First thing in the morning, we headed towards the interior of Guyana, where we visited a coconut, pineapple, and other smaller ‘cash crop’ farms. The most important pest brought to our attention was the devastation being caused by a rhinoceros beetle; a beetle that bores at the base of the coconut trees and into the main stem, resulting in total tree mortality. The growers said they have lost about 50% of their coconut trees to the rhinoceros beetle! The bore holes always appear to be right at the stem of the coconut tree. This problem made me think of the Diaprepes root weevil problem in Texas; a beetle that kills citrus plants by laying eggs on the leaves, and the larvae fall onto the soil below, burrow into the ground, and feed on the roots. Research at Texas A&M demonstrated that the weevil could be stopped by using a plastic mesh over the soil, which prevents the larvae from being able to burrow down below and the larvae subsequently die. In theory, this same solution should work to prevent the rhinoceros beetle from getting into the trees – I proposed this as a solution to the coconut growers and hopefully provides some promising results.
Bore hole created by the rhinoceros beetle
Hole made by the rhinoceros beetle
Hole created in the base of the coconut tree by the rhinoceros beetle
Coconut propagation trial
Next, we visited a region of Guyana that is known for producing chives and lettuce – most of the growers in that small area specialize on those two crops. Many of these growers are small acreage, growing mainly in their backyards in beds or shade-houses. We identified many different crop challenges, including leaf-miners, root-knot nematodes, and mealybugs. The leaf-miner appears to be a species within the genus Liriomyza– a fly that spends its larval stage between the upper and lower leaf tissue, making it really challenging to control with insecticides and tend to produce scars on leaves even if you do manage them. The mealybugs are difficult to notice until too late, as this particular group appears to feed on the roots. Root-feeding mealybugs will reduce the growth and uptake efficiency of the roots, resulting in above-ground effects but with no obvious culprits (until you take the plant out of the ground!).
Chives in raised beds in a ‘shade house’
Roots of the celery
Mealybugs on the celery roots
Small acreage fruit and vegetable farm
Leaf-miner on chives
Leaf-miner on lettuce
We saw the root-knot nematodes at some farms the day before too – so this problem is relatively widespread, it seems. One method of killing nematodes within a bed is to use the soil solarization technique – a method that involves using clear plastic to cover a bed and allow the sun to essentially ‘cook’ the bed completely of weed seeds, nematodes, insect eggs, and bacteria. They have access to clear plastic here at the local agricultural supply stores, making this a possible option for future nematode control.
Although I provide the growers with some solutions as we are making observations on their farm, the purpose of this week is really to make observations in order to develop the training programs for next week. I will be developing more specific diagnoses and multiple solutions to each challenge they are facing, with the hopes that they find at least one that is suitable and works reliably to reduce crop yield loss.
We drove to region 6, which is far down south along the coast for a total of about 3 hours commute time in each direction. Throughout the whole drive, Guyana felt like just a very large village. People are all outside, working together, talking to each other… everything seems very grass-roots. Rather than each farmer having a full set of their own equipment, individual houses along the road had different tractor equipment (tractors, harvesters, etc.), all of which would be needed to till, disk, sow, and/or harvest the different crops in the area. We saw some large rice paddy fields, rice processing plants, a couple sugar cane fields, and some pasture with livestock. Along the roads everywhere are cannals – cannals that feed a whole network of cannals and irrigation throughout the country. They also have dams that can open after heavy rains to let the excess water into the ocean, and close when rain levels are low, to prevent salt water from getting in… Can tell that the hands of the Dutch have been here!
Leon pointing out some rice paddies
Cultivated bees. There are lots of wild bees here, apparently Africanized, but they are starting to cultivate them here too for honey and wax.
One of the cannals leading to a dam that is opened during heavy rain to prevent flooding.
Cannal going under the bridge – irrigation is fed out of these cannals
One of the rice processing plants can been seen on the right in the distance
The only way across into parts of region 6 used to be a ferry, with high congestion and long wait times.
This bridge replaced the ferry and is only closed during specific hours to allow for ships to go through
The city signs (seen on the right) are sponsored by Pepsi
One of the backroads to get to our destination
Most of what we saw was rather familiar. The first couple farms were mostly peppers (i.e. bell peppers), with some tomatoes, cabbage, citrus, melons, and eggplant. There were also some tropical fruit, such as Soursop and starfruit, which I currently know very little about! Another very interesting nearby plant was the abundance of neem trees, Azadirachta indica.
