ABSTRACT A field study was conducted to compare morphological, physiological, and genetic variation among local and introduced cultivars and mutated lines of garlic (Allium sativum L.). Twenty-six garlic mutants and twenty-six local and introduced garlic cultivars were used in the study. Characteristics studied included plant height, percent of plants forming multiple shoots, disease resistance, time to maturity, bolting, farmer acceptance, bulb weight, bulb to total plant ratio, and weight loss after two-weeks and 3 mo of storage. Genetic variation among cultivars was determined using isozyme and protein electrophoretic analyses. Several introduced cultivars showed improvement in many characteristics over local characteristics. The cvs. PI383819 and Rumani were better than the local cultivars in bulb weight, bulb to total plant ratio, and resistance to white rot. However, the same cultivars received low grades in the farmers' evaluation test due to high percentage of multiple shoots. The results of this study confirmed the effectiveness of positive selection of good size bulbs in the white rot resistance mutants. The mutant lines maintained a high degree of resistance (< 2.5% infection) in addition to the increase in bulb weight compared to local cultivars. Isozyme and total protein electrophoretic analyses revealed a high level of variability among the cultivars. The cv. Hungary was distinct from other cultivars in cluster analysis, apparently because it belongs to A. ampeloprasum and not A. sativum.
{"title":"Differences in Quantitative and Qualitative Characteristics of Local and Introduced Cultivars and Mutated Lines of Garlic","authors":"B. Al-Safadi, M. Arabi, Z. Ayyoubi","doi":"10.1300/J068v09n01_04","DOIUrl":"https://doi.org/10.1300/J068v09n01_04","url":null,"abstract":"ABSTRACT A field study was conducted to compare morphological, physiological, and genetic variation among local and introduced cultivars and mutated lines of garlic (Allium sativum L.). Twenty-six garlic mutants and twenty-six local and introduced garlic cultivars were used in the study. Characteristics studied included plant height, percent of plants forming multiple shoots, disease resistance, time to maturity, bolting, farmer acceptance, bulb weight, bulb to total plant ratio, and weight loss after two-weeks and 3 mo of storage. Genetic variation among cultivars was determined using isozyme and protein electrophoretic analyses. Several introduced cultivars showed improvement in many characteristics over local characteristics. The cvs. PI383819 and Rumani were better than the local cultivars in bulb weight, bulb to total plant ratio, and resistance to white rot. However, the same cultivars received low grades in the farmers' evaluation test due to high percentage of multiple shoots. The results of this study confirmed the effectiveness of positive selection of good size bulbs in the white rot resistance mutants. The mutant lines maintained a high degree of resistance (< 2.5% infection) in addition to the increase in bulb weight compared to local cultivars. Isozyme and total protein electrophoretic analyses revealed a high level of variability among the cultivars. The cv. Hungary was distinct from other cultivars in cluster analysis, apparently because it belongs to A. ampeloprasum and not A. sativum.","PeriodicalId":169819,"journal":{"name":"Journal of Vegetable Crop Production","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132387614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT The effect of fruit maturity at harvest from a tomato field plot without detectable silverleaf whiteflies (SLWF) on subsequent internal white tissue (IWT) and external tomato irregular ripening (TIR) was assessed. SLWF damage has been documented as the primary cause of IWT and external TIR, but some symptoms are observed in the absence of detectable whiteflies. Tomato fruit were harvested at either the red-ripe or mature-green stages from four different rows of a field treated with imidacloprid to control SLWF. The mature-green fruit were placed in a ripening room (20°C) for seven days. The fruit harvested at the red-ripe stage had a mean external TIR of 5.0%, and the fruit harvested at the mature-green stage and ripened at 20°C had a mean external TIR of 8.9%. The mean percentage of vine- and ripening-room ripened fruit with IWT was 8.3% and 8.9%, respectively. There were no differences in degree of external or internal symptoms for vine- and ripening-room ripened tomato fruit. The reasons for the occurrence of TIR and IWT in tomato fruit harvested from fields with undetectable SLWF are not known.
