The distribution of Empoasca lybica (de Berg.) (Hemiptera, Cicadellidae) on cotton in the Sudan

1966 ◽  
Vol 56 (4) ◽  
pp. 635-647 ◽  
Author(s):  
D. E. Evans
Keyword(s):  
Correlation Coefficients ◽  
Side Branch ◽  
Main Stem ◽  
Similar Distribution ◽  
Leaf Vein ◽  
Cotton Plants ◽  
Empoasca Lybica ◽  
Number Of Leaves ◽  
Upper Third ◽  
Prominent Peak

The distribution on cotton plants of the eggs, nymphs and to a lesser extent the adults of Empoasca lybica (de Berg.) was studied on the varieties Bar XL1 and BAJ 7/57 in the Sudan during 1961–64. Counts of jassid nymphs in the process of hatching from eggs buried in the leaf veins showed that hatchlings were most numerous on the third to fifth expanded leaves from the main-stem apex and that most eggs had been laid either close to the point of insertion of the petiole into the leaf lamina or about half-way along the length of the veins on the underside of the leaves. The greatest number of hatchlings was found in the central leaf vein. It was concluded that eggs are most frequently laid in this position on newly expanded leaves at the apices of the main stems or side branches.The distribution of the early instars on the main-stem leaves was peaked, with maximum numbers occuring on or about the fifth expanded leaf from the apex; a similar distribution with a less prominent peak nearer to the apex leaf was found on side branches. The later instars, being more mobile, had a more even distribution. In the over-all distribution of nymphs on a typical cotton plant, a combination of the patterns found on main-stem and side-branch leaves, the greatest numbers of jassids occurred in the upper half or upper third of the plant. Co-variance analyses showed that the relation between numbers of jassids per zone and number of leaves per zone was not close and that the manner in which the plants were divided into zones for analysis of the relation greatly affected the correlation coefficients obtained.Regular counts of nymphs and adults on the upper surface of leaves throughout a period of two complete days showed that both nymphs and adults moved to the upper surface of leaves each day between 1400 and 1800 hr. local time and returned to the under surface at about 0300–0400 hr. Neither the environmental factor that stimulated this movement nor the way in which it benefited the insect was clear.

scholarly journals Tree resin as a cultivation strategy under water deficit

2021 ◽  
Vol 51 ◽  
Author(s):  
Amanda Maria Leal Pimenta ◽  
Silvânio Rodrigues dos Santos ◽  
Nelson de Abreu Delvaux Júnior ◽  
Marcos Koiti Kondo ◽  
Ignacio Aspiazú
Keyword(s):  
Soil Water ◽  
Plant Height ◽  
Water Deficit ◽  
Water Use ◽  
Water Levels ◽  
Cultivated Plants ◽  
Water Retention Capacity ◽  
Wild Radish ◽  
Cotton Plants ◽  
Number Of Leaves

ABSTRACT The search for alternatives that enable the improvement of the soil water retention capacity should focus on a better water use by cultivated plants. This study aimed to evaluate the effect of natural tree resin rates and irrigation levels on the cotton (intermediate cycle) and wild radish (short cycle) crops. Two experiments were conducted in a completely randomized design, in a 5 × 5 factorial arrangement, with three replications and five tree resin rates (0, 0.67, 1.33, 2.00 and 2.67 g plant-1), five soil water tensions (15, 30, 45, 60 and 75 kPa) for cotton plants and five irrigation water levels (40, 60, 80, 100 and 120 % of the ETc) for wild radish plants. The plant height, stem diameter and number of leaves were evaluated at 93 days after sowing (DAS) for the cotton plants; while the plant height, root diameter and number of leaves were evaluated at 30 DAS for the wild radish plants, as well as quantified the shoot and root dry weights of both plant species. The application of tree resin reduces the susceptibility of the crop to water deficit, being 2.7 g plant-1 the highest recommended rate to improve the plant development. The use of tree resin increases the water-use efficiency in cotton and wild radish crops in up to 0.68 g L-1 and 69.6 g L-1, respectively.

scholarly journals Allometric relationship and leaf area modeling estimation on chia by non-destructive method

