Seed dormancy is a state where seeds are prevented from germinating despite suitable environmental conditions. There are several causes of dormancy, including physical (impermeable seed coats), physiological (hormonal mechanisms within the embryo), morphological (underdeveloped embryos), and combinations of these. Dormancy allows for species survival after disasters, seed dispersal escape from unfavorable conditions, and longer storage of food grains. It can be broken by treatments like scarification, stratification, and hormone soaking depending on the dormancy type. Understanding dormancy mechanisms could aid in weed control and prolonging storage of crops.
intro-classification-salt accumulation in soil imapairs plant function and soil structure-physiological effects on crop growth and development-osmotic effect and specific ion effects-plant use different strategies to avoid salt injury
“Seed priming is a controlled hydration technique in which seeds are soaked in water or low osmotic potential solution to a point where germination related metabolic activities begin in the seeds but radical emergence does not occur.”
Seed dormancy breaking treatments
Seed Science & Technology
K Vanangamudi
ICAR ARS NET STO exams
TNPSC AO AAO HO ADH AHO exams
Location and cause for dormancy in certain species
Scarification for seed dormancy breaking treatments
Electrical seed treatment for seed dormancy breaking treatments
Soaking in water for seed dormancy breaking treatments
Stratification for seed dormancy breaking treatments
Temperature treatments for seed dormancy breaking treatments
Chemical methods for seed dormancy breaking treatments
Promoters - inhibitors concept for seed dormancy breaking
Soaking in chemicals for seed dormancy breaking treatments
intro-classification-salt accumulation in soil imapairs plant function and soil structure-physiological effects on crop growth and development-osmotic effect and specific ion effects-plant use different strategies to avoid salt injury
“Seed priming is a controlled hydration technique in which seeds are soaked in water or low osmotic potential solution to a point where germination related metabolic activities begin in the seeds but radical emergence does not occur.”
Seed dormancy breaking treatments
Seed Science & Technology
K Vanangamudi
ICAR ARS NET STO exams
TNPSC AO AAO HO ADH AHO exams
Location and cause for dormancy in certain species
Scarification for seed dormancy breaking treatments
Electrical seed treatment for seed dormancy breaking treatments
Soaking in water for seed dormancy breaking treatments
Stratification for seed dormancy breaking treatments
Temperature treatments for seed dormancy breaking treatments
Chemical methods for seed dormancy breaking treatments
Promoters - inhibitors concept for seed dormancy breaking
Soaking in chemicals for seed dormancy breaking treatments
Dormancy is when there is a lack of germination in seeds or tubers even though the required conditions (temperature, humidity, oxygen, and light) are provided. Dormancy is based on hard seed coat impermeability or the lack of supply and activity of enzymes (internal dormancy) necessary for germination. Dormancy is an important factor limiting production in many field crops. Several physical and chemical pretreatments are applied to the organic material (seeds/tubers) to overcome dormancy. Physical and physiological dormancy can be found together in some plants, and this makes it difficult to provide high-frequency, healthy seedling growth, since the formation of healthy seedlings from the organic material (seeds/tubers) sown is a prerequisite for plant production. This chapter will focus on the description of four different methods we have not seen reported elsewhere for overcoming dormancy.
This presentation will led you to a good knowledge about the seed dormancy , its breaking methods and importance . Its an educational material delivered by me in my college presentation.
Seed dormancy is fully explained in this ppt. it includes causes ( dormancy due to hard seed coat, dormancy due to condition of embryo, dormancy due to absence of light, dormancy due to low temperature etc. ) of seed dormancy, types of seed dormancy, various methods to remove seed dormancy like impaction, stratification, scarification, exposure of seed to light
Shortcomings with long practiced intensive tillage such as loss of soil organic matter, decline in soil productivity, subsurface soil compaction, high fuel expenditures and increased cost of cultivation led to discovery of alternate options and embarked the idea of conservation tillage. Tillage practices that are defined by the per cent of residue cover left on the soil surface with minimized frequency or intensity of tillage operations are categorized under conservation tillage. These are aimed to reduce erosion by protecting the soil surface and thereby promoting economic and environmental benefits. Impact of conservation tillage is a function of duration and therefore long term investigations of conservation tillage serve as reliable source to study different crop, soil and cultivation parameters.
Conservation tillage and problem of residue management under rice based cropping system has been much talked about. However, maize being one of the most promising crops in changing climatic conditions; was less emphasized by conservationists. Maize is an erosion permitting crop and further conventional tillage in maize based cropping system enhances soil degradation, which is followed by accelerated rate of erosion and increased loss of nutrients. Lower economic returns from maize based cropping system due to higher costs involved in tillage operations is another major issue. Intensive tillage escalates the rate of oxidation of organic matter by opening the plough layer which decreases the soil organic carbon and ultimately results into degraded soil biological health. Conventional tillage in maize based cropping systems leads to persistence of particular weed flora, poor aggregate stability, development of hard pan which also creates problem of water logging in cases of poor drainage facility under maize based systems. Therefore, tillage practices needs some modifications to arrest such deteriorations that necessitated the concepts of conservation tillage.
Minimum risk of soil erosion, enhanced soil quality has been observed with conservation tillage besides showing enhanced macro and micro nutrient concentration in soil under maize based cropping system. Adoption of conservation tillage in maize based cropping system has promised to increase system productivity and maize yield by 23% in light textured soil . Higher net return by 6000-10,000 Rs/ha and 4-5% increase in energy efficiency are promised under conservation tillage. Therefore, energetic and economics of conservation tillage was significantly better than conventional tillage for maize based cropping system . Conservation tillage improves soil structure and enhances soil aggregation stability which enhances infiltration rate of soil. Soil water storage increased by about 3-12% under conservation tillage ultimately increases water productivity by 25 percent.
customized and value added fertilizers.pptxPragyaNaithani
Customized fertilizer are defined as multi nutrient carrier designed to contain macro and / or micro nutrient forms, both from inorganic and/or organic sources, manufactured through a systematic process of granulation, satisfying the crop’s nutritional needs, specific to site, soil and stage, validated by a scientific crop model capability developed by an accredited fertilizer manufacturing/marketing company.
The objectives –
• To provide site specific nutrient management
• To achieve maximum fertilizer use efficiency for the applied nutrients
• To attain cost effective fertilizer application
• A fertilizer composition with additional nutrients as compared to conventional fertilizers, from additional sources such as humic acids, amino acids, treated biochar and proteoglycans etc., which when applied increase yields with reduced fertilizer use.
• The deficiency of secondary and micronutrients can thus be overcome easily by fortification of the presently manufactured N/P/NP/NPK fertilizers
• Value-added fertilizers can increase crop yields by 14 to 17 percent compared with same amount of traditional fertilizers.
CF & FF:- holistic nutrition solution
• In north western India, secondary nutrients (S) and micronutrients (Zn, B, Fe, Mn) deficiencies are reported, which can be tackled with the use of value added fertilizers
• Although, K is sufficiently available, K response was found better after application of customized fertilizers
• The soil survey of India reported in many areas soils and ground water were affected by nitrate pollution (Handa 1986; Kakar 2008; Rawat and Singh 2010). Thus, it is quite essential to avoid overuse and go for usage of fertilizers as per the demand of crop.
Soil texture is the relative proportion of sand, silt, and clay in a soil. Texture is considered to be a permanent characteristic of a soil since weathering only very slowly changes particle size. Furthermore, cultivation and other management practices do not alter the sizes of individual soil particles. In some cases, however, erosion or deposition may rapidly alter the particle size distribution.
