How does peanut pollination work?

How does peanut pollination work?

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I got curious about peanuts and when I found some photos on the internet, I could see they have flowers. However peanut fruit is underground.

How does pollination of peanut flowers affect the fruit underground? Or are there two kinds of fruit, one from flower and one from the underground?

How Peanuts Grow

Many people are surprised to learn that peanuts grow beneath the soil and do not grow on trees like pecans or walnuts. Below you&rsquoll discover how peanuts grow, from preparing the soil for planting to the peanut harvesting process.

First, Farmers Plant the Seeds.

Across the USA Peanut Belt, peanuts are planted after the last frost in April through May, when soil temperatures reach 65°&mdash70°F. Farmers plant specially grown peanut kernels from the previous year&rsquos crop about two inches deep, approximately one to two inches apart in rows. Pre-planting tillage ensures a rich, well-prepared seedbed. For a good crop, 140 to 150 frost-free days are required.

Seedlings Crack the Soil

Peanut seedlings rise out of the soil about 10 days after planting. They grow into a green oval-leafed plant about 18 inches tall. Unlike most plants, the peanut plant flowers above the ground, but fruits below ground.

Flowers Appear

Yellow flowers emerge around the lower portion of the plant about 40 days after planting. When the flowers pollinate themselves, the petals fall off as the peanut ovary begins to form.

&ldquo Pegging&rdquo is a Unique Feature.

This budding ovary is called a &ldquopeg.&rdquo The peg enlarges and grows down and away from the plant forming a small stem which extends to the soil. The peanut embryo is in the tip of the peg, which penetrates the soil. The embryo turns horizontal to the soil surface and begins to mature taking the form of a peanut. The plant continues to grow and flower, eventually producing some 40 or more pods. From planting to harvesting, the growing cycle of a peanut takes four to five months, depending on the type and variety.

Farmers Harvest 140 to 150 Days After Planting.

When the plant has matured and the peanuts are ready for harvest, the farmer waits until the soil is not too wet or too dry before digging. When conditions are right, he or she drives a digger up and down the green rows of peanut plants. The digger pulls up the plant, gently shakes off any lingering soil, rotates the plant and lays it back down in a &ldquowindrow&rdquo&mdashwith peanuts up and leaves down.

Combining is the Last Step.

Peanuts contain 25 to 50 percent moisture when first dug and are dried to 10 percent or less so they can be stored. They are usually left in windrows for two or three days to cure, or dry, before the next step. (Read more about the history of peanut harvesting.)

After drying in the field, a combine separates the peanuts from the vines, placing the peanuts into a hopper on the top of the machine and depositing the vines back in the field. Peanut vines can be left in the field to nourish the soil or be used as nutritious livestock feed. Freshly combined peanuts are then placed into peanut wagons for further curing with forced warm air circulating through the wagon.

Peanuts Require Less Water than Other Nuts.

Peanut plants need 1.5 to 2 inches of water per week during kernel development however, it takes just five gallons of water to produce an ounce of peanuts, compared to 80 gallons for an ounce of almonds. If rain does not meet those needs, farmers will irrigate the fields. The peanut is a nitrogen-fixing plant its roots form modules which absorb nitrogen from the air and provide enrichment and nutrition to the plant and soil.

Learn more about the characteristics of peanuts that make them such a sustainable crop:

For resources for teachers, educators and caregivers, Discover the Powerful Peanut activity cards.

To learn more about the farm to table process for peanuts and peanut butter, view the Journey of a Peanut Butter Jar.

Learn about Pollination

Pollination is an important process in the reproduction of plants that bear seeds.

Without pollination, these plants would not be able to produce fruits! Yes, almost all the fruits that we eat and the beautiful flowers that we enjoy come from pollination! If you have seen yellow grains, sometimes white, black or green colored grains in the flowers, these are pollen that help fertilize the plants’ cells and turn these into seeds. Pollen acts as the main component in pollination, helping the flowers and plants create seeds that grow into fruits.

How does pollination work?

Pollination happens when pollen created from the plant’s male reproductive system (called the anther or stamen) is moved to the female reproductive system (called the stigma or pistil). This fertilizes the plant’s cells to produce seeds.

Have you seen how bees surround your garden? If you try to observe them carefully, bees go from one flower to another as they try to gather nectar (a sugary drink) from the flowers. Nectar which turns to honey serves as food for the bees, and as the bees pass through each flower the pollen sticks from the plants’ anther onto the bees’ legs, and then gets transported to the stigma. This makes up pollination.

Sometimes bees that are bred from a big colony in a huge hive also gather pollen on purpose as they collect the nectar. This makes pollination more frequent and effective in generating seeds from the plants. Most plants rely on bees and other insects or animals for pollination, although certain plants can be pollinated by wind or water.

What are the types of pollination?

There are different ways for plants to be pollinated.

  • Cross-pollination is the more common way of pollination. This is the type of pollination that happens when bees travel from one plant to another, carrying and transferring pollen in the process. Other insects can also help pollination in plants. These insects are attracted to the pleasant scent and striking beauty of the flowers, so if you see gorgeous flowers with different pretty colours you can think that this is to attract insects that can help in pollination. The nectar from the flowers draw the insects towards it. Once a flower or plant is pollinated, seeds will start to sprout. Insects are also not the only animals that can aid in pollination. Some mammals and birds can also help transport pollen or seeds from one place to another, and help pollination. For some plants, pollination can occur through the help of wind or water. These plants either do not have attractive flowers or lack nectar, and are designed to have pollen transported by wind or water.
  • Self-pollination is a type of pollination that does not need the help of others. Pollen grains can transfer from the stamen to the pistil by itself. These plants are fertile on their own, although you will find only a few plants that have this characteristic. Certain food plants like tomatoes belong to this category. Plants that do not need others to pollinate can produce seeds that grow into fruits faster, but to create varieties of a single type of fruit needs human intervention. Some plants that use self-pollination either have the capability to move the pollen from its stamen to its pistil, or move its pollen to the pistil of another plant.

What are pollinators?

A pollinator is a living organism or animal that helps pollination. These animals may not be aware that they are helping in pollination, but isn’t it great to know that they aid in this function? Animals that help plants in pollination include insects such as bees, butterflies, moths, beetles and certain other animals such as birds and bats. Flowers that have bright colors appeal to bees, so bees mostly help pollinate flowers with yellow, orange, blue or purple colors. Butterflies are nearly the same as bees, preferring flowers with intense colors such as red, yellow and orange. Although bees are also attracted to flowers with fresh and sweet odors, butterflies tend to favor flowers that have weak scents. Hummingbirds go to long, tubular flowers that allow them to get nectar. Bats are usually drawn to flowers that open only at night.

