AIR CIRCULATION IN GROWTH CHAMBERS STUNTS TOMATO SEEDLING GROWTH

Air circulation, generally an integral part of environmentally-controlled plant growth chambers, retarded tomato (Lycopersicon lycopersicum Karstens) seedling growth seismomorphogenetically. Continuous air movement at a speed of 0.5 to 0.7 m·s-1 inhibited growth by about 40%. Growth inhibition was noticeable with as little as 15 min of daily exposure to the air circulation; a continuous exposure gave the greatest amount of growth inhibition. The retarding effect of air on seedling growth was transient and required a continued daily exposure to air movement. Continuous aeration of seedlings inhibited growth to such an extent that in a two factor experiment, ie aeration and water stress, the water stress effects were completely masked in the aerated chamber by the aeration effect. The results have important implications for plant growth experiments in chambers equipped with air circulation: seedling growth may be affected more by the air circulation in the growth chamber than by an experimental treatment.

Download Full-text

Air circulation in growth chambers stunts tomato seedling growth

Canadian Journal of Plant Science ◽

10.4141/cjps92-161 ◽

1992 ◽

Vol 72 (4) ◽

pp. 1275-1281 ◽

Cited By ~ 2

Author(s):

A. Liptay

Keyword(s):

Water Stress ◽

Plant Growth ◽

Growth Inhibition ◽

Seedling Growth ◽

Growth Chamber ◽

Daily Exposure ◽

Air Movement ◽

Movement Effect ◽

Growth Chambers ◽

Air Circulation

Air circulation, generally an integral part of environmentally controlled plant growth chambers, inhibited tomato (Lycopersicon esculentum Mill.) seedling growth seismomorphogenically. Tomato seedlings were grown either in a growth chamber having an air movement of 0.5–0.7 m s−1 or in a chamber with no air circulation. Growth inhibition was noticeable with as little as 15 min of daily exposure to air circulation, and a continuous exposure gave the greatest amount of growth inhibition. The air-movement effect on seedling growth was transient and required a continued daily exposure to air movement for growth inhibition. Continuous air circulation inhibited seedling growth to such an extent that in a two-factor experiment (i.e., air movement and water stress) the water-stress effects were completely hidden by the air-movement effect. The results have important implications for tomato plant growth experiments in chambers equipped with air circulation: seedling growth may be affected more by the inherent air circulation in the growth chamber than by an experimental treatment.Key words: Tomato growth inhibition, air movement, seismomorphogenic, short seedlings

Download Full-text

Growth Inhibition of Caladium by High Temperature

HortScience ◽

10.21273/hortsci.29.7.769 ◽

1994 ◽

Vol 29 (7) ◽

pp. 769-770

Author(s):

Brent K. Harbaugh ◽

Michael R. Evans

Keyword(s):

High Temperature ◽

Plant Growth ◽

Growth Inhibition ◽

Plant Height ◽

Soil Surface ◽

Fresh Weight ◽

Daily Exposure ◽

Leaf Emergence ◽

The Hours ◽

Plant Characteristics

Nonplanted Caladium × hortukmum Birdsey `Candidum' tubers were exposed to 26 (control), 38,43, or 48C for 1,2, or 3 days. Then tubers were planted and forced in a glasshouse for 4 weeks at 18 to 33C (air). Leaf emergence from tubers exposed to 48C for 1 or 2 days required 3-12 days longer than leaf emergence from control tubers. No leaves emerged from tubers treated at 48C for 3 days. Exposing tubers to 38C for 3 days or 43C for 1 day did not affect subsequent plant growth. Exposing tubers to 43C for 2 or 3 days or 48C for 1 or 2 days resulted in plants with reduced shoot fresh weights and fewer leaves ≥ 15 cm. In a second experiment, planted tubers were forced for 10 days at 26C so that roots had developed to the edge of the pot and shoots had emerged to the soil surface. These planted (sprouting) tubers were exposed to 43C for 0,4,8,12,16,20, or 24 hours/day for 1,3, or 5 days and then forced for 7 weeks in a glasshouse. With 3- or 5-day treatments, days to leaf emergence increased as the hours of exposure to 43C increased. Only 33% of planted tubers exposed to 43C for 24 hours/day for 5 days sprouted. Tubers exposed to 43C for≤ 12 hours/day for 3 days produced plants of similar or greater height, numbers of leaves □≥15 cm wide, and shoot fresh weights, but additional hours of daily exposure decreased these plant characteristics. At 5 days, plant height, number of ≥ 15-cm-wide leaves, and shoot fresh weight decreased linearly with increased hours of exposure of tubers to high temperature.

Download Full-text

Tomato Early Seedling Height Control Using a Paclobutrazol Seed Soak

HortScience ◽

10.21273/hortsci.41.3.768 ◽

2006 ◽

Vol 41 (3) ◽

pp. 768-772 ◽

Cited By ~ 3

Author(s):

Juan P. Brigard ◽

Richard L. Harkess ◽

Brian S. Baldwin

Keyword(s):