Texture is an important property of soils because particle size determines the surface area of solids per unit volume or mass of soil. Texture also influences the pore size distribution in soil. A sandy soil is dominated by large individual soil particles and, therefore, has a relatively small total surface area and large pore spaces between soil particles. At the other extreme, a clay soil consists of tiny individual particles and has a large total surface area but small pore spaces. However, small soil particles tend to be associated with one another to form aggregates of soil particles. Thus, the pore space in a clay soil consists of small intra aggregate pores and much larger inter aggregate pores. In fact, the total volume of pore space per unit volume of soil (porosity) of a sandy soil is actually smaller than the porosity of a clay soil.
A transgenic crop plant contains a gene or genes which have been artificially inserted, instead of the plant acquiring them through pollination. The inserted gene sequence (known as the transgene) may come from another unrelated plant, or from a completely different species: for example, transgenic Bt corn, which produces its own insecticide, contains a gene from a bacterium. Plants containing transgenes are often called genetically modified or GM crops.
What is the need of transgenic plants?
A plant breeder tries to assemble a combination of genes in a crop plant which will make it as useful and productive as possible. The desirable genes may provide features such as higher yield or improved quality, pest or disease resistance, or tolerance to heat, cold and drought. This powerful tool enables plant breeders to do what they have always done - generate more useful and productive crop varieties containing new combinations of genes - but this approach expands the possibilities beyond the limitations imposed by traditional cross pollination and selection techniques.
Pros and cons of VRT in Indian Agriculture as compared to Developed countries PragyaNaithani
Variable-rate technology (VRT) allows fertilizer,
chemicals, lime, gypsum, irrigation water and other farm
inputs to be applied at different rates across a field,
without manually changing rate settings on equipment
or having to make multiple passes over an area.
Variable-rate application (VRA) can range from the
simple control of flow rate to the more complex
management of rate, chemical mix and application
pattern. VRA can match changes in crop yield potential
with specific input rates resulting in a more efficient
system and minimising potential environmental impacts.
VRT can be used to deal with spatial variability between
paddocks or between management zones/classes. There
are two types of VRT:
1. Map-based control: a map of application rates is
produced for the field prior to the operation.
2. Real-time control: decisions about what rates
to apply in different locations are made using
information gathered during the operation. This
requires sensors to detect necessary information
‘on-the-go’ and is usually designed for a specific
job such as herbicide application.
Climate change and Agriculture: Impact Aadaptation and MitigationPragyaNaithani
Climate change refers to a statistically significant variation in either the mean state of the climate or in its Variability, persisting for an extended period (typically decades or longer). For the past some decades, the gaseous composition of earth’s atmosphere is undergoing a significant change, largely through increased emissions from energy, industry and agriculture sectors; widespread deforestation as well as fast changes in land use and land management practices. These anthropogenic activities are resulting in an increased emission of radiatively active gases, viz. carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), popularly known as the ‘greenhouse gases’ (GHGs)
These GHGs trap the outgoing infrared radiations from the earth’s surface and thus raise the temperature of the atmosphere. The global mean annual temperature at the end of the 20th century, as a result of GHG accumulation in the atmosphere, has increased by 0.4–0.7 ºC above that recorded at the end of the 19th century. The past 50 years have shown an increasing trend in temperature @ 0.13 °C/decade, while the rise in temperature during the past one and half decades has been much higher. The Inter-Governmental Panel on Climate Change has projected the temperature increase to be between 1.1 °C and 6.4 °C by the end of the 21st Century (IPCC, 2007). The global warming is expected to lead to other regional and global changes in the climate-related parameters such as rainfall, soil moisture, and sea level. Snow cover is also reported to be gradually decreasing.
Therefore, concerted efforts are required for mitigation and adaptation to reduce the vulnerability of agriculture to the adverse impacts of climate change and making it more resilient.
The adaptive capacity of poor farmers is limited because of subsistence agriculture and low level of formal education. Therefore, simple, economically viable and culturally acceptable adaptation strategies have to be developed and implemented. Furthermore, the transfer of knowledge as well as access to social, economic, institutional, and technical resources need to be provided and integrated within the existing resources of farmers.