Why are bees and other insects so important?

Without bees and animals that act as pollinators, pollination will not happen. Most plants are designed for insects and animals to help transfer pollen and trigger fertilization of seeds, and cannot be pollinated by virtue of wind or water, or self-pollination. Losing pollinators will damage plants and wildlife that mostly rely on these insects and animals to grow. A thriving garden exists because of these pollinators. If bees and insects die, no one will be able to pollinate plants, and we will lose our source of food and oxygen.

We need bees and other animals to help encourage pollination and help cultivate plants. Some children play with insects and kill them, not knowing that by doing this they are damaging the environment. Tell your family and friends how bees and other insects are great contributors to raising plants and make them aware of why they are important to the environment and to us.

What Is Artificial Pollination?

Artificial pollination is the process of applying pollen to plants that would normally be applied by the insects that pollinate plants. Artificial pollination can be accomplished with the use of a brush to apply the pollen. This is a technique similar to the one biologist Mendel used while studying genetics and inheritance. There are several benefits to artificial pollination, including gaining greater control over the genetic population of the crops.

When considering artificial pollination, the viability of the flowers must be considered. The duration of viability determines how often the pollen is applied. Other factors to consider are the number of pollen grains and the number of insects required to pollinate the plant in nature.

When insects are not pollinating a plant sufficiently, a grower can introduce more insects to the crop or opt for artificial pollination. Artificial pollination increases fruit size and results in a high conversion of flowers to export fruit. It also reduces costs. A fruit with a higher seed number is better able to compete for resources such as carbohydrates and vine resources. It can also accumulate more dry matter than a fruit with lower seed numbers. Financial gains of several thousands of dollars from better pollination has been verified through research.

Dietary management of peanut and tree nut allergy: what exactly should patients avoid?

Peanut and tree nut allergies are the commonest cause of life-threatening food-allergic reactions and significantly affect quality of life in children and their families. Dietary nut avoidance and provision of emergency medication is currently the mainstay of treatment. Nut avoidance has consequences on both quality of life and nutrition. We review the terminology that may cause confusion and lead to unnecessary dietary restrictions. In peanut or tree nut-allergic children, introduction of specific nuts to which the child is not allergic may improve quality of life and should be considered in patients with multiple foods allergies, vegan or ethnic-specific diets, in whom nuts are an important source of protein. Nut-allergic consumers do not just need to avoid foods containing nuts as an ingredient, but also contend with pre-packed foods which frequently have precautionary allergen labelling (PAL) referring to possible nut contamination. Although the published rate of peanut contamination in 'snack' foods with PAL (see Box ) ranges from 0.9-32.4%, peanut contamination in non-snack items with PAL is far less common. We propose that in some peanut-allergic patients (depending on history of reactivity to trace levels of peanut, reaction severity, other medical conditions, willingness to always carry adrenaline, etc.), consideration may be given to allow the consumption of non-snack foods containing PAL following discussion with the patient's (and their family's) specialist. More work is needed to provide consumers with clearer information on the risk of potential nut contamination in pre-packed food. We also draw attention to the change in legislation in December 2014 that require mandatory disclosure of allergens in non-pre-packed foods.

© 2014 The Authors. Clinical & Experimental Allergy Published by John Wiley & Sons Ltd.

Hybridization Technique (With Diagram) | Plant Breeding

The plant breeder must have a clear idea about the plants which he wants to use as parents — a subject which may be called crop botany. The time of flowering, the stage of flower development at which the anthers burst (anthesis) and the stigmas become receptive and also the time period for which the pollens remain viable and the stigmas remain receptive must be known beforehand.

Crop plants are mostly annual plants and in such plants the pollens remain viable for several days after anthesis, and so pollen viability is not a critical factor. But in annuals stigmas remain receptive for a short period, usually for several hours and very often for not more than a day. In many plants the stigma becomes receptive at a particular time of the day as in rice, it becomes receptive in the morning, at around 8 a.m.

The receptivity period of the stigma is a vital factor, because if pollination is not done within this period, fertilization normally does not occur. Similarly, if pollination is done with immature pollens or with pollens which have lost their viability, fertilization normally does not take place.

The plant breeder should take all necessary precautions so that no unwanted pollination occurs. This, in turn, depends upon the nature of the crop — whether it is a naturally self-pollinated or cross-pollinated crop, as also the percentage of cross-pollination.

To prevent any unwanted pollination the flowers are kept covered by bags long before they open. Necessity of isolation increases with increase in the percentage of natural cross-pollination.

The plant breeder first selects the two varieties which he wants to use as parents mid also determines which variety will be used as male parent and which one as the female parent. The two parents are grown in adjacent plots.

The breeder must have prior knowledge about the cultivation of the crop, the natural growing season of the crop, the time of sowing of the seeds as also, the preparation of the land, i.e., ploughing, manuring and watering of the plot.

The anthers of the male parent should be just ripe when the stigma of the female parent become receptive. For this, sometimes it becomes necessary to space out the sowing of the seeds of the two parents.

In plants where the flowers are rather small and remain too much crowded on the inflorescence, it is necessary to remove some of the flowers early, so that the breeding work can be done easily. This is specially true in case of cereals like rice and wheat where just 10-12 flowers are left on the inflorescence and the rest clipped-off.

Hybridization Technique # Step 2. Emasculation:

At a certain stage of flower development the anthers become ripe and dehisce to liberate the pollens. This is known as anthesis. These anthers must be removed before anthesis from the flowers of the female parent to prevent self-pollination. This is called emasculation. Fig. 4.1 shows the plant breeder’s kit which is specially needed for emasculation.

The exact technique of emasculation varies from plant to plant depending upon the structure of the flower. In plants with relatively large flowers, such as tomato or brinjal, the corolla is forcibly opened just prior to anthesis, the anthers are plucked with a forceps and thrown-off. The forceps must be sterilized by dipping in rectified spirit.

Care should be taken not to injure the floral parts, particularly the carpels. The anthers should not be broken while plucking them off. Emasculation becomes progressively difficult as the flowers become smaller and smaller and is most difficult in the cereals where the glumes are very small and often brittle as in rice. In such plants, special techniques of emasculation are applied.

Hybridization Technique # Step 3. Bagging:

The emasculated flowers should be kept properly covered so that no untoward cross-pollination takes place. This is done by enclosing the emasculated flowers in muslin, oil paper or polythene bags (Fig. 4.2).

