Comparison of Lygus elisus Van Duzee and Lygus hesperus Knight (Hemiptera: Miridae) Feeding Injury to Pre-bloom Cotton

2005 ◽  
Vol 40 (2) ◽  
pp. 143-148 ◽  
Author(s):  
J. Scott Armstrong ◽  
Leonardo D. A. Camelo ◽  
Harlan G. Thorvilson ◽  
Leslie D. Thompson

Feeding injury and abscission of 6th, 9th and 11th node, first-position cotton squares exposed to Lygus hesperus Knight and L. elisus Van Duzee for 24 h were investigated in field and laboratory studies in 2001 and 2002. Square abscission was not significantly different for L. elisus or L. hesperus in six separate field trials over 2 yrs; however, the control was significantly lower in abscission in two of the six trials. Final square abscission averaged across the 2 yrs was 82.5% for the control, 90.0% for L. hesperus, and 86.3% for L. elisus. Square injury, as measured by estimating the surface area affected by Lygus feeding, was significantly higher for L. elisus compared with L. hesperus in three of the six of trials (6th node in 2002, 11th node for 2001 and 2002) indicating that, in some cases, L. elisus damage is higher than L. hesperus. However, when seed-cotton yield was obtained from squares that did not abcise, there was no significant difference for the control or the two Lygus species. This result was similar to other published studies of infesting cotton with L. lineolaris (Palisot de Beauvois) where yield compensation negated any differences in yield when infested cotton was compared to the control. Lygus elisus, a little known and often misidentified plant bug pest of Texas High Plains cotton, should be considered as damaging as L. hesperus.

2016 ◽  
Vol 164 ◽  
pp. 317-330 ◽  
Author(s):  
Pradip Adhikari ◽  
Srinivasulu Ale ◽  
James P. Bordovsky ◽  
Kelly R. Thorp ◽  
Naga R. Modala ◽  
...  

Author(s):  
Bilal Nawaz, Saira Sattar, Tanwir Ahmad Malik

The experiment was laid to analyze genetic features, genotypic and phenotypic correlation coefficients, path analysis with regression analysis among yield contributing traits in a selected F3 populations of upland cotton including parents. In this research experiment ANOVA showed significant difference among all individual plants in F3 populations. Monopodia per plant and bolls per plant possessed maximum value of PCV% and GCV%. Maximum broad sense heritability (≥ 90) was found in all recorded traits except seeds per boll, fiber length and lint percentage. Correlation studies revealed that Seed cotton yield positively correlated with all yield contributing traits i.e. plant height, monopodial branches per plant, Number of bolls per plant, boll weight, lint weight, seed index, lint index, seeds per boll, fiber fineness, fiber strength and fiber uniformity at both genotypic and phenotypic level whereas it depicted negative relationship with staple length. Path coefficient analysis showed that maximum direct positive effect was found of lint weight (2.6005) on seed cotton yield followed fiber fineness (1.2628), seed index (1.1449) and bolls per plant (1.0027). Regression study exhibited that maximum value of R2 for lint weight (0.9509) and boll weight (0.3735) depicted that 95.09% and 37.35% variation in the seed cotton yield, due to its relationship with lint weight and boll weight. It is concluded that there is a great genetic potential in F3 populations for mostly yield contributing traits for further enhancing yield. So those traits should be used as selection criteria during breeding for yield.


2006 ◽  
Vol 27 ◽  
pp. 165-168 ◽  
Author(s):  
KB Basnet

A field experiment was conducted to study the impact of topping at different growth stages (3-4, 6-7, 9-10 and 12-13 sympodial branches) on productivity of two (Tamcot SP-37 and H-777) cotton varieties under rainfed condition at the Kumbher Farm (Bardiya district) of Cotton Development Board in 1995. The experiment was laid out in a Randomized Complete Block Design with four replications. The interaction effect between variety and stages of topping showed that significantly higher yield (1.23 t/ha) was produced by topping plants at the stage of 12-13 sympodial banches of the variety Tamcot SP-37 as compared to all other treatments. At all stages of topping the yield produced by Tamcot SP-37 was significantly higher than H-777. The average seed cotton yield (1.03 t/ha) of Tamcot SP-37 was significantly higher than that of H- 777 (0.71 t/ha) and the difference in yield was 45.0%. The seed-cotton yield increased from 0.75 to 1.00 t/ ha with the postponed of topping from 3-4 to 12-13 sympodial branches, but significant difference was recorded between late (12-13 sympodial branches) and early (3-4 and 6-7 sympodial branches) stages of topping. Thus, for rainfed condition of Bardiya Tamcot SP-37 was a suitable variety with 12-13 sympodial branches as an appropriate stage of topping for sustainable production of cotton. Key words: Variety, topping, sympodial branches. J. Inst. Agric. Anim. Sci. 27:165-168 (2006)


