scholarly journals EFFECTS OF UNICONAZOLE MEDIA DRENCH AND FOLIAR SPRAY APPLICATIONS ON GROWTH OF PYRACANTHA, PHOTINIA, AND DWARF BURFORD HOLLY

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1125c-1125
Author(s):  
Robert M. Frymire ◽  
Janet C. Henderson

Uniform liners of pyracantha (Pyracantha coccinea Roem `Lalandei'), photinia (Photinia × fraseri Dress) and dwarf Burford holly (Ilex cornuta Lindl. and Paxt. `Burfordii Nana') were potted into 3.8 liter containers in a pine bark:sand medium. Ten weeks later, plants received uniconazole treatments as a media drench or foliar spray. The uniconazole drench rates were 0, 0.5, 1.0, and 3.0 mg ai per container for all three plant species. The foliar application rates were 0, 50, 100 and 150 ppm for pyracantha, 0, 25, 50 and 100 ppm for photinia, and 0, 10, 25, and 50 ppm for dwarf Burford belly. Plant heights and widths were recorded at 3 week intervals, and leaf chlorophyll content was determined by calorimeter at the same time as height and weight measurements. At harvest, leaf counts, leaf areas, and shoot, leaf and root dry weights were determined. Initial results indicate that both foliar and media drench treatments of uniconazole reduced growth of pyracantha and photinia at all rates. Only the two highest rates decreased growth of dwarf Burford holly when applied as either a media drench or a foliar spray.

2021 ◽  
Vol 948 (1) ◽  
pp. 012087
Author(s):  
H F Fawwaz ◽  
S Lathifatunnisa ◽  
N M Hemelda ◽  
R Yuniati

Abstract Lettuce is a crop sensitive to water availability as it needs more water in cultivation. Kaolin has been reported to reduce the impact of drought stress in plants. However, the use of kaolin to increase lettuce growth under drought condition has not been reported yet. In this study, the effect of kaolin to increase the growth of lettuce under suboptimal watering condition was investigated. Kaolin foliar application (3%, 5%, and 6%) was tested on a group consisting of 5 lettuce plants grown under reduced watering condition in a greenhouse. Lettuce height, number of leaves, root length, leaf length and width, fresh and dry weight of lettuce, and leaf chlorophyll content were observed. Kaolin applications significantly increased the growth of lettuce in most parameters compared to the negative control (reduced watering condition, without kaolin). Kaolin 3% application presented the best treatment to increase growth parameters. All kaolin applications did not affect chlorophyll content significantly under lower watering condition. In conclusion, kaolin was able to reduce the impact of reduced watering condition and increase lettuce growth but showed no effect on the leaf chlorophyll content. Thus, further evaluation of kaolin application in lettuce under drought condition is needed.


2019 ◽  
Vol 11 (13) ◽  
pp. 1572 ◽  
Author(s):  
Qiu ◽  
Chen ◽  
Croft ◽  
Li ◽  
Zhang ◽  
...  

Leaf chlorophyll content plays a vital role in plant photosynthesis. The PROSPECT model has been widely used for retrieving leaf chlorophyll content from remote sensing data over various plant species. However, despite wide variations in leaf surface reflectance across different plant species and environmental conditions, leaf surface reflectance is assumed to be the same for different leaves in the PROSPECT model. This work extends the PROSPECT model by taking into account the variation of leaf surface reflection. In the modified model named PROSPECT-Rsurf, an additional surface layer with a variable refractive index is bounded on the N elementary layers. Leaf surface reflectance (Rs) is characterized by the difference between the refractive indices of leaf surface and interior layers. The specific absorption coefficients of the leaf total chlorophyll and carotenoids were recalibrated using a cross-calibration method and the refractive indices of leaf surface and interior layers were obtained during model inversion. Chlorophyll content (Cab) retrieval and spectral reconstruction in the visible spectral region (VIS, 400–750 nm) were greatly improved using PROSPECT-Rsurf, especially for leaves covered by heavy wax or hard cuticles that lead to high surface reflectance. The root mean square error (RMSE) of chlorophyll estimates decreased from 11.1 µg/cm2 to 8.9 µg/cm2 and the Pearson’s correlation coefficient (r) increased from 0.81 to 0.88 (p < 0.01) for broadleaf samples in validation, compared to PROSPECT-5. For needle leaves, r increased from 0.71 to 0.89 (p < 0.01), but systematic overestimation of Cab was found due to the edge effects of needles. After incorporating the edge effects in PROSPECT-Rsurf, the overestimation of Cab was alleviated and its estimation was improved for needle leaves. This study explores the influence of leaf surface reflectance on Cab estimation at the leaf level. By coupling PROSPECT-Rsurf with canopy models, the influence of leaf surface reflectance on canopy reflectance and therefore canopy chlorophyll content retrieval can be investigated across different spatial and temporal scales.


Author(s):  
Toshiyuki Sakai ◽  
Akira Abe ◽  
Motoki Shimizu ◽  
Ryohei Terauchi

Abstract Characterizing epistatic gene interactions is fundamental for understanding the genetic architecture of complex traits. However, due to the large number of potential gene combinations, detecting epistatic gene interactions is computationally demanding. A simple, easy-to-perform method for sensitive detection of epistasis is required. Due to their homozygous nature, use of recombinant inbred lines (RILs) excludes the dominance effect of alleles and interactions involving heterozygous genotypes, thereby allowing detection of epistasis in a simple and interpretable model. Here, we present an approach called RIL-StEp (recombinant inbred lines stepwise epistasis detection) to detect epistasis using single nucleotide polymorphisms in the genome. We applied the method to reveal epistasis affecting rice (Oryza sativa) seed hull color and leaf chlorophyll content and successfully identified pairs of genomic regions that presumably control these phenotypes. This method has the potential to improve our understanding of the genetic architecture of various traits of crops and other organisms.


1990 ◽  
Vol 117 (2) ◽  
pp. 167 ◽  
Author(s):  
Amrita G. de Soyza ◽  
Dwight T. Kincaid ◽  
Carlos R. Ramirez

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