scholarly journals Investigating the Type of Gene Action Conditioning Tolerance to Aluminum (Al) Toxicity in Tropical Maize

2019 ◽  
pp. 1-8
Author(s):  
Victoria Ndeke ◽  
Langa Tembo
Keyword(s):  
Root Length ◽  
Aluminum Toxicity ◽  
Gene Action ◽  
Abiotic Factors ◽  
Al Toxicity ◽  
High Yield ◽  
Small Scale ◽  
Tropical Maize ◽  
Maize Varieties ◽  
Small Scale Farmers

Maize is a third important cereal crop in the world after wheat and rice. In Zambia, it is an important staple crop. Its production is however hampered by both biotic and abiotic factors. Among the abiotic factors, Aluminum (Al) toxicity causes high yield losses and is directly linked to acidic soils. Application of lime can ameliorate this problem, but it is expensive for small scale farmers. Developing maize varieties that are tolerant to Al toxicity is cheaper and feasible for small scale farmers. The purpose of this research was to investigate the type of gene action conditioning tolerance to aluminum toxicity in tropical maize.  Eleven inbred lines were mated in an 8 male (4 moderately tolerant and 4 susceptible) x 3 female (resistant) North Carolina Design II. Results revealed that general combining ability (GCA) effects due to both males and females were highly significant (P≤ 0.001) for root biomass. The shoot length GCA effects due to both male and female respectively were significant (P≤ 0.01). Similarly, the GCA effects due to females and males for root length were significant, P≤ 0.01 and P≤ 0.05 respectively. The genotype CML 511 had the most desirable significant GCA effect value (1.40) for root length among the male lines while CML 538 had the most desirable significant GCA effect value (0.92) among the female lines. The baker’s ratio for root length was found to be 0.49 implying that both additive and non-additive gene action were important in conditioning aluminum toxicity tolerance in tropical maize.

scholarly journals Simplified Orange (Citrus spp.) Production Guide for Small-scale Farmers

2020 ◽  
pp. 23-27
Author(s):  
Hillary M. O. Otieno
Keyword(s):  
Soil Analysis ◽  
Fruit Fly ◽  
Codling Moth ◽  
Water Infiltration ◽  
High Yield ◽  
Small Scale ◽  
Leaf Miners ◽  
Land Preparation ◽  
False Codling Moth ◽  
Small Scale Farmers

Orange production provides both nutritional and financial benefits to farmers across Africa. However, these farmers do not realize the full benefits due to low yields caused by poor agronomic practices currently applied in the region. This guide, therefore, highlights key practices that farmers need to adopt for better yields. Farmers should always follow the best practices right from the selection of a variety to harvesting practices for high yield and better quality fruits to be achieved. Proper land preparation helps in early weed control and improves water infiltration and growth of roots. Weeds should always be kept below economic thresholds to ensure efficiencies in the use of water and nutrient. Like other plants, oranges require proper nutrition for growth and development of big fruits. Both manure and inorganic fertilizers should be applied depending on the availability and cost. Soil analysis helps in determining the rates of application. During production, farmers should scout for pests such as aphids, false codling moth, whiteflies, leaf miners, thrips, fruit fly and common spiral nematode and diseases like Pseudocercospora leaf and fruit spot, Phytophthora spp. and orange fruit scab which are common in the area. These pests cause significant yield losses if not timely controlled. When ready, harvesting of fruits should be careful and gentle without causing injuries.

scholarly journals Potentials of hybrid maize varieties for small-holder farmers in Kenya: A review based on swot analysis

2013 ◽  
Vol 13 (57) ◽  
pp. 7562-7586
Author(s):  
C Schroeder ◽  
◽  
T Onyango K’Oloo ◽  
NB Ranabhat ◽  
NA Jick ◽  
...  
Keyword(s):  
Food Security ◽  
Positive Impact ◽  
Smallholder Farmers ◽  
Fertilizer Application ◽  
Small Scale ◽  
Maize Production ◽  
Marginal Areas ◽  
Maize Varieties ◽  
Small Scale Farmers ◽  
Hybrid Maize