{"title":"Interior White Tissue and External Tomato Irregular Ripening Are Not Increased by Harvesting Tomato Fruit at the Mature-Green Stage","authors":"C. Powell, P. Stoffella","doi":"10.1300/J068v08n02_08","DOIUrl":"https://doi.org/10.1300/J068v08n02_08","url":null,"abstract":"ABSTRACT The effect of fruit maturity at harvest from a tomato field plot without detectable silverleaf whiteflies (SLWF) on subsequent internal white tissue (IWT) and external tomato irregular ripening (TIR) was assessed. SLWF damage has been documented as the primary cause of IWT and external TIR, but some symptoms are observed in the absence of detectable whiteflies. Tomato fruit were harvested at either the red-ripe or mature-green stages from four different rows of a field treated with imidacloprid to control SLWF. The mature-green fruit were placed in a ripening room (20°C) for seven days. The fruit harvested at the red-ripe stage had a mean external TIR of 5.0%, and the fruit harvested at the mature-green stage and ripened at 20°C had a mean external TIR of 8.9%. The mean percentage of vine- and ripening-room ripened fruit with IWT was 8.3% and 8.9%, respectively. There were no differences in degree of external or internal symptoms for vine- and ripening-room ripened tomato fruit. The reasons for the occurrence of TIR and IWT in tomato fruit harvested from fields with undetectable SLWF are not known.","PeriodicalId":169819,"journal":{"name":"Journal of Vegetable Crop Production","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129236392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Optimum age of onion (Allium cepa L.) transplants for use in current and expanding onion-growing areas in Ghana is not well understood. Field studies were conducted at two locations in Ghana during the 1996–97 and 1997–1998 onion growing seasons. Transplants that were 20, 30, 40, 50, 60 or 70 days old, and of uniform size at each age, were used. The effect of transplant age on bulb yield components of onion was determined. The tallest plants were developed from 40-day-old transplants and the shortest were developed from 70-day-old transplants. Harvest index (bulb weight/total biomass weight) of onion decreased significantly as transplant age increased. The heaviest onion bulbs, 57.2 g, were from plants derived from 40-day-old transplants, and the lightest, 26.1 g, were from plants developed from 70-day-old transplants. Plants developed from 20- to 40-day-old transplants produced the highest yields. The results indicate that using 20- to 40-day-old transplants will give optimal bulb yields.
{"title":"Influence of Transplanting Age on Bulb Yield and Yield Components of Onion (Allium cepa L.)","authors":"R. Kanton, L. Abbey, R. Hilla, M. Tabil, N. Jan","doi":"10.1300/J068v08n02_04","DOIUrl":"https://doi.org/10.1300/J068v08n02_04","url":null,"abstract":"ABSTRACT Optimum age of onion (Allium cepa L.) transplants for use in current and expanding onion-growing areas in Ghana is not well understood. Field studies were conducted at two locations in Ghana during the 1996–97 and 1997–1998 onion growing seasons. Transplants that were 20, 30, 40, 50, 60 or 70 days old, and of uniform size at each age, were used. The effect of transplant age on bulb yield components of onion was determined. The tallest plants were developed from 40-day-old transplants and the shortest were developed from 70-day-old transplants. Harvest index (bulb weight/total biomass weight) of onion decreased significantly as transplant age increased. The heaviest onion bulbs, 57.2 g, were from plants derived from 40-day-old transplants, and the lightest, 26.1 g, were from plants developed from 70-day-old transplants. Plants developed from 20- to 40-day-old transplants produced the highest yields. The results indicate that using 20- to 40-day-old transplants will give optimal bulb yields.","PeriodicalId":169819,"journal":{"name":"Journal of Vegetable Crop Production","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115701242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT A 2-year experiment was conducted to determine the potential for crisphead lettuce production on mineral soils compared to the production on organic soils of Quebec, during the warmest period of the season when quality often decreases. For each soil type, there were three experimental sites and two planting dates. For each soil type by site by planting date combination, three varieties, ‘Ithaca’, ‘Emperor’ and ‘Salinas 88’ were tested within four blocks. Transplanting occurred from 11 to 28 June 1999, and from 11 June to 5 July 2000, and harvest was from 21 July to 5 August 1999, and from 27 July to 10 August 2000. Lettuce on organic soils matured 4 to 7 days earlier and generally produced larger and heavier, firmer and more uniform heads. Soil type did not affect percentage of heads with the physiological disorders rib blight and tipburn. ‘Ithaca’ produced large, heavy and very firm heads, particularly on organic soil. Although this variety showed tolerance to bolting, it was susceptible to rib blight (50%), but less to tipburn (19%). ‘Emperor’ had heads that were lighter than those of the other two varieties on organic soil and matured later, and it had significantly less rib blight (22%) but more tipburn (34%) than the other two varieties. Although it produced a head with good weight, ‘Salinas 88’ tended to be fluffy and bolted early on both soil types. The potential for mid-season production of crisphead lettuce seems limited under current production methods.
