The significance of the varieties as a prerequisite for increased efficiency in vegetable growing is manifested strongly in the conditions of market economy and increased competition. The cucumbers are main greenhouse culture with important economic importance. The cucumber varieties should correspond to some basic requirements like high yield even taste qualities, durability in preserving and diseases resistance [7]. Great attention is paid also to the indexes that characterize the varieties suitability for the separate directions of consumption [6; 3]. In the Bulgarian greenhouse production during the past years more significant part take foreign vegetable varieties. In their mostly part they conduct study in the Executive variety study, approbation and seed control agency but only by DHS/distinction, homogeneity and stability/. The varieties are not evaluated by biological and market qualities. On other hand the accompanying characteristic of the imported varieties is connected mostly with their productivity and stability to economically imported diseases but there is no official information for their climate adaptation to the conditions in Bulgaria [8]. Some authors [1; 2; 9; 5] pay attention to the influence of the variety and the way of growth of greenhouse cucumbers.
The investigation purpose is to conduct comparative testing of different greenhouse cucumber varieties.
Material and methods. The experimental work is conducted in non-heated steel-glass house Venlo type in Maritsa VCRI – Plovdiv with eight cucumber varieties of Enza Zaden — Cratos; E31. 2090; Carlin; Imea; E31. 2028; Voreas; Defense and Airbus and one cucumber variety Kиара- Maritsa VCRI, grown as a soil culture.
Experiment conditions: Sowing: 20. 03.; Planting: 18. 04.; Crops: till: 08. 08; Sowing density: 1,44 plant/m2; removing the growing top – till reaching the supporting wire. The study is set by the method of the long plots in 3 repetitions.
Investigation indexes: Microclimate conditions. At 8 o`clock and at 14 o`clock the following results were registered: — air temperature. It was registered with minimum-maximum thermometer. — the substrate temperature at 10 cm. depth. With soil thermometer. — sun radiation. With portable luxmeter. The relative air humidity was measured at the same hours.
Biometric analysis. The stem growth pace and leaves formation were defined. The measurements were made weekly till removing the growth top.
Yield. The production and the total yield were defined three times a week (Monday, Wednesday and Friday).
Mathematical data processing. Duncan`s method multidirectional comparative analysis was conducted for the mathematical processing of the gained numerical data [5].
Results and discussion. The experiments with the cucumbers were conducted in steal-glass houses Venlo type without heating with restricted possibility for microclimate management and maintaining. Due to that the litter is influenced mainly of the outside climate factors and for the grown culture.
Illumination conditions. The average values of illumination of the green house reach the optimal illumination conditions during the months with most intensive sunshine.
The restriction of the sun radiation stream to the plants after April was achieved through shading the greenhouse with whitening solution (table 1).
Table 1.
Greenhouse illumination (Lux), average by months
| Time | 18-30 April |
May | June | July |
01-08 |
| 08.00h | 10300 | 8556 | 8946 | 10833 | 10800 |
| 14.00h | 13000 | 12966 | 13598 | 15843 | 14375 |
Heat conditions. For each of the three experimental years, the average minimum air temperature in the greenhouse had the lowest values in the second half of April and in May – 10.7оС — 11.9оС (Table 2).
Table 2.
Heat conditions
| Temperature | 18-30 April |
May | June | July |
01-08 August |
|||||
| Av. Min.ТоС | 7,8 | 11,9 | 15,3 | 16,8 | 18,3 | |||||
| Av. Max.ТоС | 35,3 | 36,2 | 34,0 | 34,3 | 35,6 | |||||
|
800h |
1400h | 800h | 1400h | 800h | 1400h | 800h | 1400h | 800h |
1400h |
|
| Av.Air | 15,4 | 30,9 | 19,6 | 32,6 | 20,6 | 31,9 | 25,8 | 33,2 | 27,1 | 34,8 |
| Av.soil | 15,7 | 24,5 | 17,7 | 24,4 | 19,4 | 23,9 | 21,0 | 24,2 | 22,2 | 25,0 |
The minimum temperature rose in June, averaging at 15,5 оС, and in July and first ten days of August it reached – 16,5 oС and 17,8 oС, respectively.