Maize is the primary staple crop in Kenya and plays an important role in the livelihood of the people of Kenya. Its availability and abundance determines the level of welfare and food security in the country. In Kenya, future increases in maize production to meet domestic demand will have to rely on improvements in yield per hectare rather than on the expansion of maize production area. Enhanced maize productivity can be achieved by increased use of modern production techniques such as the adoption of hybrid maize varieties, the use of chemicals and fertilizer application. Small-scale maize prodcution plays a major role in Kenya’s maize economy and adoption of hybrid technology by small-scale farmers would have the potential to address sustainability and supply issues. However, such modern technologies are still rarely used by Kenya’s small-scale farmers, particularly by those in marginal areas. This study, therefore, tries to review the reasons for the low rate of adoption of hybrid maize varieties among small-scale farmers with focus on those smallholders in Kenya’s marginal areas. Lack of awareness of existing or newly released hybrid varieties, lack of hybrid varieties adapted to marginal areas, lack of confidence in the quality of some hybrid maize seeds, poor access to stockists, low profitability due to high seed cost, inadequate access to credit, the need for fertilizer application and low literacy level have been found to be important factors explaining the low adoption rates by smallholder maize producers in marginal areas. In addition, these constraints might also explain the widespread practice of recycling hybrid grain among small-scale farmers once they have adopted hybrid maize varieties. Therefore, it is hoped that by overcoming these constraints, the adoption of hybrid maize varieties among smallholder farmers could be greatly enhanced, which in turn could lead to a significant positive impact on the country’s food security situation.

scholarly journals Tropical Maize Synthetics Breeding in Moisture-Stress Tolerance for Small-Scale Farmers in Brazilian Semi Arid Regions

2004 ◽  
Vol 3 (1) ◽  
pp. 69-76
Author(s):  
E.E.G. Gama ◽  
S.N. Parentoni ◽  
F.O.M. Durães ◽  
C.E.P. Leite ◽  
M.X. Santos ◽  
...  
Keyword(s):  
Stress Tolerance ◽  
Arid Regions ◽  
Moisture Stress ◽  
Small Scale ◽  
Tropical Maize ◽  
Small Scale Farmers ◽  
Semi Arid

scholarly journals Detection of Transgenes in Local Maize Varieties of Small-Scale Farmers in Eastern Cape, South Africa

PLoS ONE ◽  
2014 ◽  
Vol 9 (12) ◽  
pp. e116147 ◽  
Author(s):  
Marianne Iversen ◽  
Idun M. Grønsberg ◽  
Johnnie van den Berg ◽  
Klara Fischer ◽  
Denis Worlanyo Aheto ◽  
...  
Keyword(s):  
South Africa ◽  
Small Scale ◽  
Eastern Cape ◽  
Maize Varieties ◽  
Small Scale Farmers

Productivity, efficiency and structural problems in Chinese dairy farms

2012 ◽  
Vol 4 (2) ◽  
pp. 168-175 ◽  
Author(s):  
Xiaohua Yu
Keyword(s):  
Technical Efficiency ◽  
Scale Effects ◽  
Dairy Farms ◽  
Data Availability ◽  
High Yield ◽  
Small Scale ◽  
Structural Problem ◽  
Content Type ◽  
Structural Problems ◽  
Small Scale Farmers

