Plant breeding and improvement of the cotton plant

1980 ◽  
Vol 10 (4) ◽  
pp. 152-158
Author(s):  
G A Niles
Keyword(s):  
Plant Breeding ◽  
Cotton Plant ◽  
Insect Pests ◽  
Unit Area ◽  
Cotton Breeding ◽  
Economic Profit ◽  
Breeding Research ◽  
Breeding Programmes

Cotton breeding research is directed to the development of cultivars that can be grown with maximum economic profit. Yield is a function of bolls per unit area, seed per boll and lint per seed, and its improvement depends on favourable alternatives to one or more of these components. Some breeding programmes place emphasis on fibre and spinning characteristics, while resistance to disease and insect pests and adaptation to mechanized harvesting are increasingly important objectives.

Plant biotechnology and its application to agriculture

1989 ◽  
Vol 324 (1224) ◽  
pp. 525-535 ◽  
Keyword(s):  
Plant Breeding ◽  
Insect Pests ◽  
Plant Biotechnology ◽  
Field Trials ◽  
Genetically Engineered ◽  
The Public ◽  
New Genes ◽  
Breeding Programmes ◽  
The Media ◽  
Genetically Engineered Plants

The predicted expansion of plant genetic engineering has occurred since publication of the Spinks Report, but routes to profit have emerged much more slowly than the media predicted. The U.K. made a strong start in the science but its position relative to the U.S.A. has declined because of the relatively massive investment in the U.S.A. by industry and the public sector. An impressive list of plant species have been transformed with new genes over the past few years. Of relevance to agriculture, genes have been identified, isolated, characterized, reconstructed and inserted into plants that confer tolerance to some leading herbicides, insect pests and viruses. Some field trials of the engineered plants have been carried out. Field trials of genetically engineered potato plants have been undertaken in the U.K. The conditions under which genetically engineered plants are to be released into commercial agriculture is currently a very important topic of debate. The detection of favourable genotypes in plant breeding programmes is currently time consuming and expensive in some instances. The ability to assay genetic variation in all regions in the genome by restriction fragment length polymorphism mapping is providing promise to plant breeding programmes for identifying favourable genotypes.

PARTICIPATORY PLANT BREEDING IS BETTER DESCRIBED AS HIGHLY CLIENT-ORIENTED PLANT BREEDING. II. OPTIONAL FARMER COLLABORATION IN THE SEGREGATING GENERATIONS

2006 ◽  
Vol 42 (1) ◽  
pp. 79-90 ◽  
Author(s):  
J. R. WITCOMBE ◽  
S. GYAWALI ◽  
S. SUNWAR ◽  
B. R. STHAPIT ◽  
K. D. JOSHI
Keyword(s):  
Plant Breeding ◽  
Market Failure ◽  
Supply And Demand ◽  
Cost Effective ◽  
Participatory Plant Breeding ◽  
Participatory Varietal Selection ◽  
Breeding Research ◽  
Breeding Programmes ◽  
New Varieties ◽  
Cost Effective Alternative

Many public-sector breeding programmes do not use explicit techniques to orient their programmes close to their clients' needs. Participatory techniques can be used to achieve high client orientation but these techniques do not have to involve farmers making selections during the segregating generations. This particularly applies when a sound initial market survey has been made or the learning from a participatory varietal selection (PVS) programme provides feedback to scientists. However, some published results on selection by farmers in the segregating generations (collaborative selection) indicate that it can produce appropriate varieties more effectively than less collaborative research. There is also evidence, from the few cases reported in the literature, that it is cost-effective. Alternative, less collaborative, approaches are also effective. Consultative forms of farmer participation, i.e. where farmers evaluate material grown by scientists, to aid selection in the segregating generations are more widely applicable because they demand fewer resources than collaborative methods. For more time-consuming tasks, such as in the selection of aromatic rice in segregating material, the most appropriate from of participation is contractual i.e., farmers are paid for their work. Mainly using examples from our research in Nepal, we present the particular circumstances in which the involvement of farmers in selection in the segregating generations is desirable or essential. These include: the occurrence of market failure (where the usual mechanisms of supply and demand have failed so there is no incentive to breed new varieties) and supply can only be met by actively involving farmers in the breeding process; when there are cost advantages to involving farmers – this is determined by the particular resources available to the institute undertaking the plant breeding research; when grain quality is both important and determined by a complex set of factors that are difficult to measure in the laboratory; when the objective is to learn in more detail about farmers' selection criteria to better orient the breeding programme to client needs; and when the goal is to empower farmers.

scholarly journals Appraisal of cowpea cropping systems and farmers’ perceptions of production constraints and preferences in the dry savannah areas of Nigeria

