EFFECTIVE FLOWERING TIME VARIATIONS IN UPLAND COTTON (GOSSYPIUM HIRSUTUM) AT DIFFERENT PLANTING DATES AND STAND DENSITIES IN BENIN

2007 ◽  
Vol 43 (2) ◽  
pp. 173-182 ◽  
Author(s):  
EMMANUEL SEKLOKA ◽  
BERNARD HAU ◽  
ERIC GOZÉ ◽  
SYLVIE LEWICKI ◽  
GRÉGOIRE THOMAS ◽  
...  
Keyword(s):  
Gossypium Hirsutum ◽  
Flowering Time ◽  
Growth Cycle ◽  
Planting Dates ◽  
Flower Opening ◽  
Late Planting ◽  
Breeding Programmes ◽  
Cycle Lengths ◽  
Time Variations ◽  
The Difference

Effective flowering time in Gossypium hirsutum cotton plants was studied with the aim of enhancing decision making on the best varieties to plant according to the planting date under rainfed cropping conditions. Trials were conducted at two sites in a cotton-growing area of Benin in 2002 and 2003. A split-split plot design with three replicates was used to compare 10 cotton varieties, with different growth cycle lengths and morphology, at three stand densities (42 000, 125 000, 167 000 plants ha−1) and two planting dates (standard planting in June and late planting). The flowering period was characterized by the mean first flower opening date (FF), which is an indicator of flowering earliness, and by the opening date of the last flower giving rise to a first-position boll on fruiting branches (LFP1). Effective flowering time (EFT) was calculated as the difference between LFP1 and FF. EFTs differed markedly in the 10 cotton varieties tested and this parameter could not be predicted on the basis of flowering earliness. Late planting and high planting rates delayed first-flower opening, accelerated last-boll development and reduced the effective flowering time. This latter factor should be taken into account in cotton breeding programmes so that varieties adapted to local rainfall constraints can be recommended to growers while also enhancing crop management sequences.

BREEDING NEW COTTON VARIETIES TO FIT THE DIVERSITY OF CROPPING CONDITIONS IN AFRICA: EFFECT OF PLANT ARCHITECTURE, EARLINESS AND EFFECTIVE FLOWERING TIME ON LATE-PLANTED COTTON PRODUCTIVITY

2008 ◽  
Vol 44 (2) ◽  
pp. 197-207 ◽  
Author(s):  
EMMANUEL SEKLOKA ◽  
JACQUES LANÇON ◽  
ERIC GOZE ◽  
BERNARD HAU ◽  
SYLVIE LEWICKI-DHAINAUT ◽  
...  
Keyword(s):  
Flowering Time ◽  
Vegetative Growth ◽  
Central Africa ◽  
Stand Density ◽  
Extended Period ◽  
Breeding Strategy ◽  
Planting Dates ◽  
Flower Opening ◽  
Fruiting Branch ◽  
Node Ratio

SUMMARYIn most cotton-growing regions of West and Central Africa where rainfed conditions prevail, cropping conditions are highly diversified since the crop is planted over an extended period. We studied production and development patterns in 10 cotton (Gossypium hirsutum) varieties to determine the most efficient strategies that could be transformed into breeding traits. Four trials were carried out between 2002 and 2003 in two cotton-growing areas in Benin to compare the 10 varieties at three stand densities and two planting dates. The parameters monitored were the mean first flower opening date (FF), effective flowering time (EFT), plant height at harvest (HH), height to node ratio (HNR), length of fruiting branch (LFB), number of vegetative branches (NVB) and average boll retention at the first position of the fruiting branches (RP1). We identified two ideotypes that yielded better than the others: (i) Mar 88-214 performed well under late planting–high stand density conditions and was characterized by low vegetative growth and early flowering onset, a short flowering period and low RP1; (ii) H 279-1 performed especially well under early planting–low stand density conditions and was characterized by high vegetative growth, late flowering, long EFT and high RP1. We propose a breeding strategy for both ideotypes based on seven indicators with high heritability (FF, HH, HNR, and LFB) or medium heritability (NVB, EFT, and RP1).

scholarly journals Impact of Row Spacing and Planting Date on the Canopy Environment, Abundance of Lesser Cornstalk Borer and Other Arthropods, and Incidence of Aflatoxigenic Fungi in Peanuts

1997 ◽  
Vol 24 (1) ◽  
pp. 52-59
Author(s):  
S. D. Stewart ◽  
K. L. Boweri ◽  
T. P. Mack ◽  
J. H. Edwards
Keyword(s):  
Climatic Conditions ◽  
Planting Date ◽  
Row Spacing ◽  
Planting Dates ◽  
Canopy Development ◽  
Late Planting ◽  
Elasmopalpus Lignosellus ◽  
Soil Temperatures ◽  
Lepidoptera Pyralidae ◽  
Wide Row Spacing

