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ECHO Research Notes are topic-specific publications about crops and agricultural practices important to those working in the tropics and subtropics. Our material is authored by ECHO staff (past and present) as well as outside writers, all with experience and knowledge of their subject. These documents are free for your use and will hopefully serve a valuable role in your working library of resources in agricultural development!


Fill it Full: A Simple Way to Reduce Weevil Damage in Maize Seed Stored in Airtight Containers

Rocheteau Dareus

Postharvest losses inflicted by insect pests in stored grains represent major challenge smallholder famers face in the global South. The maize weevil (Sitophilus zeamais) is one of the most important postharvest pests in maize. We hypothesized that reducing air space within sealed containers will help control maize weevil in stored maize seeds by depriving them of oxygen. This approach works if the container is hermetically sealed, meaning that there are no leaks that would allow the movement of outside air into the container. To conduct the experiment, we used 12 jars that we filled with maize seed: 4 jars with 100% of their volume occupied with seeds, 4 jars with 50% of their volume occupied with seeds, and 4 jars with 25% of their volume occupied with seeds. Results for the parameters investigated, though not all statistically significant, met our expectations of less weevil damage with full than partially filled (25% to 50%) containers. None of the treatments achieved 100% weevil mortality, but the damage caused by weevils was lower in jars that were at least half full than those filled to 25% of their volume.

Does Wood Ash Help Preserve Tomatoes (Solanum lycopersicum)?

Rocheteau Dareus

Following the astonishing findings in an article published in November 2016 of a farmer preserving freshly harvested tomatoes in wood ash for up to 5 to 6 months, the research team at ECHO Florida decided to further investigate the potential of this technique to prolong the storage life of fresh tomatoes. We assumed that, in comparison to a control treatment of sifted sand, wood ash would extend the time over which tomatoes can be marketed or processed. To test this hypothesis, a randomized complete block design was used with tomatoes placed in boxes (4 tomatoes per box) filled with wood ash or sand. At the start of the trial, tomatoes were already ripe but unspoiled. Data were collected biweekly for tomato sugar content, visual quality, pH and carbon dioxide production. Differences in the measured parameters, between ash and sand, were not statistically significant. We were only able to preserve our tomatoes for 6 weeks. Differences between our findings and what the farmer was able to achieve could be related to ripening stage or source of wood ash. Future work could be done with tomato fruit at early (mature with slight change in color from green to red) versus more advanced stages of ripeness and with wood ash from various species of trees. 

Crop responses to natural farming soil drenches on sandy soils

Stacy Swartz and Tim Motis

Between 2017 and 2018, a trial was conducted comparing IMO, EM, mulch, and no mulch on a raised bed system on the ECHO Florida campus. Each of these main treatments was evaluated with and without NPK fertilizer in a split-plot, randomized complete block design. Less cotton was decomposed in the soil of the control treatment than soil of the EM soil drench treatment (P=0.0542) suggesting lower rates of microbial activity. Fertilized split treatments produced more grams of edible product than unfertilized split treatments (P<0.05). This study was conducted in a sandy soil with low organic matter. IMO or EM products may need to be “stepped up” to more stable carbon sources such as bran, compost, or manure before being utilized in soils low in organic matter.

Maize Production with Manure- Amended Compost

Andy Deaville and Ruth Portnoff

Information from ECHO Network member Daryl Edwards from his work in Zimbabwe suggested that using quality compost containing 10% cow manure results in a maize harvest similar to that obtained with 100% cow manure. This could be significant to farmers who have small farm sizes and limited livestock and manure resources. The proposition was tested in the field on ECHO’s demonstration farm in North Fort Myers, Florida. Four compost mixes (10%, 25%, and 100% cow manure, as well as 25% Mucuna pruriens; remaining portions of each compost mix were made up of equal parts of woody and leafy green plant material) were applied as pre-plant fertilizers to maize planting stations established according to a conservation farming system called Foundations For Farming (FFF). The compost was made in September (2010), and the trial was carried out between May and September of 2011. Data were collected on seed germination, tasseling, number of ears per plant and yield (dried on-cob and shelled weights of the harvested corn). Maize grain yield ranged from 4.4 to 5.4 t/ha. During the same season, a non-fertilized maize plot on another section of the ECHO Global Farm yielded 2.2 t/ha. Compost treatment had no effect on yield or any other crop growth parameter measured. Results indicate that, with compost comprised of as little as 10% cow manure or 25% Mucuna pruriens, farmers can obtain similar maize yields as 100% composted cow manure.

Low-Cost Natural Building Options for Storing Seed in Tropical Southeast Asia

Patrick Trail, Yuwadee Danmalidoi, Saw Moo Pler, Abram Bicksler and Boonsong Thansrithong

Keeping in mind the insulating qualities and low-cost of construction of natural building techniques, ECHO Asia began testing different methods at the Asia Impact. In 2018, ECHO conducted a small experiment in Thailand and Myanmar to test these hypotheses, specifically within the Southeast Asian context, where temperature and humidity are higher than the climates in which these facilities have previously been implemented. Lablab seeds were stored over the course of one year inside of three different natural building facilities: (1) an Earth Bag House, (2) a Hillside Bunker, and (3) a Buried Clay Cistern. Seeds were placed inside of each facility, with half of the seeds being sealed in jars using a modified Bicycle Vacuum Pump, while the other half remained unsealed in paper bags. The underground facilities, the buried cistern and the hillside bunker, recorded very high rates of humidity, while the freestanding earth bag house appears to have achieved lower overall humidity. In combination with vacuum-sealing, seed germination rates in each of the 3 storage facilities remained steady over the course of one year, maintaining germination rates above 90% at the end of the experiment.

Making On-Farm Pig Feed: Farm-Generated Formulas vs. Commercial Feeds

Patrick Trail, Boonsong Thansrithong, & Sombat Chalermliamthong

This article was first published in ECHO Asia Note # 42

The integration of livestock on the smallholder farm is often a key component to the long-term sustainability of the farm, specifically by means of critical nutrient cycling. Livestock play a unique and critical role on the farm, transforming plant and waste materials into important sources of energy, either for consumption on the farm, or for sale beyond it. As omnivores, pigs are one of the most efficient converters of on-farm ‘waste’, transforming materials unsuited for human consumption, into meat, manure, and income. 

On the ECHO Asia Farm we seek to create our own ‘Farm-Generated Feeds’ for the purpose of leveraging the materials we have available to us, while bringing down our costs of livestock production. In addition to the meat and income produced through our cows, pigs, chickens, and fish, we also value them for their manure, which we compost and use in crop production among other things.

Production of Vegetable Fern (Diplazium esculentum Reytz.) Under Varying Levels of Shade

Patrick Trail, Yuwadee Danmalidoi, Abram Bicksler, and Rick Burnette

Several species of edible ferns exist around the world, ranging from the tropics to more temperate regions, and most commonly include the bracken ferns (Pteridium spp.), ostrich fern (Matteuccia struthiopteris), and the Stenochlaena spp. ferns. However, the focus of this study is on the vegetable fern (Diplazium esculentum Reytz.), a tropical perennial vegetable crop typically found growing in the Asia and Oceania regions. Sakai et.al. (2016) categorize this edible vegetable fern as a Non-Timber Forest Product or NTFP. It is a regionally significant vegetable crop in India, Bangladesh, Thailand, Malaysia, Philippines, and the US state of Hawaii (Lin et al., 2009). The young tender fronds of the fern (commonly referred to as ‘fiddleheads’) are typically eaten fresh, boiled, blanched, or cooked in curries, depending on the region in which they are consumed (Duncan, 2012).