Guava with Trichoderma-enriched fertilizer: better root-knot nematode control, better growth, higher yields and tastier fruit

A great ally for plants against pests and diseases: Trichoderma is here! After 17 years of research and development, the Taichung District Agricultural Research and Extension Station selected Trichoderma TCT768, which suits Taiwan's environment. Added to compost and spread over fields and orchards, it lets crops absorb nutrients quickly, grow stronger and more vigorous, and it can induce beneficial bacteria that help plants resist the troublesome "root-knot nematode."

In recent years, because of climate change, root-knot nematodes have become a headache for all kinds of crops, especially guava and dragon fruit; after a long period of cultivation, root-knot nematodes appear on the roots. But if actinomycetes are used directly for control, the application rate affects how well the control works, and the raw culture costs 1800-2000 yuan per 1 kg, which is quite expensive. To lower farmers' costs, inoculating spent mushroom substrate with Trichoderma can produce compost containing large amounts of actinomycetes; it has both fertilizer effect and actinomycetes, is cheap, and works even better.

At present, the Taichung District Agricultural Research and Extension Station has transferred the Trichoderma technology and cooperated with industry to develop the solid fertilizer "Gubaojun" and a liquid fertilizer. Trials have been carried out on many crops, including guava orchards and bitter gourd fields in central Taiwan, with remarkable results: on average, fruit drop can be reduced by 30%, while yields increase by 25%-50%.

A tropical strain made to measure, helping plants resist extreme climates

As the name suggests, Trichoderma was originally "a fungus found on moldy wood." In the laboratory of Chen Chunwei, director of the Puli Branch Station of the Taichung District Agricultural Research and Extension Station, he took out Trichoderma strains he had cultured and preserved in the past and explained, "There are many varieties of Trichoderma, commonly divided into temperate and tropical types. Because Taiwan's climate is hot and humid, we ultimately selected the tropical type TCT768."

Recalling the starting point of the research, Chen Chunwei, director of the Puli Branch Station of the Taichung District Agricultural Research and Extension Station, said, "Actually, the main focus at the beginning was not Trichoderma, but compost." Starting in year 93 of the Republic of China, the Taichung District Agricultural Research and Extension Station researched and developed compost. To improve the odors during compost fermentation, researchers kept looking for materials that could speed up fermentation, and that was how they found Trichoderma.

Speeding up nutrient decomposition, Trichoderma becomes a crop guard

Trichoderma is a kind of fungus; the shiitake mushrooms and wood ear mushrooms commonly seen in supermarkets are its relatives. The key to speeding up fermentation is that it can break down cellulose, splitting the originally larger cellulose into smaller mono- and disaccharides, making it easy for bacteria to consume. It is like a newborn baby who needs its mother to chew food first so it is easier to swallow.

The protective mechanism Trichoderma uses for plants is this: Trichoderma first converts nutrients into mono- and disaccharides, which stimulates the proliferation of actinomycetes that feed on mono- and disaccharides, and actinomycetes can suppress an important crop pest: the root-knot nematode. Actinomycetes multiply in large numbers in the soil, decomposing the chitin-based root-knot nematodes and their eggs in one go, thus protecting the plants.

With Trichoderma added, spent mushroom wood chips are worth ten times more

The Taichung District Agricultural Research and Extension Station's impetus for developing compost with added Trichoderma was to solve two major agricultural wastes across Taiwan: chicken manure and spent mushroom wood chips. After 6 years of screening to find Trichoderma TCT768, which suits Taiwan's climate, cooperation with the Taichung Jingyuan Mushroom Farm began in year 105 of the Republic of China, through the introduction of Lin Zhangji, chairman of the Taichung Taiping District Farmers' Association.

The Jingyuan Mushroom Farm, which has been operating for 18 years, has a vast factory building that can hold 288,000 mushroom bottles, mainly producing king oyster mushrooms. Sterilized plastic bottles are filled with wood, rice bran, soybean meal, and so on, then inoculated with king oyster mushroom spawn, and they can multiply and grow. Because each bottle of king oyster mushrooms is harvested only once, not continuously like shiitake mushrooms, the material underneath is still rich in nutrients and is good material for making compost.

Behind the factory building, two small hills are piled up. One is the material used to fill the plastic bottles, and the other is the waste material after mushroom cultivation; 8 tonnes of waste are produced every day. Farm director Lin Zhangde said, "In the past, this waste was sold to recycling yards, and one truckload could bring in at most 4000 to 5000 yuan. Now it is used as compost material, and the same truckload by weight can bring back 60,000 yuan."