Depending upon the nature of the plant, the flowers, the inflorescence, or the entire plant is bagged or caged. The bags are kept loosely tied at the bases of the plants so that gaseous exchange remains unhampered. Ordinarily the bags are kept till seed setting is complete.

Hybridization Technique # Step 4. Pollination:

When the stigma of the emasculated flower becomes mature (receptive) it is artificially pollinated by pollens taken from the male parent. During pollination whole, freshly dehisced anthers are plucked from the flowers of the male parent by means of forceps (then sterilized with rectified spirit) and dusted on the stigma. The bags are temporarily removed at the time of pollination and replaced, as before, after pollination.

The crossed flowers should always be kept properly tagged or labelled. Fine, rectangular and thin sheets of aluminium make good tags. Other types of tags are also available.

The tag should be brief but complete. It should bear the names of the parents. The name of the female parent should be written first. It must contain a number referring to the field notebook. All necessary particulars about the cross should be recorded in the field notebook under that number.

Hybridization Technique # Step 5. Selection:

The seeds are allowed to mature within the bags. They are then harvested and stored with proper labelling. From the next growing season onwards the hybrid seeds are grown, allowed self-pollination and selection is carried on to find out the desired phenotypes and make them homozygous.

Section can be done following the Bulk Method or the Pedigree Method. Selection is followed by field trial and then only it can be recommended for large scale cultivation.

How Pollen Works

Plants evolved pollen as a reproductive means more than 375 million years ago, and since then, they haven't looked back [source: Dunn]. A large portion of the plant life that's spread far and wide across the planet today displays this evolutionary ingenuity. The main reason pollen -- and by extension the process of pollination -- is so important, is because it means plants don't have to rely on water to transport the biological components necessary for fertilization. Plants that bear pollen also tend to offer protection to their offspring after fertilization in the form of hard seeds -- and in some cases, those seeds are even nestled inside fleshy fruits.

Pollen grains are, in essence, plant sperm. Or perhaps more technically, sperm sedans. Inside, they contain the male portion of DNA needed for plant reproduction. There's great variation when it comes to the size of pollen grains, and there's no correlation between the size of the plant and the size of the pollen it produces. Large plants might generate some of the tiniest grains of pollen, while diminutive plants may yield pollen that puts those to shame. Pollen grains may not look like much to the naked eye, they often look like dusty specks, but upon closer inspection, they take an endless array of fascinating shapes with all manner of textures and features.

Whether conical, spherical, cylindrical or some other fantastical shape, many grains of pollen resemble something else, be it coral, succulent, seashell or sea anemone. Some grains are dotted with little spikes others have weblike surfaces. Still more appear enshrined in ropey tangles, while others sport delicate dimples or have ribs that resemble the stripes on a watermelon.

Many of these unique adaptations are to help the pollen get where it needs to go -- namely, its own species' female counterpart. Surface features help grains cling to different modes of transportation, such as bird feathers, bee legs or animal fur. Or they help pollen sail through the air on appendages that resemble airplane wings or hot air balloons. Some of these features even help a pollen grain perform successfully when it reaches its destination. We'll discuss what happens when that happy event occurs on the next page.

The Process of Pollination

In most pollen-producing plants, a grain of pollen successfully completes its journey when it travels from the male portion of a plant specimen to the corresponding female portion. Ideally, it finds its way to an entirely different plant to increase outcrossing borne from crosspollination. That's not always a hard and fast requirement, however, although it's important to note that many plant species have ways to prevent a particular plant from pollinating itself. Some are even genetically self-incompatible.

Once a grain of pollen reaches the plant's female portion, in most cases an ovule, one of the lucky sperm (typically out of two) lodged within the pollen will fertilize the egg cell inside. After fertilization occurs, the ovule will gradually develop into a seed, and that seed will transport its embryonic plant to a new home.

Plants that follow this basic reproductive path are known as gymnosperms. Trees that have pinecones and similar reproductive structures, as is the case with most conifers, are examples of gymnosperms. Let's take a closer look at conifers, the most numerous and widespread gymnosperms on Earth today, and pines in particular, since they're some of the most familiar species.

Pinecones generally come in male and female varieties, and they can be all sorts of shapes, textures and sizes, depending on the species. One makes the pollen, and the other receives it. Once a pollen grain arrives at an ovule -- usually adhering with the help of a sticky substance produced by the female pinecone -- it absorbs water, germinates and starts slowly growing a pollen tube in order to place the newly generated sperm inside. Fertilization occurs, and a seed eventually forms. The length of time it takes for the overall process to complete itself varies greatly in many pine species, the pollination process takes more than a year from start to finish. Once it's finished, the seed is liberated from the cone, to travel on its way.

But although the development of the pollination process was revolutionary, it still had some kinks that could be worked out. On the next page, we'll take a look at the plants who whipped out the evolutionary iron and made the method that much more reliable.

Many people suffer from allergic rhinitis, and pollen is a big contributor. Different plant species produce different pollens, and those different pollens are composed of different buffets of proteins. Some of those proteins cause allergy sufferers' immune systems to go into overdrive.

Flower Power and Pollination

Some plants -- the angiosperms -- evolved to take the pollination process a step further. These are the flowering plants, and not only do they produce seeds, they also flower and produce protective fruits. These reproductive safety nets are also better at luring mobile organisms into assisting them successfully complete their life cycles in fact, many evolved in tandem with the creatures who pilot the pollination process. In terms of species, angiosperms are the most prolific type many species of trees and shrubs, along with all manner of fruits, vegetables, grains, cacti and wildflowers are considered angiosperms [source: Raven].

So let's look at how this works in your typical flower and dig down a little deeper into the development of pollen in general. Pollen grains are created through the process of meiosis, during which cells divide and grow in number. The grains of pollen are often located in pollen sacs on the ends of the stamen (the male parts of the flower), which typically surround the carpel (the female parts of the flower). The stamen generally come in two sections: the two-lobed anther, which house the pollen sacks, and the filament, the stalk on which the anther perch. Each grain gradually develops a tough outer wall to shelter it during its journey.

Once it's deposited at its destination, grains of pollen settle on a flower's stigma -- the entrance to the ovary. Like with the gymnosperms, germination and pollen-tube formation follow fertilization, but this time both sperm are used. While one fertilizes the egg cell, the other is tasked with fertilizing another cell that will develop into the endosperm, which is what growing plant embryos consume before and during the sprouting process.

Different flowers grow in different configurations, and while many, in fact the majority of angiosperms, carry both stamen and carpal components, some do not. For those species, male and female reproductive parts can be found on different flowers of the same plant -- similar to how many gymnosperms' pinecones are commonly configured. Or, in some cases, each particular plant specimen may feature only one or the other, varying the process slightly.

