scholarly journals Potential growing model for the standard carnation cv. Delphi

2014 ◽  
Vol 32 (2) ◽  
pp. 196-204 ◽  
Author(s):  
Miguel Ángel Lopez M. ◽  
Bernardo Chaves C. ◽  
Víctor Julio Flórez R.

The cut flower business requires exact synchronicity between product offer and demand in consumer countries. Having tools that help to improve this synchronicity through predictions or crop growth monitoring could provide an important advantage to program standards and corrective agronomic practices. At the Centro de Biotecnología Agropecuaria, SENA (SENA's Biotechnology, Agricultural and Livestock Center), located in Mosquera, Cundinamarca, a trial with standard carnation cv. Delphi grown under greenhouse conditions was carried out. The objective of this study was to build a simple model of dry matter (DM) production and partition of on-carnation flower stems. The model was based on the photosynthetically active radiation (PAR) MJ m-2 d-1 and temperature as exogenous variables and assumed no water or nutrient limitations or damage caused by pests, disease or weeds. In this model, the daily DM increase depended on the PAR, the light fraction intercepted by the foliage (FLINT) and the light use efficiency (LUE) g MJ-1. The LUE in the vegetative and reproductive stages reached values of 1.31 and 0.74 g MJ-1, respectively. The estimated extinction coefficient (k) value corresponded to 0.53 and the maximum FLINT was between 0.79 and 0.82. Partitioning between the plant vegetative and reproductive stages was modeled based on the hypothesis that the partition is regulated by the source sink relationship. The estimated partition coefficient for the vegetative stage of the leaves was 0.63 and 0.37 for the stems. During the reproductive stage, the partitioning coefficients of leaves, stems and flower buds were 0.05, 0.74, and 0.21, respectively.

2021 ◽  
Vol 13 (12) ◽  
pp. 2349
Author(s):  
Jingchun Ji ◽  
Jianli Liu ◽  
Jingjing Chen ◽  
Yujie Niu ◽  
Kefan Xuan ◽  
...  

Topdressing accounts for approximately 40% of the total nitrogen (N) application of winter wheat on the Huang-Huai-Hai Plain in China. However, N use efficiency of topdressing is low due to the inadaptable topdressing method used by local farmers. To improve the N use efficiency of winter wheat, an optimization method for topdressing (THP) is proposed that uses unmanned aerial vehicle (UAV)-based remote sensing to accurately acquire the growth status and an improved model for growth potential estimation and optimization of N fertilizer amount for topdressing (NFT). The method was validated and compared with three other methods by a field experiment: the conventional local farmer’s method (TLF), a nitrogen fertilization optimization algorithm (NFOA) proposed by Raun and Lukina (TRL) and a simplification introduced by Li and Zhang (TLZ). It shows that when insufficient basal fertilizer was provided, the proposed method provided as much NFT as the TLF method, i.e., 25.05% or 11.88% more than the TRL and TLZ methods and increased the yields by 4.62% or 2.27%, respectively; and when sufficient basal fertilizer was provided, the THP method followed the TRL and TLZ methods to reduce NFT but maintained as much yield as the TLF method with a decrease of NFT by 4.20%. The results prove that THP could enhance crop production under insufficient N preceding conditions by prescribing more fertilizer and increase nitrogen use efficiency (NUE) by lowering the fertilizer amount when enough basal fertilizer is provided.


2022 ◽  
Vol 278 ◽  
pp. 108430
Author(s):  
Olusegun Idowu ◽  
Yuanzheng Wang ◽  
Koki Homma ◽  
Tetsuya Nakazaki ◽  
Zhengjin Xu ◽  
...  

2011 ◽  
Vol 40 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Hernan Vielmo ◽  
Amadeu Bona Filho ◽  
André Brugnara Soares ◽  
Tangriani Simioni Assmann ◽  
Paulo Fernando Adami

The objective of this study was to evaluate the effect of different doses of liquid swine slurry on dry matter accumulation rate and nutritive values (crude proten and neutral detergent fiber) of Tifton 85 grass pasture cultivated in southwestern Paraná from October 2005 to March 2006. It was used a complete random experimental design in a 4 x 4 factorial scheme composed of four doses of swine slurry in the plots (0, 80, 160 and 320 m³/ha) and four consecutive cuts in the subplots of the pasture. It was carried out two applications, one in the beginning of the experiment and other after 80 days. Cuts were performed every time pasture height was 40 cm. There was a dose versus cut interaction for all variables. Swine slurry promoted increase on dry matter accumulation rate only on the first cut after its application (cuts 1 and 3). Dry matter maximal yield (24.2 t/ha) was obtained at 249 m³/ha of swine slurry manure (143 and 106 m³/ha, respectively for applications 1 and 2), corresponding to 450 kg of N/ha. Percentage of crude protein increases and neutral detergent fiber of Tifton 85 grass decreases as dose of swine slurry increases, improving forage nutritive value. Use efficiency and nitrogen recovery rate decrease with addition of swine slurry doses.