Abstract Three row spacings and two planting dates for peanuts, Arachis hypogaea L., were examined in 1993 and 1994 to determine the influence of the canopy environment on lesser cornstalk borer, Elasmopalpus lignosellus (Zeller) (Lepidoptera: Pyralidae), other arthropods, and alflatoxigenic fungi. Climatically, 1993 and 1994 were disparate years. Decreasing row spacing increased relative leaf area and light interception by the canopy but, compared to difference between planting dates or years, had a relatively small impact on soil temperatures and relative humidity within the canopy. Late planting produced smaller plants, retarded canopy development, and reduced yield in both years, but especially in 1993 when it was hot and dry. The wide row spacing did not yield as well as twin and normal row spacings in either year. Lesser cornstalk borer damage and aflatoxin concentration were higher in the late planting than in the early planting of 1993, but were unaffected by row spacing. Fewer predatory arthropods were caught as row spacing decreased in both beat and pitfall samples, but planting date had variable effects. Prevailing climatic conditions and planting date appeared to be more important in influencing the canopy environment and pest densities than was row spacing.

Growth dynamics of determinate soybean in narrow and wide rows at late planting dates

1990 ◽  
Vol 25 (3-4) ◽  
pp. 203-213 ◽  
Author(s):  
J.E. Board ◽  
B.G. Harville ◽  
A.M. Saxton
Keyword(s):  
Growth Dynamics ◽  
Planting Dates ◽  
Late Planting

Scandinavian mutation research during the past 90 years - a historical review.

2021 ◽  
pp. 10-23
Author(s):  
Udda Lundqvist
Keyword(s):  
Phenotypic Diversity ◽  
Historical Review ◽  
Chemical Mutagenesis ◽  
Induced Mutations ◽  
Spike Density ◽  
Early Maturity ◽  
Breeding Programmes ◽  
The Difference ◽  
Effects Of Radiation ◽  
Wax Coating

Abstract In 1928, the Swedish geneticists Herman Nilsson-Ehle and Åke Gustafsson started to act on their own ideas with the first experiments with induced mutations using diploid barley. They started with X-rays and UV irradiation. Very soon the first chlorophyll mutations were obtained and followed by the first 'vital' mutations Erectoides (ert) (Franckowiak and Lundqvist, 2001). Several other valuable mutations were identified as early maturity, high yielding, lodging resistant and characters with altered plant architecture. The experiments expanded to include other different types of irradiation, followed by chemical mutagenesis starting with mustard gas and concluding with sodium azide. The research brought a wealth of observations of general biological importance, such as the physiological effects of radiation as well as the difference in the mutation spectrum with respect to mutagens. This research was non-commercial, even if some mutants have become of important agronomic value. It peaked in activity during the 1950s to 1980s and, throughout, barley was the main experimental crop. About 12,000 different morphological and physiological mutants with a very broad phenotypic diversity were brought together and are incorporated in the Nordic Genetic Resource Centre (NordGen), Sweden. Several important mutant groups have been analysed in more detail genetically, with regard to mutagen specificity and gene cloning. These are: (i) early maturity mutants (Praematurum); (ii) six-rowed and intermedium-spike mutants; (iii) mutants affecting surface wax coating (Eceriferum); and (iv) mutants affecting rachis spike density (Erectoides). Some of these groups are presented in more detail in this review. Once work with induction of mutations began, it was evident that mutations should regularly be included in breeding programmes of crop plants. In Sweden, direct X-ray induced macro-mutants have been successfully released as cultivars, some of them having been used in combination breeding. Their importance for breeding is discussed in more detail.

scholarly journals Integrated Management of Haricot Bean Foliage Beetle in Northeastern Ethiopia

2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Setu Bazie ◽  
Yohannes Ebabuye ◽  
Sang Woo Kim ◽  
Youn Su Lee
Keyword(s):  
Cost Benefit Analysis ◽  
Integrated Management ◽  
Maximum Yield ◽  
Cost Benefit ◽  
Planting Dates ◽  
Late Planting ◽  
Seed Dressing ◽  
Net Profit ◽  
Beetle Damage ◽  
The Cost

A field experiment was conducted to determine the integrated effect of planting dates, insecticides, and their interaction on the reduction of yield and yield related components of haricot bean caused by haricot bean foliage beetle damage at Sirinka Agriculture Research Center, Ethiopia. Planting dates were normal planting (NP) and late planting (10 days after normal planting) (LP), while insecticides comprised Apron star seed dressing (A) and without insecticide (WI). The combined analysis revealed that late planting combined with Apron star seed dressing (LPA) resulted in the highest yield (1223.7 Kg/ha). On the other hand, normal planting date without insecticide application (NPWI) gave the lowest yield (209.6 kg/ha) and the maximum yield loss (209.6%). The cost-benefit analysis showed that use of LPA gave by far better high net profit over control. Thus, LPA are recommended for haricot bean foliage beetle management in northeastern Ethiopia.