The Transporters of Pollen

Pollen can be carried by wind, rafted by water or shuttled around by any manner of creatures, be they bees, beetles, birds or bats, and deposited on the female reproductive part of another flower. That might sound pretty hit or miss, and it is, which is why plants -- particularly gymnosperms -- produce lots of pollen.

In order for plants to successfully spread their pollen, many coevolved with other creatures to get the job done more frequently and more efficiently. This happened a number of ways. With flowering plants, for example, those with the tastiest pollen were more likely to attract pollinators, so they were the ones that had the best chance of propagating their species. Flowering plants also leverage shape, color and scent to bring in more customers, sometimes in ways that might seem surprising. Many beetle species are attracted to flowers that produce scents we would consider highly unappealing. Some of these plants, among them the common household philodendron, attract beetles by heating up through a chemical reaction. It causes them to produce an odor reminiscent of decomposing organic matter, which the beetles are naturally drawn to. One Sumatran plant, known as the devil's tongue, smells so foul it has reportedly made people pass out. It's pollinator? A species of carrion beetle.

Bright colorful flowers are most likely to attract diurnal creatures, while white or light yellow ones are most likely to be spotted by nocturnal animals. There's also the production of nectar. Many proficient pollinators, such as bees, bats and hummingbirds thrive on nectar, so having nectar cups suited for the pollinator's mouthparts was another important specialization to develop. Lastly, the positioning of plants' sexual parts evolved, too. Those specimens whose arrangement best catered to a potential pollinator's feeding habits were most successful. So stamen that were most likely to be brushed against by a pollinator -- and therefore more likely to be brushed off and carried away -- were the most ideally positioned for evolutionary perseverance.

Bees provide a great example of co-evolution in action and they're incredibly important pollinators. They consume nectar and pollen, collecting both while they forage. Flowers have evolved into specific color, fragrance and shape combinations that make them attractive and accessible to bees (and often unappealing or inaccessible to their competitors). Bees have paid back such flowers by evolving specific body parts that make them more efficient at collecting -- and inadvertently passing on certain portions of -- pollen as they make their rounds.

Plants, pollen and pollinators are obviously of great importance to humans. People surely passed on knowledge of plants throughout our species' long evolution, but some 11,000 years ago, we drastically changed the game [source: Starr]. That's around the time people began domesticating crop plants -- selecting favorite specimens from wild breeds and cultivating them for certain desirable attributes like high yield, pest resistance or heat tolerance. Fast forward to today, and our crop production methods have again leapt forward dramatically from those early beginnings. Now many crops are genetically modified organisms, or GMOs, and our artificial tampering has left lots of people wondering what impact it will have on naturally evolved organisms.

Scientists study whether and under what circumstances GMO crops have the potential to interbreed with conventional crops, as well as related species. One study conducted in Africa, an area where GMOs could have a considerable impact, determined bees there venture close to 4 miles (3 kilometers) away from the nest while foraging [source: Science Daily]. Such range could allow the trangenes of introduced GMO crops to infiltrate wild species. In order to control instances of crosspollination, international bodies such as the European Coexistence Bureau advocate certain isolation measures. These include spatial and temporal steps in other words, planting crops at certain distances from plants that might be cross-pollinated, as well as timing such plantings so the species flower at different times of the year.

Pollen is also useful stuff to study for other reasons. By taking core samples, scientists who specialize in fields of palynology -- the study of pollens, spores and similar microscopic plant life -- can get a good idea as to what plants were prevalent during different eras of the Earth's history. For example, pollen and other palynomorphs can help determine when agricultural cultivation starts or stops in a certain area, when a stretch of land was wooded or meadowed, or when changes in climate occurred.

On the next page, learn lots more about pollen -- and what to do when it starts you sneezing.

Here are a few more distinctions that might help you decide what to grow this season:

  • Open-pollination is when pollination occurs by insect, bird, wind, humans, or other natural mechanisms.
    • Because there are no restrictions on the flow of pollen between individuals, open-pollinated plants are more genetically diverse. This can cause a greater amount of variation within plant populations, which allows plants to slowly adapt to local growing conditions and climate year-to-year. As long as pollen is not shared between different varieties within the same species, then the seed produced will remain true-to-type year after year.
    • An heirloom variety is a plant variety that has a history of being passed down within a family or community, similar to the generational sharing of heirloom jewelry or furniture.
      • An heirloom variety must be open-pollinated, but not all open-pollinated plants are heirlooms. While some companies create heirloom labels based on dates (such as a variety that is more than 50 years old), Seed Savers Exchange identifies heirlooms by verifying and documenting the generational history of preserving and passing on the seed.
      • Hybridization is a controlled method of pollination in which the pollen of two different species or varieties is crossed by human intervention.
        • Hybridization can occur naturally through random crosses, but commercially available hybridized seed, often labeled as F1, is deliberately created to breed a desired trait. The first generation of a hybridized plant cross also tends to grow better and produce higher yields than the parent varieties due to a phenomenon called ‘hybrid vigor’. However, any seed produced by F1 plants is genetically unstable and cannot be saved for use in following years. Not only will the plants not be true-to-type, but they will be considerably less vigorous. Gardeners who use hybrid plant varieties must purchase new seed every year. Hybrid seeds can be stabilized, becoming open-pollinated varieties, by growing, selecting, and saving the seed over many years.


        Each of us depends on pollinators in a practical way to provide us with the wide range of foods we eat.

        Pollination services from honey bees and other insects provide the backbone to ensuring our diets are diverse and plentiful with fruits, nuts, and vegetables. In all, there are over 100 crops grown in the United States that depend on pollination. USDA supports the critical role pollinators play in agriculture through research and data collections, diagnostic services and pollinator health monitoring, pollinator habitat enhancement programs, and pollinator health grants.

        View Secretary Vilsack's National Pollinator Week Proclamation (PDF, 67.7 KB)

        Engage with us during Pollinator Week!

        Pest Management

        Agricultural Marketing Service (AMS) conducts a monthly National Honey Report, which collects prices paid of extracted and unprocessed honey, price by honey type, primary nectar source visited, and estimates the export and import of honey with major trading partners.

        Animal Plant Health Inspection Service (APHIS) safeguards honey bees against the entry, establishment, and spread of economically and environmentally significant pests, and facilitates the safe trade of agricultural product. Information on the National Honey Bee Pests and Diseases Survey, Exotic Bee and Bee Mite ID guides, outreach videos on the parasitic Varroa mite and introductions to beekeeping can be found at this site.