Willie Nelson Net Worth: A Journey Through Music, Movies, and Business Venturesgreendigital
Willie Nelson is a name that resonates within the world of music and entertainment. Known for his unique voice, and masterful guitar skills. and an extraordinary career spanning several decades. Nelson has become a legend in the country music scene. But, his influence extends far beyond the realm of music. with ventures in acting, writing, activism, and business. This comprehensive article delves into Willie Nelson net worth. exploring the various facets of his career that have contributed to his large fortune.
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Introduction
Willie Nelson net worth is a testament to his enduring influence and success in many fields. Born on April 29, 1933, in Abbott, Texas. Nelson's journey from a humble beginning to becoming one of the most iconic figures in American music is nothing short of inspirational. His net worth, which estimated to be around $25 million as of 2024. reflects a career that is as diverse as it is prolific.
Early Life and Musical Beginnings
Humble Origins
Willie Hugh Nelson was born during the Great Depression. a time of significant economic hardship in the United States. Raised by his grandparents. Nelson found solace and inspiration in music from an early age. His grandmother taught him to play the guitar. setting the stage for what would become an illustrious career.
First Steps in Music
Nelson's initial foray into the music industry was fraught with challenges. He moved to Nashville, Tennessee, to pursue his dreams, but success did not come . Working as a songwriter, Nelson penned hits for other artists. which helped him gain a foothold in the competitive music scene. His songwriting skills contributed to his early earnings. laying the foundation for his net worth.
Rise to Stardom
Breakthrough Albums
The 1970s marked a turning point in Willie Nelson's career. His albums "Shotgun Willie" (1973), "Red Headed Stranger" (1975). and "Stardust" (1978) received critical acclaim and commercial success. These albums not only solidified his position in the country music genre. but also introduced his music to a broader audience. The success of these albums played a crucial role in boosting Willie Nelson net worth.
Iconic Songs
Willie Nelson net worth is also attributed to his extensive catalog of hit songs. Tracks like "Blue Eyes Crying in the Rain," "On the Road Again," and "Always on My Mind" have become timeless classics. These songs have not only earned Nelson large royalties but have also ensured his continued relevance in the music industry.
Acting and Film Career
Hollywood Ventures
In addition to his music career, Willie Nelson has also made a mark in Hollywood. His distinctive personality and on-screen presence have landed him roles in several films and television shows. Notable appearances include roles in "The Electric Horseman" (1979), "Honeysuckle Rose" (1980), and "Barbarosa" (1982). These acting gigs have added a significant amount to Willie Nelson net worth.
Television Appearances
Nelson's char
Artificial Reefs by Kuddle Life Foundation - May 2024punit537210
Situated in Pondicherry, India, Kuddle Life Foundation is a charitable, non-profit and non-governmental organization (NGO) dedicated to improving the living standards of coastal communities and simultaneously placing a strong emphasis on the protection of marine ecosystems.
One of the key areas we work in is Artificial Reefs. This presentation captures our journey so far and our learnings. We hope you get as excited about marine conservation and artificial reefs as we are.
Please visit our website: https://kuddlelife.org
Our Instagram channel:
@kuddlelifefoundation
Our Linkedin Page:
https://www.linkedin.com/company/kuddlelifefoundation/
and write to us if you have any questions:
info@kuddlelife.org
Characterization and the Kinetics of drying at the drying oven and with micro...Open Access Research Paper
The objective of this work is to contribute to valorization de Nephelium lappaceum by the characterization of kinetics of drying of seeds of Nephelium lappaceum. The seeds were dehydrated until a constant mass respectively in a drying oven and a microwawe oven. The temperatures and the powers of drying are respectively: 50, 60 and 70°C and 140, 280 and 420 W. The results show that the curves of drying of seeds of Nephelium lappaceum do not present a phase of constant kinetics. The coefficients of diffusion vary between 2.09.10-8 to 2.98. 10-8m-2/s in the interval of 50°C at 70°C and between 4.83×10-07 at 9.04×10-07 m-8/s for the powers going of 140 W with 420 W the relation between Arrhenius and a value of energy of activation of 16.49 kJ. mol-1 expressed the effect of the temperature on effective diffusivity.
