• Title/Summary/Keyword: leaf lettuce

Search Result 306, Processing Time 0.036 seconds

Image Processing Methods for Measurement of Lettuce Fresh Weight

  • Jung, Dae-Hyun;Park, Soo Hyun;Han, Xiong Zhe;Kim, Hak-Jin
    • Journal of Biosystems Engineering
    • /
    • v.40 no.1
    • /
    • pp.89-93
    • /
    • 2015
  • Purpose: Machine vision-based image processing methods can be useful for estimating the fresh weight of plants. This study analyzes the ability of two different image processing methods, i.e., morphological and pixel-value analysis methods, to measure the fresh weight of lettuce grown in a closed hydroponic system. Methods: Polynomial calibration models are developed to relate the number of pixels in images of leaf areas determined by the image processing methods to actual fresh weights of lettuce measured with a digital scale. The study analyzes the ability of the machine vision- based calibration models to predict the fresh weights of lettuce. Results: The coefficients of determination (> 0.93) and standard error of prediction (SEP) values (< 5 g) generated by the two developed models imply that the image processing methods could accurately estimate the fresh weight of each lettuce plant during its growing stage. Conclusions: The results demonstrate that the growing status of a lettuce plant can be estimated using leaf images and regression equations. This shows that a machine vision system installed on a plant growing bed can potentially be used to determine optimal harvest timings for efficient plant growth management.

Treatment Time and Concentration of GA3 for Increasing Efficiency of the Lettuce Seed Production for Lettuce Breeding and Selection (상추 육성 및 선발을 위한 채종 효율증진을 위한 GA3 처리시기 및 농도)

  • Lee, K.H.;Ryu, G.M.
    • Journal of Practical Agriculture & Fisheries Research
    • /
    • v.14 no.1
    • /
    • pp.119-130
    • /
    • 2012
  • To increasing efficiency of the seed production through GA3 treatment, treatment of GA3 20mg/ℓ at its fourteen leaf stage had an effect on 21% increasing seed yield at leaf lettuce (cv.'Ttugseomjeokchugmyeon') in seed production from 50.9ℓ/10a to 61.7ℓ/10a, and 'GA3 50mg/ℓ at its eight leaf and fourteen leaf stage had a effect on 14% increasing the seed yield of head lettuce (cv.'Urake') at seed production from 14.2ℓ/10a to 21.1ℓ/10a reducing rate of dead plant in field. Especially, it will be recommended for planting after June for seed production of head lettuce owing to decreasing rate of dead by soft rot and stem rot.

Development of a 2-DOF Robot System for Harvesting a Lettuce (2 자유도 상추 수확 로봇 시스템 개발)

  • 조성인;장성주;류관희;남기찬
    • Journal of Biosystems Engineering
    • /
    • v.25 no.1
    • /
    • pp.63-70
    • /
    • 2000
  • In Korea, researches for year-round leaf vegetables production system are in progress and the most of them are focused on environment control. Automation technologies for harvesting , transporting and grading need to be developed. This study was conducted to develop harvesting process automation system profitable to a competitive price. 1. Manipulator and end-effector are to be designed and fabricated , and fuzzy logic controller for controlling these are to be composed. 2. The entire system constructed is to be evaluated through a performance test. A robot system for harvesting a lettuce was developed. It was composed of a manipulator with 20DOF (degrees of freedom) an end-effector, a lettuce feeding conveyor , an air blower , a machine vision device, 6 photoelectric sensors and a fuzzy logic controller. A fuzzy logic control was applied to determined appropriate grip force on lettuce. Leaf area index and height index were used as input parameters, and voltage was used as output parameter for the fuzzy logic controller . Success rate of the lettuce harvesting system was 93.06% , and average harvesting time was about 5 seconds per lettuce.

  • PDF

Effect of Remained Leaf Number on the Growth and Yield of Hydroponically Grown Leaf Lettuce (잔존엽수가 수경재배 잎 상추의 생육 및 수량에 미치는 영향)

  • Chi Sung Han
    • Journal of Bio-Environment Control
    • /
    • v.14 no.1
    • /
    • pp.63-67
    • /
    • 2005
  • This study was conducted to investigate the effect of remained leaf number on leaf, stem and root growth of leaf lettuce (Lactuca sativa L. var. Chungchima). Plants were grown hydroponically in $0.45\pm0.15\pm3.0m$ growth channels using a recirculating DFT (Deep Flow Technique) system. The growth response to remained leaf number was evident in leaf and stem than root of leaf lettuce. Leaf fresh weight increased and leaf quality was lowered with increasing of remained leaf number. Results indicate that 4 to 6 leaves could be optimum remained leaf number of hydroponically grown leaf lettuce.