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Saba Baba Mohammed ◽  
Daniel Kwadjo Dzidzienyo ◽  
Muhammad Lawan Umar ◽  
Mohammad Faguji Ishiyaku ◽  
Pangirayi Bernard Tongoona ◽  
...  
Keyword(s):  
Plant Density ◽  
Insect Pests ◽  
Cropping Systems ◽  
Pairwise Comparison ◽  
High Yield ◽  
Crop Failure ◽  
Production Constraints ◽  
Cowpea Varieties ◽  
Breeding Programmes ◽  
Sole Cropping

Abstract Background Low plant density and wide intra-plant spacing in traditional cowpea cropping systems are among the factors responsible for low yield on farmers’ fields. Sole cropping and improved intercropping systems have been advocated in the last few years to increase yield in the dry savannah areas of Nigeria. This study investigated the level of adoption of high yielding cowpea cropping systems including factors that influenced their use and farmers’ perceived production constraints and preferences. A total of 420 farmers across 36 villages of northern Nigeria were interviewed, and data collected was analyzed using descriptive statistics to appraise farmers predominant cowpea cropping systems and factors that determine the use of sole versus intercropping were identified with the aid of binary logit regression. Furthermore, pairwise comparison ranking was deployed to understand farmers’ view of cowpea production constraints and preferred traits. Results The results revealed that, many of the farmers (42%) still grow cowpeas in the traditional intercropping and a good number (25%) cultivate the crop as a sole crop, while 23% had fields of cowpeas in both sole and intercropping systems. Farmers reported the incidence of high insect pests, limited access to land, desire to have multiple benefits, and assurance in the event of crop failure as reasons for preference for intercropping over sole planting. The pairwise comparison ranking of constraints and preferences revealed insect pests, Striga, drought and poor access to fertilizers as major constraints to increased productivity. Many farmers indicated high yield as the most preferred trait. Conclusions Findings indicate a need for increased education and training of cowpea farmers on the importance of growing cowpeas in sole cropping and or improved intercropping systems. Genetic improvement efforts should focus on developing cowpea varieties that address farmers production constraints and reflect the diversity of consumers’ preferences for the crop. Hence, breeding for resistance to insect pests and high yield is recommended as an important priority of cowpea breeding programmes in the region.

Effect of the Cotton Plant in the Sudan Gezira on Certain Leaf-feeding Insect Pests

Nature ◽  
1958 ◽  
Vol 182 (4647) ◽  
pp. 1463-1464 ◽  
Author(s):  
R. J. V. JOYCE
Keyword(s):  
Cotton Plant ◽  
Insect Pests ◽  
Sudan Gezira

Haploidy and plant breeding

1981 ◽  
Vol 292 (1062) ◽  
pp. 499-507 ◽  
Keyword(s):  
Plant Breeding ◽  
Doubled Haploids ◽  
Chromosome Complement ◽  
Basic Research ◽  
Breeding Value ◽  
Additive Variance ◽  
Ploidy Levels ◽  
Breeding Programmes ◽  
Dh Lines

A haploid is an organism that looks like a sporophyte, but has the chromosome complement of a reduced gamete. There are several ways in which haploids can occur or be induced in vivo : spontaneously, mostly associated with polyembryony, and through abnormal processes after crosses, like pseudogamy, semigamy, preferential elimination of the chromosomes of one parental species, and androgenesis. In the crops described, haploids are or are near to being used in basic research and plant breeding. The application of haploids in breeding self-pollinated crops is based on their potential for producing fully homozygous lines in one generation, which can be assessed directly in the field. Early generation testing of segregating populations is possible through haploids, because doubled haploids (DH) possess additive variance only. Haploids can also be applied in classical breeding programmes to make these more efficient through improved reliability of selection. The application of haploids in cross-pollinated crops is also based on a rapid production of DH-lines, which can be used as inbred lines for the production of hybrid varieties. By means of haploids all natural barriers to repeated selfing are bypassed. In autotetraploid crops there are two types of haploid. One cycle of haploidization leads to dihaploids; a second cycle produces monohaploids. The significance of dihaploids is in their greatly simplified genetics and breeding and in the possibility of estimation of the breeding value of tetraploid cultivars by assessing their dihaploids. The main drawback of dihaploids is their restriction to two alleles per locus. Also, after doubling, it is impossible to achieve tetra-allelism at many loci, the requirement for maximal performance of autotetraploid cultivars. Tetra-allelism can be obtained when improved dihaploids have a genetically controlled mechanism of forming highly heterozygous restitution gametes with the unreduced number of chromosomes. Monohaploids, after doubling or twice doubling, may lead to fully homozygous diploids and tetraploids. These are important for basic research, but not yet for practical application. Meiotic data of potato homozygotes at three ploidy levels are presented.

Synthesis of monoenic aliphatic pheromones of insect pests of the cotton plant

1988 ◽  
Vol 24 (5) ◽  
pp. 535-547
Author(s):  
G. G. Verba ◽  
A. A. Abduvakhabov ◽  
V. S. Abdukakharov ◽  
G. A. Irgasheva
Keyword(s):  
Cotton Plant ◽  
Insect Pests
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