Seasonal variations in leaf nutrient concentrations in three fig (Ficus carica L.) varieties

Author(s):  
Nicholas Moustakas ◽  
Nicholas Moustakas ◽  
Konstantina Benou ◽  
Dafni Ioannou
1984 ◽  
Vol 2 (4) ◽  
pp. 117-119
Author(s):  
A. Steven Messenger

Foliar samples from green and chlorotic red maple trees (Acer rubrum L.) were collected during each of three periods of the growing season, and analyzed for nutrient element concentrations. Compared to green leaf nutrient concentrations, those in chlorotic leaves were statistically different as follows: high P and K, and low Mn in late spring; high N, P, K, Fe, and Zn, and low Mn in mid-summer; high K and Mg, and low Mn in late summer. Considering lowest individual nutrient concentrations per period in green leaves as critical values, most chlorotic leaves were deficient in Mn, a few were deficient in Cu or Zn, and none was deficient in Fe. Using a similar method for identifying excesses, most chlorotic leaves contained excessive K, accompanied by excessive P in mid-summer. Chlorotic leaves with no apparent micronutrient deficiencies were excessively high in some individual or combination of macronutrients, primarily K, but consistently accompanied by P in mid-summer.


HortScience ◽  
1994 ◽  
Vol 29 (8) ◽  
pp. 871-873 ◽  
Author(s):  
Patrick H. Brown

Concentrations of N, P, K, Ca, Mg, B, Fe, Cu, Zn, and Mn in mature commercial fig (`Calimyrna'; `Sari Lop') leaves are presented throughout the growing season. These data can be used as preliminary norms for the interpretation of tree nutrient status for high-yielding commercial fig orchards. In comparison with other deciduous tree crops growing in the same regions {almond [Prunus amygdalus Batsch syn. P. dulcis (Mill) D.A. Webb], walnut (Juglans regia L.), peach [Prunus persica (L.) Batsch]}, productive fig trees have relatively low leaf N, P, and K concentrations (2.1%, 0.1%, and 1.0% dry weight, respectively) in July, although tissue Mn and Ca concentrations often exceed those typically found in other deciduous species growing in the same soils. Seasonal variations in fig leaf nutrient concentrations are similar to those of other tree crops. Marked declines in tissue K and N concentrations toward the end of the season may indicate a need for supplemental N and K fertilization in highly productive orchards. The potential for K deficiency in fig also is indicated by the generally lower leaf K concentrations in the low-vigor orchards examined.


Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 201 ◽  
Author(s):  
Dalong Jiang ◽  
Qinghong Geng ◽  
Qian Li ◽  
Yiqi Luo ◽  
Jason Vogel ◽  
...  

Nutrient resorption from senescing leaves is one of the plants’ essential nutrient conservation strategies. Parameters associated with resorption are important nutrient-cycling constraints for accurate predictions of long-term primary productivity in forest ecosystems. However, we know little about the spatial patterns and drivers of leaf nutrient resorption in planted forests worldwide. By synthesizing results of 146 studies, we explored nitrogen (N) and phosphorus (P) resorption efficiency (NRE and PRE) among climate zones and tree functional types, as well as the factors that play dominant roles in nutrient resorption in plantations globally. Our results showed that the mean NRE and PRE were 58.98% ± 0.53% and 60.21% ± 0.77%, respectively. NRE significantly increased from tropical to boreal zones, while PRE did not significantly differ among climate zones, suggesting differential impacts of climates on NRE and PRE. Plant functional types exert a strong influence on nutrient resorption. Conifer trees had higher PRE than broadleaf trees, reflecting the adaptation of the coniferous trees to oligotrophic habitats. Deciduous trees had lower PRE than evergreen trees that are commonly planted in P-limited low latitudes and have long leaf longevity with high nutrient use efficiency. While non-N-fixing trees had higher NRE than N-fixing trees, the PRE of non-N-fixing trees was lower than that of N-fixing trees, indicating significant impact of the N-fixing ability on the resorption of N and P. Our multivariate regression analyses showed that variations in NRE were mainly regulated by climates (mean annual precipitation and latitude), while variations in PRE were dominantly controlled by green leaf nutrient concentrations (N and P). Our results, in general, suggest that the predicted global warming and changed precipitation regimes may profoundly affect N cycling in planted forests. In addition, green leaf nutrient concentrations may be good indicators for PRE in planted forests.


Author(s):  
J. B. Sykes ◽  
A. D. Boney

Until recently there has been very little information on the quantities of phytoplankton nutrients in the Irish Sea. Slinn (1958–1966) has reported the weekly variations in the nutrient concentrations at a station off Port Erin, Isle of Man, and studies on the nutrient conditions in the Menai Straits have been carried out by Jones (unpublished) and Ewins & Spencer (1967). Liss (1969) has reported on the results of winter surveys of reactive silicate near the Irish coast, and from three stations near the Welsh coast (Anglesey, the Lleyn Peninsula and Fishguard). The present paper describes studies carried out in the inshore waters near Aberystwyth in Cardigan Bay during 1967 and 1968. This investigation formed part of a study of the seasonal occurrence of the phytoplankton and the growth conditions in this shallow, inshore region.


HortScience ◽  
2016 ◽  
Vol 51 (11) ◽  
pp. 1378-1383
Author(s):  
Mehdi Sharifi ◽  
Julia Reekie ◽  
Andrew Hammermeister ◽  
Mohammed Zahidul Alam ◽  
Taylor MacKey

There is an increasing interest for use of cover crops in orchards; however, the species that are most likely to be successfully implemented and their impact on yield and soil productivity have not been fully explored under Maritimes climate. This study investigated the effect of various cover crops treatments on organic apple (Malus domestica Borkh cv. Honeycrisp) yield and leaf nutrient concentrations in Nova Scotia over 3 years. Various cover crop mixtures including legumes, cereals, and grasses were planted using a modified Swiss Sandwich System (SSS). The cover crops treatments did not affect apple yield. In 2012, the input of biomass to the soil was 89% and 144% greater for alfalfa (ALF) and other cover crop treatments than unseeded (CON) treatment, respectively. The pea, oats, vetch mixture (POVM) contributed 24% higher biomass N to soil compared with average of other cover crops in 2012. Soil available K concentration in the tilled strip was increased in the 3rd year of the study compared with the initial values across cover crop treatments. The red clover oats mixture (RCOM), POVM, and Triple Mix (TM) treatments appeared to add the greatest amount of available K to the soil among treatments. The CON, TM, and ALF treatments resulted in higher leaf Mn concentration in only 2012 and CON, sweet clover and oats mixture (SCOM), and ALF resulted in higher leaf P concentration in 2014, compared with other treatments. Cover crops did not compete with apple trees and their most beneficial and consistent contribution was to total C, total N, and K input to the soil.


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