2021 ◽  
Vol 30 (1) ◽  
pp. 1
Author(s):  
Eshetu Agegnehu Abebe ◽  
Mulatu BAYEH ◽  
TEBKEW TEBKEW ◽  
Wakgari MULATU

Field trials were conducted to determine the reaction of cotton varieties to cotton flea beetle infestation. The experiment was laid out in a Randomized Complete Block Design with three replications comprising twelve cotton varieties. The results showed significant (P < 0.01) differences among varieties in the populations of adult beetle they hosted and the injury they sustained at 15, 22, 29, 36 and 43 days after sowing (DAS). At 15 DAS, the highest numbers of adult beetle per plant (6.3), percent leaf area damaged (60.32 %) and number of shot-holes per attacked leaf (53.4) was recorded in Cucurova variety, whereas the lowest in Bulk-202 (2.05 beetles, 26.15% leaf area damaged and 23.16 shot-holes). The rate of incidence and damages decreased with the increase of the age of the cotton plants. Significant differences were also observed among cotton varieties in some agronomic characteristics i.e. in number of plants counted per plot at harvest and seed cotton yield in terms of kilogram per hectare. Seed cotton yield obtained from all cotton varieties varied from 602.36 to 1644.71 kilogram per hectare and the highest was obtained from Bulk-202, while the lowest from Local variety. Based on these findings, Cucurova, Local, Ionia and Acala SJ-2 varieties showed highly susceptible response, while Candia, Sille-91 and Deltapine-90 were moderately susceptible to cotton flea beetle. However, Bulk-202, Delcero and Claudia were relatively more tolerant varieties followed by CCRI-12 and Cuokra. These results will be important for the most proper management of cotton flea beetle.


2021 ◽  
Vol 12 (6) ◽  
pp. 766-773
Author(s):  
B. Ram Prasad ◽  
◽  
D. Ashwini ◽  

The field trials were conducted for two consecutive years during kharif, 2018 and 2019 seasons in the Regional Agricultural Research Station, Warangal, Telangana, India. The susceptible hybrid RCH-2 was grown during both the years of study. Among the treatments, significant (25.4%) reduction of aphids was recorded in neem oil, clothianidin and flonicamid sequential spray. The sequence chlorpyriphos, flonicamid and clothianidin achieved superior efficacy against jassids with 32.3% reduction over control during the two seasons. The highest reduction (25.2%) of thrips was observed in neem oil, clothianidin, flonicamid sequential spray. The incidence of whitefly was low during the experimental period, however, the highest white fly reduction (15.0%) was observed in chlorpyriphos, flonicamid, clothianidin spray. The lowest number of PBW larvae per 10 green bolls was observed in profenophos, spinetoram, chlorpyriphos+cypermethrin sequential spray that reduces up to 61.9% incidence. The lowest number of (38.5) damaged locules per 100 fully opened bolls were observed in profenophos, spinetoram, chlorpyriphos+cypermethrin sequential spray. But, the highest seed cotton yield (1414 kg ha-1) as well as benefit cost ratio (1.02) was recorded in chlorpyriphos, flonicamid, emamectin benzoate, clothianidin, indoxacarb+acetamiprid sequential spray. The study further revealed that, initial control of sucking pests menace especially jassid was crucial in deciding the cotton yield as compared to later stage pink bollworm menace. During both the years, it was noticed that during peak incidence of jassid, the treated plot with flonicamid against jassid in first instance had given highest seed cotton yield.


