Limitations of the K:N ratio in the nutrient feed of drip-irrigated greenhouse tomatoes as a crop-management tool

1993 ◽  
Vol 73 (1) ◽  
pp. 289-296
Author(s):  
Athanasios P. Papadopoulos ◽  
Shalin Khosla
Keyword(s):  
Fruit Quality ◽  
Concentration Ratio ◽  
Yield Loss ◽  
Management Tool ◽  
Marketable Yield ◽  
Osmotic Effect ◽  
Greenhouse Tomato ◽  
Tomato Cultivars ◽  
Greenhouse Tomatoes ◽  
Nutrient Feed

Greenhouse tomato cultivars were grown over three spring (1987, 1988 and 1989) and two fall (1987 and 1988) seasons in soil to assess the yield and fruit-quality effects of the potassium (K):nitrogen (N) concentration ratio in the fertigation solution. In the spring, the K:N ratio was varied over the first 11 wk following planting to provide a high, medium or low K:N ratio in the fertigation solution. The K:N ratio in the fertigation solution varied from 14:1 (week 1) to 2:1 (week 11) or from 8:1 (week 1) to 2:1 (week 11) or remained steady at 2:1 (weeks 1–11) for the high-, medium- and low-K:N treatments, respectively. In the fall the K:N ratio varied from 3:1 (week 3) to 9:1 (week 10), or from 2.3:1 (week 3) to 6:1 (week 10), or from 1.5:1 (week 3) to 3:1 (week 10) for the high-, medium- and low-K:N treatments, respectively. The marketable yields harvested averaged around 7.5 kg plant−1 in the spring and 2.5 kg plant−1 in the fall. The K:N ratio in the fertigation solution had no significant effect on early, or final, total or marketable yield. Similarly, there were no significant effects on fruit quality. It was concluded that provided a recommended overall osmotic effect (measured as electrical conductivity) of the nutrient solution is maintained, fertilizers can be selected and used on the basis of cost, or other important criteria, without concern for yield loss due to undesirable K:N ratio effect. Key words: Lycopersicon esculentum, marketable yield

scholarly journals Air Blowers Are Less Effective Pollinators of Greenhouse Tomatoes than Electric Vibrators but Cost Less to Operate

2004 ◽  
Vol 14 (1) ◽  
pp. 104-107
Author(s):  
H.Y. Hanna
Keyword(s):  
Yield Loss ◽  
Labor Cost ◽  
Fruit Weight ◽  
Operating Costs ◽  
Marketable Yield ◽  
Greenhouse Tomato ◽  
Air Blower ◽  
Greenhouse Tomatoes ◽  
Effective Pollinators ◽  
Number Of Seeds

A study was conducted to determine if air blowers would be less time consuming, more economical, and as effective as hand-held electric vibrators to pollinate two greenhouse tomato (Lycopersicon esculentum) cultivars. Vibrator-pollinated plants of each cultivar produced greater marketable yield than did blower-pollinated plants. Within cultivars, marketable yield was greater and yields of culls were lower with vibrator-pollinated plants. Fruit weight and diameter and the number of seeds per fruit were greater in vibrator-pollinated plants. Marketable yield of `Trust' was greater and cull yield was lower than that of `Caruso' in 1996. However, marketable yield of `Caruso' was greater than that of `Trust' and cull yield was about the same in 1997. Interactions between pollinating tools and cultivar were not significant except for fruit weight in 1997. The time needed to pollinate 640 plants for 13 weeks was 7.13 and 11.75 person-hours using the air blower and the electric vibrator, respectively. Labor cost for pollination was $49.92 for the air blower and $82.25 for the vibrator. Yield loss using the air blower for pollination was not offset by the savings in operating costs.

Irrigation of greenhouse tomatoes grown in "Harrow" peat-bags

1991 ◽  
Vol 71 (3) ◽  
pp. 947-949 ◽  
Author(s):  
Athanasios P. Papadopoulos ◽  
Chin S. Tan
Keyword(s):  
Lycopersicon Esculentum ◽  
Key Words ◽  
Environmental Conditions ◽  
Total Yield ◽  
Fruit Size ◽  
Irrigation Frequency ◽  
Marketable Yield ◽  
Greenhouse Tomato ◽  
Greenhouse Tomatoes ◽  
Fertilizer Solution

Three spring and two fall crops of greenhouse tomato (Lycopersicon esculentum L. Mill; various cultivars) grown in "Harrow" peat bags were irrigated 1, 4, 8 or 16 times daily. All plants received the same volume of fertilizer solution which varied with time from 0.2 to 1.0 L plant−1 d−1 according to crop and environmental conditions. The results showed little or no effect of irrigation frequency on early or total yield, number of grade no. 1 fruit, or fruit size. Key words: Lycopersicon esculentum, marketable yield

scholarly journals Effects of Cultivars and Culture Systems on Yield and Postharvest Quality of Greenhouse Tomato