UNDERSTANDING WHAT GREEN WASHING IS!.pdfJulietMogola
Many companies today use green washing to lure the public into thinking they are conserving the environment but in real sense they are doing more harm. There have been such several cases from very big companies here in Kenya and also globally. This ranges from various sectors from manufacturing and goes to consumer products. Educating people on greenwashing will enable people to make better choices based on their analysis and not on what they see on marketing sites.
Natural farming @ Dr. Siddhartha S. Jena.pptxsidjena70
A brief about organic farming/ Natural farming/ Zero budget natural farming/ Subash Palekar Natural farming which keeps us and environment safe and healthy. Next gen Agricultural practices of chemical free farming.
"Understanding the Carbon Cycle: Processes, Human Impacts, and Strategies for...MMariSelvam4
The carbon cycle is a critical component of Earth's environmental system, governing the movement and transformation of carbon through various reservoirs, including the atmosphere, oceans, soil, and living organisms. This complex cycle involves several key processes such as photosynthesis, respiration, decomposition, and carbon sequestration, each contributing to the regulation of carbon levels on the planet.
Human activities, particularly fossil fuel combustion and deforestation, have significantly altered the natural carbon cycle, leading to increased atmospheric carbon dioxide concentrations and driving climate change. Understanding the intricacies of the carbon cycle is essential for assessing the impacts of these changes and developing effective mitigation strategies.
By studying the carbon cycle, scientists can identify carbon sources and sinks, measure carbon fluxes, and predict future trends. This knowledge is crucial for crafting policies aimed at reducing carbon emissions, enhancing carbon storage, and promoting sustainable practices. The carbon cycle's interplay with climate systems, ecosystems, and human activities underscores its importance in maintaining a stable and healthy planet.
In-depth exploration of the carbon cycle reveals the delicate balance required to sustain life and the urgent need to address anthropogenic influences. Through research, education, and policy, we can work towards restoring equilibrium in the carbon cycle and ensuring a sustainable future for generations to come.
WRI’s brand new “Food Service Playbook for Promoting Sustainable Food Choices” gives food service operators the very latest strategies for creating dining environments that empower consumers to choose sustainable, plant-rich dishes. This research builds off our first guide for food service, now with industry experience and insights from nearly 350 academic trials.
2. What is seed dormancy?
Seed dormancy is defined as a state in which
seeds are prevented from germinating even under
environmental conditions normally favorable for
germination.
These conditions are a complex combination of
water, light, temperature, gasses, hard seed coats, and
hormones.
3. S.No Types Causes Embryo character Pre-treatment
1 Physical Seedcoat impermeable
Fully developed, non-
dormant
Scarification (Mechanical and acid)
2 Physiological
Physiological inhibiting
mechanism of germination in
the embryo
Fully developed
dormant
Seed soaking in growth regulators
(GA3, Ethrel, and chemical solutions
(KNO3, Thiourea)
3 Combinations 1+2
Fully developed
dormant
Scarification followed by chemical
treatment
4 Morphological Under developed embryo
Under developed non-
dormant
Cold stratification
5
Morpho-
physiological
Under developed embryo,
physiological
Under developed
dormant
Stratification followed by chemical
soaking.
Comprehensive Classification of seed dormancy
4. Harper, 1957
Nature of origination Innate Induced Enforced
Time/Cause of origin Primary Secondary
Location of dormancy Exogenous Endogenous Combined
Most extensively used classification system of seed dormancy
5. Mechanism of Dormancy
Hormonal control theory.
Temperature and gaseous exchange restriction theory.
Metabolic control theory.
6. Hormonal control theory
Dormancy causing hormones are ABA andethylene.