2017 ◽  
Vol 32 (1) ◽  
pp. 60-65 ◽  
Author(s):  
Matheus G. Palhano ◽  
Jason K. Norsworthy ◽  
Tom Barber

AbstractWith the recent confirmation of protoporphyrinogen oxidase (PPO)-resistant Palmer amaranth in the US South, concern is increasing about the sustainability of weed management in cotton production systems. Cover crops can help to alleviate this problem, as they can suppress weed emergence via allelochemicals and/or a physical residue barrier. Field experiments were conducted in 2014 and 2015 at the Arkansas Agricultural Research and Extension Center to evaluate various cover crops for suppressing weed emergence and protecting cotton yield. In both years, cereal rye and wheat had the highest biomass production, whereas the amount of biomass present in spring did not differ among the remaining cover crops. All cover crops initially diminished Palmer amaranth emergence. However, cereal rye provided the greatest suppression, with 83% less emergence than in no cover crop plots. Physical suppression of Palmer amaranth and other weeds with cereal residues is probably the greatest contributor to reducing weed emergence. Seed cotton yield in the legume and rapeseed cover crop plots were similar when compared with the no cover crop treatment. The seed cotton yield collected from cereal cover crop plots was lower than from other treatments due to decreased cotton stand.


2021 ◽  
Vol 9 (3) ◽  
pp. 105-109
Author(s):  
V. J. Zapadiya ◽  

A field experiment was conducted to evaluate the 45 F1 hybrids derived from 10×10 half diallel fashion along with ten parents and one standard check GN.Cot.Hy-14 were sown in randomized block design with three replications during kharif -2017 at Cotton Research Station, Junagadh Agricultural University, Junagadh. The genetic components of variation were determined for 12 characters viz., days to 50% flowering, days to 50% boll opening, plant height (cm), number of monopodia per plant, number of sympodia per plant, number of bolls per plant, boll weight (g), seed cotton yield per plant (g), ginning percentage (%), seed index (g), lint index (g) and oil percentage (%).The estimate of the components of variation revealed significant results for both additive (D) as well as dominance effects (H1 and H2) for all the characters except plant height non-significant H2 component, but in majority of traits (except plant height, lint index) H1 was higher than D indicating dominance components were important in the inheritance of seed cotton yield and its components. The average degree of dominance (H1/D)1/2 was found to be more than unity for all the traits (except plant height, number of monopodia per plant and lint index indicating partial dominance) indicating over dominance. Asymmetrical distribution of positive and negative genes in the parents was observed for all the traits. High estimates of heritability in narrow sense was observed for days to 50% flowering, days to 50 % boll bursting, number of monopodia per plant, ginning percentage (%), lint index (g) and oil content (%) suggesting that selection based on these attribute would lead to rapid improvement. Due to preponderance of non-additive gene effects of seed cotton yield per plant and most of its component traits, heterosis breeding would also be practically feasible in cotton.


Author(s):  
Bilal Nawaz ◽  
Saira Sattar ◽  
Bilal Bashir ◽  
Muhammad Jamshaid ◽  
Khadim Hussain ◽  
...  

Background: Cotton (Gossypium hirsutum L.) is grown in more than sixty countries worldwide. It is an important fiber crop in the world. It plays a vital role in our national economy being the source of earning of foreign exchange, therefore, it is considered to be the backbone of the economy of Pakistan. In Pakistan, millions of families are associated with cotton and textile industry for their livelihood.  Results: In this experiment F2 population of the cross L. A. Frego Bract x CIM-600 and their parents was sown in randomized complete block design with three replications during normal growing season of the year 2014 to sort out best performing genotypes for yield related traits. Analysis of variance (ANOVA) revealed that parental and their F2 population showed significant differences for all the observed agronomic traits (plant height, number of monopodia branches, number of sympodial branches, number of bolls per plant, boll weight, ginning out turn, bract type, boll shape, beak size, seed cotton yield, staple length, fiber strength and fiber fineness). Estimation of correlation revealed that seed cotton yield was found positively correlated sympodial branches, fiber fineness and boll weight while ginning out turn, bract type, beak size, staple length and fiber strength were negatively associated with seed cotton yield. Epistasis was not found to be involved in any of the traits. Conclusion:  The correlation and genetics study of various yield related traits provides us useful information for effective selection and sustainable breeding programs. Estimation of broad sense heritability ( ) in F2 populations for different traits vary as following order; ginning out turn>plant height>seed cotton yield>sympodia branches>fiber length>fiber strength>bolls per plant>monopodia branches>boll weight>fiber fineness with heritability 0.90, 0.79, 0.78, 0.75, 0.73, 0.71 0.67, 0.64, 0.63 and 0.50 respectively. Results suggested form heritability and correlation that these traits can be improved either through appropriate selection method or hybrid breeding programme.


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