foliar analysis of natural deciduous tree species of basswood (tilia americana l.) (ba), american beech (acer grandifolia enrh) (be), and white ash (fraxinus americana l.) (wa) was carried out in 1994 in southern quebec. the diagnosis and recommendation integrated system (dris) was developed from the traditional method to find the preliminary norm and indices of n, p, k, ca, and mg for the ...

the present study was conducted to determine the most appropriate tree species planted in the same ecological condition considering different variables at darabkola forest, mazandran province. for this purpose, the success of planted species (maple, walnut, oak, pine, ash and elm) was assessed according to ninecriteria (soil nitrogen, soil phosphorus, soil potassium, leaf nitrogen, leaf phospho...

Although tree nutrition has not been the primary focus of large climate change experiments on trees, we are beginning to understand its links to elevated atmospheric CO₂ and temperature changes. This review focuses on the major nutrients, namely N and P, and deals with the effects of climate change on the processes that alter their cycling and availability. Current knowledge regarding biotic an...

sulfur (s) is an essential macronutrient influencing plant growth, nutrient efficiency, quality and health of agricultural crops. the purpose of this research was to study the effects of s rates and sources on growth and fruit quality of apple (malus domestica l.) trees of ‘golden delicious’ at west azerbaijan, iran. experiment was conducted during four seasons (2003-2007), using a factorial ra...

mastic (chatlanqosh or turpentine) is a valuable tree species in most parts of the country, particularly around the southern slopes of the alborz and zagros mountain range distributed. wild mastic tree is mainly due to the adaptability and hard rocky ground tree and needless to excessive irrigation, it doesn't usually crop. it is the mountain range of the plant, giving it less water. the soil a...

Background and Purpose: Survival tree model is a nonparametric method which can be used to identify the affecting factors from a specific time to the onset of an event. In this method, the categories are selected according to the most important factors. The purpose of this study was to determine the factors affecting the duration of breastfeeding in mothers and introduce the homogeneous subgrou...

pomegranate is one of the major horticultural crops in iran, but studies about this product; especially its pruning is very little. therefore this study was carried out to assess the effect of pruning and nutrition on pomegranate cultivar “robab” in qaemieh, fars province during 2008-2009. this research was conducted factorial experiment based on randomized complete block design (rcbd) with 5 p...

The avocado grower is usually familiar with deficiency symptoms such as those caused by lack of sufficient iron (3), zinc (11), and nitrogen (4). Also excesses of certain elements produce characteristic symptoms which may be readily identified, e. g. chloride and sodium (2, 9). However, little information is available concerning the remaining elements absorbed by the tree, their symptoms along ...