scholarly journals Foliar analysis in experimentally grown Lacatan bananas in relation to leaf production and bunch weight.

1962 ◽  
Vol 10 (2) ◽  
pp. 118-126 ◽  
Author(s):  
W.J. Brezowsky ◽  
J. Van Biesen
Keyword(s):  
Rainy Season ◽  
Foliar Analysis ◽  
Depressing Effect ◽  
Leaf Production ◽  
Positive Effect ◽  
Leaf N

Foliar analyses from October to April (the drier part of the year) showed a positive effect of an increased potash application on leaf K, and a depressing effect on leaf Mg. Both these effects were statistically insignificant just before and during the period when most of the plants started to shoot. There was no significant effect of increased N applications on leaf N, except in the early part of the rainy season. Increased K also had a significant effect on bunch weight, hand weight and the number of hands per stem.-Cameroons Develop. Corp. (Abstract retrieved from CAB Abstracts by CABI’s permission)

The depressing (negative) effect of oestradiol benzoate on the in vitro secretion of LH and FSH by the pituitary gland of the LRH-pretreated long-term ovariectomized rat changes into the augmentative (positive) effect after discontinuation of the LRH-pretreatment

1985 ◽  
Vol 110 (3) ◽  
pp. 329-337 ◽  
Author(s):  
G. A. Schuiling ◽  
H. Moes ◽  
T. R. Koiter
Keyword(s):  
Depressing Effect ◽  
Ovx Rats ◽  
Gonadotrophin Secretion ◽  
Oestradiol Benzoate ◽  
Negative Effect ◽  
Positive Effect ◽  
Perifusion System

Abstract. The effect of pretreatment in vivo with oestradiol benzoate on in vitro secretion of LH and FSH was studied in long-term ovariectomized (OVX) rats both at the end of a 5-day continuous in vivo pretreatment with LRH and 4-days after cessation of such LRH pretreatment. Rats were on day 0 sc implanted with osmotic minipumps which released LRH at the rate of 250 ng/h. Control rats were implanted with a piece of silicone elastomer with the dimensions of a minipump. On days 2 and 4 the rats were injected with either 3 μg EB or with oil. On day 5 part of the rats were decapitated and the in vitro autonomous (i.e. non-LRH-stimulated) and 'supra-maximally' LRHstimulated release of LH and FSH was studied using a perifusion system. From other rats the minipumps were removed on day 5 and perifusion was performed on day 9. On the 5th day of the in vivo LRH pretreatment the pituitary LH/FSH stores were partially depleted; the pituitaries of the EB-treated rats more so than those of the oil-injected rats. EB alone had no significant effect on the content of the pituitary LH- and FSH stores. On day 9, i.e. 4 days after removal of the minipumps, the pituitary LH and FSH contents had increased in both the oil- and the EB injected rats, but had not yet recovered to control values. In rats not subjected to the 5-days pretreatment with LRH EB had a positive effect on the supra-maximally LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. EB had no effect on the non-stimulated secretion of FSH. After 5 days of in vivo pretreatment with LRH only, the in vitro non-stimulated and supra-maximally LRH-stimulated secretion of both LH and FSH were strongly impaired, the effect correlating well with the LRH-induced depletion of the pituitary LH/FSH stores. In such LRH-pretreated rats EB had on day 5 a negative effect on the (already depressed) LRH-stimulated secretion of LH (not on that of FSH). EB had no effect on the non-stimulated LH/FSH secretion. It could be demonstrated that the negative effect of the combined LRH/EB pretreatment was mainly due to the depressing effect of this treatment on the pituitary LH and FSH stores: the effect of oestradiol on the pituitary LRH-responsiveness (release as related to pituitary gonadotrophin content) remained positive. In LRH-pretreated rats, however, this positive effect of EB was smaller than in rats not pretreated with LRH. Four days after removal of the minipumps there was again a positive effect of EB on the LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. The positive effect of EB on the pituitary LRH-responsiveness was as strong as in rats which had not been exposed to exogenous LRH. The non-stimulated secretion of FSH was again not affected by EB. The results demonstrate that the effect of EB on the oestrogen-sensitive components of gonadotrophin secretion consists of two components: an effect on the pituitary LRH-responsiveness proper, and an effect on the pituitary LH/FSH stores. The magnitude of the effect of EB on the LRH-responsiveness is LRH dependent: it is very weak (almost zero) in LRH-pretreated rats, but strong in rats not exposed to LRH as well as in rats of which the LRH-pretreatment was stopped 4 days previously. Similarly, the effect of EB on the pituitary LH and FSH stores is LRH-dependent: in the absence of LRH, EB has no influence on the contents of these stores, but EB can potentiate the depleting effect of LRH on the LH/FSH-stores. Also this effect disappear after cessation of the LRH-pretreatment.

