth and yield performance of cv. BARI Gom-24 as affected by different dates of sowing under Agro-ecological Zone-12 (AEZ-12) of Bangladesh. The experiment was laid out in randomized complete block design with six replications, comprising five different dates of sowing viz. November 5, November 15, November 25, December 5 and December 15. Results reveal that the tallest plant, leaf area index, total dry matter, and crop growth rate were observed in November 25 sown crop and leaf area index, total dry matter and crop growth rate were higher at booting, grain filling, and tillering stages of the crop. Maximum effective tillers hill-1 (3.49), spikes m-2, (311), number of grains spike-1 (42.20) and 1000-grain weight (52.10 g) were produced by November 25 sown crop exhibited the highest grain (4.30 t ha-1) and straw yield (4.94 t ha-1) as well as harvest index (46.88%) of the crop. Lowest performance was observed both in early (November 5) and late sown crop (December 15). The overall results indicated that November 25 sown crop showed better performance in respect of growth and yield of wheat under charland ecosystem of Bangladesh.J. Bangladesh Agril. Univ. 14(2): 147-154, December 2016


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.


1981 ◽  
Vol 11 ◽  
pp. 207-220 ◽  
Author(s):  
Thomas W. Brakke ◽  
Edward T. Kanemasu ◽  
Jean L. Steiner ◽  
Fawwaz T. Ulaby ◽  
Ed Wilson

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.


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