Performance of Atesta and Intact Peanut Seed in Field Plots, Field Microplots, Germination and Pathogenicity Tests1

Abstract Stands from atesta (bald) seed 10 and 20 days after planting were 32.0 and 35.5% less than stands from intact seed in field plots. Thirty-two and 62 days after planting the fresh weights of plants from bald seed were 32.3 and 15.3% less than those from intact seed. Pod yield of plants from bald seed was 20.4% less than that from intact seed. Sound mature kernels (SMK) produced by plants from bald seed was 1.2% less than the SMK from intact seed. When plant populations in field plots were adjusted by covariance analysis to equal numbers, no difference in yield was predicted. Plants grown from bald and intact seed in field microplots fumigated with metam-sodium had no difference in yield or SMK. Bald seed germinated in 24 hr cycles of 20 C/16 hr + 30 C/8 hr had fewer normal rapid and more normal slow germinating seedlings than intact seed. At temperatures of 30 C/16 hr + 20 C/8 hr, there was no difference in germination percentages. In soil infested with Aspergillus niger van Tieghem at 21 C/12 hr + 27 C/12 hr there was no difference in seedling emergence from bald or intact seed after 22 days. At temperatures of 15 C/12 hr + 21 C/12 hr, seedling emergence from bald seed in A. niger infested and noninfested soil was less than that of intact seed in control soil. Emergence of seedlings from bald seed was zero and that from intact seed was less than other treatments at both temperature regimes in soil infested with Rhizoctonia solani Kühn anastomosis group 4.

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(188) Evaluation of Edamame Cultivars in Central Pennsylvania

HortScience ◽

10.21273/hortsci.40.4.1031a ◽

2005 ◽

Vol 40 (4) ◽

pp. 1031A-1031

Author(s):

Elsa Sánchez ◽

Kathleen Kelley ◽

Lynn Butler

Keyword(s):

Field Trial ◽

Seedling Emergence ◽

Economic Feasibility ◽

Effect Of Temperature ◽

Night Temperature ◽

Plant Populations ◽

Temperature Regimes ◽

Central Pennsylvania ◽

Plant Compensation ◽

Soybean Plants

Eight edamame [Glycine max (L.) Merrill] cultivars were evaluated in the field in 2002, 2003, and 2004 to determine their suitability for growing in central Pennsylvania. Each cultivar was direct seeded and data collected included plant populations (percentage of stand) and marketable yields. Plant populations ranged from less than 1% to 81% and, with one exception in 2002, were below 80%. Eighty percent plant populations or higher are considered optimal. Based on sub-optimal plant populations, none of the edamame cultivars evaluated in the field were determined to be suitable for direct seeding in central Pennsylvania. The effect of temperature on seedling emergence, and therefore, plant populations was then studied. Four of the edamame cultivars used in the field trial were evaluated in growth chambers programmed with varying day/night temperature regimes. Seedling emergence varied by cultivar and was generally below 80% with two exceptions. When grown in a 21.1 °C day/15.6 °C night temperature regime, `Butterbeans' and `Early Hakucho' exceeded 80% seedling emergence. These methods could be used to produce transplants; however, the economic feasibility of doing so should first be evaluated. In the field trial, conclusions on marketable yields were unattainable because soybean plants are known to compensate in yield for plants missing in sub-optimal plant populations. Plant compensation and sub-optimal plant populations rendered yield comparisons between cultivars questionable. The issue of sub-optimal seedling emergence and plant population needs to be studied further before suitability of growing these edamame cultivars in central Pennsylvania can be determined.

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Effect of Wirestem Severity on Survival and Head Production of Transplanted Broccoli and Cabbage

Plant Disease ◽

10.1094/pdis.2001.85.6.639 ◽

2001 ◽

Vol 85 (6) ◽

pp. 639-643 ◽

Cited By ~ 4

Author(s):

Anthony P. Keinath ◽

Mark W. Farnham

Keyword(s):

Rhizoctonia Solani ◽

Brassica Oleracea ◽

Field Experiments ◽

Anastomosis Group ◽

Group 4 ◽

Severity Levels ◽

Highly Correlated ◽

Field Plots

Field experiments were conducted with transplants of Brassica oleracea with known severity levels of wirestem caused by Rhizoctonia solani anastomosis group 4. Seedlings of broccoli and cabbage were grown in steamed soil infested with R. solani at 5 to 25 sclerotia/kg. Two weeks after inoculation, plants were separated into five severity classes based on wirestem symptoms, then transplanted into fumigated field plots in the spring and fall of 1995. The percentage of plants with and without aboveground symptoms was assessed at 14 and 42 days after transplanting. Marketable-sized heads were harvested eight times. In both seasons, percentages of symptomless plants, surviving (symptomless plus symptomatic) plants, and plants producing a marketable-sized head decreased as wirestem severity increased. Only 33 and 29% of cabbage transplants with >75% of the stem circumference girdled survived and produced a marketable head, respectively, compared with 95 and 83% of healthy transplants, respectively. For broccoli, only 15% of transplants with girdled stems survived and produced heads in spring but, in the fall, 74 and 72% of transplants with girdled stems survived and produced heads, respectively. Percentage of plants producing a marketable-sized head was highly correlated (P = 0.0001) with percentage of symptomless plants at 14 days after transplanting and percentage of surviving plants at 42 days after transplanting.