Plant Growth ◽

Seedling Growth ◽

Residual Effect ◽

Hypocotyl Elongation ◽

Long Term Effects ◽

Tomato Seedling ◽

Height Control ◽

Tomato Seedlings ◽

Light Levels ◽

Early Seedling

Tomato seedling hypocotyls elongate rapidly after germination resulting in weak seedlings. The effects of 0, 250, 500, 750, or 1000 mg paclobutrazol (PB)/L seed soak and soaking times from 1 to 12 hours on tomato (Solanum lycopersicum L.) seed germination, seedling growth, and plant growth were tested. Adequate height control was obtained with 250 mg PB/L while soaking time did not affect seedling growth. In a second experiment, PB was tested at 0, 50, 100, 150, 200, or 250 mg PB/L soaking the seed for 1 hour. A concentration of PB at 100 mg·L–1 provided optimum control of hypocotyl elongation with minimal residual effect on subsequent plant growth. In a third experiment, seed soaked at the different PB concentrations were germinated and grown under light intensities of 0.09, 50, 70, or 120 μmol·m–2·s–1. Seedlings grown under 0.09 μmol·m–2·s–1 were not affected by PB treatment and did not develop an epicotyl. PB seed soak treatment gave greater growth suppression under 50 μmol·m-2·s-1 than under the two higher light levels. Soaking tomato seeds in 100 mg PB/L for 1 hour prevented early hypocotyl stretch of tomato seedlings with no long term effects on plant growth. This treatment effectively prevented excessive hypocotyl elongation when seeds were germinated under low PAR while not over controlling elongation under high PAR conditions.

Download Full-text

Effect of Penicillium Extractsa on Germination Vigor in Subsequent Seedling Growth of Tomato (Solanum Lycopersicum L.)

Plant Breeding and Seed Science ◽

10.2478/v10129-011-0049-3 ◽

2014 ◽

Vol 65 (1) ◽

pp. 71-77

Author(s):

Ghazala Nasim ◽

Sobia Mushtaq ◽

Irum Mukhtar ◽

Ibatsam Khokhar

Keyword(s):

Plant Growth ◽

Seedling Growth ◽

Growth Promotion ◽

Tomato Seedling ◽

Growth And Survival ◽

Tomato Seedlings ◽

Solanum Lycopersicum L ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Germination Vigor

AbstractPenicilliumspp. are well known to produce a variety of beneficial metabolites for plant growth and survival, as well as defend their hosts from attack of certain pathogens. In this study, effects of culture filtrate of differentPenicilliumspp. were tested on tomato seeds. On the whole, presoaking of seeds in filtrates of the ninePenicilliumisolates tested, significantly increased seed germination when compared with the control seeds. Cultural extracts ofP. expensumandP. billiwere highly effective in growth promotion up to 90%. It was also observed thatP. implicatumandP. oxlalicamsignificantly enhanced the root growth in tomato seedling as compare to other species. In case of shoot length,P. verrucosum(3.38),P. granulatum(2.81) andP. implicatum(2.62) were effective. HoweverP. implicatumwas quite promising to increase shoot and root length in tomato seedlings. Where asP. simplicissimiumandP. citrinumwere leas effective on seedling growth. The plant growth promoting ability ofPenicilliumstrains may help in growth permotion in other plants and crops.Penicilliumspp. are already known for producing mycotoxin and enzymes. Plant growth promoting ability ofPenicilliumspp will open new aspects of research and investigations. The role ofPenicil-liumspp. in tomato plant growth requires further exploration.

Download Full-text

Design of an Air Blowing Device Above Seedbed: The Effect of Air Disturbance on the Microenvironment and Growth of Tomato Seedlings

HortScience ◽

10.21273/hortsci15136-20 ◽

2020 ◽

Vol 55 (8) ◽

pp. 1308-1314

Author(s):

Yang Li ◽

Juanqi Li ◽

Guoxiu Wu ◽

Yanman Li ◽

Aimin Shen ◽

...

Keyword(s):

Seedling Growth ◽

Physiological Activity ◽

Canopy Temperature ◽

Dry Mass ◽

Air Velocity ◽

Tomato Seedling ◽

Tomato Seedlings ◽

Root Shoot Ratio ◽

Air Blowing ◽

Air Circulation

In recent years, air circulation has been used in protected cultivation to improve the microenvironment around seedlings, which in turn enhances photosynthesis and seedling growth. However, a practical and precise air circulation device has not yet been reported, especially one for growing seedlings in a greenhouse. Considering the use of a seedbed in seedling cultivation, a blower that can move back and forth on the seedbed and accurately control the air velocity is designed. In this experiment, we take the nonblowing treatment as the control (CK); three air velocities (0.3, 0.6, and 0.9 m/s) were selected to investigate the effect of interval blowing on the microenvironment of the canopy, physiology of seedling growth, stomatal characteristics of leaves, and stem mechanics of tomato seedlings. The three air velocities were found to significantly reduce the canopy temperature by 0.44, 0.78, and 1.48 °C lower than the CK, respectively, and leaf temperature by 0.83, 1.57, and 2.27 °C lower than the CK, respectively, in cultivated seedlings during summer. The relative humidity of the tomato seedling canopy decreased by 2.7% to 7.0%. Compared with the CK, the plant height of tomato seedlings decreased by 13.54% and root dry mass, root-shoot ratio, and seedling quality index (SQI) increased by 34.63%, 21.43%, and 14.29%, respectively, at 0.6 m/s. In addition, mechanical indexes such as hardness and elasticity of the tomato seedling stem were higher under air disturbance than those of the CK. The best effect was seen in the treatment with the air velocity of 0.6 m/s, in which the hardness and elasticity of the stem base and the first node were significantly higher than that of the CK. In conclusion, air disturbance generated by the air blowing device we designed effectively improved the microenvironment around the plants, enhanced the physiological activity of the seedlings, and thereby promoted seedling growth.

Download Full-text