MULTAN: Agriculture experts on Saturday said that citrus orchards can survive heat up to 40 Celsius, however, warned any rise above this level can compromise fruit size and overall production, and necessitated remedial measures to keep soil moisture up to the mark.

In a statement carrying recommendations for better management of citrus orchards during hot weather conditions, experts said that leaf of citrus plants start turning yellow after temperature crosses 40 Celsius mark and green material that produce carbohydrates start disappearing.

“Consequently, fruit do not get carbohydrates and begin to turn yellow before they fall on the ground prematurely. Not only it affects size of the fruit, overall production and other characteristics are also compromised.”

Experts advised farmers to start giving water to the plants as soon as they notice leaf turning yellow in summer season. Farmers must not be complacent when tensiometer showed the figure 40 and give water to plants immediately.

Such measures be adopted that prevent or minimize vaporization and enable soil retain moisture for a longer duration.

Farmers can also opt for mulching process on the soil under the tree; experts said explaining that they should lay 10cm thick layer of grass on the soil to keep soil temperature moderate and soil cool. This technique would also improve organic material in soil and leave good impact on fruit.

Farmers must not let the skin of trunk damaged and apply a liquid mixture of blue vitriol (Copper Sulphate) and lime on the trunk from ground up to 1.5 feet height for safety against sunlight impact. It would also save trunk from other diseases like citrus Gummosis.

Farmers were further advised to avoid repeated ploughing and deep hoeing in summer season to avoid damaging roots. Soil be ploughed only once and then be leveled to retain moisture, experts recommended.