        Agricultural Research Service (ARS) Bee Research Laboratories are located across the country. These labs look at a wide range of issues that impact bee health. The primary labs include:

          focuses on a wide range of bee pests and diseases, and offers a free Bee Disease Diagnosis Service of pests and diseases for beekeepers across the United States. focuses on honey bee breeding, genetics, and physiology research. studies the biology, management, and systematics of pollinating insects. focuses on improved nutrition and Varroa control.

        Farm Service Agency (FSA) administers the Conservation Reserve Program (CRP), which implements long-term rental contracts with growers to voluntarily remove environmentally sensitive land from agricultural production, and to plant species that will improve environmental health and quality, such as for pollinator and wildlife habitat.

        National Agricultural Statistics Service (NASS) conducts statistically based surveys of beekeepers, including the Bee and Honey Inquiry Survey and the Colony Loss Survey.

        National Institute for Food and Agriculture (NIFA) provides grants to universities, including Land-Grant institutions, to address high priority pollinator research. They also work to provide funding to U.S. Land-Grant institutions and counties through the Cooperative Extension System to conduct information and technology transfer to stakeholders on pollinator health.

        Natural Resources Conservation Service (NRCS) offers more than three dozen conservation practices that can benefit pollinators. Although many of these practices target improving grazing lands or reducing soil erosion, small modifications to the practices can yield benefits to pollinator species. The shared link provides an overview of NRCS conservation work for pollinators and pollinator conservation and habitat enhancement resources.

        Office of Pest Management Policy (OPMP) analyses policy questions that address questions related to the interface of crop pest management and pollinator health and works closely with the USDA’s National Agricultural Statistic Service on data collections to better understand pollinator Best Management Practices. The link provides an exhaustive summary of crops that are attractive and/or pollinated by both honey bees and other bees in the United States.

        Risk Management Agency (RMA) administers the Emergency Assistance for Livestock, Honey Bees, and Farm-Raised Fish (ELAP) program which provides financial assistance to eligible producers of honey bees due to disease and certain adverse weather events or loss conditions. ELAP assistance is provided for losses not covered by other disaster assistance programs authorized by the 2014 Farm Bill and the Bipartisan Budget Act of 2018.

        170 Pollination and Fertilization

        By the end of this section, you will be able to do the following:

        • Describe what must occur for plant fertilization
        • Explain cross-pollination and the ways in which it takes place
        • Describe the process that leads to the development of a seed
        • Define double fertilization

        In angiosperms, pollination is defined as the placement or transfer of pollen from the anther to the stigma of the same flower or another flower. In gymnosperms, pollination involves pollen transfer from the male cone to the female cone. Upon transfer, the pollen germinates to form the pollen tube and the sperm for fertilizing the egg. Pollination has been well studied since the time of Gregor Mendel. Mendel successfully carried out self- as well as cross-pollination in garden peas while studying how characteristics were passed on from one generation to the next. Today’s crops are a result of plant breeding, which employs artificial selection to produce the present-day cultivars. A case in point is today’s corn, which is a result of years of breeding that started with its ancestor, teosinte. The teosinte that the ancient Mayans originally began cultivating had tiny seeds—vastly different from today’s relatively giant ears of corn. Interestingly, though these two plants appear to be entirely different, the genetic difference between them is miniscule.

        Pollination takes two forms: self-pollination and cross-pollination. Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant. Cross-pollination is the transfer of pollen from the anther of one flower to the stigma of another flower on a different individual of the same species. Self-pollination occurs in flowers where the stamen and carpel mature at the same time, and are positioned so that the pollen can land on the flower’s stigma. This method of pollination does not require an investment from the plant to provide nectar and pollen as food for pollinators.

        Explore this interactive website to review self-pollination and cross-pollination.

        Living species are designed to ensure survival of their progeny those that fail become extinct. Genetic diversity is therefore required so that in changing environmental or stress conditions, some of the progeny can survive. Self-pollination leads to the production of plants with less genetic diversity, since genetic material from the same plant is used to form gametes, and eventually, the zygote. In contrast, cross-pollination—or out-crossing—leads to greater genetic diversity because the microgametophyte and megagametophyte are derived from different plants.

        Because cross-pollination allows for more genetic diversity, plants have developed many ways to avoid self-pollination. In some species, the pollen and the ovary mature at different times. These flowers make self-pollination nearly impossible. By the time pollen matures and has been shed, the stigma of this flower is mature and can only be pollinated by pollen from another flower. Some flowers have developed physical features that prevent self-pollination. The primrose is one such flower. Primroses have evolved two flower types with differences in anther and stigma length: the pin-eyed flower has anthers positioned at the pollen tube’s halfway point, and the thrum-eyed flower’s stigma is likewise located at the halfway point. Insects easily cross-pollinate while seeking the nectar at the bottom of the pollen tube. This phenomenon is also known as heterostyly. Many plants, such as cucumber, have male and female flowers located on different parts of the plant, thus making self-pollination difficult. In yet other species, the male and female flowers are borne on different plants (dioecious). All of these are barriers to self-pollination therefore, the plants depend on pollinators to transfer pollen. The majority of pollinators are biotic agents such as insects (like bees, flies, and butterflies), bats, birds, and other animals. Other plant species are pollinated by abiotic agents, such as wind and water.

        Incompatibility Genes in Flowers In recent decades, incompatibility genes—which prevent pollen from germinating or growing into the stigma of a flower—have been discovered in many angiosperm species. If plants do not have compatible genes, the pollen tube stops growing. Self-incompatibility is controlled by the S (sterility) locus. Pollen tubes have to grow through the tissue of the stigma and style before they can enter the ovule. The carpel is selective in the type of pollen it allows to grow inside. The interaction is primarily between the pollen and the stigma epidermal cells. In some plants, like cabbage, the pollen is rejected at the surface of the stigma, and the unwanted pollen does not germinate. In other plants, pollen tube germination is arrested after growing one-third the length of the style, leading to pollen tube death. Pollen tube death is due either to apoptosis (programmed cell death) or to degradation of pollen tube RNA. The degradation results from the activity of a ribonuclease encoded by the S locus. The ribonuclease is secreted from the cells of the style in the extracellular matrix, which lies alongside the growing pollen tube.

        In summary, self-incompatibility is a mechanism that prevents self-fertilization in many flowering plant species. The working of this self-incompatibility mechanism has important consequences for plant breeders because it inhibits the production of inbred and hybrid plants.