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Edamame Production as Influenced by Seedling Emergence and Plant Population

HortTechnology ◽

10.21273/horttech.15.3.0672 ◽

2005 ◽

Vol 15 (3) ◽

pp. 672-676 ◽

Cited By ~ 7

Author(s):

Elsa Sánchez ◽

Kathleen Kelley ◽

Lynn Butler

Keyword(s):

Glycine Max ◽

Seedling Emergence ◽

Commercial Production ◽

Effect Of Temperature ◽

Night Temperature ◽

Plant Populations ◽

Major Constraint ◽

Temperature Regimes ◽

Central Pennsylvania ◽

Growth Chambers

Eight edamame (Glycine max) cultivars were evaluated in the field in 2002, 2003, and 2004 to determine suitability for growing in central Pennsylvania. Data collection included plant populations (percent stand), marketable and unmarketable yields and edamame pod and bean quality indicators. Plant populations varied by year and cultivar and were generally below 80%. The effect of temperature on seedling emergence, and therefore plant populations, was evaluated for four edamame cultivars by using growth chambers programmed with varying day/night temperature regimes. Seedling emergence varied by cultivar and was generally below 80% with two exceptions. When grown in a 70/60 °F day/night temperature regime, `Butterbeans', and `Early Hakucho' exceeded 80% seedling emergence. In the field trial, plant populations affected marketable yields. Pod and bean quality were dependent on cultivar. Results indicated that `Butterbeans', `Early Hakucho', `Green Legend', `Shironomai', `Butterbaby', and `Lucky Lion' appear promising for growing in Pennsylvania based on pod and bean quality. However, the issue of poor seedling emergence and plant populations presents a major constraint to commercial production and needs to be studied further.

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Microclimate Modification and Insect Pest Exclusion Using Agronet Improve Pod Yield and Quality of French Bean

HortScience ◽

10.21273/hortsci.49.10.1298 ◽

2014 ◽

Vol 49 (10) ◽

pp. 1298-1304 ◽

Cited By ~ 18

Author(s):

Elisha Otieno Gogo ◽

Mwanarusi Saidi ◽

Jacob Mugwa Ochieng ◽

Thibaud Martin ◽

Vance Baird ◽

...

Keyword(s):

Environmental Conditions ◽

Average Pore Size ◽

Seedling Emergence ◽

French Bean ◽

Export Market ◽

Average Pore ◽

Black Bean ◽

Pod Yield ◽

Yield And Quality

French bean [Phaseolus vulgaris (L.)] is among the leading export vegetable in Africa, mostly produced by small-scale farmers. Unfavorable environmental conditions and heavy infestations by insect pests are among the major constraints limiting production of the crop. Most French bean producers grow their crop in open fields outdoors subject to harsh environmental conditions and repeatedly spray insecticides in a bid to realize high yield. This has led to rejection of some of the produce at the export market as a result of stringent limits on maximum residue levels. Two trials were conducted at the Horticulture Research and Teaching Field, Egerton University, Kenya, to evaluate the potential of using agricultural nets (herein referred to as agronets) to improve the microclimate, reduce pest infestation, and increase the yield and quality of French bean. A randomized complete block design with five replications was used. French bean seeds were direct-seeded, sprayed with an alpha-cypermethrin-based insecticide (control), covered with a treated agronet (0.9 mm × 0.7 mm average pore size made of 100 denier yarn knitted into a mesh impregnated with alpha-cypermethrin), or covered with an untreated-agronet (0.9 mm × 0.7 mm average pore size made of 100 denier yarn knitted into a mesh not impregnated with insecticide). Alpha-cypermethrin and agronets were manufactured by Tagros Chemicals (India) and A to Z Textile Mills (Tanzania), respectively. Covering French bean with the agronets modified the microclimate of the growing crop with air temperature increased by ≈10%, relative humidity by 4%, and soil moisture by 20%, whereas photosynthetic active radiation (PAR) and daily light integral (DLI) were decreased by ≈1% and 11.5%, respectively. Populations of silverleaf whitefly [Bemisia tabaci (Gennadius)] and black bean aphids [Aphis fabae (Scopoli)] were reduced under agronet covers as contrasted with control plots. Furthermore, populations of both pests were reduced on French bean grown under impregnated agronets compared with untreated agronets, but only on three of the five sampling dates [30, 44, and 72 days after planting (DAP)] for silver leaf whitefly or at only one of the five sampling dates (30 DAP) for black bean aphid. Covering French bean with agronets advanced seedling emergence by 2 days and increased seedling emergence over 90% compared with control plots. French bean plants covered with both agronet treatments had faster development, better pod yield, and quality compared with the uncovered plants. These findings demonstrate the potential of agronets in improving French bean performance while minimizing the number of insecticide sprays within the crop cycle, which could lead to less rejection of produce in the export market and improved environmental quality.

