Is it possible to grow temperate fruit apples in a tropical nation like the Philippines? Can a female tilapia be turned into a male? Is there a sustainable method that can control the problem of soil erosion in the uplands?
The responses to those inquiries were once deemed unattainable. However, due to the creativity and resourcefulness of certain pioneering individuals, what was once considered impossible has now been realized.
Benzone Kennedy F. Sepe from Kapatagan, Digos City, has demonstrated that it is now feasible to cultivate apples in the Philippines. Dr. Rafael D. Guerrero III from Los Baños, Laguna, successfully raised all-male tilapia in a pond without the need for the tedious process of manual sexing. American missionary Harold R. Watson achieved the remarkable feat of mitigating soil erosion by establishing hedgerows with nitrogen-fixing trees and shrubs.
Fascinating stories exist regarding how these individuals achieved their innovations through a combination of curiosity and extensive research.
The apple story
While growing up in an area near the rolling foothills of Mount Apo, the country’s highest peak, Benzone often pondered why apple trees were absent while mango trees flourished abundantly in his province of Davao del Sur. Both fruits were a familiar sight during the festive seasons of Christmas and New Year.
It was not until he was in high school that he discovered the explanation for this phenomenon. However, this revelation did not deter him from wishing to see a real apple tree in his lifetime.
While taking up agriculture in college, his curiosity was reignited. Sometime in 2013, he bought some apples from the local market and managed to obtain three seeds. After planting them in a pot, he was pleasantly surprised to see them sprout, which filled him with excitement.
Upon reaching a height of five inches, the apple seedlings were transferred to seedling bags. After a period of six months, the young seedlings were planted in the ground. Regrettably, only one plant managed to survive.
In early 2018, he noticed flowers emerging from the tree. Three weeks later, he was thrilled to see that the flowers had developed into fruit buds. From this lone tree, he successfully harvested 32 ripe apples.
“There was no distinction between the apple I picked from my farm and the apple I purchased from the public market, as both exhibited the same juiciness and crunchiness,” remarked Sepe, who graduated from Davao del Sur State College (DSSC).
Benzone took several apples to DSSC for “Brix” testing, a method used to assess the sugar content, which is a crucial aspect of agricultural product quality evaluation. The findings revealed that the apple cultivated by Benzone was significantly sweeter, achieving a score of 17.5 degrees Brix, in contrast to the 13 degrees of commercially available apples.
According to him, apples intended for export must meet a minimum standard of 12 degrees. It means his apples have surpassed that requirement.
The Kapatagan Apple Orchard, as his farm is known, originated from a single apple tree and now boasts approximately 330 trees. “I began cultivating apples on our residential lot, which spans 640 square meters,” he remarked.
Currently, there are at least 30 apple trees thriving in the home yard. The remaining 300 trees are situated in front of their church and on a half-hectare plot that he leases. He aspires to expand his planting efforts as a means of contributing to the reforestation of Kapatagan, an area that has suffered deforestation due to banana cultivation and vegetable farming.
Benzone primarily propagates his apple trees from seeds, employing techniques such as marcottage, bud grafting, and grafting. Once planted, seedlings that are grafted with a branch from a mature tree typically begin to produce fruit within two to three years.
From female to male tilapia
“Tilapias are prolific,” says Dr. Rafael D. Guerrero III, a fishery expert and an academician with the National Academy of Science and Technology (NAST). They breed frequently, often every 30 days. Female tilapias may spawn from 100 to thousands of eggs, depending on its size.
At such a growth rate, there were more fish in the pond and competition for food escalated. With reduced nutrition, the best attainable market size for tilapia after four months was only 150 grams.
In order for the tilapia to grow bigger, the females should be separated from males. Once left to grow, the males can grow to the size which the market needs. But manual sexing, separating males from females, is labor-extensive.
“Artificial sex reversal is considered the most effective, efficient and economical method for solving the major drawback of growing tilapias to market-size caused by unwanted reproduction,” Dr. Guerrero says.
Dr. Guerrero is regarded as the “Father of Tilapia Sex Reversal.” In 2004, he was conferred on the Mgr. Jan D. F. Heine Memorial Award by the International Tilapia Foundation for his work.
The sex reversal technology (SRT) is based on the theory that the development of the sex organ (testis for male and ovary for female) in the fish can be artificially influenced by feeding of a synthetic sex hormone (methyl testosterone for male and estrone for female) during the “sexless period” of the young. Hormonal or induced sex reversal was first demonstrated in the 1950s by T. K-O. Yamamoto of Japan in the medaka, an aquarium fish.