        Pollination by Insects

        Bees are perhaps the most important pollinator of many garden plants and most commercial fruit trees ((Figure)). The most common species of bees are bumblebees and honeybees. Since bees cannot see the color red, bee-pollinated flowers usually have shades of blue, yellow, or other colors. Bees collect energy-rich pollen or nectar for their survival and energy needs. They visit flowers that are open during the day, are brightly colored, have a strong aroma or scent, and have a tubular shape, typically with the presence of a nectar guide. A nectar guide includes regions on the flower petals that are visible only to bees, and not to humans it helps to guide bees to the center of the flower, thus making the pollination process more efficient. The pollen sticks to the bees’ fuzzy hair, and when the bee visits another flower, some of the pollen is transferred to the second flower. Recently, there have been many reports about the declining population of honeybees. Many flowers will remain unpollinated and not bear seed if honeybees disappear. The impact on commercial fruit growers could be devastating.

        Many flies are attracted to flowers that have a decaying smell or an odor of rotting flesh. These flowers, which produce nectar, usually have dull colors, such as brown or purple. They are found on the corpse flower or voodoo lily (Amorphophallus), dragon arum (Dracunculus), and carrion flower (Stapleia, Rafflesia). The nectar provides energy, whereas the pollen provides protein. Wasps are also important insect pollinators, and pollinate many species of figs.

        Butterflies, such as the monarch, pollinate many garden flowers and wildflowers, which usually occur in clusters. These flowers are brightly colored, have a strong fragrance, are open during the day, and have nectar guides to make access to nectar easier. The pollen is picked up and carried on the butterfly’s limbs. Moths, on the other hand, pollinate flowers during the late afternoon and night. The flowers pollinated by moths are pale or white and are flat, enabling the moths to land. One well-studied example of a moth-pollinated plant is the yucca plant, which is pollinated by the yucca moth. The shape of the flower and moth have adapted in such a way as to allow successful pollination. The moth deposits pollen on the sticky stigma for fertilization to occur later. The female moth also deposits eggs into the ovary. As the eggs develop into larvae, they obtain food from the flower and developing seeds. Thus, both the insect and flower benefit from each other in this symbiotic relationship. The corn earworm moth and Gaura plant have a similar relationship ((Figure)).

        Pollination by Bats

        In the tropics and deserts, bats are often the pollinators of nocturnal flowers such as agave, guava, and morning glory. The flowers are usually large and white or pale-colored thus, they can be distinguished from the dark surroundings at night. The flowers have a strong, fruity, or musky fragrance and produce large amounts of nectar. They are naturally large and wide-mouthed to accommodate the head of the bat. As the bats seek the nectar, their faces and heads become covered with pollen, which is then transferred to the next flower.

        Pollination by Birds

        Many species of small birds, such as the hummingbird ((Figure)) and sun birds, are pollinators for plants such as orchids and other wildflowers. Flowers visited by birds are usually sturdy and are oriented in such a way as to allow the birds to stay near the flower without getting their wings entangled in the nearby flowers. The flower typically has a curved, tubular shape, which allows access for the bird’s beak. Brightly colored, odorless flowers that are open during the day are pollinated by birds. As a bird seeks energy-rich nectar, pollen is deposited on the bird’s head and neck and is then transferred to the next flower it visits. Botanists have been known to determine the range of extinct plants by collecting and identifying pollen from 200-year-old bird specimens from the same site.

        Pollination by Wind

        Most species of conifers, and many angiosperms, such as grasses, maples and oaks, are pollinated by wind. Pine cones are brown and unscented, while the flowers of wind-pollinated angiosperm species are usually green, small, may have small or no petals, and produce large amounts of pollen. Unlike the typical insect-pollinated flowers, flowers adapted to pollination by wind do not produce nectar or scent. In wind-pollinated species, the microsporangia hang out of the flower, and, as the wind blows, the lightweight pollen is carried with it ((Figure)). The flowers usually emerge early in the spring, before the leaves, so that the leaves do not block the movement of the wind. The pollen is deposited on the exposed feathery stigma of the flower ((Figure)).

        Pollination by Water

        Some weeds, such as Australian sea grass and pond weeds, are pollinated by water. The pollen floats on water, and when it comes into contact with the flower, it is deposited inside the flower.

        Pollination by Deception Orchids are highly valued flowers, with many rare varieties ((Figure)). They grow in a range of specific habitats, mainly in the tropics of Asia, South America, and Central America. At least 25,000 species of orchids have been identified.

        Flowers often attract pollinators with food rewards, in the form of nectar. However, some species of orchid are an exception to this standard: they have evolved different ways to attract the desired pollinators. They use a method known as food deception, in which bright colors and perfumes are offered, but no food. Anacamptis morio, commonly known as the green-winged orchid, bears bright purple flowers and emits a strong scent. The bumblebee, its main pollinator, is attracted to the flower because of the strong scent—which usually indicates food for a bee—and in the process, picks up the pollen to be transported to another flower.

        Other orchids use sexual deception. Chiloglottis trapeziformis emits a compound that smells the same as the pheromone emitted by a female wasp to attract male wasps. The male wasp is attracted to the scent, lands on the orchid flower, and in the process, transfers pollen. Some orchids, like the Australian hammer orchid, use scent as well as visual trickery in yet another sexual deception strategy to attract wasps. The flower of this orchid mimics the appearance of a female wasp and emits a pheromone. The male wasp tries to mate with what appears to be a female wasp, and in the process, picks up pollen, which it then transfers to the next counterfeit mate.

        Double Fertilization

        After pollen is deposited on the stigma, it must germinate and grow through the style to reach the ovule. The microspores, or the pollen, contain two cells: the pollen tube cell and the generative cell. The pollen tube cell grows into a pollen tube through which the generative cell travels. The germination of the pollen tube requires water, oxygen, and certain chemical signals. As it travels through the style to reach the embryo sac, the pollen tube’s growth is supported by the tissues of the style. In the meantime, if the generative cell has not already split into two cells, it now divides to form two sperm cells. The pollen tube is guided by the chemicals secreted by the synergids present in the embryo sac, and it enters the ovule sac through the micropyle. Of the two sperm cells, one sperm fertilizes the egg cell, forming a diploid zygote the other sperm fuses with the two polar nuclei, forming a triploid cell that develops into the endosperm . Together, these two fertilization events in angiosperms are known as double fertilization ((Figure)). After fertilization is complete, no other sperm can enter. The fertilized ovule forms the seed, whereas the tissues of the ovary become the fruit, usually enveloping the seed.