What’s interesting about neem trees is that we actually have several insecticides in the USA that are based on Neem, specifically neem oil (which covers and suffocates the insects) and azadiracthin; a compound extracted from neem seeds that has some repellency and growth disruption (insect growth regulator) effects.
The Farmers themselves were all very kind, welcoming, and generous. A couple of them were rather young too and Leon confirmed that more young people are getting into farming. One of them may actually be a great resource, because he knew a lot about what was wrong with the plants and could quickly recognize symptoms.
Young pepper plants (up front) and older pepper plants (back)
Young farmer and a donkey
Pepper plants in shade house. This operation was a side hobby of a builder
Farmers and collaborators discussing next to the peppers
Without a doubt, the growers here face some serious yield loss. One of the growers estimated 20% of pepper yields to disease, another 60% loss of melons to a rot, and another 45% yield loss of cauliflower due to diamondback moth. Their rainy season sees very high humidity (currently 87% RH outside) and high moisture, making diseases difficult to prevent in the first place for disease-susceptible crops/cultivars. Some other crop challenges they face include some cultural practices (nutrient management), whiteflies (and subsequent diseases transmitted by them), “gandhi” (known as “stink bugs” in the US), leaf-footed bugs, thrips, spider mites (in the dry seasons), flea beetles, root-knot nematodes, and goats… yes, goats… just to name a few. The goats appear to be rather crafty – in one instance, they pushed a fence over and go to an entire plot of large pepper plants and chewed them up quite good! I guess that’ll just help fatten up the goats a bit…
I found it interesting that they call stink bugs “gandhi”, specifically because “gand” in the Persian language means “stinky”. Used in a sentence, my mother would say something like “Erfan, put on some deodorant, you smell like gand!” during my teenage years (FYI. I wear deodorant much more regularly now…). I wonder if gandhi in an Indian language (one of the main cultures in Guyana) means “stinky” (for stinkbug) and the Persian language shares the same root.
The Soursop also had an interesting insect pest – a borer that goes straight for the seeds! After some quick research and based on the description of the damage, the culprit appears to be a wasp (commonly referred to as the Soursop wasp) that lays eggs into the seeds with a long ovipositor (organ used to lay eggs) when the fruit is small. When the fruit is larger, the larvae emerge from the seeds and exit out of the fruit, causing these large holes on the outside of the fruit. This provides an opportunity for other insects and diseases to also infiltrate the fruit, increasing the problem, and ruins the seeds for future plantings.
Soursop with exit holes from the fruit
Cutting the fruit open, we can see the seeds are eaten/ruined
In this case, it appears to be a scale or mealybug on the fruit
The peppers faced a range of issues. They appear to be affected by a bacterial leaf spot, possibly anthracnose, feeding damage from stink bugs, and root-knot nematodes. Root-knot nematodes can be a challenge to manage, even in the US. They resort to some of the harsh (Danger-level) nematicides, such as Vydate, and even then, appear to have lots of nematodes. With the way the water constantly moves around the land here, nematode management may prove challenging. With all of the pesticides they spray, people may be concerned how it affects the surrounding environment – but the abundance of frogs, dragonflies, and ludicrous quantity of mosquitoes suggests that the ‘environment’ may be doing reasonably well. Below are several images of some of the types of plants disease and insect damage that we saw today. If you see anything that you definitely recognize, please feel free to provide your insight!
What appears to be “cat-facing” of some of the Soursop, which can be caused by stink bugs
Some light green between leaf veins, may be a sign of lack of nutrients (i.e. nitrogen)
Common problem afflicting peppers, may be Anthracnose
Disease afflicting the melons. May be bacterial fruit blotch or bacterial rind necrosis.
Disease afflicting the melons. May be bacterial fruit blotch or bacterial rind necrosis.
Root-knot nematodes choking up the pepper plants
Pepper plants that were dying prematurely
A small brown stink bug, or “Gandhi”, as they referred to them here.
A small green stink bug, or “Gandhi”, as they referred to them here.