{"title":"Yield and Quality of Crisphead Lettuce Cultivated on Organic or Mineral Soils","authors":"S. Jenni, J. Dubuc","doi":"10.1300/J068v08n02_02","DOIUrl":"https://doi.org/10.1300/J068v08n02_02","url":null,"abstract":"ABSTRACT A 2-year experiment was conducted to determine the potential for crisphead lettuce production on mineral soils compared to the production on organic soils of Quebec, during the warmest period of the season when quality often decreases. For each soil type, there were three experimental sites and two planting dates. For each soil type by site by planting date combination, three varieties, ‘Ithaca’, ‘Emperor’ and ‘Salinas 88’ were tested within four blocks. Transplanting occurred from 11 to 28 June 1999, and from 11 June to 5 July 2000, and harvest was from 21 July to 5 August 1999, and from 27 July to 10 August 2000. Lettuce on organic soils matured 4 to 7 days earlier and generally produced larger and heavier, firmer and more uniform heads. Soil type did not affect percentage of heads with the physiological disorders rib blight and tipburn. ‘Ithaca’ produced large, heavy and very firm heads, particularly on organic soil. Although this variety showed tolerance to bolting, it was susceptible to rib blight (50%), but less to tipburn (19%). ‘Emperor’ had heads that were lighter than those of the other two varieties on organic soil and matured later, and it had significantly less rib blight (22%) but more tipburn (34%) than the other two varieties. Although it produced a head with good weight, ‘Salinas 88’ tended to be fluffy and bolted early on both soil types. The potential for mid-season production of crisphead lettuce seems limited under current production methods.","PeriodicalId":169819,"journal":{"name":"Journal of Vegetable Crop Production","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130523394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT The current spatial arrangement and density of onion plants adopted by producers in Northern Ghana was found to limit onion production. A study was carried out at two onion-growing locations in Northern Ghana, during the 1996–97 and 1997–98 onion growing seasons, to evaluate the response of onion cv. Bawku Red to eight spacings, i.e., 0.18 × 0.15, 0.15 × 0.15, 0.18 × 0.10, 0.15 × 0.13, 0.15 × 0.10, 0.13 × 0.10, 0.10 × 0.10, and 0.8 × 0.8 m, which gave the following plant densities: 37.04; 44.44; 51.28; 55.56; 66.67; 76.92; 100 and 156.25 plants/m2, respectively. The experimental variables measured were plant height, number of leaves, number of marketable bulbs, number of culls, neck diameter, mean bulb weight, bulbing index and bulb yield. Plant population density significantly (P < 0.05) affected bulb yields and yield components of onion. Bulb neck diameter, mean bulb weight and plant height decreased as population density increased. Total bulb yield increased significantly (P < 0.05) as population density increased. Number of marketable bulbs increased significantly (P < 0.05) with higher planting density. Onion bulb yield in the study ranged between 20.9 and 33.1 t·ha−1. It was concluded that sowing onion at densities above 76.92 plants/m2 increased marketable onion bulb yields.
{"title":"Density Affects Plant Development and Yield of Bulb Onion (Allium cepa L.) in Northern Ghana","authors":"R. Kanton, L. Abbey, R. Hilla, M. Tabil, N. Jan","doi":"10.1300/J068v08n02_03","DOIUrl":"https://doi.org/10.1300/J068v08n02_03","url":null,"abstract":"ABSTRACT The current spatial arrangement and density of onion plants adopted by producers in Northern Ghana was found to limit onion production. A study was carried out at two onion-growing locations in Northern Ghana, during the 1996–97 and 1997–98 onion growing seasons, to evaluate the response of onion cv. Bawku Red to eight spacings, i.e., 0.18 × 0.15, 0.15 × 0.15, 0.18 × 0.10, 0.15 × 0.13, 0.15 × 0.10, 0.13 × 0.10, 0.10 × 0.10, and 0.8 × 0.8 m, which gave the following plant densities: 37.04; 44.44; 51.28; 55.56; 66.67; 76.92; 100 and 156.25 plants/m2, respectively. The experimental variables measured were plant height, number of leaves, number of marketable bulbs, number of culls, neck diameter, mean bulb weight, bulbing index and bulb yield. Plant population density significantly (P < 0.05) affected bulb yields and yield components of onion. Bulb neck diameter, mean bulb weight and plant height decreased as population density