PurposeThe purpose of this paper is to identify the structural problem in the Chinese dairy sector. There exists a large number of low‐efficiency, small‐scale farms, and productivity inequality between small and large farms keeps increasing, which is a possible driving force behind the Melamine scandal in 2008.Design/methodology/approachUsing the stochastic frontier production function, this paper estimates and compares the changes in technology and technical efficiency between backyard, small‐scale, medium‐scale and large‐scale dairy farms in China over the period between 2004 and 2008.FindingsThere are compensating effects between technology and technical efficiency. However, low yield for backyard farms is mainly caused by traditional low‐yield varieties, even though the technical efficiency is very high, which cannot compensate for the low technology.Research limitations/implicationsThe author put the assumption of constant return to scale mainly due to the data availability. Such an assumption implies that there are no scale‐effects between the different scales in productivity, and the productivity difference is explained by technology and technical efficiency.Practical implicationsIn order to solve the structural problems, Chinese governments should help small‐scale farmers to adopt new high‐yield varieties, to subsidize small‐scale farmers, and to train farmers to master the complicated skills for raising high‐yield varieties.Originality/valueThe paper gives another possible explanation for the Melamine scandal of milk powder in 2008. If the structural problem cannot be solved, similar food safety scandals could happen once again.

scholarly journals Farmers Perception of Low Soil Fertility and Hybrid Maize and the Implications in Plant Breeding

2017 ◽  
Vol 6 (2) ◽  
pp. 1
Author(s):  
Priscilla F. Ribeiro ◽  
Baffour Badu-Apraku ◽  
Vernon E. Gracen ◽  
Eric Y. Danquah ◽  
Manfred B. Ewool ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Insect Pests ◽  
Crop Productivity ◽  
Small Scale ◽  
Maize Production ◽  
Maize Hybrids ◽  
Maize Productivity ◽  
Resistant Varieties ◽  
Maize Varieties ◽  
Small Scale Farmers

In spite of efforts by national and international scientists to improve crop productivity, varieties of crops grown in Africa have low productivity. Varieties improved for yield have had low adoption rates among small scale farmers. Productivity of maize remains low in the smallholder sector because the crop continues to be grown under stress-prone environments and with limited resources. Participatory Rural Appraisal (PRA) tools, including two focus group discussions and interviews with 120 individual farmers were conducted in Wenchi and Ejura-Sekyedumase districts in Ghana to determine maize production constraints, assess farmers’ perceptions of low soil fertility in maize production and their coping strategies for the control of low soil fertility. Opportunities for breeding new maize varieties with tolerance to low soil fertility and improving farmers' perception on adoption and utilisation of maize hybrids were also examined. Results from interviews revealed that low soil fertility, drought, diseases and insect pests are the dominant constraints in maize productivity in the two districts. Farmers in the study area also have preference for low soil nitrogen (low N) tolerant, drought tolerant, disease and pest resistant varieties that require lower inputs. They prefer maize varieties which produce slender cobs that are light in weight with lots of grain. The farmers lack knowledge about hybrids but are willing to adopt maize hybrids that are tolerant to low N.

scholarly journals Daya gabung dan aksi gen komponen hasil jagung profilik hasil tinggi menggunakan analisis line X tester

Jurnal Agro ◽  
10.15575/9209 ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 113-129
Author(s):  
Roy Efendi ◽  
Slamet Bambang Priyanto ◽  
Muhammad Azrai
Keyword(s):  
Combining Ability ◽  
Gene Action ◽  
General Combining Ability ◽  
Yield Component ◽  
High Yield ◽  
Main Role ◽  
Lattice Design ◽  
Maize Varieties ◽  
Hybrid Maize ◽  
Two Stages