Dormancy causing hormones and dormancy provoking
hormones (GA & Cytokinin) ratio determine the fate of
dormancy.
Chilling treatment, light exposure increases Gibberellin
level in seeds & causes germination.
7. HORMONAL MECHANISM:
ABA and GA have antagonistic roles in germination and
dormancy respectively.
ABA induces and maintains seed dormancy during embryo
maturation. The key to ABA metabolism are some specific genes
encoding key enzymes are of NCED family (NCED6 and
NCED9)
( Nine-cis-epoxy carotenoid dioxygenase)
Embryonic identity protein (FUS3), which positively
regulates ABAsynthesis.
8. Temperature and gaseous exchange theory
Restricted oxygen uptake (due to hard seed coat) and
high temperature induces dormancy in seeds.
Oxygen deficiency leads to inhibition of
Cytochrome oxidase activity which leads to
dormancy.
9. Metabolic control theory
Dormancy in seed is controlled by metabolic energy
produced in seeds.
Respiratory system blocked ATPsynthesis blocked increase in
AMP andADP leads to increase in the activity of Glycolytic
pathway.
Production of growth inhibitors at lower concentration of
oxygen.
10. Causes of Seed Dormancy
Hard seed coat
Immature embryo
Germination inhibitors
Dormancy due to specific light requirement.
Period after ripening
Temprature
Excessive Salts
11. Hard seed coat
19
• Water impermeability:
Leguminosae, Gramineae, Malvaceae,, Geraniaceae,
Ohenopodiaceae, Solanaceae, Chenopodiaceae,
Convolvulaceae, and Nymphaeaceae etc.
• Gasimpermeability :
Xanthium
• Mechanical resistance (physically prevents the expansion of the embryo)
: Alisma, Amaranthus, Capsella
12. Immature Embryo
• Rudimentary and poorly developed embryo :
• Embryo fully developed but unable to
resume growth :
22
13. Rudimentary and poorly developed embryo
The embryo does not develop as rapidly as surrounding tissues.
Embryos are still immature and rudimentary when the seeds are dispersed.
Anemone nemorosa,
Fraxinus,
Caltha palustris,
Ginkgo biloba,
members of Orchidaceae, Orobanchaceae etc.
Seeds need time for maturity
.
14. Embryo fully developed but unable to resume growth
Iris, cherry, tulip, poplar, apple, peach, pines, peas,
etc.
Seeds need Stratification or after- ripening.
15. Specific Light Requirement :
There two type of seeds for light sensitivity:
Positive photoblastic seeds: Remain dormant in the dark, germinate when exposed to light
Ficus, Lettuca sativa (requires red light (660nm) or white light)
Rhododendron, Tomato, Bignonia (requires a photoperiod of 12 or more hours)
Negative photoblastic seeds: Remain dormant when exposed to light, germinate only in the
dark.
Tobacco, Amaranthus, Nigella, Phlox, Nemophila and Silene
The light sensitive seeds are called photoblastic.
16.
17. Germination Inhibitors
Found in the pulp of the fruits, seed coat, endosperm and embryos or
structures surrounding them
Tomato fruit pulp – Caffeic acid and Ferulic acid
Avena sp.- glumes
Chemical substances
Organic Acids, Phenolics, Tannins, Alkaloids, Cyanides, Indoles, ABA,
Ammonia, Phthalides, Coumarin, Parascorbic Acid, Cyanides, Ferulic Acid,
Dinitrophenols,Aldehydes, Fluorides, Unsaturated Lactones
18. S.No Species Location of inhibitor Name of inhibitor
1 Gossypium spp. Pericarp, testa Absicic acid (ABA)
2 Coriandrum sativum Pericarp Coumarin
3 Helianthus annus Pericarp, testa Hydrocyanic acid
4 Oryza sativa Hull Probably ABA
5 Triticum spp. Pericarp, testa
Catechin, catechin tannins, several
unknowns
6 Hordeum vulgare Hull Coumarin, Phenolic acids. scopoletin
7 Elaegnus angustfolia Pericarp, testa Possibly coumarin
8 Beta vulgaris Pericarp
Phenolic acids, Possibly ABA, high
concentration of inorganic ions
9 Avena sativa Hull Unknown
Location and name of germination inhibitors in certain species
Top
19. Temperature
Some seeds require chilling treatment for germination.
