Effect of ammonium/nitrate ratio on growth and development of avocado plants under hydroponic conditions

2007 ◽  
Vol 87 (1) ◽  
pp. 99-103 ◽  
Author(s):  
P. Lobit ◽  
L. López-Pérez ◽  
R. Cárdenas-Navarro ◽  
V. C. Castellanos-Morales ◽  
R. Ruiz-Corro
Keyword(s):  
Carbon Content ◽  
Dry Matter ◽  
Nitrogen Concentration ◽  
Leaf Nitrogen ◽  
Dry Matter Accumulation ◽  
Hydroponic System ◽  
Architectural Analysis ◽  
Matter Production ◽  
The Relationship ◽  
Hydroponic Conditions

An experiment was carried out to study the effects of the proportion of ammonium (NH4+) and nitrate (NO3−) in the nutrient solution on avocado plants in a hydroponic system. Five treatments were applied, consisting of the following proportions of ammonium to nitrate ions in the solution: T0 = 0:4, T1 = 1:3, T2 = 2:2, T3 = 3:1 and T4 = 4:0 at a constant nitrogen concentration of 4 mM. After 4 months, the plants were harvested and fresh and dry matter accumulation, leaf area, and leaf nitrogen and carbon content were measured. An architectural description of the shoot (length, number of nodes and branching) was made. Dry matter of shoots and leaves all decreased with increasing NH4+ concentrations. In contrast, water content in aerial organs increased with NH4+ concentration. Nitrogen and carbon content and the relationship between dry matter production and leaf nitrogen were not significantly affected by the treatments. The architectural analysis showed that the shoots developed over time in one or two distinct growth units. While nitrogen form affected both growth units, the second one was more severely affected, showing decreased length, number of nodes, and branching when NH4+ concentration increased. Key words: Avocado, nitrogen, nitrate, ammonium, development

scholarly journals Nitrogen fertilization in banana grown on a highly weathered soil of the humid mountain region of Puerto Rico.

1969 ◽  
Vol 86 (1-2) ◽  
pp. 15-26
Author(s):  
Héber Irizarry ◽  
Ricardo Goenaga ◽  
Ulises Chardón
Keyword(s):  
Total Nitrogen ◽  
Nitrogen Uptake ◽  
Dry Matter ◽  
Nitrogen Concentration ◽  
Maximum Yield ◽  
Leaf Nitrogen ◽  
Dry Matter Production ◽  
Nitrogen Rate ◽  
Matter Production ◽  
Nitrogen Rates

A 40-month experiment was conducted to re-evaluate the nitrogen fertilization recommendation for banana grown on a clayey, mixed isohyperthermic Aquic Haplohumults under rainfed conditions. Five nitrogen rates (0, 85,170, 255 and 340 kg/ha/crop) were arranged in a randomized compíete block design with three replications. The nitrogen treatments were applied with 24.4 kg/ha of phosphorus, 651,7 kg/ha of potassium, and a minor element mixture containing 22.7 kg/t of fertilizer. Treatments were applied every three months. Applications of magnesium alone were also applied between treatments at the rate of 55 kg/ha in the plant crop (PC) and 110 kg/ha in each of two ratoon crops (R1, R2). During growth and development of three crops we collected data of plant and bunch traits, green and oven-dry biomass weight, nitrogen concentration in various plant organs, and bunch marketable weight at harvest. Results showed that the rate x crop interaction was highly significant (P < 0,01) for total nitrogen uptake, and for nitrogen concentration in the leaf-lamina four months before bunch harvest, and significant (P < 0.05) for total dry matter production. Total nitrogen uptake, leaf nitrogen concentration, and total dry matter production linearly increased with increments in the nitrogen rates. Overall total nitrogen uptake and total dry matter production were always significantly higher in the R2 than in the PC, Regardless of the nitrogen rate, a significantly higher nutrient concentration was always found in the leaf-lamina of the R1 plants than in either the PC or the R2 plants. Crop had no significant effect on yield, but nitrogen rate significantly influenced yield. A maximum yield of 57,060 kg/ ha/crop was obtained with an estimated nitrogen application of 240 kg/ha. This amount corresponded to a leaf nitrogen concentration of between 2.75 and 2.85 g/kg. Since the maximum yield for all crops was obtained with a nitrogen application of only 240 kg/ha, we concluded that the linear response to fertilization in excess of this amount for total nitrogen uptake, nutrient concentration, and total dry matter production may be attributed to luxury consumption of nitrogen.

scholarly journals Dry matter accumulation, distribution and fresh tuber yield of grafted accessions of Hausa potato

2020 ◽  
Vol 55 (2) ◽  
pp. 86-96
Author(s):  
K.K. Nanbol ◽  
O.A.T. Namo
Keyword(s):  
Dry Matter ◽  
Tuber Yield ◽  
Dry Matter Accumulation ◽  
Randomized Design ◽  
Matter Production ◽  
Production Distribution ◽  
Sink Capacity ◽  
Tuber Crop ◽  
A Minor ◽  
The Relationship

The Hausa potato is a minor tuber crop with nutritional and medicinal values. A lack of balance between the photosynthetic source potential and the sink capacity in terms of dry matter accumulation and distribution is believed to affect fresh tuber yield. This study was aimed to investigate the dry matter production, distribution and tuber yield of reciprocal grafts of some accessions of the Hausa potato. The grafts were made in all possible combinations and laid out using the completely randomized design in four replicates. Results showed that harvest index increased with time in most of the grafts. The proportion of dry matter partitioned to the tubers was generally lower than those of the leaves and stems in all the grafts. The highest rootstock-scion ratio of 0.97 was observed in the graft Bokkos 2 - Manchok 2 while the lowest (0.07) was observed in the self-graft of Bokkos 2. Fresh tuber yield was generally low, ranging from 0.03 t ha -1 to 0.09 t ha-1. Apart from dry matter accumulation and distribution, the relationship between the source potential and sink capacity as well as the rate of translocation of assimilates from the photosynthetic source to the sink need to be investigated.

Variations in the relationship between maximum leaf carboxylation rate and leaf nitrogen concentration

2014 ◽  
Vol 38 (6) ◽  
pp. 640-652 ◽  
Author(s):  
YAN Shuang ◽  
◽  
ZHANG Li ◽  
JING Yuan-Shu ◽  
HE Hong-Lin ◽  
...  
Keyword(s):  
Nitrogen Concentration ◽  
Leaf Nitrogen ◽  
Leaf Nitrogen Concentration ◽  
The Relationship

Mass to height relationships in annual pastures and prediction of sheep growth rates

2014 ◽  
Vol 54 (9) ◽  
pp. 1305
Author(s):  
S. M. Robertson
Keyword(s):  
Feed Intake ◽  
Dry Matter ◽  
Dry Matter Accumulation ◽  
Sheep Grazing ◽  
Software Model ◽  
Low Mass ◽  
Grazing Systems ◽  
Sheep Production ◽  
Relationship Of ◽  
The Relationship

The relationship between pasture height and mass influences the availability of pasture for grazing, and is important for predicting intake of pasture and liveweight change by sheep. The relationship between pasture mass and structure and sheep production is poorly defined for low-mass, clumpy pastures in low-rainfall regions. Between 2001 and 2004, 480 quadrats of pastures were measured in 23 paddocks throughout the Victorian Mallee. Pasture height was related to live mass for medic (linear; r2 = 0.70; P < 0.001) and grassy medic (asymptotic; r2 = 0.64; P < 0.001) pastures, and prediction of grassy medic pasture height was improved by inclusion of proportion live groundcover. During 2004, pasture dry matter accumulation and liveweight changes in sheep grazing annual pastures were measured and compared with predicted outputs from GrazFeed, a software model used to estimate feed intake and liveweight change in sheep. Improved predictions of liveweight gain in grazing sheep were obtained using measured height rather than the GrazFeed default height. The results show that the height to mass relationship of annual pastures in the Victorian Mallee differs between pasture types, between years, and may differ from other published relationships. This study provides information that may assist in the development of models of grazing systems.

Discrimination in Carbon Isotopes of Leaves Correlates With Water-Use Efficiency of Field-Grown Peanut Cultivars

1988 ◽  
Vol 15 (6) ◽  
pp. 815 ◽  
Author(s):  
GC Wright ◽  
KT Hubick ◽  
GD Farquhar
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Dry Matter Yield ◽  
Strong Negative Correlation ◽  
Matter Production ◽  
Whole Plant ◽  
Use Efficiency ◽  
The Relationship

Variation in water-use efficiency (W, g of total dry matter produced/kg water used), and its correlation with cultivar isotope discrimination in leaves (Δ) was assessed in peanut plants grown in small canopies in the field. Plants were grown in separate minilysimeters that were both embedded in the ground and positioned above the crop. Differences among cultivars were found in W and � and the relationship between W and Δ was compared for plants grown in open and closed canopies. Genetic variability in W in plants grown in the field under non-limiting water conditions was demonstrated, with Tifton-8, of Virginia habit, having the highest W (3.71 g/kg) and Rangkasbitung, an Indonesian cultivar of Spanish habit, the lowest (2.46 g/ kg). Variability in W was due to variation in total dry matter production more than that of water use. A strong negative correlation was found between Δ and W, and also between Δ and total dry matter. The relationship between whole plant W, including roots, and Δ was stronger than that between shoot W, without roots and Δ. The improvement occurred because of variation among cultivars in the root to shoot ratio. This highlights the importance of taking account of root dry matter in studies concerning W. There were significant differences in W and Δ between plants in pots above-ground compared to pots in the ground, with above-ground plants having significantly lower values of both W and Δ. The ranking of W and Δ among cultivars was not affected by the contrast in environment, which suggests these parameters are under strong genetic control. Total above-ground dry matter yield at maturity was negatively correlated with Δ, while pod yield was not. It appears a negative association between harvest index and Δ may exist; however not all cultivars used in this and other studies follow this response. Both water-use efficiency, Wand total dry matter production are negatively correlated with Δ in leaves of peanut plants grown in small canopies in the field. Measurement of Δ may prove a useful trait for selecting cultivars with improved W and total dry matter yield under field conditions.

Common Sunflower (Helianthus annuus) Interference in Soybean (Glycine max)

1996 ◽  
Vol 10 (2) ◽  
pp. 317-321 ◽  
Author(s):  
Patrick W. Geier ◽  
Larry D. Maddux ◽  
Loren J. Moshier ◽  
Phillip W. Stahlman
Keyword(s):  
Dry Matter ◽  
Market Price ◽  
Yield Reduction ◽  
Soybean Yield ◽  
Sunflower Plant ◽  
Matter Production ◽  
Competition Study ◽  
Soybean Canopy ◽  
Relationship Of ◽  
The Relationship

An in-row competition study was conducted in 1991 and 1992 near Silver Lake, KS to determine the relationship of noncultivated common sunflower density to soybean yield, PAR at the soybean canopy, and common sunflower dry matter production. Because of environmental differences, year main effect interactions occurred, so results are presented by year. For example, 0.3 common sunflower plant/m2produced 4030 kg/ha of aboveground dry matter in 1991 and 1300 kg/ha in 1992. Soybean yield reduction ranged from 19 and 17% with 0.3 common sunflower plant/m2to 97 and 95% with 4.6 plant/m2, in 1991 and 1992, respectively. Assuming a treatment cost of $35/ha and a soybean market price of $0.21/kg, economic threshold levels were 0.1 common sunflower plant/m2in 1991, and 0.07 in 1992. Common sunflower at 0.3 plant/m2reduced PAR at the soybean canopy by 390 and 300 μE/m2/s, or 24 and 18% in 1991 and 1992, respectively. We conclude that the ability of common sunflower to intercept PAR above the soybean canopy is an important component in its interference with soybean.

Boron toxicity in soil solution

Soil Research ◽  
1988 ◽  
Vol 26 (4) ◽  
pp. 605 ◽  
Author(s):  
RL Aitken ◽  
LE Mccallum
Keyword(s):  
Soil Solution ◽  
Soil Type ◽  
Dry Matter ◽  
Boron Concentration ◽  
Boron Toxicity ◽  
Controlled Environment ◽  
Dry Matter Accumulation ◽  
Undisturbed Soil ◽  
Toxicity Threshold ◽  
The Relationship

The relationship between soil solution boron concentration and the dry-matter accumulation and boron concentration in sunflower (Helianthus annuus cv. Hysun 31) was investigated in a 14-day study in a controlled environment. Plants were grown in each of six soils previously equilibrated with various levels of boron applied as H3BO3. The soil, wet to 10 kPa matric suction, was retained in polypropylene containers and the soil solution was extracted by centrifugation from the entire undisturbed soil volume immediately after the top growth had been harvested. Above a threshold of 1.9 �g B mL-1 in soil solution, yield reductions due to boron toxicity occurred. In the toxicity range there was a linear relationship between relative dry matter yield and log10[B] in soil solution. At high levels of boron, the relationship between boron concentration in plant tops and hot 0.01 M CaCl2-extractable boron depended on soil type, whereas the relationship between plant boron concentration and soil solution boron concentration did not depend on soil type. It is suggested that, at high levels of boron, plants were responding to soil solution boron (intensity), while hot 0.01 M CaCl2-extractable boron estimates a quantity factor. The results obtained indicate that the apparatus and technique used in this study could be used to derive toxicity threshold concentrations for a range of plant species.

Nitrogen and dry-matter accumulation in high lysine and normal varieties of barley

1976 ◽  
Vol 86 (1) ◽  
pp. 57-64 ◽  
Author(s):  
A. P. Rhodes ◽  
G. Jenkins
Keyword(s):  
Dry Matter ◽  
Dry Matter Accumulation ◽  
Plant Nitrogen ◽  
High Lysine ◽  
Comparative Efficiency ◽  
Yield And Quality ◽  
Normal Varieties ◽  
Matter Production ◽  
Total Plant ◽  
Nitrogen Treatments

SUMMARYDry matter and Kjeldahl nitrogen estimations were made on the roots and shoots of the barley varieties Riso 1508, Hiproly and Maris Mink from the seedling stage to maturity under three nitrogen treatments. After heading, the shoots were further separated into ears and stems plus leaves. Total plant nitrogen uptake was greatest in the high lysine variety Riso 1508 and was associated with a greater production of dry matter. However, the proportion of total plant nitrogen and dry matter in the grain was highest in the variety Maris Mink and this effect increased with increasing nitrogen supply. The comparative efficiency of dry-matter production and nitrogen translocation of these varieties is discussed in relation to breeding barley of improved protein yield and quality.

Influence of row spacing on growth, light and water use by sorghum

1991 ◽  
Vol 116 (3) ◽  
pp. 329-339 ◽  
Author(s):  
M. McGowan ◽  
H. M. Taylor ◽  
J. Willingham
Keyword(s):  
Water Use ◽  
Dry Matter ◽  
Ground Cover ◽  
Field Capacity ◽  
Bare Soil ◽  
Row Spacing ◽  
Dry Matter Accumulation ◽  
Matter Production ◽  
Use Efficiency ◽  
Reduced Water

SUMMARYGrain sorghum (Sorghum bicolor L. Moench) was grown in Texas in 1985 at a constant population density of c. 6·6 plants/m2 in rows 0·5, 1·0 and 1·5 m apart and with the soil profile at field capacity at planting time. Dry matter production and yield were least at the widest spacing, principally because of a reduction in number of tillers. Dry matter accumulation was in direct proportion to the amount of light intercepted and largely independent of spacing between rows, with a conversion coefficient of 1·71 g dry matter/MJ energy intercepted. The most widely spaced crop used less water but not in proportion to the extent that ground cover was reduced. Water use efficiency was also less in the most widely spaced crop, probably because of heat advection from the bare soil between rows.

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