Peningkatan produktivitas jagung dapat dilakukan melalui perakitan varietas jagung yang memiliki tingkat prolifikasi tinggi. Ketersediaan galur-galur yang memiliki tingkat prolifikasi tinggi dan daya gabung yang baik akan memberikan peluang besar dalam perakitan jagung hibrida prolifik dengan hasil tinggi. Penelitian ini bertujuan memilih galur-galur prolifik yang memiliki daya gabung yang baik pada karakter prolifikasi dan mengevaluasi tingkat prolifikasi dan produktivitas jagung hibrida yang dibentuk dari galur-galur tersebut serta mengetahui aksi gen yang berperan pada karakter komponen hasil. Percobaan dilakukan dua tahap yaitu pembentukan hibrida dari galur-galur prolifik dengan metode testcross dan evaluasi hibrida yang terbentuk dengan menggunakan rancangan alfa lattice dengan tiga ulangan. Hasil penelitian menunjukkan galur G7 memiliki nilai daya gabung umum yang baik untuk karakter persentase tanaman prolifik. Hibrida G35/G102612 merupakan hibrida uji dengan persentase tanaman prolifik tertinggi 55,8%. Hibrida G7/Mal03 dengan hasil biji 12,9 t ha-1 dan persentase tanaman prolifik 53,9% merupakan jagung hibrida prolifik dengan hasil tinggi. Aksi gen non aditif lebih berperan dalam penampilan karakter komponen hasil pada jagung prolifik.AbstractMaize productivity can be increased by improving maize varieties with high prolificacy. The adequate of high prolificacy lines with a good combining ability will provide great opportunities to form a high yield prolific maize. The research aimed to select the prolific line which has good combining ability on the prolificacy and evaluate the prolificacy and productivity of the hybrid maize from these lines and to know the gene action which plays role in the yield component characters. The research was carried out in two stages, i.e. the formation of hybrids from the prolific line using the testcross method and evaluation of hybrids using the alpha lattice design with three replications. The results showed that line G7 had a good general combining ability for the percentage of prolific plants. Hybrid G35/G102612 was the test hybrid with the highest percentage of prolific plants of 55,8%. Hybrid G7/ Mal03 which had the yield of 12,9 t ha-1and percentage of prolific plants 53,9% was the prolific hybrid maize with the high yield. The non-additive effect played the main role for yield component characters of prolific hybrid maize.

scholarly journals Nature of Inheritance to Heat Stress and Selection of Inherent Genotypes in Tropical Maize

2020 ◽  
pp. 40-47
Author(s):  
Chiseche Mwanza ◽  
Mebelo Mataa ◽  
Langa Tembo
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Combining Ability ◽  
Gene Action ◽  
Abiotic Factors ◽  
Block Design ◽  
Control Site ◽  
Sub Saharan Africa ◽  
Tropical Maize ◽  
Sub Saharan

Maize is an important cereal in sub-Saharan Africa. Its production is however hampered by both biotic and abiotic factors. Among the abiotic factors, heat stress has been reported to cause yield losses. The objective of this study was therefore to identify tolerant genotypes to heat stress and determine the type of gene action conditioning heat tolerance in tropical maize. To achieve these objectives, five maize inbred lines (L2 [P1]; DTS 6,36 [P2]; L5527 [P3]; DTS 6,6 [P4] and DTS 6,92 [P5]) were mated in a 5 x 5 half diallel. Their progeny were evaluated at a heat prone site (Lusitu) and at the University of Zambia (UNZA), a control site. The experiment was laid as a randomised complete block design with two replications in each site. Highly significant differences (P ≤ 0.01) were obtained among genotypes in Lusitu with regards to all measured parameters. The crosses[P2 (DTS 6,36) x P4 (DTS 6,6)] and [P4 (DTS 6,6) x P5 (DTS 6,92)]were identified as tolerant genotypes to heat stress. Further analysis showed that the general combining ability (GCA) effects for parent P4 (DTS 6, 6) and P3 (L5527) were positively and negatively significantly different (P ≤ 0.01) from zero respectively with regards to all measured parameters. On the other hand, crosses [P1 (L2) x P3 (L5527)] & [P4 (DTS 6,6) x P5 (DTS 6,92)]were found to possess desirable significant (P ≤ 0.05) specific combining ability (SCA)effects from zero. The results of baker’s ratio obtained for responseto heat stress for all secondary traits measured were found to be greater than 0.88. This implied that additive gene action was more important in conditioning the response of these traits to heat tolerance.

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