Cambodia
October 15, 2020
The Grow Against the Flow researchers find grafted tomatoes thriving in experimental plots.
Although heavy, frequent rain drenched Cambodia during the first two weeks of October 2020, the researchers running a tomato grafting trial for the Grow Against the Flow project at Kbal Koh Vegetable Research Station were delighted to find a silver lining in some of those dark thunderclouds.
From October 9-11, flood waters covered about one-third of the height of the planting beds in the plot. By October 12, the water level rose to two-thirds of the bed height. And by October 13, the plots were completely inundated.
Yet, when they checked the experimental plots, the research team members discovered that all the grafted tomato plants survived the flood.
The non-grafted check was not so fortunate: 30-40% of those plants wilted due to the excess water.
Grow Against the Flow promotes off-season vegetable production to help ensure nutrient-rich food is available to consumers at times of the year when the supply is usually low. “Grafting is a simple practice farmers can use to overcome some difficult climatic conditions in the rainy months,” said Project Manager Uon Bonnarith.
Grafting involves attaching the rootstock, or bottom, of a flood- or disease-resistant tomato or eggplant variety to the scion, or top, of a preferred tomato variety that lacks resistance. The simple process requires a bit of bicycle tubing, a razor blade, and nimble fingers. The stems of two young plants are joined with the tubing and placed in a dark, moist enclosure to allow the join to heal, which usually takes about a week. The grafted plants are then set out in the field with the graft above the soil line.
When farmers are able to produce tomatoes despite the rain and keep up a steady supply to markets, consumers can more often enjoy the taste and nutritional benefit of fresh tomatoes. Farmers’ incomes increase from off-season production as well.
Researchers harvested fruit from the experimental plots on October 8, 11 and 14.
They tracked data including the number of plants transplanted, number of plants that survived flooding, days to first harvest, yield (2-3 times), fruit size (width and length), fruit weight measured by 10 fruits from each plot, calcium deficiency and pest and disease damage. WorldVeg improved line VI041996 served as the rootstock.
Based on the collected data, Uon has concluded that the grafted plants are resistant to flooding, despite the roots and stems being underwater for at least six days. His team is now pumping floodwaters out of the fields to continue the fruit harvest for other aspects of the experiment.
Funding from the German Federal Ministry of Cooperation and Development (BMZ) for Grow Against the Flow is gratefully acknowledged.
Species