2021 ◽  
Vol 25 (5) ◽  
pp. 305-311
Author(s):  
Patrícia C. H. Goergen ◽  
Isabel Lago ◽  
Natalia T. Schwab ◽  
Alexandre F. Alves ◽  
Charles P. de O. Freitas ◽  
...  
Keyword(s):  
Leaf Area ◽  
Block Design ◽  
Main Stem ◽  
Allometric Relationship ◽  
Linear Quadratic ◽  
Predictive Capacity ◽  
Randomized Block Design ◽  
Number Of Leaves ◽  
Salvia Hispanica L ◽  
Non Destructive

ABSTRACT This study aimed to obtain equations to estimate leaf area from linear leaf dimensions and establish the allometric relationship between leaf area and the number of leaves on the main stem of chia (Salvia hispanica L.) at different sowing times. The experiment was conducted in the agricultural year 2016/2017 on five sowing times in Santa Maria, RS, Brazil, in a randomized block design with four repetitions. In each plot, ten random plants were marked weekly during the vegetative phase to determine the number of leaves (NL) in the main stem, and three of these for the determination of leaf area (LA). A total of 70 leaves of different sizes were used to calibrate the model. Another 106 leaves were used to test the predictive capacity of the equations by various statistical indices. The length (L) and the largest leaf width (W) were measured. Leaf collection was carried out during the cycle, in all sowing times to represent all leaf sizes. The linear, quadratic, exponential, and potential models were adjusted. The non-destructive method, through the linear dimensions of the leaf, is appropriate for estimating the leaf area in chia. The general equation LA = 0.642 (L x W) can be used to estimate the leaf area of the chia plants without loss of precision. The potential model is appropriate to characterize the allometric relationship between leaf area evolution and the number of leaves accumulated in the main stem of chia at different sowing times.

scholarly journals Studiul unor trăsături asociate cu productivitatea la hibrizi experimentali de floarea-soarelui

2021 ◽  
Author(s):  
Clapco Steliana Clapco ◽  
◽  
Aliona Cucereavii ◽  
Ion Gisca ◽  
Maria Duca ◽  
...  
Keyword(s):  
Plant Height ◽  
Seed Yield ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Physiological Parameters ◽  
Leaf Number ◽  
Head Diameter ◽  
Number Of Leaves ◽  
Positive Correlations

The relationships between seed yield and some morpho-physiological parameters, such as plant height, head diameter, leaf number, number and weight of total and full seeds per head and 1000 seeds in 32 local hybrids has been studied. The analyses of Pearson correlation coefficients showed significant, but low, positive correlations between yield and number of full seeds per calatidium, weight of total seeds per calatidium, weight of 1000 seeds and hectolitre weight. There were also observed positive correla-tions between plant height and number of leaves.

scholarly journals Relation between leaf number and final leaf area of rye.

1964 ◽  
Vol 12 (1) ◽  
pp. 30-39
Author(s):  
R.F. Hoogland
Keyword(s):  
Leaf Area ◽  
Surface Area ◽  
Correlation Coefficients ◽  
Leaf Number ◽  
Total Leaf Area ◽  
Average Surface ◽  
Flag Leaves ◽  
Average Surface Area ◽  
Number Of Leaves ◽  
The Relationship

In rye cv. Petkus and Zelder the date of emergence of the flag leaves was almost the same for all plants irrespective of the number of leaves (10-13) produced. Correlation coefficients for the relationship between total leaf area and number of leaves were + 0.45 and + 0.44 and for that between number of spikelets per ear and number of leaves + 0.61 and + 0.69 for the 2 varieties, respectively. Average surface area per leaf increased with increasing number of leaves.-R.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Use of different criteria for estimating precocity of heterosis maize hybrids in forest-steppe conditions

2021 ◽  
Vol 1 (99) ◽  
pp. 162-168
Author(s):  
S. P. Kotsyuba ◽  
◽  
Zh N. Novak ◽  
O. P. Naklioka
Keyword(s):  
Moisture Transfer ◽  
Growing Season ◽  
Main Stem ◽  
Forest Steppe ◽  
Early Maturity ◽  
Important Indicator ◽  
Maize Hybrids ◽  
Grain Moisture ◽  
Early Maturing ◽  
Number Of Leaves