Spots on the citrus
Leaf-footed bugs – a common insect pest in North American gardens too
Lastly, I wanted to mention the melons. Seen above is a melon that has a spot starting to form on it that eventually expands and takes over the whole fruit; in my quick search, I found either bacterial fruit blotch or bacterial rind necrosis as the possible culprits. The farmer here described this disease as a “terrible tragedy” with the melons right now, with around 60% of yields lost to this problem. What makes it worse – it only appears after the fruit is just about to ripen, meaning that the plant and fruit has taken the space, water, and nutrients before it completely rots.
In the next few days I will be visiting some more farmers to see whether they face any additional unique challenges. Once I have consolidated all of the photos and information on their crop challenges, I can break it down by region and start forming workshop materials to hopefully provide practical solutions to at least some of their crop yield losses. I have also been taking notes and photographing their pesticides application practices and will consolidate that in a separate post later in the week – information that will be vital to understand current management practices and how they can be improved. Spoiler: farms here may benefit from chemical rotation to prevent promotion of pesticide-resistant pests.
Our flight arrived early this morning, from Miami to Guyana. Our driver recognized us using our F2F hats we were provided in our orientation packages and started the one-hour driver to Georgetown. Like the couple other countries I have visited in South and Central America, ‘highways’ are two or maybe four lanes (maximum), with houses, businesses and all kinds of vendors along the roadside – in other words, it doesn’t quite feel like a ‘highway’. I was a bit surprised to learn that there’s another F2F volunteer here this week at the same time as me, Patrick, who focuses on solar panels and sustainable energy sources for farms.
We arrived at the F2F headquarters, where were given telecommunications devices from a large brown envelope – ok fine, it’s a cell phone for our use during our time here, but it took me a while to remember how to even add a phone number and/or text on this thing! In a way, it’s a bit nostalgic. At the headquarters, we were briefed on the ten administrative regions of Guyana, with the fruit and vegetable production focused along the coast in regions 1-6. F2F has been operational in Guyana for about 30 years with new volunteers coming in every two weeks with different specializations! It’s rather impressive how the small local F2F team is able to quickly address the needs of the local farmers by recruiting foreign specialists and coordinating grower visits/programs for every week.
F2F Local team (Jermaine Joseph, Kelvin Craig, and Leon Peters from left-to-right) and volunteers (Patrick and myself)
F2F briefing room
The F2F local headquarters
It’s also quite impressive to see how much Partners of America is able to accomplish, with activity in 30 countries, 5,870+ volunteers worth $1.8M USD in 2017 alone.
Energy in Guyana is expensive and they periodically experience power loss for 3 – 12 hrs. That’s where Patrick’s work with solar power comes in, especially for some of the growers in the region that are producing hydroponically. The local F2F personnel also emphasized that the growers use ‘shade houses’ (rather than greenhouses), with basic frames, plastic (to reduce direct rain) and netting (to reduce sunlight). Apparently water is not an issue in Guyana, which literally means “Land of Many Waters”. Tomorrow I’ll have my first grower visit and look forward to learning more about specific crops and pest management challenges.
The vegetation here is quite different than Texas (of course!). I have seen an abundance of palms, cacti, and lotus. The lotus, Nelumbo nucifera, is actually not native to Guyana and covers the small creeks between the roads and private properties. One of the spindly plants at our hotel was rather peculiar, but felt familiar after touching it due to the white waxy residue that stuck to my fingers. The Pencil Cactus, Euphorbia enterophora (or other related species), is in the same genus as poinsettias (which I do an abundance of work with) and looks like a bunch of green ‘stems’ with disproportionately small leaves.
Related to poinsettias
Pereskia, a unique genus of cacti
Lotus plants occupying the streams, often found flanking the roads.
That’s all for now! Look forward to taking more photos and sharing with y’all more as the week goes on.
This week, one of our Texas growers held an internal full-day training program and were kind enough to allow me to take notes and share them with the rest of you growers! One of the many things I continue to really appreciate and like about the green industry in Texas: they are collaborative and help each other out. See below for speakers and notes related to their presentations.
Please note that I do not personally endorse the products mentioned by the presenters below – the notes provided below are “as-is”, as written as accurately I could based on the information provided by the presenters. Any lack of information or misinformation is not intentional.
