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Ask George – Q&A from the Field
George has been active in the field of agriculture for 32 years, 13 of them at Hazera. Before George joined Hazera, he worked in the field of vegetable cultivation and plant protection at the Israeli Ministry of Agriculture. George has a graduate degree in Plant Protection. The primary crops George dealt with are tomatoes, melons, watermelons, onions and leaf plants.George’s primary field of expertise is the examination of new varieties during the early cultivation stages, and their modification for the relevant cultivation regions and countries.
Over the past 3 years George has served as the Product Promotion manager for tomatoes in the major target countries for Hazera tomatoes.Based on his extensive and rich experience in tomato crop cultivation methods, fertilization, irrigation and plant protection, George is happy to put the knowledge he has acquired over the years at your disposal.
We invite you to send George any questions you may have about growing tomatoes to:
Ask-george@hazera.com
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Yellowing of leaves during the winter season
Mr. Hitoshi Kifuji, Maebashi-City, Gumma, Japan
Question:
We have planted tomatoes in our greenhouse using original hydroponic system. The sowing date was September 10th and transplanting was on the 25th of same month. The harvesting started at the beginning of January. The problem, as you can see in the enclosed photo, is the yellowing of leaves during the winter season. Though leaves of some varieties have recovered as temperatures became warmer, other varieties are still yellow. Our local expert suggested that one of the reasons might be the low temperatures, as greenhouse temperature dropped to 10°C on several occasions. However, he thinks that fertilization might also be involved. I would appreciate your opinion as to what could have caused this problem and ways to avoid it.
George:
I examined the photos and though it is not like looking at the plants themselves I feel that the yellowing of the leaves is not due to light or temperature but due to mineral deficiency. This phenomenon is more pronounced when growing in culture (soil-less). It seems that the yellowing is mainly around the clusters that are becoming red and these are the clusters that require most of the nutrients. The solution is increasing the micro-elements (mainly Mg and Mn) in the fertilizing mix. Please consult a local fertilization expert for more details. |
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