These minimum temperatures were recorded at night. Throughout the period of the experimental work they were by 15-18 oC lower than the optimum (25-28 oC) and in the last ten days of April and in May, the minimum temperatures were lower than the minimum requirements for plant growth and development. In the morning hours (about 8,00 h), the temperature increased by an average of 6-8 oC. As the day progresses (at 2,00 h) it averaged at 37,7 oC for the second half of April; the average temperature measured at 2pm decreased to 32,1°C and 33.9°C during the months of May and June and then increased gradually to reach values of 34,9 oC in July and 35.0 oC for the first ten days of August. The average values of the maximum air temperature were the highest during the second half of April (38.8 oC) and then decreased and were between 36.0 – 36.6 oC. The average temperature amplitude varied from 19 to 21 oC, which adversely affects the growth and development of plants
Relative air humidity. The air humidity was regulated through ventilation, irrigation and refreshing sprinkling during the three year period of growing the cucumber plants. Despite that due to higher ventilation the relative air humidity decreased and was under the optimal for cucumbers (80% – 85%) – at 8 o`clock it was within the range of 44.3 – 62.0 % and at 14 o`clock – from 40.3 to 45.9 %.
The registered data from the microclimate factors showed that during the period of the studies they have different from the optimal for that culture values which gives unfavorable influence.
Nutrition regime. The study was conducted in same nutrition background, favorable for the cucumber culture. For its maintaining it was made basic fertilization of the area with 40 kg/da triple superphosphate and 50 kg/da potassium sulphate and during the period of end of May – beginning of August – weekly feed up with ammonium saltpetre nitre and potassium sulphate by 3,5 kg/da.
Growth expressions. For the entire experimental period of comparative testing of new greenhouse cucumber varieties, the plants with the fastest central stem growth rate were the Carlin variety — 6,12 cm/24h, while the slowest rates were measured in the Defense variety – 3,54 cm/24h. The difference in the growth between the Carlin variety and the Defense and Airbus variety and the line E31. 2090 was proven (Table 3).
Table 3.
Biometric indexes
| Variety | Stem height, cm | Growth pace,
cm/24 h / |
Number of leaves | Formation pace,
pc./24h/ |
||
| begin.cm | end cm | av. cm/day | pc.l.begin. | pc.l. end | av.pc.l./day | |
| 1. Cratos | 72,0 | 284,3 | 4,91 ab | 14,6 | 40,9 | 0,62 n.s |
| 2. E31. 2090 | 100,3 | 248,7 | 4,15 b | 18,6 | 39,8 | 0,54 n.s |
| 3. Carlin | 14,0 | 271,0 | 6,12 a | 5,0 | 31,9 | 0,64 n.s |
| 4. Imea | 94,2 | 230,9 | 3,37 b | 18,2 | 38,2 | 0,51 n.s |
| 5. E31. 2028 | 61,7 | 245,3 | 4,35 ab | 13,0 | 37,3 | 0,57 n.s |
| 6. Voreas | 74,5 | 290,1 | 5,15 ab | 13,2 | 39,2 | 0,62 n.s |
| 7. Defense | 66,7 | 202,3 | 3,54 b | 13,4 | 32,0 | 0,50 n.s |
| 8. Киара | 71,4 | 247,9 | 4,23 ab | 14,5 | 38,7 | 0,58 n.s |
| 9. Airbus | 65,0 | 239,6 | 4,16 b | 13,4 | 40,8 | 0,65 n.s |
a,b, — p<0,05 (Duncan’s Multiple Range Test)
The statistical analysis did not register any differences in the rate of leaf-formation between the individual varieties. The largest values were measured in Airbus — 0,65 leaves /24h, Carlin — 0,64 leaves /24h and Voreas and Cratos with 0,62 leaves/24h hours. The Defense variety has the slowest rate of formation of leaves – 0,50 leaves /24h hours.
The growth expressions of the Carlin (6,12 cm, 0,64 leaves/24 h) and Voreas varieties (5,15 cm, 0,53 leaves/24h) exceed those of all the other plants. The registered values expressing the growth and leaf-formation rates in the Imea (3,37 cm 0,51 leaves /24h) and Defense varieties (3,54 cm and 0,50 leaves /24h) are the lowest.
Yield. Out of the tested varieties, in conditions of spring planting and limited control of the microclimate conditions in the steel glass greenhouse, the highest quantities of first-quality production was measured in the Voreas variety — 3452 kg/da, while the lowest were in the Carlin variety — 1458 kg/da (Fig. 1). The difference between the individual varieties’ yield values is statistically significant. The highest total yield was recorded in the varieties Voreas – 5974 kg/da and Cratos — 5774 kg/da. This indicator has the lowest average values in the Imea variety — 3647 kg/da and the Carlin variety – 3918 kg/da. The differences between the results in the most productive varieties of cucumbers and those with the lowest total yield are mathematically proven.
a,b, — p<0,05 (Duncan’s Multiple Range Test)
Figure 1. Yield kg/da
Comparing the results regarding the first quality production as part of the total yield of the individual varieties throughout the period of the experiment, we can say that the greenhouse varieties with the highest percentage of production of first quality are the Defense and Voreas with respectively 59.7% and 57.8% (Fig. 2).
