Phomopsis Blight

Causal Agent: Phomopsis vexans 

Distribution: Worldwide, in tropical and subtropical areas

Symptoms: 

This fungus attacks seedlings soon after emergence. Dark-brown lesions develop on the stem above the soil line. Eventually a dry rot or canker girdles the stem and the seedling collapses and dies. When older plants are infected, circular or irregular gray to brown lesions develop on lower leaves and stems. Lesions enlarge and coalesce, causing complete yellowing of foliage and severe defoliation. Cankers on stems can cause wilting and death of the upper plant. Fruit lesions start as soft, light-brown, sunken oval areas. Later fruit lesions deepen, enlarge and coalesce to develop a soft, spongy rot. In dry weather, fruit may shrink and mummify. A diagnostic characteristic is the minute black fruiting bodies (pycnidia) that develop in a circular pattern in the center of mature lesions. Pycnidia are the inoculum source for later infections.

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Conditions for Disease Development: 

This fungus can survive in plant debris or in mummified fruit in the soil. Infection may occur when rain or overhead irrigation splash inoculum to foliage and stems. Seed produced on plants grown in affected fields can be infested with fungal spores and may initiate disease on seedlings. Phomopsis blight is favored by hot, wet weather.

Control:

Sow high quality seed to pathogen-free transplants. Remove and destroy all infected plant material and establish a crop rotation to break the disease cycle. Mulch and furrow irrigate to reduce splashing of water and soil. A regular schedule of protectant fungicide sprays may reduce damage in areas where the disease is known to occur.

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Phytophthora Blight

Causal Agent: Phytophthora capsici 

Distribution: Worldwide

Symptoms: 

All plant parts can be infected. Root infection typically results in a rapid wilting of the plant. Infected roots turn dark-brown and the outer cortex sloughs off easily. Crown infections start as dark-green, water-soaked lesions that turn dark-brown as they expand. A cross-section through the infected crown reveals dark-brown discoloration that may extend throughout the cortex. Leaf symptoms start as small irregular, water-soaked lesions. As lesions expand, infected tissue dries and turns tan. Sporulation may be observed on leaf surfaces under conditions ideal for fungal growth. Infected stems may be girdled and later die back. Fruit lesions initially appear dark-green and water-soaked. As infection expands, fruit shrivel but typically do not drop. Fungal spores and mycelium may be observed on fruit surfaces.

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Conditions for Disease Development: 

Rainfall, wet soils and poor drainage favor disease development and spread. In climates where irrigation is used, extended periods of soil wetness also favor the root and crown rot stage of phytophthora blight. Disease spread usually follows the direction of surface water run-off. In climates with heavy rainfall, foliar blight as well as root and crown rot occur. Splashing rain and wind spread disease from plant to plant. Spread can also occur when soil is carried on equipment and boots. Phytophthora capsici can survive in the soil for years in tropical, subtropical and temperate climates.

Control: 

Use fungicide sprays in combination with cultural practices such as water management and crop rotation to manage Phytophthora blight. Plant on raised beds to promote water drainage away from plant roots. Resistance has been identified but is not yet available in commercial hybrids.

Bacterial Canker

Causal Agent: Clavibacter michiganensis subsp. michiganensis 

Distribution: 

Australia, Brazil, China, Israel, South Korea and USA (California, Indiana, Michigan, and Ohio)

Symptoms: 

Symptoms of bacterial canker in pepper include leaf and fruit spots and, less frequently, systemic wilt. In localized infections, symptoms first appear as small blisters or raised white spots on leaves and stems. Later the centers of the leaf spots become brown and necrotic, and develop a white halo. Stem lesions often develop a crusty appearance and elongate to form cankers. Symptoms on fruit first appear as very small, round, slightly raised spots. These spots gradually increase in size and may develop a brown center and a white halo. When numerous, spots merge and take on a crusty appearance. In systemic infections, a gradual wilting occurs followed by plant death

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Conditions for Disease Development: 

The bacterium enters the plant via wounds and stomata. Clavibacter may be seedborne and may infest the seed externally or uncle” the seed coat. High relative humidity and daytime temperature between 25 and 30 C (77 and 86 F) favor the diesease. Dense plant populations and overhead irrigation also provide an ideal environment to spread the bacterium. Insects, tools, and human contact may also aid spread.