scholarly journals Response to fertilizer nitrogen and water of post-rainy season sorghum on a Vertisol. 1. Biomass and light interception

1998 ◽  
Vol 131 (4) ◽  
pp. 417-428 ◽  
Author(s):  
T. J. REGO ◽  
J. L. MONTEITH ◽  
PIARA SINGH ◽  
K. K. LEE ◽  
V. NAGESWARA RAO ◽  
...  
Keyword(s):  
Rainy Season ◽  
Andhra Pradesh ◽  
Root Zone ◽  
Growth Period ◽  
Peninsular India ◽  
N Application ◽  
Radiation Coefficient ◽  
Optimum Application ◽  
Main Growth ◽  
Leaf N

In parts of peninsular India, sorghum (Sorghum bicolor L.) is grown during the dry season using water stored in the root zone. The optimum application of nitrogen is difficult to assess because no comprehensive model exists for the interaction of water and N. To explore this system as a basis for modelling in the first instance and ultimately for better management, sorghum (cv. SPH–280) was grown in the post-rainy season at ICRISAT (Andhra Pradesh, India) with and without irrigation and at six rates of nitrogen from zero to 150 kg/ha applied before sowing. The biomass of top components was measured weekly and of roots every 2 weeks. Interception of solar radiation was monitored continuously in all treatments.Leaf expansion was strongly influenced both by water and by N, whereas specific leaf area was almost independent of treatment. In the irrigated treatment, the Biomass Radiation Coefficient (e) for the main growth period was almost independent of N application at 1·3–1·4 g/MJ and was also independent of leaf N. In consequence, the main source of differences in yield was a decrease in radiation interception with decreasing N. In contrast, without irrigation, biomass, yield, e and leaf N were all maximal at 60 kg/ha N.At 33 days after emergence (DAE), root mass was almost independent of N whether water had been applied or not, but was somewhat smaller with irrigation. Later, root, leaf, and panicle mass all responded to N and to water, but stem mass was unresponsive to N with irrigation. There was evidence of translocation from stem to grain in most treatments. With irrigation, a maximum grain yield of 4·8 t/ha was obtained at 150 kg/ha N and without irrigation the maximum was 3·2 t/ha at 90 kg/ha.

scholarly journals Diagnose apricot nutritional status according to foliar analysis

2011 ◽  
Vol 57 (No. 7) ◽  
pp. 301-306 ◽  
Author(s):  
T. Milošević ◽  
N. Milošević
Keyword(s):  
Nutritional Status ◽  
Seasonal Changes ◽  
Foliar Analysis ◽  
Full Bloom ◽  
Nutritional Values ◽  
Vegetative Cycle ◽  
Leaf P ◽  
Leaf N