increased. Total bulb yield increased significantly (P < 0.05) as population density increased. Number of marketable bulbs increased significantly (P < 0.05) with higher planting density. Onion bulb yield in the study ranged between 20.9 and 33.1 t·ha−1. It was concluded that sowing onion at densities above 76.92 plants/m2 increased marketable onion bulb yields.","PeriodicalId":169819,"journal":{"name":"Journal of Vegetable Crop Production","volume":"246 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124704031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT The type of tillage system used and the rate of nitrogen fertilizer applied may affect fruit quality and total fruit yield of tomato (Lycopersicon esculentum Mill.). The treatments were either conventional tillage or rye (Secale cereale L.) mulch with or without 50 kg·ha−1 N. In both tillage systems, the application of 50 kg·ha−1 of N reduced the concentric cracking of tomato fruit, except for ‘UC82’ in conventional tillage and ‘Cherry Express II’ in rye mulch. When harvested at the same stage of maturity, chroma and hue along with acetic and citric acid concentrations of fruit were not affected by tillage system or N treatment. Fruit yields ranged from 34.0 to 60.6 Mg·ha−1. Total yield of ‘UC82’ was not affected by cropping system. Depending on the year, total yields of ‘Mountain Supreme’, ‘Pik Red’, and ‘Cherry Express II’ were reduced in the rye mulch. Although rye mulch had a minimal effect on fruit quality, the delay in fruit maturity and resultant lower total yields will limit acceptance of the system. Later applications of fertilizer or combining rye with plastic mulches might overcome these limitations.
{"title":"Nitrogen and Tillage Effects on the Fruit Quality and Yield of Four Tomato Cultivars","authors":"Amy Oberly, M. Kushad, J. Masiunas","doi":"10.1300/J068v08n02_07","DOIUrl":"https://doi.org/10.1300/J068v08n02_07","url":null,"abstract":"ABSTRACT The type of tillage system used and the rate of nitrogen fertilizer applied may affect fruit quality and total fruit yield of tomato (Lycopersicon esculentum Mill.). The treatments were either conventional tillage or rye (Secale cereale L.) mulch with or without 50 kg·ha−1 N. In both tillage systems, the application of 50 kg·ha−1 of N reduced the concentric cracking of tomato fruit, except for ‘UC82’ in conventional tillage and ‘Cherry Express II’ in rye mulch. When harvested at the same stage of maturity, chroma and hue along with acetic and citric acid concentrations of fruit were not affected by tillage system or N treatment. Fruit yields ranged from 34.0 to 60.6 Mg·ha−1. Total yield of ‘UC82’ was not affected by cropping system. Depending on the year, total yields of ‘Mountain Supreme’, ‘Pik Red’, and ‘Cherry Express II’ were reduced in the rye mulch. Although rye mulch had a minimal effect on fruit quality, the delay in fruit maturity and resultant lower total yields will limit acceptance of the system. Later applications of fertilizer or combining rye with plastic mulches might overcome these limitations.","PeriodicalId":169819,"journal":{"name":"Journal of Vegetable Crop Production","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125941164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Field studies were conducted during 1998 and 1999 to determine the effect of different color plastic mulches and row covers on total and marketable yield and US grades of three varieties of potatoes, ‘Kueka Gold’, ‘AF1437-1’ and ‘Dark Red Norland’. Although there was an observed increase in the rate of emergence and growth of the potato plants with row covers, there was no significant effect on yield of any of the varieties. In both years all mulch treatments significantly increased marketable yields compared to no mulch. In 1998, yields of ‘Dark Red Norland’ showed a statistically significant difference between mulch color, with metallized silver and red being higher than black. In 1999, both total and marketable yields of ‘Dark Red Norland’ were significantly higher with the use of metallized silver rather than black mulch. For ‘AF1437-1’ total yield, with the use of metallized silver, was significantly higher than that of red mulch, and for marketable yield only metallized silver was significantly higher than for black mulch. Metallized silver mulch resulted in the highest marketable yields for all varieties of potatoes.