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Effects of Environmental Factors on Seed Germination and Emergence of Velvetleaf (Abutilon theophrasti)

Planta Daninha ◽

10.1590/s0100-83582018360100122 ◽

2018 ◽

Vol 36 (0) ◽

Cited By ~ 2

Author(s):

RC. XIONG ◽

Y. MA ◽

HW. WU ◽

WL. JIANG ◽

XY. MA

Keyword(s):

Seed Germination ◽

Environmental Factors ◽

Field Experiments ◽

Cropping Systems ◽

Control Strategies ◽

Seedling Emergence ◽

Central China ◽

Burial Depth ◽

Temperature Regimes ◽

Alternating Temperature

ABSTRACT: Velvetleaf, an annual broadleaf weed, is a common and troublesome weed of cropping systems worldwide. Laboratory and field experiments were conducted to determine the effects of environmental factors on germination and emergence of velvetleaf. Seeds germinated over a range of constant temperatures from 10 to 40 oC regardless of light conditions, but no germination occurred at temperature below 5 oC and beyond 50 oC. Seeds germinated at alternating temperature regimes of 15/5 to 40/30 oC, with maximum germination (>90%) at alternating temperatures of 40/30 oC. Germination was sensitive to water stress, and only 0.4% of the seeds germinated at the osmotic potential of -0.4 MPa. There was no germination at ? 0.6 MPa. Moreover, germination was reduced by saline and alkaline stresses and no germination occurred at ³ 150 mM NaCl or ³ 200 mM NaHCO3 concentrations. However, pH values from 5 to 9 had no effect on seed germination. Seedling emergence was significantly affected by burial depth and maximum emergence (78.1-85.6%) occurred at the 1-4 cm depth. The results of this study have contributed to our understanding of the germination and emergence of velvetleaf and should enhance our ability to improve control strategies in cropping systems in central China.

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Effect of Environmental Factors on Seed Germination and Early Seedling Emergence of Carolina geranium (Geranium carolinianum)

Planta Daninha ◽

10.1590/s0100-83582018360100136 ◽

2018 ◽

Vol 36 ◽

Author(s):

X. LIU ◽

T. ZONG ◽

Y. LI ◽

X. ZHOU ◽

L. BAI

Keyword(s):

Control Strategies ◽

Germination Rate ◽

Seedling Emergence ◽

Burial Depth ◽

Invasive Weed ◽

Temperature Regimes ◽

Dark Regime ◽

Early Seedling ◽

Effects Of Temperature ◽

And Control

ABSTRACT: Carolina geranium (Geranium carolinianum) is an emerging invasive weed in rape and wheat fields in China. A better understanding of its germination and emergence ecology will enable the development of integrated weed control strategies. In this study, we investigated the effects of temperature, photoperiod, soil water content, salinity, and burial depth, on germination and emergence of Carolina geranium. Germination percentages were over 74% under 15/20 and 20/25 oC night/day temperature regimes. Germination rate was independent of light/dark regime. Increasing salinity reduced germination of Carolina geranium from 81.1% at 0 mM to 0% at 160 mM NaCl. Seeds germination was peaked at 50% soil moisture, but was completely inhibited at < 20% and > 90%. The seedling emergence above 82.2% was observed when seeds were placed at a depth from 0 to 1 cm, and no seedlings emerged from seeds placed at a depth of 7 cm. Current work provide the basic information to effectively prevent and control this invasive weed in Chinese rape and wheat fields.

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TEMPERATURE AND DROUGHT STRESS EFFECTS ON GROWTH AND DEVELOPMENT OF BAMBARA GROUNDNUT (VIGNA SUBTERRANEA L.)