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 847D-847
Author(s):  
Serge Gagnon ◽  
Mohamed Mzouri ◽  
André Gosselin
Keyword(s):  
Shelf Life ◽  
Fruit Quality ◽  
Culture System ◽  
Soluble Sugars ◽  
Postharvest Quality ◽  
Culture Systems ◽  
Titrable Acidity ◽  
Greenhouse Tomato ◽  
Tomato Cultivars

Our purpose was to determine cultivar and culture system effects on yield and postharvest quality of greenhouse tomato Lycopersicon esculentum. Nine tomato cultivars were sown into rockwool cubes on 2 Feb. 1994. The plants were transplanted into peat bags or nutrient film (NFT) systems on 9 Mar. Harvesting began on 2 May until 26 Sept. for a total of 21 harvest weeks. Fruit yield, rejected or nonmarketable fruit and four fruit quality indicators (fruit texture, color, titrable acidity, and soluble sugars) were measured during the harvest period. In addition, these indicators were further evaluated every 7 days during 28 days of storage at 20C and 90% RH for `Trust' and `Cencara', a long shelf-life cultivar. `Bounty', `Panther', and `Cencara' gave higher yields on rockwool but `Irazu', `Correct', `73-53', and `Medallion' gave better results on NFT. `Trust' produced the best yield for either rockwool or NFT. Culture systems (peat bags or NFT) did not affect fruit quality. `Cencara', which is a long shelf-life cultivar, kept high texture quality until 28 days of storage. However, titrable acidity of `Cencara' was higher and soluble sugars content was lower than that of `Trust'

scholarly journals Agronomic and physiological responses of tomato plants grown in different soilless systems to saline conditions

2017 ◽  
Author(s):  
Wilbert Michael Rodriguez-Ortega ◽  
Vicente Martinez ◽  
Manuel Nieves ◽  
Jose Maria Camara-Zapata ◽  
Francisco Garcia-Sanchez
Keyword(s):  
Yield Loss ◽  
Saline Water ◽  
Water Status ◽  
Physiological Responses ◽  
Quality Parameters ◽  
Gas Exchange Parameters ◽  
Marketable Yield ◽  
Tomato Production ◽  
Osmotic Effect ◽  
Nutrient Film Technique

Background. The tomato is the most important horticultural crop in the world, regarding area of cultivation and yield. The main production areas have arid and semi-arid climates, with scarce rainfall, which forces the use of saline water for irrigation - leading to a decrease in the agronomic yield of the crop. Currently, many soilless cultivation systems are considered for tomato production, although the behavior of the plants when saline water is used for irrigation is not known in detail. Methods. In this work we study the agronomic and physiological responses of the tomato variety ‘Óptima’, using different soilless crop systems (perlite substrate, hydroponics, and the nutrient film technique) and several levels of salinity in the irrigation water. The yield, quality parameters, vegetative growth, mineral composition, water relations, and gas exchange parameters were measured. Results and conclusions. Salinity caused changes in the water status of the plants, toxicity due to Cl- and Na+, and nutritional imbalances that altered the physiology of the plants, thereby reducing yield, although the fruit quality was improved. Regarding the crop system, hydroponics gave a higher marketable yield, both with and without salinity, with a consumption of nutrient solution intermediate between that of the nutrient film and perlite. Salinity reduced yield similarly in all systems. Plants cultivated with the nutrient film technique had the highest concentrations of Cl- and Na+ and the highest Na+/K+ ratio. The concentrations of Cl- and Na+ in the plants were not related directly to the yield loss. Therefore, the combined influence of the toxicity, osmotic effect, and nutritional imbalance seems to have been responsible for the yield loss.

scholarly journals Effect of Shade on Quality of Greenhouse Tomato

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 759A-759
Author(s):  
Martin P.N. Gent*
Keyword(s):  
Light Transmission ◽  
Total Yield ◽  
Fruit Size ◽  
Marketable Yield ◽  
Greenhouse Tomato ◽  
Yield And Quality ◽  
Shade Cloth ◽  
Marketable Fruit ◽  
Greenhouse Tomatoes

Shading a greenhouse increased the fraction of tomatoes that were marketable, and the marketable yield, in a comparison of greenhouse tomato yields across years, in some of which the greenhouses were shaded. In 2003, the yield and quality of greenhouse tomatoes were compared directly when grown in spring and summer in Connecticut in identical greenhouses that differed only in the degree of shade. Each half of four greenhouses was either unshaded or shaded using reflective aluminized shade cloth rated to reduced light transmission by 15%, 30%, or 50%. Each shade treatment was repeated in two houses. Tomatoes were germinated in February and transplanted in March The houses were shaded when fruit began to ripen in early June. Picking continued through August. The effect of shade on total yield developed gradually. Yields in June were unaffected by shade, but in August yield under no shade was about 30% higher than under 50% shade. In contrast, there was an immediate effect of shade on fruit size. Fruit picked in June from plants under 50% shade was 16% smaller than from plants grown under no shade. This difference declined later in the season, to 6 and 9%, in July and August respectively. The highest yield of marketable fruit in 2003 was picked from houses under no shade, but this was only 10% more than picked from the houses under 50% shade. Shade increased the fraction of marketable fruit, from 54% under no shade to 63% under 50% shade. Certain defects were decreased by shade. For instance the fraction of fruit with cracked skin was decreased from 33% to 25%. In general, effects on fruit quality varied linearly with the degree of applied shade.