{"title":"Production of Drip Irrigated Potatoes as Affected by Plastic Mulches and Row Covers","authors":"W. Lamont, M. Orzolek, B. Dye","doi":"10.1300/J068v08n02_05","DOIUrl":"https://doi.org/10.1300/J068v08n02_05","url":null,"abstract":"ABSTRACT Field studies were conducted during 1998 and 1999 to determine the effect of different color plastic mulches and row covers on total and marketable yield and US grades of three varieties of potatoes, ‘Kueka Gold’, ‘AF1437-1’ and ‘Dark Red Norland’. Although there was an observed increase in the rate of emergence and growth of the potato plants with row covers, there was no significant effect on yield of any of the varieties. In both years all mulch treatments significantly increased marketable yields compared to no mulch. In 1998, yields of ‘Dark Red Norland’ showed a statistically significant difference between mulch color, with metallized silver and red being higher than black. In 1999, both total and marketable yields of ‘Dark Red Norland’ were significantly higher with the use of metallized silver rather than black mulch. For ‘AF1437-1’ total yield, with the use of metallized silver, was significantly higher than that of red mulch, and for marketable yield only metallized silver was significantly higher than for black mulch. Metallized silver mulch resulted in the highest marketable yields for all varieties of potatoes.","PeriodicalId":169819,"journal":{"name":"Journal of Vegetable Crop Production","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129306130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Westerveld, M. R. Mcdonald, C. Scott-dupree, A. W. McKeown
ABSTRACT Mineral nutrition may affect the ability of plants to resist harmful insects or diseases. The effects of nitrogen (N) nutrition on pests of onions (Allium cepa L.), carrots (Daucus carota L.), and cabbage (Brassica oleracea var. capitata L.) were evaluated on organic and mineral soils in Ontario, Canada in 2000 and 2001. Onions (cvs. Norstar and Winner) and carrots (cvs. Indiana, Idaho, and Annapolis) were grown on both soil types, and cabbage (cv. Atlantis) was grown on mineral soil. Nitrogen was applied at 0,50,100,150, and 200% (carrots and cabbage) and 0, 100, and 200% (onions) of the rate recommended by the Ontario Ministry of Agriculture, Food, and Rural Affairs using calcium ammonium nitrate preplant and potassium nitrate for sidedress applications. In cabbage, onion thrips (Thrips tabaci L.) damage was rated at harvest. Onion thrips (OT) populations were monitored in onions weekly. In carrots, the combined leaf blight symptoms caused by Cercospora carotae and Alternaria dauci was evaluated biweekly using a visual rating. The incidence and severity of cavity spot (Pythium spp.) was rated at harvest. The damage caused by OT was lower on cabbage that received 100–200% and 150% of the recommended N rate in 2000 and 2001, respectively, than the no N treatment in both years, and 200% of the recommended rate in 2001. This effect may have been due to delayed maturity of plants that received low and high N levels. Onion thrips populations in onions were not affected by N rate in either year or location. Leaf blight severity decreased with increasing N rate in most cases. There was no effect of N rate on cavity spot. Nitrogen management should be considered in the integrated pest/crop management program for cabbage, onions, and carrots.
{"title":"The Effect of Nitrogen on Insect and Disease Pests of Onions, Carrots, and Cabbage","authors":"S. Westerveld, M. R. Mcdonald, C. Scott-dupree, A. W. McKeown","doi":"10.1300/J068v08n02_09","DOIUrl":"https://doi.org/10.1300/J068v08n02_09","url":null,"abstract":"ABSTRACT Mineral nutrition may affect the ability of plants to resist harmful insects or diseases. The effects of nitrogen (N) nutrition on pests of onions (Allium cepa L.), carrots (Daucus carota L.), and cabbage (Brassica oleracea var. capitata L.) were evaluated on organic and mineral soils in Ontario, Canada in 2000 and 2001. Onions (cvs. Norstar and Winner) and carrots (cvs. Indiana, Idaho, and Annapolis) were grown on both soil types, and cabbage (cv. Atlantis) was grown on mineral soil. Nitrogen was applied at 0,50,100,150, and 200% (carrots and cabbage) and 0, 100, and 200% (onions) of the rate recommended by the Ontario Ministry of Agriculture, Food, and Rural Affairs using calcium ammonium nitrate preplant and potassium nitrate for sidedress applications. In cabbage, onion thrips (Thrips tabaci L.) damage was rated at harvest. Onion thrips (OT) populations were monitored in onions weekly. In carrots, the combined leaf blight symptoms caused by Cercospora carotae and Alternaria dauci was evaluated biweekly using a visual rating. The incidence and severity of cavity spot (Pythium spp.) was rated at harvest. The damage caused by OT was lower on cabbage that received 100–200% and 150% of the recommended N rate in 2000 and 