Phytotoxic Effect of Lettuce (Lactuca sativa L.) Leaf Extract on Seedling Growth of Crops and Weeds

  • Chon, Sang-Uk;Choi, Seong-Kyu
    • Plant Resources
    • /
    • v.7 no.1
    • /
    • pp.69-76
    • /
    • 2004
  • Lettuce (Lactuca sativa L.) is known to contain water-soluble substances that are biologically active. Aqueous or methanol extracts and residues from leaves of lettuce plants were assayed to determine their allelopathic effects, and the causative allelochemicals from fractions were quantified by means of HPLC analysis and bioassayed. Extracts from oven-dried leaf samples were more phytotoxic than those from freeze-dried samples. Leaf extracts of 40 g L$^{-1}$ were completely inhibitory on root growth of alfalfa (Medicago sativa L.), while root growths of barley (Hordeum vulgare L.) and soybean (Glycine max L.) were less sensitive. Early seedling growth of both alfalfa and barnyard grass (Echinochloa crus-galli) was significantly reduced by methanol leaf extracts. The major allelopathic substances analyzed by HPLC were coumarin, trans-cinnamic acid, o-coumaric acid, p-coumaric acid and chlorogenic acid. Of them p-coumaric acid was found as the greatest amount (8.9 mg 100 g$^{-1}$ ) in the EtOAc fraction; only coumarin was found in all the fractions. Hexane and EtOAc fractions of L. sativa reduced alfalfa root growth more than did BuOH and water fractions. These results suggest that lettuce had potent herbicidal activity, and that its activity differed depending on type and amount of causative compounds by fraction.

  • PDF

Selection of Promising 'Ssam' Vegetable for Summer Production in Highland (고랭지 여름출하용 유망 쌈채소 선발)

  • Jang, Suk-Woo;Kim, Won-Bae;Ryu, Kyoung-Ou
    • Horticultural Science & Technology
    • /
    • v.19 no.2
    • /
    • pp.140-144
    • /
    • 2001
  • Field investigations were initiated to determine possible new 'ssam' vegetable that could be grown during the summer season in highland. Korean 'ssam' means cooked rice in vegetables. The 'ssam' vegetable is called that those leaves has been used for wrapping at meal. Seventeen leafy vegetables were studied, including chard (Beta vulgaris L. var. flavescens DC.), leaf broccoli (Brassica oleracea L. var. italica), Chinese leek (Allium tuberosum Rottl.), Japanese hornwort (Cryptotaenia japonica Hassk), red leaf mustard (Brassica juncea L.), green leaf mustard (Brassica juncea L.), leaf parsley (Petroselinum crispum Nijim), pakchoi (Brassica campestris L. ssp. chinensis Jusl.) tatsoi (Brassica campestris var. narisoma), kale (Brassica oleracea var. acephala), collard (Brassica oleracea var. acephala), Korean mint (Agastache rugosa O. Kuntze), romaine lettuce (Lactuca sativa L. var. longifolia Lam.), red leaf chicory (Cichorium intybus L. var. folisum), red chicory (Cichorium intybus L. var. folisum), green leaf chicory (Cichorium intybus L. var. folisum), and sprouting broccoli (Brassica oleracea L. var. italica). Date of the first harvest in 1999 was July 10th in chard, leaf broccoli, red mustard, mustard, leaf parsley, pakchoi, tatsoi, kale, collard, Korean mint, red leaf chicory, red chicory, green leaf chicory, and sprouting broccoli. Date of the first harvest for Chinese leek, Japanese hornwort, and romaine lettuce was from the middle of June to the late of August. Based on ratings on marketable yield, we found good leaf shape, taste and yield in chard, red leaf mustard, green leaf mustard, pakchoi, tatsoi, romaine lettuce, red leaf chicory, red chicory, and green leaf chicory. Even though the most of all these vegetables were obtained high scores by test panels in shape, taste and quality, but some of them revealed inadequate leaf size as a 'ssam' vegetable. That problem will be solved by control of harvesting time. On the basis of this observation, chard, red leaf mustard, green leaf mustard, pakchoi, tatsoi, romaine lettuce, red leaf chicory, red chicory, and green leaf chicory were rated as promising 'ssam' vegetable by analysis of profits, adaptation, and quality.