In the article it is shown the results of the study of heterosis hybrids of corn on the signs of early ripening, such as: the growing season, the number of leaves on the main stem, the moisture yield of grain during harvest. To distribute our corn material by precocity, a number of studies were conducted, namely: estimating the length of the growing season "shoots – full ripeness", which was determined in days, and a very important indicator today is the moisture content of grain when harvested in percentage, it allowed to distribute heterosis hybrids into two groups: early-maturing (106–114) and middle-early – 114–123 days. Over the years of testing, the weather conditions varied considerably, which made it possible to evaluate in detail the material under study. In 2020, the growing season was within 107.8 days, which is almost three days less than in 2021. At the same time, the longer vegetation period was in 2021. Therefore, the aim of our study was to analyze the rate of moisture yield of corn grain of the studied hybrids of the two maturity groups. The conducted researches allowed to trace the dynamics of grain moisture yield of early-maturing maize hybrids and one hybrid of the middle-ripening group of maturity, to determine the variability of hybrid grain moisture in different periods of grain maturation. The year 2021 was more favorable for growing corn, the plants formed a large vegetative mass, but the grain had a high humidity during the harvest period. This is due to a significant amount of precipitation (69.9 mm) in August 2021. Hybrids that had high harvest humidity were characterized by a long growing season, such as № 47 × № 33. Therefore, our selected hybrids can be successfully used in planning a strategy for early maturity. In establishing the patterns of moisture transfer of grain when it reaches, in particular, the influence of the conditions of the year, in our study group were identified two hybrids consistently better in terms of grain moisture. Preference should be given to hybrids № 31 × № 37 and № 83 × № 125, which combine indicators of early maturity: the shortest growing season, the number of leaves on the main stem and the rate of moisture.

Concept for Monitoring the Growth and Development of Cotton Plants Using Main-Stem Node Counts

jpa ◽  
1992 ◽  
Vol 5 (4) ◽  
pp. 532-538 ◽  
Author(s):  
F. M. Bourland ◽  
D. M. Oosterhuis ◽  
N. P. Tugwell
Keyword(s):  
Growth And Development ◽  
Main Stem ◽  
Stem Node ◽  
Cotton Plants

scholarly journals Relationship between panicle differentiation and main stem leaf number in rice genotypes and red rice biotypes

2009 ◽  
Vol 66 (2) ◽  
pp. 195-203 ◽  
Author(s):  
Nereu Augusto Streck ◽  
Isabel Lago ◽  
Leosane Cristina Bosco ◽  
Gizelli Moiano de Paula ◽  
Felipe Brendler Oliveira ◽  
...  
Keyword(s):  
Oryza Sativa L ◽  
Flag Leaf ◽  
Daily Basis ◽  
Main Stem ◽  
Leaf Number ◽  
Red Rice ◽  
Cultivated Rice ◽  
Sowing Dates ◽  
Number Of Leaves ◽  
Rice Genotypes

Panicle differentiation (DP) is a key developmental stage in rice (Oryza sativa L.) because at this stage plant switches from vegetative to reproductive development and source-sink relation changes to allocate part of the photoassimilates for growing spikelets and kernels. The objective of this study was to determine the main stem Haun Stage (HS) and the number of leaves that still have to emerge until flag leaf at PD in several cultivated rice genotypes and red rice biotypes in different sowing dates. A two-year field experiment was conducted in Santa Maria, Rio Grande do Sul State, Brazil, during the 2005-2006 and 2006-2007 growing seasons, and three sowing dates each year. Nine cultivated rice genotypes and two red rice biotypes were used. PD was identified as the R1 stage of the COUNCE scale, by sampling four plants from each genotype on a daily basis. When 50% of the sampled plants were at R1, the main stem HS was measured in 20 plants per genotype. The main stem final leaf number (FLN) was measured in these 20 plants when the collar of the flag leaf was visible. HS at PD is related to FLN in many cultivated rice genotypes and red rice biotypes, and that at PD, the number of leaves still to emerge until flag leaf is not constant for all the rice genotypes. These findings are not in agreement with reports in the literature.