Control: 

Sow only tested seed and certified transplants. Do not transplant peppers into ground used for tomatoes during the previous season. Clean cultivation equipment before entering a new field, avoid entering fields when foliage is wet and incorporate plant debris immediately after harvest to help reduce losses. Never harvest fruit from symptomatic plants. Rogue all symptomatic and adjacent plants. Rotate to a non-host for a minimum of three years if the disease is found in a field.

 

Whiteflies

The greenhouse whitefly (Trialeurodes vaporariorum), the sweet potato whitefly (Bemisia tabaci), and the silverleaf whitefly (B. argentifolii), are serious insect worldwide. Over 500 plant species including weeds, vegetable, ornamental and agronomic crops are attacked by whiteflies.  Immature and adult whiteflies colonize the underside of leaves. The larval stages are sedentary, whereas the tiny (1 mm) adults fly short distances from leaf-to-leaf or plant-to-plant, or are carried for miles by wind. Once established, populations build up rapidly due to a life cycle of 20 days or less in dry, warm climates. Rain and cold weather reduce whitefly populations. Plant damage is similar to that caused by aphids. Whiteflies feed on phloem, and produce sugary honeydew on leaves and fruit. Sooty mold fungi colonize the honeydew, reducing fruit quality and yield. Whitefly infestations can also slow plant growth and cause stunting and defoliation.

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Natural predators around will prevent whiteflies from ever exploding in population. Ladybugs, spiders, lacewing larvae, and dragonflies are a few of many beneficial insects that can control a whitefly population. Hummingbirds are another natural predator of whiteflies. Chemical insecticides should not be used for their control as they are usually resistant to insecticides and beneficial insects might be killed instead. Similarly, yellow index cards coated with petroleum jelly should be used to monitor whiteflies, especially when it comes to tomatoes, peppers, sweet potatoes, or cabbage crops.

Damage done by aphids to crops

Aphids are small insects ranging in length between 1.5 to 3.5 mm having soft body. Aphids come under the family Aphididae of order Hemiptera causing damage to the plants by sucking action mainly found in temperate climatic zones of North America, Europe, Central and Eastern Asia.

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Aphids use their stylet to explore the epidermis into mesophyll and parenchyma by choosing a suitable host plant for feeding. The major damage shown by continued feeding of plants by aphids are yellowing, wilting and stunting of plants. Physical damage to the plants are shown only by some species of aphids, whereas, some aphids show necrosis symptoms forming galls at the point of feeding. Severe damage leads to death and decay of plants due to infestation by small sticky aphids.

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Direct feeding of plants by aphids deplete the nutrients of plants that prevails reduced leaf area, slow growth, yield loss and the premature death of the plant. Excess sap excreted by aphids coat the host plants cause an economic loss on fruits and vegetables because of the growth of sooty mold fungus. Indirect damage to the plants is caused by the aphids due to vector role of several viruses. Saliva of aphid is the causative agent of damage to the plant tissues even in the absence of virus transmission. Different species of aphids feed over 250 agricultural and horticultural crops throughout the world, for example, bean aphid, Aphis craccivora on cowpea; mustard aphid, Lipaphis erysimi on rapeseed and mustard; coriander aphid and Hyadaphis coriandri on coriander.

 

Global Food Security

 

The term agriculture is associated with the production of essential food crops. It is a fundamental part of almost all societies and plays critical role on boosting up the economy of society as well. Global population is increasing day by day and meeting the demand of increasing population is the major challenge human are facing now. Therefore, agricultural system must adapt or even transform in order to overcome the growing number of challenges and constraints.

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After the Second World War the vast majority of the world’s countries became threatened of food shortage. World-wide food insecurity coupled with dramatic increment of world population led to Green Revolution. Norman Borlaug’s Green Revolution was the technological response to world-wide devastation. Green Revolution transformed farming practice in many region of the world with the introduction of high yielding varieties, new chemical fertilizers, synthetic herbicides and pesticides. As a result of Green Revolution the agricultural industry was able to produce much larger quantities of food. Furthermore, increase in productivity made it possible to feed the growing human population. Green Revolution ruled out for few decades. However, in spite of several benefits Green Revolution created some issues that affected both the environment and society. Overuse of chemical fertilizers dramatically influenced the environment as well as had remarkable impacts on soil fertility. Later on people realized that continuous environmental damage will undermine food security. Major transformations in agriculture during Green revolution served as an instant solution for meeting challenge of expanding food production but failed to ensure sustainable management of natural resources. Today, world needs a sustaining agricultural revolution- one major technological innovation that boost up the agricultural productivity through environmentally sustainable natural resource management and assure global food security. In addition, innovation must be able to ensure the reduction in  pressure placed on the environment such as pollution, deforestation, overexploitation of natural resources, mining, land degradation, greenhouse gas emissions and threats to biodiversity which are the major reasons of climate change and climatic variability the world is facing currently.