2004 ◽  
Vol 84 (2) ◽  
pp. 169-176 ◽  
Author(s):  
B. L. Ma ◽  
M. Li ◽  
L. M. Dwyer ◽  
G. Stewart

Little information is available comparing agronomic performance and nitrogen use efficiency (NUE) for N application methods such as foliar spray, soil application, and ear injection in maize (Zea mays L.). The objective of this study was to investigate the effects of various N application methods on total stover dry matter, grain yield, and NUE of maize hybrids using a 15N-labeling approach. A field experiment was conducted on a Dalhousie clay loam in Ottawa and a Guelph loam in Guelph for 2 yr (1999 and 2000). Three N application methods were tested on two maize hybrids, Pioneer 3893 and Pioneer 38P06 Bt. At planting, 60 kg N ha-1 as ammonium nitrate was applied to all treatments. In addition, 6.5 kg N ha-1 and 13.5 kg N ha-1 as 15N-labeled urea were applied to either foliage (Treatment I) or soil (Treatment II) at V6 and V12 stages, respectively. In Treatment III, 20 kg N ha-1 as 15N-labeled urea was injected into space between ear and husks at silking. The results showed that compared with soil N application neither foliar spray nor injection through ear affected grain yield or stover dry matter. The NUE values ranged from 12 to 76% for N fertilizer applied at V6 a nd V12 stages, or at silking for all treatments. There was no interaction of hybrid × N application methods on any variables measured with the only exception that for soil N application, grain NUE in Pioneer 38P06 Bt was significant higher than in Pioneer 3893. The difference in total N and NUE of grain and stover between soil N application and foliar N spray was inconsistent. However, NUE was substantially higher for N injection through the ear than for foliar or soil application without differential responses between the two hybrids. Nitrogen injection through the ear at silking might have altered N redistribution within the plant and improved NUE. Hence, it can potentially enhance grain protein content. Foliar N spray is not advocated for maize production in Ontario. Key words: Maize, Zea mays, nitrogen application methods, nitrogen-15, yield, nitrogen use efficiency


2013 ◽  
Vol 41 (2) ◽  
pp. 560 ◽  
Author(s):  
Ayfer Alkan TORUN ◽  
Nazife ERDEM ◽  
Yildiz AKA KACAR ◽  
Sedat SERCE

The cultivated strawberry Fragaria × ananassa Duch. is the natural hybrid of F. chiloensis (L.) Mill. and F. virginiana Mill. The progenitor species have high genetic diversity compared with the cultivated genotypes; therefore, the use of wild relative in F. chiloensis breeding could provide a good for broadening the available genetic variations of cultivated species. In present study, 13 genotypes selected from strawberry super core collection were tested under Fe (-) and Fe (+) conditions for their response against Fe deficiency conditions in a growth medium (GM) (soil + sand + perlite), potentially able to simulate the actual GM in nature. SPAD-meter readings indicating chlorophyll levels of the leaf, shoot dry matter yield, Fe-efficiency rate, shoot total and active Fe concentrations were determined to evaluate the resistance levels of strawberry genotypes against Fe deficiency. Results of this study indicated that different response for strawberry subspecies and genotypes of the same subspecies grown in GM against Fe deficiency. Symptom for Fe deficiency of genotypes varied between 1-5, SPAD-meter readings 3, shoot dry matter yields and shoot Fe concentrations varied between 6.5-38, 1.02-6.06 g plant-1 and 41.8-233.1 mg kg-1 respectively. Iron-efficiencies of genotypes were found between 58–98%. Strawberry subspecies, F. virginiana spp. glauca, F. chiloensis ssp. chiloensis and F. chiloensis ssp. pacifica showed Fe-efficiency values of 93.8, 79.5 and 79.1% respectively. We concluded that shoot growth performance, Fe intake from GM, transfer of Fe from roots to shoots, shoot Fe-use efficiency, Fe deficiency symptom levels and SPAD-meter readings indicating chlorophyll levels were significant parameters to evaluate the resistance of strawberry genotypes against Fe deficiency. The most Fe-efficient genotypes belonging to F. virginiana spp. glauca could be used in breeding programs aiming at developing new strawberry genotypes suitable for growing under Fe deficient conditions.


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