“SRT is the process by which genetic female tilapia fry are converted into functional males through hormone manipulation,” Dr. Guerrero explains.
A sex-reversed tilapia is very virile, has a high sperm count, capable of fertilizing five to ten females, according to Dr. Guerrero. Female tilapias are separated from the rest, with a few males added to do the fertilization of eggs.
How does sex reversal occur? When the fry in the breeding ponds or units are about 7 to 10 days old, and about 9 to 11 millimeters long, they are stocked in treatment units. The density of stocking is 250 to 1,000 per square meter. In the first week, they are fed a sex reversal diet containing synthetic male hormones at the rate of two grams per day in four feedings at regular intervals from 8:00 in the morning to 4:00 in the afternoon per 1,000 fries.
For the second week, the feed is increased to 7.5 grams per day. In the third week, the feeding rate is 12 grams per day. After the 21-day treatment, the male population ranges from 95-99 percent. The fingerlings are then transferred to regular nursery units or stocked directly in predator-free culture ponds.
The application of tilapia sex reversal has undergone a number of innovations. While at first it was believed that the treatment of fry could only be done under a shade, it is now being done in outdoor tanks and ponds.
Controlling soil erosion
When Harold R. Watson arrived in the Philippines in the late 1960s, he observed that production of most farms in the uplands were miniscule despite using hybrid seeds and commercial fertilizer. After a thorough study, he and his Filipino counterparts discovered the land was devoid of its topsoil.
“Soil erosion is an enemy to any nation – far worse than any outside enemy coming into a country conquering it because it is an enemy you cannot see vividly,” said Watson, who’s from Mississippi and has already retired. “It’s a slow creeping enemy that soon possesses the land.”
To solve the problem, he suggested planting two hedgerows of “ipil-ipil” (Leucaena leucocephala) to stop erosion. Every 15 days, the hedges were cut and the cuttings were used as an organic source of fertilizer. It was as if hitting two birds in one shot.
Watson called the system Sloping Agricultural Land Technology (SALT). Basically, the SALT method involves planting of field and permanent crops in 4–5-meter bands between double-controlled rows of nitrogen fixing trees and shrubs. Aside from “ipil-ipil,” other nitrogen fixing trees and shrubs like “kakawate,” rensonii, indigofera, and flemengia can also be used as hedgerow species.
Examples of field crops are the legumes (beans, peas, and pulses), cereals (upland rice, corn, and sorghum), root crops (sweet potato, cassava, carrot, and taro), and vegetables (cabbage, ampalaya, tomato, eggplant, etc.). Permanent crops include cacao, coffee, banana, citrus, and fruit trees.
Most farmers are locked into one crop. For instance, a farmer may plant eggplant in his farm and when he harvests the crop, there would be a glut in the market as there is too much supply than the demand.
But with SALT, a farmer can harvest every now and then. “The farmer has something to look forward to,” Adang says. “Because the harvested crops are just enough for the market, there is a tendency that the price of his produce is much higher.”
Aside from production, the SALT system can help control erosion. A seven-year study conducted at the MBRLC showed that a farm tilled in the traditional manner erodes at the rate of 1,163.4 metric tons per hectare per year. In comparison, a SALT farm erodes at the rate of only 20.2 metric tons per hectare per year.
The rate of soil loss in a SALT farm is 3.4 metric tons per hectare per year, which is within the tolerable range. Most soil scientists place acceptable soil loss limits for tropical countries like the Philippines within the range of 10-12 metric tons per hectare per year. The non-SALT farm has an annual soil loss rate of 194.3 metric tons per hectare.
Transforming the landscape
All three individuals have changed the landscape of farming in the Philippines. Soon, there will be a lot of farmers growing apples in various parts of the country. Senator Cynthia Villar has bought some planting materials from Benzone and grows them in her farm. Benzone also received orders for apple planting materials from Cebu and most parts of Mindanao.
SRT, which Dr. Guerrero has innovated, is now popular not only in the Philippines but in other countries as well. About 90% of tilapia sold in the market today in the country have been raised by this technology.
“At least 50% of the tilapia produced in the United States, Canada, Israel, the Caribbean and Asia is sex-reversed,” Dr. Guerrero said.
Soil erosion is still a problem in the uplands. But some areas have been rehabilitated already, thanks to the SALT system. For encouraging international utilization of SALT and other farming schemes which MBRLC has developed, Watson was bestowed the prestigious Ramon Magsaysay award for international understanding.
In the coming years, it is anticipated that additional innovative technologies will be developed by farmers and scientists, thus contributing to a more sustainable and profitable agricultural sector in the country.