scholarly journals Agronomic and physiological responses of tomato plants grown in different soilless systems to saline conditions

2017 ◽  
Author(s):  
Wilbert Michael Rodriguez-Ortega ◽  
Vicente Martinez ◽  
Manuel Nieves ◽  
Jose Maria Camara-Zapata ◽  
Francisco Garcia-Sanchez
Keyword(s):  
Yield Loss ◽  
Saline Water ◽  
Water Status ◽  
Physiological Responses ◽  
Quality Parameters ◽  
Gas Exchange Parameters ◽  
Marketable Yield ◽  
Tomato Production ◽  
Osmotic Effect ◽  
Nutrient Film Technique

Background. The tomato is the most important horticultural crop in the world, regarding area of cultivation and yield. The main production areas have arid and semi-arid climates, with scarce rainfall, which forces the use of saline water for irrigation - leading to a decrease in the agronomic yield of the crop. Currently, many soilless cultivation systems are considered for tomato production, although the behavior of the plants when saline water is used for irrigation is not known in detail. Methods. In this work we study the agronomic and physiological responses of the tomato variety ‘Óptima’, using different soilless crop systems (perlite substrate, hydroponics, and the nutrient film technique) and several levels of salinity in the irrigation water. The yield, quality parameters, vegetative growth, mineral composition, water relations, and gas exchange parameters were measured. Results and conclusions. Salinity caused changes in the water status of the plants, toxicity due to Cl- and Na+, and nutritional imbalances that altered the physiology of the plants, thereby reducing yield, although the fruit quality was improved. Regarding the crop system, hydroponics gave a higher marketable yield, both with and without salinity, with a consumption of nutrient solution intermediate between that of the nutrient film and perlite. Salinity reduced yield similarly in all systems. Plants cultivated with the nutrient film technique had the highest concentrations of Cl- and Na+ and the highest Na+/K+ ratio. The concentrations of Cl- and Na+ in the plants were not related directly to the yield loss. Therefore, the combined influence of the toxicity, osmotic effect, and nutritional imbalance seems to have been responsible for the yield loss.

scholarly journals Developing Value-added Practices and Branding for High-Sugar Tomatoes

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 777D-777
Author(s):  
Christopher D. Harlow ◽  
Elizabeth S. Larrea ◽  
Mary M. Peet*
Keyword(s):  
North Carolina ◽  
Fruit Quality ◽  
Cultural Practices ◽  
Value Added ◽  
High Sugar ◽  
Greenhouse Tomato ◽  
The North ◽  
Tomato Cultivars ◽  
Fertilizer Regimes ◽  
High Fertilization

Research was initiated at the N.C. State Univ. Horticultural Field Laboratory, Raleigh, to identify cultural practices and tomato cultivars giving superior taste under North Carolina greenhouse conditions. The specialty cultivars `67', `Diana', `Elegance', `Momotaro', and `S630' were grown and harvested, as well as `Trust', which is grown on 85% of the North American greenhouse tomato acreage. Additionally, two fertilizer regimes were provided to the plants: standard greenhouse tomato fertilization (EC ≈1.75 dS·m-1) or high fertilization (EC ≈3.75 dS·m-1). Fertilizers were the same in both treatments. Seeds were started in October 2002 and transplanted, 2 per pot, into `Bato' buckets containing perlite in November. Standard cultural practices were followed, and plants were fertigated using the Harrow Fertigation Manager™ system. Taste tests conducted on three dates revealed differences among cultivars, with `67', `Elegance' and `Momotaro' consistently scoring well. Overall, all test varieties were scored higher than `Trust'; however flavor was somewhat less sweet than anticipated, especially early in the season, averaging 2-3 on a scale of 5, where 5 was “best”. No significant differences were seen between the standard and high fertilization treatments. Differences in total harvest weight were seen among cultivars. `Elegance' and `67' produced fruit consistently well through the harvest season, while the remaining cultivars' yields were sporadic. Harvested fruit were homogenized, and Brix was measured as an indicator of fruit quality. Significant differences in Brix were seen among the cultivars, with `67' significantly higher than all other varieties and `Elegance' and `Momotaro' higher than the remaining cultivars. All specialty cultivars had higher °Brix than `Trust'.

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