Macronutrient and boron deficiencies in three varieties of mulberry tree (Morus alba L)

Slipes of the varieties Fernão Dias, Formosa and Calabreza were grew in pots containing pure quartz sand. Several times a day all the plants were irrigated with Hoagland and Arnon's solution of 30 days. After, that period, groups of plants (5) were irrigated with nutrient solution lacking one nutrient (-N,-P,-K,-Ca,-Mg,-S and -B). Soon as the deficiences symptoms become visible the plants were harvested and analysed for the macronutrients and boron. The plants showed deficiencies symptoms in the following order: nitrogen, magnesium, calcium, phosphorus, potassium and boron. No sulphur deficiencies symptoms were observed. The tissue analysis of the leaves of plants showing deficiencies symptoms or not were: