scholarly journals Seasonal Changes in Root Metabolic Activity and Nitrogen Uptake for Two Cultivars of Creeping Bentgrass

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 822-826 ◽  
Author(s):  
Qingzhang Xu ◽  
Bingru Huang
Keyword(s):  
Nitrogen Uptake ◽  
Seasonal Changes ◽  
Carbon Allocation ◽  
N Uptake ◽  
Creeping Bentgrass ◽  
Dry Weight ◽  
Root Dry Weight ◽  
Turf Quality ◽  
Metabolic Activities ◽  
Nr Activity

Roots play important roles in plant responses to environmental changes. The objective of this study was to investigate seasonal changes and cultivar variation in root growth, respiratory activity, nitrogen uptake, and carbon allocation in relation to turf performance for two cultivars of creeping bentgrass [Agrostis stolonifera L. var. palustris (Huds.)] under field conditions. Two cultivars, `Penncross' and `L-93', were managed under USGA-specification putting green conditions, with daily irrigation and mowing at a 3-mm height from May to November in 1999 and 2000. Turf quality of both cultivars declined from the highest rating of 7 to 9 in May to 4 to 5 in August and September, and recovered to above 7 in October and November in both years. This corresponded to seasonal changes in root dry weight, dehydrogenase activity, nitrate reductase (NR) activity, carbon allocation to roots, and 15N uptake. Compared to Penncross, L-93 generally maintained better turf quality, as well as higher root dry weight, 15N uptake, NR activity, and carbon allocation during summer months. Previous studies often emphasize the important of a large, extensive root system. The results in the present study demonstrated that root metabolic activities followed the same seasonal pattern and cultivars variation as turf performance, and suggested that decline in root metabolic activities could be contributed to summer decline in turf quality for creeping bentgrass.

scholarly journals Peningkatan Populasi, Pertumbuhan dan Serapan Nitrogen Tanaman Kedelai dengan Pemberian Azotobacter Penghasil Eksopolisakarida

2017 ◽  
Vol 45 (1) ◽  
pp. 30-35 ◽  
Author(s):  
Reginawanti Hindersah ◽  
Neni Rostini ◽  
Arief Harsono ◽  
Dan Nuryani
Keyword(s):  
Nitrogen Uptake ◽  
Phase 1 ◽  
N Uptake ◽  
Dry Weight ◽  
Azotobacter Chroococcum ◽  
Growth Media ◽  
Two Phase ◽  
Randomized Design ◽  
Batch Fermenter ◽  
Liquid Inoculant

Nitrogen-fixing Azotobacter is widely used as biofertilizer in sustainable agriculture. The bacteria produce exopolysaccharide which might have a significant role in enhancing soybean nitrogen uptake and growth. The objective of this research was to obtain growth media of Exopolysaccharide–producing Azotobacter; and increase shoot and root growth as well as nitrogen uptake of soybean var. Anjasmoro at early vegetative phase following inoculation of Azotobacter chroococcum liquid. Research consist of two phase, 1) determination of organic-based media for A. chroococcum liquid inoculant production, and 2) pot experiment for application of liquid inoculant on soybean.  The first experiment was performed  in a series of  batch fermenter consisted of several organic media for 72 hours.  The second experiment was set in completely randomized design consisted of three density of liquid inoculant. The results verified that the best media which induced exopolysachharide production of A. chroococcum was 1% molase enriched with 0.1% NH4Cl. Liquid inoculant clearly enhanced population of Azotobacter in soybean rhizosphere, plant height, roots dry weight and N uptake of 21 day old soybean. This research implied that A. chroococcum might be used as biofertilizer at early growth of soybean. Keywords: Azotobacter chroococcum, biofertilizer, liquid inoculat

scholarly journals Nitrite Concentration Effects on NO3-N Uptake and Reduction, Growth, and Fruit Yield in Strawberry

2001 ◽  
Vol 126 (5) ◽  
pp. 560-563 ◽  
Author(s):  
Rebecca L. Darnell ◽  
Gary W. Stutte
Keyword(s):  
Developmental Stages ◽  
N Uptake ◽  
Dry Weight ◽  
Fruit Yield ◽  
Concentration Effects ◽  
Stage Of Development ◽  
N Concentration ◽  
Uptake Rates ◽  
Vegetative And Reproductive Growth ◽  
Nr Activity

Strawberries (Fragaria xananassa Duch. .Osogrande.) were grown hydroponically with three NO3-N concentrations (3.75, 7.5, or 15.0 mM) to determine effects of varying concentration on NO3-N uptake and reduction rates, and to relate these processes to growth and fruit yield. Plants were grown for 32 weeks, and NO3-N uptake and nitrate reductase (NR) activities in roots and shoots were measured during vegetative and reproductive growth. In general, NO3-N uptake rates increased as NO3-N concentration in the hydroponics system increased. Tissue NO3-. concentration also increased as external NO3-N concentration increased, reflecting the differences in uptake rates. There was no effect of external NO3-N concentration on NR activities in leaves or roots during either stage of development. Leaf NR activity averaged ~360 nmol NO2 formed/g fresh weight (FW)/h over both developmental stages, while NR activity in roots was much lower, averaging ~115 nmol NO2 formed/g FW/h. Vegetative organ FW, dry weight (DW), and total fruit yield were unaffected by NO3-N concentration. These data suggest that the inability of strawberry to increase growth and fruit yield in response to increasing NO3-N concentrations is not due to limitations in NO3-N uptake rates, but rather to limitations in NO3 - reduction and/or assimilation in both roots and leaves.

scholarly journals Seasonal Changes and Cultivar Difference in Turf Quality, Photosynthesis, and Respiration of Creeping Bentgrass

HortScience ◽  
2001 ◽  
Vol 36 (6) ◽  
pp. 1131-1135 ◽  
Author(s):  
Xiaozhong Liu ◽  
Bingru Huang
Keyword(s):  
Respiration Rate ◽  
Photosynthetic Rate ◽  
Seasonal Changes ◽  
Photochemical Efficiency ◽  
Creeping Bentgrass ◽  
Turf Quality ◽  
Putting Green ◽  
Summer Decline ◽  
Plant Respiration ◽  
Photosynthesis And Respiration

Summer decline in turf quality of creeping bentgrass (Agrostis palustris Hud.) is a major problem in golf course green management. The objective of this study was to examine whether seasonal changes and cultivar variations in turf performance are associated with changes in photosynthesis and respiration rates for creeping bentgrass. The study was conducted on a USGA-specification putting green in Manhattan, Kans., during 1997 and 1998. Four creeping bentgrass cultivars, `L-93', `Crenshaw', `Penncross', and `Providence', were examined. Grasses were mowed daily at 4 mm and irrigated on alternate days to replace 100% of daily water loss. In both years, turf quality, canopy net photosynthetic rate (Pn), and leaf photochemical efficiency (Fv/Fm) were high in May and June and decreased to the lowest levels in July through September. Whole-plant respiration rate (R) and canopy minus air temperature (▵T) increased during summer months. In October, turf quality and Pn increased, whereas R and T decreased. During summer months, turf quality was highest for `L-93', lowest for `Penncross', and intermediate for `Providence' and `Crenshaw'. Seasonal changes and cultivar variations in turf quality were associated with the decreasing photosynthetic rate and increasing respiration rate.

scholarly journals 429 PB 168 NET AMMONIUM UPTAKE BY ROOTS OF FIELD-GROWN PEACH TREES IS INVERSELY RELATED TO TREE NITROGEN STATUS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 492f-492
Author(s):  
F.J.A. Niederholzer ◽  
S.A. Weinbaum
Keyword(s):  
Prunus Persica ◽  
N Uptake ◽  
External Solution ◽  
Dry Weight ◽  
Fruit Trees ◽  
Ammonium Uptake ◽  
Uptake Capacity ◽  
Root Dry Weight ◽  
Uptake Rates ◽  
N Status

The relationship between nitrogen (N) status and N uptake capacity has not been assessed in fruit trees. Determination of root uptake capacity by depletion of unlabeled N from external solution is less costly than methods using 15N, but is reportedly not suited for excised root studies due to reductions in uptake rates with time (Pearcy, R.W. et al. (eds). 1989. Plant Physiological Ecology, p. 195. Chapman and Hall. New York.). We tested two hypotheses: I) excised peach root NH4+ uptake rates are constant over several hours exposure to NH4+ solution and 2) excised peach root NH4+ uptake rates are negatively correlated with tree N status. Mature, N deficient, field grown `O'Henry' trees on `Lovell' peach (Prunus persica L. Batch.) rootstocks and growing in Winters, CA received (NH4)2SO4 at a rate of 200 kg N/ha on September 29, 1993. An equal number of control trees received no N fertilizer. Foliar N deficiency symptoms of fertilized trees disappeared within 3 weeks of fertilization. On Nov. 9, 1993 (prior to leaf fall), excised roots were obtained from two fertilized and two unfertilized trees. Root NH4+ accumulation rates per unit root dry weight or root length were constant over 5 hours of exposure to 70 μM NH4+ (initial concentration) for both fertilized and unfertilized trees. Unfertilized tree root NH4+ uptake rates were significantly greater than those of fertilized trees on a root dry weight or length basis. Excised root NH4+ uptake may prove to be a sensitive index of fruit tree N status.

scholarly journals Timing and Temperature of Physiological Decline for Creeping Bentgrass

2006 ◽  
Vol 131 (5) ◽  
pp. 608-615 ◽  
Author(s):  
John Pote ◽  
Zhaolong Wang ◽  
Bingru Huang
Keyword(s):  
Root Biomass ◽  
Root Zone ◽  
Creeping Bentgrass ◽  
Dry Weight ◽  
Root Number ◽  
Root Zone Temperature ◽  
Cytokinin Content ◽  
Turf Quality ◽  
Active Root ◽  
Zone Temperature

Knowledge of the level of soil temperatures that is detrimental for shoot and root growth for cool-season grasses may help develop heat-tolerant plants and effective management practices to improve summer performance. The objectives of this study were to determine the level and duration of high temperatures in the root zone that will induce decline for various growth and physiological parameters and to compare the responses of different physiological parameters and cultivars to high root-zone temperatures. Nine creeping bentgrass [Agrostis stolonifera L. var. palustris (Huds.) Farw.] cultivars were subjected to eight root-zone temperatures (20, 21, 22, 23, 25, 27, 31, 35 °C) in water baths while exposed to a constant air temperature of 20 °C for 54 days. Root number, dry weight, and depth, active root biomass, turf quality, leaf cytokinin content, and canopy net photosynthetic rate (Pn), decreased in all nine cultivars as root-zone temperature increased from 20 to 35 °C, but the time and temperature at which the decline occurred varied for each parameter measured. Pn, cytokinin content, root number, and turf quality declined at 23, 27, 27, and 35 °C, respectively, after 28 days of exposure. Active root biomass, root number, root dry weight, turf quality, and rooting depth declined at 23, 25, 25, 25, and 35 °C, respectively, at 54 days. At a 31 °C root-zone temperature the decline in root number, cytokinin content, and turf quality occurred at 19, 37, and 47 days, respectively. The results suggest that root-zone temperatures of 23 °C or above this level were detrimental to root activities, Pn, and overall turf growth. Root and Pn decline at lower temperatures and earlier in the study than turf quality suggest that the disturbance of physiological activities of roots and leaves could lead to turfgrass quality decline at high root-zone temperatures.

scholarly journals Spring Nitrogen Uptake, Use Efficiency, and Partitioning for Growth in Iris germanica ‘Immortality’

HortScience ◽  
2016 ◽  
Vol 51 (5) ◽  
pp. 563-566 ◽  
Author(s):  
Xiaojie Zhao ◽  
Guihong Bi ◽  
Richard L. Harkess ◽  
Jac J. Varco ◽  
Eugene K. Blythe
Keyword(s):  
Nitrogen Uptake ◽  
Leaf Growth ◽  
N Uptake ◽  
Dry Weight ◽  
N Content ◽  
Total N ◽  
Nitrogen Uptake Efficiency ◽  
Iris Germanica ◽  
N Derived From Fertilizer ◽  
Total Plant

This study investigated how spring nitrogen (N) application affects N uptake and growth performance in tall bearded (TB) iris ‘Immortality’ (Iris germanica L.). Container-grown iris plants were treated with 0, 5, 10, 15, or 20 mm N from 15NH415NO3 through fertigation using a modified Hoagland’s solution twice a week for 6 weeks in Spring 2013. Increasing N rate increased plant height, total plant dry weight (DW), and N content. Total N content was closely related to total plant DW. The allocation of N to different tissues followed a similar trend as the allocation of DW. In leaves, roots, and rhizomes, increasing N rate increased N uptake and decreased carbon (C) to N ratio (C/N ratio). Leaves were the major sink for N derived from fertilizer (NDFF). As N supply increased, DW accumulation in leaves increased, whereas DW accumulation in roots and rhizomes was unchanged. This indicates increasing N rate contributed more to leaf growth in spring. Nitrogen uptake efficiency (NupE) had a quadratic relationship with increasing N rate and was highest in the 10 mm N treatment, which indicates 10 mm was the optimal N rate for improving NupE in this study.

Genetic variation for rate of establishment in caucasian clover

1998 ◽  
pp. 213-217
Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Seedling Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Red Clover ◽  
Dry Weight ◽  
Cool Season ◽  
Trifolium Ambiguum ◽  
Root Dry Weight

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum

Respon Akar Bibit Aren Genjah (Arenga pinnata) Di Pembibitan Pada Pemberian Dosis dan Interval Pupuk Organik Cair Nasa

2018 ◽  
Vol 7 (1) ◽  
pp. 28
Author(s):  
Yetti Elidar
Keyword(s):  
Organic Fertilizer ◽  
Dry Weight ◽  
Treatment Combination ◽  
Root Dry Weight ◽  
Randomized Design ◽  
Dose Study ◽  
Palm Sugar ◽  
Wet Weight ◽  
Completely Randomized Design ◽  
Leaf Dry Weight

Research on the response of roots of palm sugar palm seeds (Arenga pinnata) in nurseries at doses and intervals of Nasa liquid organic fertilizer. Aims to determine the dosage, interval and combination of dosages and fertilization intervals with Nasa liquid organic fertilizer which can provide the best dry weight of the roots in the nursery. The research design used was a Completely Randomized Design (CRD) with 3x3 factorial experiments and each treatment was repeated 8 (eight) times, consisting of: the first factor was the treatment of POC Nasa dose in a concentration of 3 cc POC Nasa per liter of water (D) consists of 3 levels, namely: d1 = 300 ml POC Nasa, d2 = 400 ml POC Nasa, d3 = 500 ml POC Nasa, while the second factor is the treatment of POC Nasa Interval (I) consisting of 3 levels, namely: i1 = 2 once a week, i2 = once every 3 weeks, i3 = once every 4 weeks. The results of the POC Nasa dose study had a significant effect on leaf wet weight, leaf dry weight, root wet weight and root dry weight. The best dose at this level are: d2 (400 ml of Nasa liquid organic fertilizer), the interval of liquid organic fertilizer Nasa has a significant effect on leaf wet weight, leaf dry weight, root wet weight and root dry weight. The best dose at this level is: i1 (once every 2 weeks). The treatment combination has no significant effect on all parameters. 

scholarly journals Biosolids Benefit Yield and Nitrogen Uptake in Winter Cereals without Excess Risk of N Leaching

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1482
Author(s):  
Silvia Pampana ◽  
Alessandro Rossi ◽  
Iduna Arduini
Keyword(s):  
Triticum Turgidum ◽  
N Uptake ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
N Leaching ◽  
Specific Rate ◽  
Mineral Fertilization ◽  
Hordeum Vulgare L ◽  
Mineral N ◽  
Winter Cereals

Winter cereals are excellent candidates for biosolid application because their nitrogen (N) requirement is high, they are broadly cultivated, and their deep root system efficiently takes up mineral N. However, potential N leaching from BS application can occur in Mediterranean soils. A two-year study was conducted to determine how biosolids affect biomass and grain yield as well as N uptake and N leaching in barley (Hordeum vulgare L.), common wheat (Triticum aestivum L.), durum wheat (Triticum turgidum L. var. durum), and oat (Avena byzantina C. Koch). Cereals were fertilized at rates of 5, 10, and 15 Mg ha−1 dry weight (called B5, B10, and B15, respectively) of biosolids (BS). Mineral-fertilized (MF) and unfertilized (C) controls were included. Overall, results highlight that BS are valuable fertilizers for winter cereals as these showed higher yields with BS as compared to control. Nevertheless, whether 5 Mg ha−1 of biosolids could replace mineral fertilization still depended on the particular cereal due to the different yield physiology of the crops. Moreover, nitrate leaching from B5 was comparable to MF, and B15 increased the risk by less than 30 N-NO3 kg ha−1. We therefore concluded that with specific rate settings, biosolid application can sustain yields of winter cereals without significant additional N leaching as compared to MF.

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