Experimental Agriculture ◽

10.1017/s0014479713000379 ◽

2013 ◽

Vol 50 (1) ◽

pp. 72-89 ◽

Cited By ~ 7

Author(s):

IBRAHEEM AL SHAREEF ◽

DEBBIE SPARKES ◽

SAYED AZAM-ALI

Keyword(s):

Low Temperature ◽

Growth And Development ◽

Dry Matter ◽

Bambara Groundnut ◽

Vigna Subterranea ◽

Pod Yield ◽

Growing Seasons ◽

Temperature Regimes ◽

Moderate Drought ◽

Final Yield

SUMMARYThe effect of drought and temperature on the growth and development of bambara groundnut (Vigna subterranea (L.) Verdc.) was studied in controlled environment glasshouses in the United Kingdom. There were two landraces, S19-3 (from a hot, dry environment; Namibia) and Uniswa Red (from a cool, wet environment; Swaziland), two temperature regimes (23 °C and 33 °C) and three watering regimes (2006; fully irrigated), 2007 (drought imposed at 77 days after sowing (DAS)) and 2008 (drought imposed at 30 DAS)). Bambara groundnut responded to drought by slowing the rate of leaf area expansion and reducing final canopy size and total dry matter (TDM). Drought also caused significant reductions in pod dry matter, pod numbers and harvest index (HI), leading to a decrease in final yield that was different between landraces. Throughout the three growing seasons, landraces grown at 33 °C produced more TDM than the landraces grown at 23 °C. The two landraces differed in their phenology; S19-3 exhibited a reduced phenology where leaf numbers started to decrease before Uniswa Red at both temperatures, while Uniswa Red maintained the longest life cycle. The lowest pod yield was produced by Uniswa Red in 2008 at 33 °C (maximum of 35.5 gm−2), while S19-3 produced a minimum pod yield of 56.6 gm−2 at 33 °C, also in 2008. However, both landraces produced considerably more pod yield at 23 °C throughout the three growing seasons (minimum of 151 gm−2 and 162 gm−2 for Uniswa Red and S19-3, respectively). Under moderate drought, S19-3 at 33 °C gave the highest pod yield (365 gm−2) among the treatments throughout the three growing seasons and maintained HI better under drought. Despite being from a hot, dry environment, S19-3 also performed well at low temperature, which indicates the adaptation of S19-3 to low temperature that it also experiences in the country of origin.

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Factors Affecting Seed Germination and Seedling Emergence of Asia Minor Bluegrass (Polypogon fugax)

Weed Science ◽

10.1614/ws-d-14-00093.1 ◽

2015 ◽

Vol 63 (2) ◽

pp. 440-447 ◽

Cited By ~ 12

Author(s):

Xian Wu ◽

Jun Li ◽

Hongle Xu ◽

Liyao Dong

Keyword(s):

Seed Germination ◽

Seedling Emergence ◽

Late Summer ◽

Asia Minor ◽

Burial Depth ◽

Optimum Temperature ◽

Large Area ◽

Factors Affecting ◽

Temperature Regimes ◽

Grass Weed

Little published information is available related to seed germination and seedling establishment of Asia Minor bluegrass, a problematic grass weed in some regions of China. The objective of this study was to examine the effects of different environmental factors on Asia Minor bluegrass seed germination. The optimum temperature for germination was around 10 to 20 C, and more than 90% of seeds germinated under 20/10 and 25/15 C temperature regimes. Also, light and pH did not appear to have any effect on seed germination. Asia Minor bluegrass was sensitive to osmotic stress, but tolerant of NaCl. No seedlings emerged when seeds were buried 4 cm deep. The result suggested that Asia Minor bluegrass has the potential to spread into a large area in China. To prevent its spreading, measures such as soil cultivation can be used to limit seed germination from increased burial depth and/or nonselective herbicides can be applied to kill early-germinating weed seedlings in late summer.

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Severity, Distribution, and Losses from Taproot Cankers Caused by Rhizoctonia solani in Peanuts1

Peanut Science ◽

10.3146/i0095-3679-15-2-8 ◽

1988 ◽

Vol 15 (2) ◽

pp. 73-75 ◽

Cited By ~ 1

Author(s):

John T. Turner ◽

Paul A. Backman

Keyword(s):

Rhizoctonia Solani ◽

Surface Area ◽

Disease Severity ◽

Negative Correlation ◽

Root Rot ◽

High Frequency ◽

Significant Negative Correlation ◽

Anastomosis Group ◽

Group 4

Abstract Research on the ecology of peanut roots from fields in Georgia, Florida, and Alabama revealed a high frequency of sunken, dark cankers on the taproot which persisted to harvest. Isolations from these cankers resulted in recovery of Rhizoctonia solani anastomosis group 4 (AG-4) from more than 50% of the cankers. A survey of peanut fields being harvested during early September revealed that 28% of the fields had an average of more than 50% of the taproot surface area cankered. In contrast, for fields in the same area harvested one month later, 77% had disease severities of less than 25% and none were greater than 50%. In an experiment conducted in 1984, roots from 64 plots were examined and rated for root rot severity and yield. When taproot disease severity was regressed against yield, a highly significant negative correlation (r2 − 0.60, P<0.01) was found.

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