To begin with, as defined by the United Nations’ Committee on world food security, food security is the condition in which all people, at all times, have physical, social and economic access to sufficient safe and nutritious food, that meets their dietary needs and food preferences for an active and healthy life. Alteration of human being has profound impact on food security. On the recent decades, we can realize the major global issues such as changing climate, growing global population, prohibitive food prices and so on are creating major hurdle on securing global food security. Besides that several policies and strategies are being launched targeted to mitigate ingrained problem from its root. Recently, one of the major steps taken by United Nation under the name of ‘Sustainable Development Goals’ integrate food security as one of the seventeen proposed goals under Goal number 2 as “End hunger”, aiming to achieve food security and improved nutrition, and promote sustainable agriculture”. Despite of UN efforts to eradicate hunger, latest data revealed unexpected increment on hunger. As per the recent survey world hunger is on the rise: the estimated number of undernourished people increased from 777 million in 2015 to 815 million in 2016, affecting 11 percent of the global population (FAO, SOFI 2017). The current world population of 7.3 billion is estimated to reach 9.7 billion by 2050 and 11.2 billion by 2100 (“world population forecast” Worldometers. Retrieved 26 June 2016).  On the other hand, we need to increase food production by 60-70% by 2050 and even some of the developing countries have to double their production in order to feed currently growing population. Now, the strategy must be much more ambitious and effective in order to achieve food security along with addressing probable consequences.

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Moreover, after the failure of enormous strategy to increase production, term sustainability is getting on limelight. Traditional farming practices were healthy but production used to be very low. Now, innovation should be such that production should be high while maintaining the quality of the environment and conserving natural resources. Smallholder farmers shares the major percentage of global food producers and they have the responsibility to increase their production exponentially to meet the mounting global population. So, it is vital that they are to be supported with technology (especially high quality inputs, including mechanization). That is why sustainable agricultural mechanization can be the promising solution for this problem. Sustainable mechanization considers technological, economic, social, environmental and cultural aspects when contributing to the sustainable development of food and agriculture.

 

HUNGER AND DESTITUTION

Hunger and destitution, the two related terms or which can be called as the two parts of a coin.  Destitution or Poverty means the deprivation of basic requirements which commonly includes food, water, sanitation, clothing, shelter and health care. Poverty is the state for the majority of the world’s people and nations. It means insecurity, powerlessness and exclusion of individuals, households and communities.

                                      Hunger is a terrible symptom of poverty. In a world of plenty, a huge number go hungry. Hunger is more than just the result of food production and meeting demands. The causes of hunger are related to the causes of poverty. One of the major causes of hunger is poverty itself.h

           The world is suffering because of the poverty which, in turn, leads to hunger and ends up with bad consequences. The food scarcity part of the argument in the population debate is an interesting one. People are hungry not because the population is growing so fast that food is becoming scarce, but because people cannot afford it.  Food may be scarce, but it is international trade, economic policies and the control of land that have lead to immense poverty and hunger and therefore less access to food, not food scarcity due to over population. Why the world is suffering? If only the people of the state are responsible for all these? Or it can be so called their fate? What about the governmental policies of the country??? Hunger and necessity are poor teachers of morality. A society that cannot provide the basics of life does get its laws obeyed. And all these create war in the nation, in the world. A great line said by a great personality-“You cannot build a peaceful world on empty stomachs and human misery’’ which reveals the human nature. Food insecurity exists in every part of the world.                                                                                                I .

                                People are hungry not due to lack of availability of food, but because people do not have the ability to purchase food and because distribution of food is not equitable. In addition, there is also a lot of politics influencing how food is produced, who it is produced by, and for what purposes the food is produced. Eradication of hunger is of one the major issues of the present world.