This experiment was conducted in Cacak (Western Serbia) during 2004 and 2005 to determine the influence of Belosljiva, Dragacevka, Stanley, Kolenstockzwetsche, Wangenheim, Pozegaca, and Kapavac interstocks budded on Myrobalan seedlings on the seasonal changes, leaf macronutrient contents at 120 days after full bloom (DAFB) and deviation from optimum percentage (DOP) of Vera apricot cultivars. The macronutrients analyzed were N, P, K, Ca, and Mg. Nitrogen was consistently decreased during the vegetative cycle on all interstocks, while leaf P, Ca, and Mg had a tendency of increasing, except P on Kapavac. Potassium had a tendency to increase from 60 to 150 AFB, and decreased through 180 DAFB. Leaf N at 120 DAFB was higher in 2005, and P, K, Ca, and Mg in 2004 on all interstocks. Leaf macronutrients were significantly influenced by interstocks, except K. On the basis of DOP index, leaf N, Ca, and Mg were lower than optimum on all interstocks in both years. Leaf P and K were higher than optimum. Stanley and Wangenheim showed the weakest balanced nutritional values than the rest of interstocks.  

scholarly journals Down-Regulation of Photosynthesis to Elevated CO2 and N Fertilization in Understory Fraxinus rhynchophylla Seedlings

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1197
Author(s):  
Siyeon Byeon ◽  
Kunhyo Kim ◽  
Jeonghyun Hong ◽  
Seohyun Kim ◽  
Sukyung Kim ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
N Fertilization ◽  
Leaf Nitrogen ◽  
N Availability ◽  
Down Regulation ◽  
Leaf Production ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Regulation Of Photosynthesis ◽  
Leaf N

(1) Background: Down-regulation of photosynthesis has been commonly reported in elevated CO2 (eCO2) experiments and is accompanied by a reduction of leaf nitrogen (N) concentration. Decreased N concentrations in plant tissues under eCO2 can be attributed to an increase in nonstructural carbohydrate (NSC) and are possibly related to N availability. (2) Methods: To examine whether the reduction of leaf N concentration under eCO2 is related to N availability, we investigated understory Fraxinus rhynchophylla seedlings grown under three different CO2 conditions (ambient, 400 ppm [aCO2]; ambient × 1.4, 560 ppm [eCO21.4]; and ambient × 1.8, 720 ppm [eCO21.8]) and three different N concentrations for 2 years. (3) Results: Leaf and stem biomass did not change under eCO2 conditions, whereas leaf production and stem and branch biomass were increased by N fertilization. Unlike biomass, the light-saturated photosynthetic rate and photosynthetic N-use efficiency (PNUE) increased under eCO2 conditions. However, leaf N, Rubisco, and chlorophyll decreased under eCO2 conditions in both N-fertilized and unfertilized treatments. Contrary to the previous studies, leaf NSC decreased under eCO2 conditions. Unlike leaf N concentration, N concentration of the stem under eCO2 conditions was higher than that under ambient CO2 (4). Conclusions: Leaf N concentration was not reduced by NSC under eCO2 conditions in the understory, and unlike other organs, leaf N concentration might be reduced due to increased PNUE.

Avaliação de Produção de Serapilheira em Planície Inundável no Pantanal Mato-Grossense

2018 ◽  
Vol 21 (3) ◽  
pp. 148
Author(s):  
Ana Carolina Amorim Marques ◽  
Osvaldo Borges Pinto Junior ◽  
George Louis Vourlitis
Keyword(s):  
Rainy Season ◽  
Nutrient Dynamics ◽  
Biogeochemical Cycles ◽  
Sensu Stricto ◽  
Dry Season ◽  
Litter Production ◽  
Distilled Water ◽  
Leaf Production ◽  
Shoot Production