THE EFFECT OF ADRENALECTOMY AND ADRENOCORTICAL HORMONES ON THE HAIR GROWTH CYCLE IN THE RABBIT AND RAT

1958 ◽  
Vol 17 (2) ◽  
pp. 167-NP ◽  
Author(s):  
H. J. WHITELEY
Keyword(s):  
Body Weight ◽  
Mitotic Activity ◽  
Hair Growth ◽  
Inhibitory Action ◽  
Growth Cycle ◽  
Bilateral Adrenalectomy ◽  
Hair Regrowth ◽  
Cycle Growth ◽  
The Difference

SUMMARY The effect of cortisone and adrenalectomy on the hair regrowth cycle of the rat and rabbit was investigated. It was found that bilateral adrenalectomy had no effect on the rate of regrowth of hair or on the quality of the coat in the rabbit, but there was decreased mitotic activity of the follicles on the 2nd and 7th day of the regrowth cycle and increased mitotic activity of the epidermis on the 7th day of this cycle. In the rat bilateral adrenalectomy, apart from causing a generalized wave of hair growth, which was not observed in the rabbit, had no effect on the hair regrowth cycle. The local application of hydrocortisone had a slight inhibitory action in the early stages of the cycle, but i.m. injection of cortisone produced profound inhibition. In the rabbit doses of 12·5 mg/kg body weight caused suppression of the usual regrowth cycle, but in some animals the outercoat hairs were unaffected. There was depression of the mitotic activity of the epidermis on the 7th and 10th days of the cycle. If cortisone was given during different stages of the regrowth cycle growth of undercoat hair was much more inhibited than that of the outercoat hair. Similar results were observed in the rat. These results are discussed and it is postulated that the difference in response between the two types of hair might be related to differences in blood supply of the outercoat and undercoat hairs.

The effect of sublethal heating on Staphylococcus aureus at different physiological ages

1974 ◽  
Vol 20 (5) ◽  
pp. 765-768 ◽  
Author(s):  
Andre Hurst ◽  
Ashton Hughes ◽  
David L. Collins-Thompson
Keyword(s):  
Staphylococcus Aureus ◽  
Stationary Phase ◽  
Heat Resistance ◽  
Growth Cycle ◽  
High Salt ◽  
Early Stationary Phase ◽  
Heat Injury ◽  
The Difference

Sublethal heat injury was measured by the difference in the numbers of colonies developing on trypticase soy agar and trypticase soy agar containing 7.5% NaCl. This difference was largest with late logarithmic and early stationary phase cells because, at this stage, cells had a greatly increased heat resistance. In contrast, the ability to form colonies on high salt agar after sublethal heating varied little during the growth cycle.

Planting date and suboptimal seedbed temperature effects on dry bean establishment, phenology and yield

2004 ◽  
Vol 84 (1) ◽  
pp. 31-36 ◽  
Author(s):  
P. Balasubramanian ◽  
A. Vandenberg ◽  
P. Hucl
Keyword(s):  
Seed Yield ◽  
Planting Date ◽  
Planting Dates ◽  
Dry Bean ◽  
Yield And Quality ◽  
Seeding Date ◽  
Early Fall ◽  
Plant Stand ◽  
The Difference ◽  
Low Temperature Emergence

Seedbed temperatures below 15°C are detrimental to dry bean germination and emergence. This field study was conducted to determine the effects of suboptimal seedbed temperatures on dry bean emergence, and the cumulative effects of suboptimal seedbed temperatures during emergence on crop phenology and yield. Selected dry bean cultivars were planted in mid- and late May when seedbed temperatures were below and above the suboptimal temperature (15°C), respectively, at Saskatoon, SK. Emergence, cumulative thermal units to anthesis and maturity, seed yield, yield components and percent frost-damaged seeds were evaluated in 1999 and 2000. The final seedling count at 30 d after planting was 81% for the mid-May planting and 94% for the late May planting. However, the difference in plant stand was not statistically significant. Year-to-year differences in weather influenced the response of dry bean to planting date for maturity and seed yield. The mid-May planting produced the highest seed yield in 1999, when the two indeterminate cultivars in the late May planting failed to mature prior to the mid September frost. The mid-September frost also resulted in a high percent frost-damaged seeds for the late May planting. In 2000, when the first fall frost was in late September, maturity and seed yield of dry bean cultivars were equivalent for planting dates. The mid-May planted dry bean cultivars will result in higher seed yield and quality compared to the conventional late May planting in years with an early fall frost. Key words: Dry bean, seeding date, low temperature, emergence, maturity

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