Effects of harvesting programme and sowing date on leaf growth in forage barley in Cyprus

1988 ◽  
Vol 110 (2) ◽  
pp. 353-366
Author(s):  
D. Wilman ◽  
D. N. Droushiotis
Keyword(s):  
Leaf Blade ◽  
Field Experiments ◽  
Leaf Growth ◽  
Main Stem ◽  
Available Nitrogen ◽  
Leaf Production ◽  
Primary Tiller ◽  
Sowing Dates ◽  
Number Of Leaves ◽  
Applied Nitrogen

SummaryAll combinations of four harvesting treatments and two sowing dates were compared in each of 2 years in field experiments near Nicosia. In one of the years, two levels of applied nitrogen were compared. The harvesting treatments were: (1) a milk-stage cut, (2) a boot-stage cut and a regrowth cut, (3) a grazing-stage cut and a regrowth cut, and (4) three grazing-stage cuts and a regrowth cut. The sowing dates were (1) normal (12 November) and (2) early (15 October), with sufficient irrigation to ensure establishment.Applied nitrogen had virtually no effect on leaf growth, evidently because of high reserves of available nitrogen in the soil. Early sowing increased the rates of leaf emergence, extension and expansion up to the time of the first ‘grazing’ cut (when the first node was showing) and reduced the number of leaves which died in that period. Where growth was uninterrupted to the milk stage, early sowing did not affect the number of leaves produced by a main stem or primary tiller, but increased the longevity of the later leaves. Where there were three ‘grazing’ cuts, early sowing allowed time for the production of more and larger leaf blades, with longer sheaths, between the third 'grazing’ cut and the final harvest.The ‘grazing’ cuts considerably reduced the rates of extension and expansion and the final size of the leaves which emerged soon after a cut. There was good recovery subsequently, however, in rates of extension and expansion and final leaf size, particularly with October sowing.During almost all the period of leaf production on a main stem or primary tiller, several leaves (up to six) were expanding at the same time. The stage, during the period between emergence and death, at which a leaf blade reached its full length was typically half-way between emergence and death. Where growth was uninterrupted, area per leaf blade was positively correlated with both the number of days between the emergence of successive leaves and the number of days between emergence and death.

scholarly journals Interaksi Antara Daya Tumbuh Benih dengan Pertumbuhan Tanaman Semangka (Citrullus lanatus (Thunb.) Matsum dan Nakai) Pada Pemupukan Organik dan Anorganik

2017 ◽  
Vol 15 (3) ◽  
Author(s):  
Nazirwan Nazirwan ◽  
Anung Wahyudi
Keyword(s):  
Block Design ◽  
Organic Fertilizer ◽  
Fertilizer Application ◽  
Inorganic Fertilizer ◽  
Main Stem ◽  
Organic Fertilizers ◽  
Stem Length ◽  
Inorganic Fertilizers ◽  
Number Of Leaves ◽  
Organic And Inorganic Fertilizers

The aim of this research to observe and analyze the ability to grow of watermelon seeds in organic and inorganic fertilizers. Observing and analyzing the interaction between the ability to grow of watermelon seeds with plant growth in organic and inorganic fertilizers. Recommend a combination of organic and inorganic fertilizers that provide maximum results. This research was conducted in field of State Polytechnic of Lampung on June until Agustus 2014. This research uses a randomized complete block design (RCBD) with treatment in the form of thiamethoxam, inorganic fertilizers and organic fertilizers, namely: P1 = 0% organic fertilizer + 100% inorganic fertilizer; P2 = 25% organic fertilizer + 75% inorganic fertilizer; P3 = 50% organic fertilizer + 50% inorganic fertilizer; P4 = 75% organic fertilizer + 25% inorganic fertilizer; P5 = 100% organic fertilizer + 0% inorganic fertilizer. Doses of inorganic fertilizers: Urea = 300 kg.ha-1, SP-36 = 200 kg.ha-1, KCl = 100 kg.ha-1. Organic fertilizer: manure (cow manure) = 20 tons.ha-1. Data were analyzed with analysis of variance and if there is a real different treatments followed by LSD test at 5% level. The results showed that organic and inorganic fertilizer application significantly affected fruit length and fruit weight, but did not significantly affect the ability to grow, main stem length and number of leaves. The length of the longest fruit found in the treatment of inorganic fertilizer application of 75% + 25% organic fertilizer (P2). While the weight of the heaviest fruit found in the treatment of organic fertilizer application of 100% (P5). The highest ability to grow plant found in the treatment of 100% inorganic fertilizer application (P1), treatment of inorganic fertilizer application 50% + 50% organic fertilizers (P3), P2 and P5 treatment. The longest length of main stem found in P5 treatment, while the highest number of leaves found in P2 treatment. Keywords: fertilization, organic, inorganic, watermelon

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