The current population of the whole country of Guyana is under 780,000 people in about 83,000 sq. miles of land mass. For a bit of context, the Dallas-Fort Worth metroplex is about 9,286 sq. miles with a population of about 7,500,000!
Agriculture is of great economic importance in Guyana, accounting for about 1/3 of its Gross Domestic Product and about 30% of its work force (export.gov). Two of the major commodities grown in Guyana include rice and sugar. At the end of 2015, the Ministry of Agriculture had reported an increased production of rice from 635,238 tonnes of rice (2014) to 683,516 tonnes (2015). The Ministry of Agriculture is working on trials to introduce several new cultivars of rice into the market to increase yields, which is rather crucial, seeing as how the 7.6% increase in rice yields was met by a 15% decrease in rice value in the global market.
As with any major commodity, there’s bound to be a pest or pests of great economic importance. In this case, it’s the “Paddy Bug“, what appears to be a sucking insect pest in the same family as stink bugs (Pentatomidae). This wouldn’t be the first Pentatomidae that causes major economic damage and we are no strangers of major Pentatomidae pests in the USA; an example in the USA is the brown marmorated stink bug – a generalist sucking insect pest that causes damage on several different fruits and vegetables in the northeast. Some of the current best management practices for the paddy bug include removing alternative plant hosts, where they can continue to breed or survive when the rice crop is not yet planted.
Sugar also saw great increases in crop yields, but also saw a decrease in global market prices. No major pests of economic importance were mentioned in the Ministry of Agriculture report.
I do not anticipate working much with growers producing rice or sugar, but rather speciality crop producers, such as vegetables, fruits, and perhaps even ornamentals. Another devastating pest mentioned in the report is the Red palm mite, particularly on coconuts, with $49M approved to help farmers affected by the red palm mite in Guyana back in 2015.
The red palm mite is considered an invasive pest (i.e. not native to Guyana), originally found near the Middle East. In 2004, this mite started to show in several regions in Central and South America, and in 2007, was even found in Florida (Ent Department, UFL). Give it some time, and this mite could become a pest in Texas as well – so I guess it will help to get a close look at first hand it in Guyana.
Note to self: wash clothes thoroughly before bringing back to Texas.
Guyana’s Ag has seen more recent increases in specialty crops, such as spices, new vegetables (cauliflower, broccoli, red cabbage, and sweet pepper), and revitalization of crops such as coconut and cassava, according to Guyana’s National Agricultural Research & Extension Institute (similar to Texas A&Ms AgriLife Extension in Texas). Interesting note about Cassava, the dried leaves can contain about 30% protein by mass (Awoyinka et al. 1995), although the same study seems to imply that dried leaves are not super palatable. I hope to find out for myself when I’m in Guyana.
Guyana also has a Livestock Development Authority, with one objective aimed at increasing apiculture (honeybee cultivation) production to a nation-wide scale, increase yields and meet international standards. Guyana’s Pesticide and Toxic Chemical Control Board (PTCCB) is responsible for all things related to pesticide registration and application. An interesting initiative included in the PTCCB 2017 report is a pilot project aimed to educate secondary school students on pesticides nation-wide! Covering such topics at an early age may go a long way in increasing science literacy and decreasing misinformation about pesticides, which are incredibly valuable to food security, human safety, and the environment.
Some of the most imported (quantity, in kg) insecticides belong to the pyrethroid, organophosphate and neonicotinoid insecticide classes. Some specific examples include Alpha-Cypermethrin, Carbaryl, Chlorpyrifos & Cypermethrin, imidacloprid, and Triazophos. Most of these insecticides are “hammers” – they work really well, but will typically knock out beneficial insects as well. In the case of the chemical class containing imidacloprid, studies have demonstrated an outbreak of spidermites (a small plant-damaging mite) after pesticide applications (Szczepaniec et al. 2011); a phenomena that has since been attributed to the pesticide interfering with the natural defenses in the plant (Szczepaniec et al. 2013). In the case of carbaryl, it is thought that it devastates the natural predators of the herbivorous spidermites, resulting in a herbivore population that’s left unchecked. This also applies to people applying Sevin dust in their own garden; if you notice spidermite damage shortly after application, you may want to consider applying something different.