A pesquisa teve como objetivo avaliar a produção de serapilheira (litter) em planície inundável, em duas áreas distintas, sendo de fitofisionomia denominada Cerrado sensu stricto e uma área com dominância de Scheelea phalerata (Arecaceae), popularmente conhecida como acuri, localizada no município de Poconé MT.Para a coleta de dados da serapilheira produzida foram distribuídos, sistematicamente, seis coletoresnas duas áreas de estudo, totalizando 12 unidades amostrais. O material foi recolhido, mensalmente, durante 10 meses. Todas as amostras de serapilheira foram recolhidas, mensalmente, e levadas ao laboratório para lavagem com água destilada, posteriormente, sendo separada em folhas, galhos, flores, frutos e sementes, e estes levados para secagem em estufa a 65 - 70 °C por 72 horas e, posterior pesagem em balança digital. A produção de folhas foi maior na área de cerrado durante a estação da seca, contudo, a produção de galhos teve maior percentual na área de acuri na estação chuvosa, as flores se mostraram em maior quantidade na área de cerrado se comparada ao acuri (estação chuvosa), a presença de frutos somente pode ser denotada na área de acuri e as sementes apresentaram maior quantidade na área de acuri. Observou-se que a produção de serapilheira apresentou sazonalidade, ao longo do ano, sendo a maior produção no período de junho a novembro (estação seca).Palavras-chave: Ciclos Biogeoquímicos. Dinâmica de Nutrientes. Sazonalidade.AbstractThe objective of this work was to evaluate the litter production in floodplain, in two distinct areas, being of phytophysiognomy called Cerrado sensu stricto and an area identified as by Scheelea phalerata (Arecaceae), popularly known as acuri, located in the municipality of Poconé MT. In order to collect data from the litter produced, six collectors were systematically distributed in the two study areas, totaling 12 sample units. The material was collected monthly for 10 months. All litter samples were collected monthly and taken to the laboratory for washing with distilled water, then separated into leaves, branches, flowers, fruits and seeds, and oven dried at 65-70 ° C for 72 hours and subsequently weighed in digital scale. Leaf production was higher in the cerrado area during the dry season, however, the shoot production had a higher percentage in the acuri area during the rainy season, the flowers were larger in the cerrado area when compared to acuri (rainy season ), the presence of fruits could only be denoted in the acuri area and the seeds showed more quantity in the acuri area. It was observed that litter production presented seasonality throughout the year, with the highest production in the period from June to November (dry season).Keywords: Biogeochemical Cycles. Nutrient Dynamics. Seasonality.Palavras-chave: Ciclos biogeoquímicos, Dinâmica de nutrientes, Sazonalidade.

Influence of rainfall and grazing on belowground biomass dynamics in a dry tropical savanna

1992 ◽  
Vol 70 (9) ◽  
pp. 1885-1890 ◽  
Author(s):  
C. B. Pandey ◽  
J. S. Singh
Keyword(s):  
Rainy Season ◽  
Soil Depth ◽  
Rainfall Variability ◽  
Grazing Intensity ◽  
Belowground Biomass ◽  
Tropical Savanna ◽  
Rainfall Events ◽  
Seasonally Dry ◽  
Belowground Component

Root biomass and its variation with time and soil depth were studied in ungrazed and grazed treatments, in a seasonally dry tropical savanna. A greater proportion of belowground biomass was located in the 0 – 10 cm soil depth in the rainy season compared with the summer season. In contrast, in the 10 – 50 cm soil profile, belowground biomass was greater in summer than in the rainy season. Peak belowground biomass in ungrazed savanna was not correlated to the rainfall in the early part of the rainy season, but it was correlated to total rainfall received in the later part of rainy season. Apparently the belowground component responds quickly to the rainfall events and generates growth pulses in the aboveground vegetation. Peak canopy biomass increased rapidly with the increase in peak belowground biomass and then plateaued, indicating a greater potential for accumulation of biomass belowground than aboveground. Grazing reduced belowground biomass by 41 – 55%. Maximum reduction occurred in the heavily grazed savanna. Peak belowground biomass was inversely related to grazing intensity. Key words: belowground biomass, grazing intensity, phased root growth, rainfall variability, tropical savanna.

scholarly journals Contrasting Resource Dynamics in Mast Years for European Beech and Oak—A Continental Scale Analysis