        After fertilization, the zygote divides to form two cells: the upper cell, or terminal cell, and the lower, or basal, cell. The division of the basal cell gives rise to the suspensor , which eventually makes connection with the maternal tissue. The suspensor provides a route for nutrition to be transported from the mother plant to the growing embryo. The terminal cell also divides, giving rise to a globular-shaped proembryo ((Figure)a). In dicots (eudicots), the developing embryo has a heart shape, due to the presence of the two rudimentary cotyledons ((Figure)b). In non-endospermic dicots, such as Capsella bursa, the endosperm develops initially, but is then digested, and the food reserves are moved into the two cotyledons. As the embryo and cotyledons enlarge, they run out of room inside the developing seed, and are forced to bend ((Figure)c). Ultimately, the embryo and cotyledons fill the seed ((Figure)d), and the seed is ready for dispersal. Embryonic development is suspended after some time, and growth is resumed only when the seed germinates. The developing seedling will rely on the food reserves stored in the cotyledons until the first set of leaves begin photosynthesis.

        Development of the Seed

        The mature ovule develops into the seed. A typical seed contains a seed coat, cotyledons, endosperm, and a single embryo ((Figure)).

        What of the following statements is true?

        1. Both monocots and dicots have an endosperm.
        2. The radicle develops into the root.
        3. The plumule is part of the epicotyl.
        4. The endosperm is part of the embryo.

        The storage of food reserves in angiosperm seeds differs between monocots and dicots. In monocots, such as corn and wheat, the single cotyledon is called a scutellum the scutellum is connected directly to the embryo via vascular tissue (xylem and phloem). Food reserves are stored in the large endosperm. Upon germination, enzymes are secreted by the aleurone , a single layer of cells just inside the seed coat that surrounds the endosperm and embryo. The enzymes degrade the stored carbohydrates, proteins and lipids, the products of which are absorbed by the scutellum and transported via a vasculature strand to the developing embryo. Therefore, the scutellum can be seen to be an absorptive organ, not a storage organ.

        The two cotyledons in the dicot seed also have vascular connections to the embryo. In endospermic dicots , the food reserves are stored in the endosperm. During germination, the two cotyledons therefore act as absorptive organs to take up the enzymatically released food reserves, much like in monocots (monocots, by definition, also have endospermic seeds). Tobacco (Nicotiana tabaccum), tomato (Solanum lycopersicum), and pepper (Capsicum annuum) are examples of endospermic dicots. In non-endospermic dicots , the triploid endosperm develops normally following double fertilization, but the endosperm food reserves are quickly remobilized and moved into the developing cotyledon for storage. The two halves of a peanut seed (Arachis hypogaea) and the split peas (Pisum sativum) of split pea soup are individual cotyledons loaded with food reserves.

        The seed, along with the ovule, is protected by a seed coat that is formed from the integuments of the ovule sac. In dicots, the seed coat is further divided into an outer coat known as the testa and inner coat known as the tegmen .

        The embryonic axis consists of three parts: the plumule, the radicle, and the hypocotyl. The portion of the embryo between the cotyledon attachment point and the radicle is known as the hypocotyl (hypocotyl means “below the cotyledons”). The embryonic axis terminates in a radicle (the embryonic root), which is the region from which the root will develop. In dicots, the hypocotyls extend above ground, giving rise to the stem of the plant. In monocots, the hypocotyl does not show above ground because monocots do not exhibit stem elongation. The part of the embryonic axis that projects above the cotyledons is known as the epicotyl . The plumule is composed of the epicotyl, young leaves, and the shoot apical meristem.

        Upon germination in dicot seeds, the epicotyl is shaped like a hook with the plumule pointing downwards. This shape is called the plumule hook, and it persists as long as germination proceeds in the dark. Therefore, as the epicotyl pushes through the tough and abrasive soil, the plumule is protected from damage. Upon exposure to light, the hypocotyl hook straightens out, the young foliage leaves face the sun and expand, and the epicotyl continues to elongate. During this time, the radicle is also growing and producing the primary root. As it grows downward to form the tap root, lateral roots branch off to all sides, producing the typical dicot tap root system.

        In monocot seeds ((Figure)), the testa and tegmen of the seed coat are fused. As the seed germinates, the primary root emerges, protected by the root-tip covering: the coleorhiza . Next, the primary shoot emerges, protected by the coleoptile : the covering of the shoot tip. Upon exposure to light (i.e., when the plumule has exited the soil and the protective coleoptile is no longer needed), elongation of the coleoptile ceases and the leaves expand and unfold. At the other end of the embryonic axis, the primary root soon dies, while other, adventitious roots (roots that do not arise from the usual place – i.e., the root) emerge from the base of the stem. This gives the monocot a fibrous root system.

        Seed Germination

        Many mature seeds enter a period of inactivity, or extremely low metabolic activity: a process known as dormancy , which may last for months, years, or even centuries. Dormancy helps keep seeds viable during unfavorable conditions. Upon a return to favorable conditions, seed germination takes place. Favorable conditions could be as diverse as moisture, light, cold, fire, or chemical treatments. After heavy rains, many new seedlings emerge. Forest fires also lead to the emergence of new seedlings. Some seeds require vernalization (cold treatment) before they can germinate. This guarantees that seeds produced by plants in temperate climates will not germinate until the spring. Plants growing in hot climates may have seeds that need a heat treatment in order to germinate, to avoid germination in the hot, dry summers. In many seeds, the presence of a thick seed coat retards the ability to germinate. Scarification , which includes mechanical or chemical processes to soften the seed coat, is often employed before germination. Presoaking in hot water, or passing through an acid environment, such as an animal’s digestive tract, may also be employed.

        Depending on seed size, the time taken for a seedling to emerge may vary. Species with large seeds have enough food reserves to germinate deep below ground, and still extend their epicotyl all the way to the soil surface. Seeds of small-seeded species usually require light as a germination cue. This ensures the seeds only germinate at or near the soil surface (where the light is greatest). If they were to germinate too far underneath the surface, the developing seedling would not have enough food reserves to reach the sunlight.

        Development of Fruit and Fruit Types

        After fertilization, the ovary of the flower usually develops into the fruit. Fruits are usually associated with having a sweet taste however, not all fruits are sweet. Botanically, the term “fruit” is used for a ripened ovary. In most cases, flowers in which fertilization has taken place will develop into fruits, and flowers in which fertilization has not taken place will not. Some fruits develop from the ovary and are known as true fruits, whereas others develop from other parts of the female gametophyte and are known as accessory fruits. The fruit encloses the seeds and the developing embryo, thereby providing it with protection. Fruits are of many types, depending on their origin and texture. The sweet tissue of the blackberry, the red flesh of the tomato, the shell of the peanut, and the hull of corn (the tough, thin part that gets stuck in your teeth when you eat popcorn) are all fruits. As the fruit matures, the seeds also mature.