  • PDF

Growth Potential of Escherichia coli O157:H7 in Lettuce Leaf Extract and on Lettuce Leaf Surface (상추잎 즙액과 표면에서 Escherichia coli O157:H7의 생장 가능성)

  • Kim, Won-Il;Jung, Hyang-Mi;Kim, Se-Ri;Park, Kyeong-Hun;Kim, Byung-Seok;Yun, Hye-Jung;Yun, Jong-Chul;Ryu, Kyoung-Yul
    • Journal of Food Hygiene and Safety
    • /
    • v.26 no.4
    • /
    • pp.296-301
    • /
    • 2011
  • This study was to evaluate the growth potential of E. coli O157:H7 in lettuce leaf extracts and on lettuce leaf surface at various temperatures. The pathogen can survive and multiply in the extracts and leaf surface of lettuce. The population of E. coli O157:H7 in the lettuce extracts reached to 4.79 log CFU/mL at $37^{\circ}C$. The multiplication of pathogen in lettuce extracts initiated within 10 hours of inoculation over $15^{\circ}C$ conditions. And it can survive in the lettuce leaf extracts at $4^{\circ}C$ for 100 hours at least. And this pathogen can multiply on lettuce leaf surface and the population of pathogen on the lettuce leaf surface increased to 1.82 log CFU/g at $25^{\circ}C$. At $37^{\circ}C$, the pathogen density increased to 1.53 CFU/g within 3 days after inoculation. At all temperature, irrespective of the inoculation level, similar trends in growth of E. coli O157:H7 were observed. These results emphasize the growth potential of E. coli O157:H7 in lettuce leaf extract and on lettuce leaf surface. To reduce the risk of outbreak, it is important to maintain the cold chain system during storage before the consumption.

DEVELOPMENT OF A 3-DOF ROBOT FOR HARVESTING LETTUCE USING MACHINE: VISION AND FUZZY LOGIC CONTROL

  • S. I. Cho;S. J. Chang;Kim, Y. Y.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
    • /
    • 2000.11b
    • /
    • pp.354-362
    • /
    • 2000
  • In Korea, researches on year-round leaf vegetables production system are in progress, most of them focused on environmental control. Therefore, automation technologies for harvesting, transporting, and grading are in great demand. A robot system for harvesting lettuces, composed of a 3-DOF (degree of freedom) manipulator, an end-effector, a lettuce feeding conveyor, an air blower, a machine vision system, six photoelectric sensors, and a fuzzy logic controller, was developed. A fuzzy logic control was applied to determine appropriate grip force on lettuce. Leaf area index and height were used as input variables and voltage as an output variable for the fuzzy logic controller. Success rate of the lettuce harvesting was 94.12%, and average harvesting time was approximately 5 seconds per lettuce.

  • PDF

Effects of Maturation Periods of Pig Manure Composts on Growth of Leaf lettuce(Lactuca safiva L.) (돈분발효퇴비의 부숙기간이 상추 생육에 미치는 영향)

  • 박창규;이영상;조광래;원선이;최영진
    • Korean Journal of Organic Agriculture
    • /
    • v.9 no.1
    • /
    • pp.17-27
    • /
    • 2001
  • To clarify the proper and safe duration of maturation periods for sawdust-pig manure composts, leaf lettuces were applied with pig manure composts fermented for 15, 30, 45, 60, 75 days and 1 year (control) and cultivated in a plastic house with or without additional PE film tunnel. The changes in physiochemical properties of soil and leaf lettuce growth were measured. Shorter duration of maturation periods enhanced the generation of N $H_3$ gas from the composts and resulted in significant decrease in seed germination, growth and yield of leaf lettuce. Under with and without PE tunnel conditions the concentration of N $H_3$ from compost over 3.8 and 2.1 mg/100g composts, respectively induced growth reduction. In proportion to the increase of maturation duration saw-dust containing pig manure exhibited decrease in C/N ratio, N $H_4^{+}$-N, N $H_4^{+}$N $O_3^{-}$ ratio but increase in N $O_3^{-}$-N contents. In case of applying pig manure compost without PE film tunnel condition the minimum maturation period of pig manure composts for safe leaf growth was 60 days, while minimum 75 days of maturation was required when applied with PE film tunnel. tunnel.

  • PDF

Leaf Blight Caused byCurvularia intermedia on the Invasive Weed Lactuca serriola in Korea

  • Jin A Lee;Seon Young Lee;Young-Joon Choi
    • The Korean Journal of Mycology
    • /
    • v.51 no.3
    • /
    • pp.245-249
    • /
    • 2023
  • Prickly lettuce (Lactuca serriola), an invasive annual plant, poses a significant threat to the agricultural systems of many countries, including Korea. In 2020, leaf blight symptoms were observed in the prickly lettuce populations of various farms across Korea. Detailed morphological and molecular sequence analyses revealed that the disease was caused by the fungus, Curvularia intermedia. A pathogenicity test confirmed that the fungus can cause the same symptoms in healthy prickly lettuce, thereby fulfilling Koch's postulates. To the best of our knowledge, this is the first report of C. intermedia causing leaf blight on L. serriola in Korea, suggesting its potential as a biocontrol agent for this weed. However, further investigations are necessary to determine its ecological impact to prevent any non-target effects.