2021 ◽  
Vol 4 ◽  
Author(s):  
Anita Nussbaumer ◽  
Arthur Gessler ◽  
Sue Benham ◽  
Bruno de Cinti ◽  
Sophia Etzold ◽  
...  
Keyword(s):  
Leaf Growth ◽  
Fruit Production ◽  
Stem Growth ◽  
Leaf Production ◽  
Continental Scale ◽  
Resource Dynamics ◽  
Resource Storage ◽  
Resource Switching ◽  
The Impact ◽  
Leaf N

Resource allocation to different plant tissues is likely to be affected by high investment into fruit production during mast years. However, there is a large knowledge gap concerning species-specific differences in resource dynamics. We investigated the influence of mast years on stem growth, leaf production, and leaf carbon (C), nitrogen (N), and phosphorus (P) concentrations and contents in Fagus sylvatica, Quercus petraea, and Q. robur at continental and climate region scales using long-term data from the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) and similar datasets. We discussed the results in the light of opposing resource dynamics hypotheses: (i) resource accumulation before mast years and exhaustion after mast years (resource storage hypothesis), (ii) shifting resources from vegetative to generative compartments (resource switching hypothesis), and (iii) investing resources concurrently in both vegetative and generative compartments (resource matching hypothesis). Linear mixed-effects modelling (LMM) showed that both stem growth and leaf production were negatively influenced by weather conditions which simultaneously lead to high fruit production. Thus, the impact of generative on vegetative growth is intermixed with effects of environmental factors. Superposed epoch analyses and LMM showed that for mast behaviour in F. sylvatica, there are indicators supporting the resource storage and the resource switching hypotheses. Before mast years, resources were accumulated, while during mast years resources switched from vegetative to generative tissues with reduced stem and leaf growth. For the Quercus species, stem growth was reduced after mast years, which supports the resource storage hypothesis. LMM showed that leaf C concentrations did not change with increasing fruit production in neither species. Leaf N and P concentrations increased in F. sylvatica, but not in Quercus species. Leaf N and P contents decreased with increasing fruit production in all species, as did leaf C content in F. sylvatica. Overall, our findings suggest different resource dynamics strategies in F. sylvatica and Quercus species, which might lead to differences in their adaptive capacity to a changing climate.

Compudose® : its effects on the growth, offspring performance, lactational performance, and carcass characteristics of Hereford × Friesian heifers at pasture

1998 ◽  
Vol 49 (7) ◽  
pp. 1167 ◽  
Author(s):  
J. L. Burke ◽  
J. L. Burke ◽  
S. T. Morris ◽  
S. T. Morris ◽  
S. N. McCutcheon ◽  
...  
Keyword(s):  
Milk Production ◽  
Carcass Characteristics ◽  
Offspring Performance ◽  
Skeletal Size ◽  
Lactational Performance ◽  
Positive Effect

This study investigated the effects of Compudose® on growth, lactational performance, carcass characteristics, and offspring performance of Hereford × Friesian (H×F) once-bred heifers (OBH) under pastoral conditions. Nineteen H×F heifers were implanted with Compudose 400 at 90 days of age (Compudose 90), 19 were implanted with Compudose 400 at 210 days of age (Compudose 210), and 19 were not implanted (control). Neither Compudose group differed significantly in liveweight from the controls. However, there was a tendency for the Compudose 90 group to be slightly heavier, and the Compudose 210 group slightly lighter, than the controls so that the only significant differences in liveweight were between the two Compudose groups. Similarly, there were no consistent effects of Compudose on measures of body or skeletal size. The effects of Compudose on carcass characteristics were small and related mainly to a tendency for increased muscling. Compudose delayed conception slightly but had no effects on calf birthweight. However, calves born to control heifers were 15·3 kg and 16·2 kg heavier (P < 0·05) at weaning than calves born to Compudose 90 and Compudose 210 heifers, respectively. Most of this difference in liveweight was established by Week 4 of lactation. This implies that Compudose treatment inhibited milk production of the dams, particularly in the early part of lactation, an effect not detected by the weigh-nurse-weigh (WNW) method. Implanting heifers with Compudose at 90 or 210 days of age is unlikely to be beneficial, both because it has little positive effect on liveweight gain or carcass characteristics and because it may inhibit lactational performance.