2001, respectively, than the no N treatment in both years, and 200% of the recommended rate in 2001. This effect may have been due to delayed maturity of plants that received low and high N levels. Onion thrips populations in onions were not affected by N rate in either year or location. Leaf blight severity decreased with increasing N rate in most cases. There was no effect of N rate on cavity spot. Nitrogen management should be considered in the integrated pest/crop management program for cabbage, onions, and carrots.","PeriodicalId":169819,"journal":{"name":"Journal of Vegetable Crop Production","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131692095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Sweet corn (Zea mays var. rugosa Bonaf.) production was evaluated under reduced tillage in a semi-arid, subtropical environment. Cultivars Champ and Sensor (1997) and Sensor and G-90 (1998) were grown under conventional cultivation (CT), minimum or ridge tillage (RT), and no tillage (NT), which had been maintained since fall 1994. Sweet corn yields and ear weights were reduced by NT in 1997, but were not affected in 1998 when longer season cultivars were planted. There were generally cultivar differences in ear weight, length, diameter, dry matter, and incidence of earworm damage, but tillage had very little effect on these attributes. Data collected in 1998 indicated that cultivars supported different weed species underneath their canopies. ‘Sensor’ allowed more light penetration and sustained higher weed biomass than did the taller ‘G-90’ plants. Weed biomass was higher in RT and NT. Seasonal soil moisture (1998) was lowest in the RT plots, but only in the 0–15 cm profile. The 1998 soil temperatures at the 15 cm depth were similar between cultivars and tillage treatments over the growing season. Cultivar ear nutrients differed in P, S, NO3, Ca and Fe in both years. Ear nutrients were not affected by tillage system in 1998, but in 1998 N (P = 0.12), K (P = 0.14), P (P = 0.05), S (P = 0.09), and Fe (P = 0.16) were lowest in NT-grown ears. Cumulative nutrient levels tended (P = 0.08) to be lowest in 1998 NT-grown ears. In 1998, soil sampled at 0–5, 10–15, and 25–30 cm depth generally had higher levels of nutrients toward the surface, and NT soils had the greatest nutrient gradients, with the exception of Na and NO3. Total soil salts were reduced by RT and NT, but C:N ratio remained unchanged between tillage systems. Proper cultivar selection is important for the successful production of sweet corn grown with reduced tillage in subtropical environments.
{"title":"Soil But Not Sweet Corn Ear Nutrients Are Affected by Conservation Tillage","authors":"D. Makus","doi":"10.1300/J068v08n02_06","DOIUrl":"https://doi.org/10.1300/J068v08n02_06","url":null,"abstract":"ABSTRACT Sweet corn (Zea mays var. rugosa Bonaf.) production was evaluated under reduced tillage in a semi-arid, subtropical environment. Cultivars Champ and Sensor (1997) and Sensor and G-90 (1998) were grown under conventional cultivation (CT), minimum or ridge tillage (RT), and no tillage (NT), which had been maintained since fall 1994. Sweet corn yields and ear weights were reduced by NT in 1997, but were not affected in 1998 when longer season cultivars were planted. There were generally cultivar differences in ear weight, length, diameter, dry matter, and incidence of earworm damage, but tillage had very little effect on these attributes. Data collected in 1998 indicated that cultivars supported different weed species underneath their canopies. ‘Sensor’ allowed more light penetration and sustained higher weed biomass than did the taller ‘G-90’ plants. Weed biomass was higher in RT and NT. Seasonal soil moisture (1998) was lowest in the RT plots, but only in the 0–15 cm profile. The 1998 soil temperatures at the 15 cm depth were similar between cultivars and tillage treatments over the growing season. Cultivar ear nutrients differed in P, S, NO3, Ca and Fe in both years. Ear nutrients were not affected by tillage system in 1998, but in 1998 N (P = 0.12), K (P = 0.14), P (P = 0.05), S (P = 0.09), and Fe (P = 0.16) were lowest in NT-grown ears. Cumulative nutrient levels tended (P = 0.08) to be lowest in 1998 NT-grown ears. In 1998, soil sampled at 0–5, 10–15, and 25–30 cm depth generally had higher levels of nutrients toward the surface, and NT soils had the greatest nutrient gradients, with the exception of Na and NO3. Total soil salts were reduced by RT and NT, but C:N ratio remained unchanged between tillage systems. Proper cultivar selection is important for the successful production of sweet corn grown with reduced tillage in subtropical environments.","PeriodicalId":169819,"journal":{"name":"Journal of Vegetable Crop Production","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116525595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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