A short post can’t do the full scale and complexities of Guyana’s agriculture justice, but hopefully this post provided a sprench of context – I know it helped me become a bit more familiar with the agencies, crops, and pests that they may be dealing with.
In 2006, I took a course in Ecology instructed by Dr. Jeremy McNeil and subsequently chemical ecology instructed by him the next year. In this course, we learned about the interactions between plants and plants, plants and insects, and insects and insects using chemicals in the air. For example, we learned a plant could respond to an insect feeding on it by releasing chemicals that attract the herbivores predators, ultimately helping protect the plant. He provided examples of how such natural interactions between plants and insects had been used for very economic and sustainable pest management practices in regions where insecticidal or monetary resources were limited. His courses inspired me to pursue a career in entomology, specifically in the area of crop protection, and the ability to travel internationally to aid in crop protection is a wish come true.
In two days I fly to Guyana for the Farmer-to-Farmer volunteer program. I will be spending two weeks there: most of the first week will be spent visiting the farms, getting to know them and plant protection challenges. Week two I will be on a workshop/training spree, providing programs every morning and afternoon on topics ranging from scouting/monitoring, recognizing pests, recognizing beneficial insects, how to prevent pest outbreaks, physical and mechanical controls, biological control, and chemical control.
Before traveling overseas, you always need to check what kinds of vaccines or shots you need to take. Our local “travel” nurse practitioner in Tyler TX followed the CDC guidelines for travel to Guyana. I must admit, the Typhoid pills were a bit unpleasant, especially since I did not anticipate the side-effects of twisting/turning stomach and subsequent increased frequency to the porcelain throne for a few days. Interesting fact: apparently the vaccine for yellow fever is in limited is temporarily depleted, apparently due to manufacturing delays from the only supplier. An alternate is available (Stamaril) if I had time to book an appointment in Dallas. So… I’ll be rolling the dice on that one! I started taking my Malaria pills yesterday (two days before travel) – hopefully that are no unpleasant surprises with that one.
Malaria actually describes a protozoan parasite that invades the red blood cells and transmitted by mosquitoes. Interestingly, the parasite alters the feeding behavior of mosquitoes in two distinct ways: larger blood meals and more blood meal hosts (Koella et al. 1998). More specifically, they found that the mosquito takes larger blood meals when the parasite is in a stage in which the parasite can infect humans. When malaria infects humans, it can occupy both the blood (human blood cell stage) and the liver (human liver stage) (Medicines for Malaria Venture), sometimes remaining dormant in the liver for months or years before coming back in the blood and resurfacing symptoms. Speaking of symptoms, malaria infection can cause fever, chills, headache, nausea & vomiting, and muscle pain and fatigue (Mayo Clinic). In 2016 alone, it was estimated that 445,000 people died from malaria, most young children in sub-Sahara Africa (CDC: Malaria). One potential mechanism to reduce malaria is the use of transgenic mosquitoes – that is, mosquitoes that are genetically engineered to be unable to harbor the parasite, and thus, unable to vector it to humans. Marrelli and colleagues (2007) demonstrated that not only was their transgenic mosquito no longer able to vector malaria, but it actually had a fitness advantage compared to the wild mosquitoes – an important requirement if you’re going to replace all the wild mosquitoes with ones that don’t vector the virus (i.e. Gene Drive).
I finished packing and look forward to learning a lot on this trip, and hope to share what I learn, my experiences at the farms, and a bit about Guyana itself here – so stay tuned!
A recent presentation given for the Master Volunteers Entomology Specialty Training in College Station on September 12, 2018. Topics covered include basic introduction to integrated pest management, concepts in biological control, and several commercially available and naturally occurring biological control agents for managing common garden pests.
The same old annual pests, such as aphids, thrips, twospotted spider mites, and whiteflies, can be rather annoying and a constant uphill battle to manage. For the most part, however, we have a good handle of these pests and can maintain them below economic threshold levels. We run into trouble when an irregular pest, such as a quarantine international invasive pest or a pest from a neighboring state, show up on the operation. We can fail to identify the species, and as a result, fail to act quickly to keep the pest under check. In this article, we try to provide a list of some of the rising pests and how to recognize them.