        Fruits may be classified as simple, aggregate, multiple, or accessory, depending on their origin ((Figure)). If the fruit develops from a single carpel or fused carpels of a single ovary, it is known as a simple fruit , as seen in nuts and beans. An aggregate fruit is one that develops from more than one carpel, but all are in the same flower: the mature carpels fuse together to form the entire fruit, as seen in the raspberry. Multiple fruit develops from an inflorescence or a cluster of flowers. An example is the pineapple, where the flowers fuse together to form the fruit. Accessory fruits (sometimes called false fruits) are not derived from the ovary, but from another part of the flower, such as the receptacle (strawberry) or the hypanthium (apples and pears).

        Fruits generally have three parts: the exocarp (the outermost skin or covering), the mesocarp (middle part of the fruit), and the endocarp (the inner part of the fruit). Together, all three are known as the pericarp . The mesocarp is usually the fleshy, edible part of the fruit however, in some fruits, such as the almond, the endocarp is the edible part. In many fruits, two or all three of the layers are fused, and are indistinguishable at maturity. Fruits can be dry or fleshy. Furthermore, fruits can be divided into dehiscent or indehiscent types. Dehiscent fruits, such as peas, readily release their seeds, while indehiscent fruits, like peaches, rely on decay to release their seeds.

        Fruit and Seed Dispersal

        The fruit has a single purpose: seed dispersal. Seeds contained within fruits need to be dispersed far from the mother plant, so they may find favorable and less competitive conditions in which to germinate and grow.

        Some fruit have built-in mechanisms so they can disperse by themselves, whereas others require the help of agents like wind, water, and animals ((Figure)). Modifications in seed structure, composition, and size help in dispersal. Wind-dispersed fruit are lightweight and may have wing-like appendages that allow them to be carried by the wind. Some have a parachute-like structure to keep them afloat. Some fruits—for example, the dandelion—have hairy, weightless structures that are suited to dispersal by wind.

        Seeds dispersed by water are contained in light and buoyant fruit, giving them the ability to float. Coconuts are well known for their ability to float on water to reach land where they can germinate. Similarly, willow and silver birches produce lightweight fruit that can float on water.

        Animals and birds eat fruits, and the seeds that are not digested are excreted in their droppings some distance away. Some animals, like squirrels, bury seed-containing fruits for later use if the squirrel does not find its stash of fruit, and if conditions are favorable, the seeds germinate. Some fruits, like the cocklebur, have hooks or sticky structures that stick to an animal’s coat and are then transported to another place. Humans also play a big role in dispersing seeds when they carry fruits to new places and throw away the inedible part that contains the seeds.

        All of the above mechanisms allow for seeds to be dispersed through space, much like an animal’s offspring can move to a new location. Seed dormancy, which was described earlier, allows plants to disperse their progeny through time: something animals cannot do. Dormant seeds can wait months, years, or even decades for the proper conditions for germination and propagation of the species.

        Section Summary

        For fertilization to occur in angiosperms, pollen has to be transferred to the stigma of a flower: a process known as pollination. Gymnosperm pollination involves the transfer of pollen from a male cone to a female cone. When the pollen of the flower is transferred to the stigma of the same flower, it is called self-pollination. Cross-pollination occurs when pollen is transferred from one flower to another flower on the same plant, or another plant. Cross-pollination requires pollinating agents such as water, wind, or animals, and increases genetic diversity. After the pollen lands on the stigma, the tube cell gives rise to the pollen tube, through which the generative nucleus migrates. The pollen tube gains entry through the micropyle on the ovule sac. The generative cell divides to form two sperm cells: one fuses with the egg to form the diploid zygote, and the other fuses with the polar nuclei to form the endosperm, which is triploid in nature. This is known as double fertilization. After fertilization, the zygote divides to form the embryo and the fertilized ovule forms the seed. The walls of the ovary form the fruit in which the seeds develop. The seed, when mature, will germinate under favorable conditions and give rise to the diploid sporophyte.

        Science KS1 / KS2: What is pollination and how does it work?

        Ivy: Well, these pests are bothering my lovely flowers!

        Posey: They're pollinating them! It's important.

        Ivy: Are you sure? It looks like they're just headbutting them.

        Posey: That's because the flowers are attracting insects as they're an important part of making new plants. The smell from the nectaries and the prettiness of the petals draws the insects in towards them. As they dig for the sweet nectar all the pollen rubs off on their bodies from the stamen. The nectaries are right at the bottom to make sure this happens. Once the little bee has had her fill she'll fly off to find more nectar.

        Posey: When the bee digs into the next flower the pollen on her body rubs off onto the stigma of the new flower. This is called pollination. When the pollen lands on the stigma it travels down the style towards the ovary. Once the pollen reaches the ovary it hopes to find an ovule to attach to. This is called fertilisation. This is the beginning of a new seed. It is absorbed into the receptacle and fruit starts to form from the seed. It is called sexual reproduction. When the fruit is ready, the plants release the seeds which get moved into the soil.

        Posey: In a few different ways. Seeds can be blown by the wind, or eaten by animals and then pooped out in a different place.

        Posey: They can explode and scatter themselves, float on water, fall from flowers and trees and they can also stick to animals' fur and be moved. Once they are dispersed in the soil they can create new plants. So what were all the ways?

        Ivy: Blow, Eat, Explode, Fall, Float and Stick. B.E.E.F.F.S! See, I do listen!

        Posey: Well if you've really been listening. How does pollination work?

        Ivy: Oh, i'll explain. Through the medium of song. Climb into the flower to get the sweet nectar, rub past the pollen on the way out, to another flower to get the sweet nectar, rub it on the stigma that's what it's about. Busy bees, doing their thing Busy bees, pollinating. Pollen travels down the style, gets to an ovule. Makes a seed. That's fertilising. Seed gets moved away, and is replanted. Makes a new plant and it happens again. Busy bees, doing their thing, busy Bees, pollinating.

        Ivy: Posey- what are you doing?

        Posey: That's amazing. Can I put it on Youtube?

        Ivy: Youtube. Yeah, put it on my channel.

        Posey: Aunt Ivy, there are some plants which can reproduce.

        Posey: Make baby plants - on their own. This is called asexual reproduction. For example, a strawberry plant can reproduce when its stems, called runners, are replanted in new soil. This will start a new plant.

        Ivy: So it can create new plants on its own? You're exploding my mind.

        Watch the video: Pollination for Kids (May 2022).