scholarly journals Seasonal growth of "algodão-bravo" (Ipomoea carnea spp. fistulosa)

1999 ◽  
Vol 34 (2) ◽  
pp. 159-163 ◽  
Author(s):  
Rainer Haase
Keyword(s):  
Rainy Season ◽  
Dry Season ◽  
Control Measures ◽  
Seasonal Growth ◽  
Leaf Production ◽  
Woody Perennial ◽  
Seasonal Flooding ◽  
Ipomoea Carnea ◽  
Seasonally Flooded ◽  
Brazilian Pantanal

Ipomoea carnea spp. fistulosa, a native woody perennial, is capable of spreading rapidly over seasonally flooded grassland in the Brazilian Pantanal, South America's largest wetland, thus conflicting with the local cattle ranching. I. carnea is controlled by mowing at the onset of the rainy season, as close as possible before the seasonal flooding. Often, however, flooding begins after the plant has had enough time to re-sprout enabling it to survive. The objective of this study was to verify if Ipomoea carnea plant's production follows a seasonal cycle, and, if so, at which point in this cycle, the plant is most vulnerable to mechanical control measures. Seasonal dynamics of stem and leaf production of I. carnea were studied. The results showed that growth of I. carnea is fastest at the onset of the rainy season in November/December. Production declines when seasonal flooding commences in January/February and almost ceases towards the begin of the dry season in May/June. This leads to the proposal that I. carnea could be controlled more effectively if the weed were mown in the early dry season when its production and its capability to re-sprout is lowest, and if any new sprouts were cut by hand when the seasonal flooding starts.

scholarly journals Effects of five mycorrhizal fungi on biomass and leaf physiological activities of walnut

2020 ◽  
Vol 48 (4) ◽  
pp. 2021-2031
Author(s):  
Wei-Jin CHENG ◽  
Yong-Jie XU ◽  
Guang-Ming HUANG ◽  
Mohammed M. RAHMAN ◽  
Zhi-Yan XIAO ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Biomass Production ◽  
Mycorrhizal Fungi ◽  
Juglans Regia ◽  
Arbuscular Mycorrhizal ◽  
Chlorophyll B ◽  
Chlorophyll Contents ◽  
Leaf Chlorophyll ◽  
Positive Effect ◽  
Leaf N

Arbuscular mycorrhizal fungi (AMF) can benefit many plants, but their effects on walnuts are not yet known. The present study aimed to analyze the effect of five AMF species, namely, Acaulospora scrobiculata, Diversispora spurca, Glomus etunicatum, G. mosseae and G. versiforme on biomass production, chlorophyll contents, sugar fraction contents, and mineral element contents of walnut (Juglans regia L.) seedlings. The five AMF species colonized roots of walnut, established mycorrhizas in roots and hyphae in soil, and released easily extractable glomalin-related soil protein into soil, whilst D. spurca exhibited the best effect. All the AMF inoculations, except A. scrobiculata, stimulated shoot and root biomass production. Mycorrhizal fungal inoculations collectively increased leaf chlorophyll a, chlorophyll b, and total chlorophyll a+b concentrations, and thus promoted leaf sucrose accumulation, which provides an important mycorrhiza-carbon source to roots. AMF inoculations conferred a positive effect on leaf N, P, K, Mg, Fe, B, Zn and Cu contents, while they reduced leaf Mn contents. These results concluded that AMF were beneficial to the growth and physiological activities of walnut, which gives the support for the AMF application in walnut.

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