Increasing zinc yields better quality fruit in Eastern Provinces
Zinc is not only used in industrial sectors, but it is also an important nutrient needed for plant growth and efficient photosynthesis.
Soil in the Eastern provinces do not naturally lack zinc, but many orchard owners have unwittingly depleted the soil, which led to problems.
Padaeng Industry Plc, organized a visit to fruit orchards in Chantaburi province, to illustrate the importance of zinc in agriculture. Researchers discovered that more than half the orchards in the Eastern region do not have sufficient zinc in their soil, and that plants enriched with zinc produce higher yields.
Mr. Chitchai Thaveepanich, Padaeng?s Vice President of Human Resources & Corporate Administration, stated that even though the Company?s products are primarily geared towards industrial use, zinc also plays an important role in agriculture, particularly in assisting photosynthesis and improving plant growth. This ?Zinc for Agriculture? activity aims to spread the knowledge about zinc-enriched fertilizers, as a follow-up to the ?Zinc for Health? conference held at the end of 2009.
Ph.D., Associate Professor Sumitra Poovarodom, a leading soil and plant expert from Faculty of Agricultural Technology, King Mongkut?s Institute of Technology, has spent the past 12 years conducting extensive research on improving the quality of fruit, soil and food nutrients in the Eastern region. Her research, initially on durians, shifted when she noticed problems in mangosteen orchards. More than half of all mangosteen orchards in the region exhibited signs of zinc deficiency, evident from numerous small stunted leaves amongst larger healthier leaves. The presence of stunted growth indicated that the trees were not photosynthesising efficiently, and thus were not providing trees with sufficient nutrients. This deficiency was a result of excessive phosphorus (P) accumulation in the soil blocking the absorption of zinc needed by the trees. Orchard owners had mistakenly believed that phosphorus-based fertilisers would increase flowering and boost fruit yields.
Since most growers believed that plants only needed fertilisers with nitrogen, phosphorus and potassium (N-P-K), they had exclusively applied these fertilisers for decades. After being advised to spray zinc-enriched fertilizers on mangosteen leaves, trees began to show uniformly large-sized leaves. Dr. Sumitra also advised growers to add other nutrients to improve the fruit?s appearance and taste, resulting in excellent mangosteens that are highly demanded by both domestic and export markets.
Mrs. Sa-Nguan Boonyarit, an orchard grower who exports her produce participated in Dr. Sumitra?s pilot study said that after incorporating these new techniques in her orchard over a period of time, the proportion of mangosteens that qualified for the export market dramatically increased from 30% to 90%. Today, most mangosteens weigh more than 90 gms, and are attractive with glossy, unblemished thin rinds, and sweet white flesh. Problems of translucent flesh and sap in the fruit have disappeared. With high demand for quality mangosteens in Japan, the US, and China, her fruit fetches high prices. Moreover, without unnecessary fertilising, her operating costs are lower.
Ph.D., Sumitra concludes that zinc is a nutrient that plants need in only trace amounts, but it is a mineral, like other nutrients, that is absolutely vital to plant growth. Growing high-quality delicious fruit requires a nuanced and deep understanding of the unique nutritional needs appropriate to each type of plant. Given the complexity of plant nutrition, intensive research is the key to finding solutions to problems in the agricultural sector.