Apple, Walnut, and Pinus (chilling temperature of 1 -5 ºC for few
weeks)
21. Excessive Salts
Seeds contain a high concentration of solutes which
do not allow the embryo to resume its growth
Atriplex
Osmotic stress
22.
23. ApplicabilityofSeeddormancy
Species survival after natural disasters, pandemic, abiotic
stress
More time for widespread seed dispersal and escape from
unfavorable situations
Hard seed coats allow seed to come out of the alimentary
canals of birds and other animals uninjured e.g., Guava
24. Germination inhibitors present in the seed coats of
desert plants dissolves away after the rainfall. This
way dormancy ensures that seed gets proper supply
of water during its germination
Facilitates conservation of wild, rare, endangered plant
species in seed bank / gene bank artificially for the
future use
Allow storage of food grains for longer period of time
25. Groundnut:-
• Genetic manipulation of Spanish and Valencia bunch
varieties by introducing genes from the semi-
spreading and spreading varieties (Virginia types) for
seed dormancy of three to four weeks.
-Patro (2016)
OUAT,Oddisha
• Induction of Dormancy in Spanish Groundnut Seeds Using
low doses of Cobalt-60 Gamma Irradiation (50Gy) remain
dormant for five months after harvest
-Benslimani,N (2009)
26. Effect of environmental conditions on the dormancy and germination of
volunteer oilseed rape seed (Brassica napus)
Effect of time of incubation (5, 14, and 28 d), water potential (+ = 0 and -1,500 kPa), and
light conditions (FR and darkness) on induction of secondary dormancy in seed of two
cultivars of oilseed rape. Germination test at 12 C in darkness. (Data are logit transformed
values with percentage of dormant seed in parentheses)
Incubation time Potential = 0 kPa Potential =1,500 kPa
(d) Cultivar FR Dark FR Dark
5 Libravo - -1.09 (11.9) - -2.19 (0) -1.62 (4.7) - -1.88 (2.2)
Falcon - -1.87 (1.9) - -2.19 (0) -1.95 (1.1) -2.13 (0.3)
Mean - -1.48 (6.9) - -2.19 (0) -1.78 (2.9) -2.01 (1.21)
14 Libravo - -1.06 (12.8) - -2.19 (0) - -1.11 (10.8) - -1.41 (6.9)
Falcon - -0.95 (15.3) - -2.19 (0) - -1.68 (3.3) -2.01 (0.8)
Mean - 1.01 (14.1) - -2.19 (0) -1.40 (7.1) -1.71 (3.9)
28 Libravo ___b - -2.19 (0) -0.49 (26.7) -0.7 (20.3)
Falcon - - -2.19 (0) -0.95 (13.1) - -1.51 (5.0)
Mean - - -2.19 (0) -0.72 (19.9) -1.1 (12.6)
Francisca et al.,1998
27. Exploiting Weed Seed Dormancy for weed control
Soil fertility levels
• Sodium nitrite was more effective than nitrate in breaking dormancy of dehulled red
rice.
Cohn et al., 1983
• In wild oats, potassium nitrate stimulated germination of dormant seeds in the light.
Hilton et al., 1985
• Ammonium nitrate increased emergence of some moderately dormant ecotypes about
30% in pot experiments.
Agenbag et al., 1989
Light effects
• cultivation during daylight serves to increase weed populations
Wesson and Wareing, 1969
• Significantly less weed emergence takes place in plots cultivated at night than during
daylight, suggesting that this approach may have practical applications for weed
management
Hartmann and Nezadal
