Published 27/03/2015

Thai growers achieve higher yields and quality with advanced screen

In Thailand, promising result have been achieved with advanced climate screens from Svensson in hydroponic lettuce production. At the Horti Asia in Bangkok last week, Laurens Besemer and Piet Keijzer of Svensson had a nice set up on display to convince other Thai and Asian growers about the advantages of the use of climate screens compared to standard shade cloth.

horti-asia 2015

"We have achieved a better climate and crop at this Thai grower due to remarkable differences in both water and leaf temperatures in combination with more light", commented Laurens Besemer. In the trial, shading screens were compared with traditional black nets. "The results of the trial makes the choice to go for screens in hot climates quite simple."

The grower
Hydroponic lettuce grower Miss Veggi produces salad for high-end Thai supermarkets and hotels. To fulfil the growing demand, the production runs year-round. Their demand peaks during early summer months, which unfortunately is the period with low production figures due to natural conditions. During this period and April in particular, average day temperature reach 33°C and 28°C by night.

The water of the hydroponic production heats up throughout the day, which negatively impacts the actual growth. "Temperatures above 32°C are known to create substantial problems, in the month of April water temperatures at Miss Veggie can reach 35°C - causing severe production and quality losses. This is why they approached us to find a solution to fight the high temperatures."

In order to reduce the high temperatures during the day, Svensson installed a Solaro climate screen. "We compared SOLARO 6720 O E WB, our white, reflective shading screen with an ordinary local black shade net. Two lettuce crops, transplanted on the same day, were compared with one another."

More light, more yield
Remarkable differences were noted. "Both the leaf temperature and the water temperature were found to be considerably lower under the Solaro screen. This is remarkable, because Solaro transmits 10% more light than the black shade cloth."

The lower temperatures underneath the Solaro screen did not only resulted in better growth during the hot periods. "The advanced Solaro also allowed more light, which resulted in better quality and higher production. Lettuce heads under Solaro had a 40% higher weight, 53 g vs. 31 g and plant losses under Solaro were reduced from 15 to 5%."

Offer an alternative
At the Horti Asia, the white screen material of Svensson caught the attention of Thai lettuce growers. "Everybody is used to see black shade cloth above lettuce production. Now we offer them an alternative that allows better production and cooler temperatures. In addition, the local workers are also very happy with Solaro as the material creates a better cooler climate for them to work in."

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