The lowest percentage of production of first quality was measured in the Carlin variety, the value being only 1/3 of the total yield — 34.13%.
Figure 2. Production quality percentage rationing
Conclusion
- The average results of three experimental years registered differences in the growth and productive expressions of the plants of the tested varieties.
- Under the conditions of the experiment (April planting in a steel-glass greenhouse and sparsely controlled microclimate factors) differences between the test parthenocarpic varieties were proven in the growth rate only. The most rapid growth and leaf formation were expressed by the varieties Carlin and Voreas; on the other hand, the weakest growth expressions were recorded in the Imea and Defense varieties.
- The plants of the Voreas and Carlin varieties had the best productive qualities among the tested greenhouse cucumbers. The Imea variety had the lowest yield quantities. The Voreas variety had the highest quantity of first quality production.
- The rate of first quality production to the total production in these greenhouse varieties was the highest in the Defense variety and the lowest in the Carlin variety.
LITERATURE
- Желев, Д. Влияние на гъстотата на засаждане на растенията и сортовата им принадлежност върху ранозрелостта и добива при оранжерийни краставици. Научн.-техн. бюлетин, ИЗК”Марица”.1984, 4;13-15
- Набатова, Т.А. и др. Реакция гибридов огурца на различны условия выращивания. Сб.Научн.Трудов ТА, т.XX,Москва; 1988, 175-183.
- Berry, S.Z., W.A.Gould. Evaluation of processing tomato breeding lines and cultivars for mechanical harvesting and qualitu in 1979. Horticulture Series, Wooster, Ohio, 1980,
- Duncan,D. Multiple range and multiple F-test. Biometrics. 1955,11: 1-42.
- Lin, Gui Ying et al.,.Breeding of Ganfeng, 3.a neu extremely early-maturing cucumber variety. Acta Horticulturae. 1995, 402;268-272.
- Matlob, A.,. Evaluation of tomato cultivars for processing fresh marketing under the conditions at Hamman AL-Alil. Acta Hortic. 1980, 100;399-404.
- Neykov N., N. Velcheva, P. Chavdarov N. Neykov Study on economic qualities of perspective accessions cucumber (Cucumis sativus L.) from the collections of IPGR-Sadovo. Agricultural University – Plovdiv, Scientific Works, 2009, vol. LIV, 25-29.
- Peviccharova and T.Todorov. Biological value of Bulgarian and foreign determinate tomato cultivars. Proceedings of forth national scientific conference with international participation “Ecology and helth”. 2002, 51-54.
- Pigeon, M.,. Collection of greenhouse cucumber varieties for spring and summer crops. CTIFL Compte Rendu d*Experimentation /France/, 1984, №904.[schema type=»book» name=»COMPARATIVE STUDY OF GREENHOUSE CUCUMBER VARIETIES» description=»Our objective is to test and compare different varieties of greenhouse cucumbers. The experimental work is carried out with eight cucumber varieties of Enza Zaden (The Netherlands) and one cucumber variety selected by the Maritsa Vegetable Crops Research Institute (VCRI Maritsa) grown as soil cultures. The average results of the three experimental years registered differences in the growth and yield of the plants of the tested varieties. Under the conditions of the experiment (planted in April in a steel-glass greenhouse; sparsely controlled microclimate factors) the only difference which was proven was the growth pace of the tested parthenocarpic varieties. The Carlin and Voreas varieties displayed the most rapid growth and leaf formation pace; at the same time, the weakest growth pace was found out with the Imea and Defense varieties. The plants of the Voreas and Carlin varieties have the best productive qualities among the greenhouse cucumbers. The Imea variety formed the lowest yields. Voreas has the highest quantity of first quality production. The rate of first quality production to the total yield in the greenhouse varieties is the highest in Defense and the lowest in the Carlin variety.» author=»Arnaoudov Boyan Dimov, Boteva Hriska Manusheva, Dintcheva Tsvetanka Ivanova» publisher=»БАСАРАНОВИЧ ЕКАТЕРИНА» pubdate=»2016-12-25″ edition=»euroasian-science.ru_25-26.03.2016_3(24)» ebook=»yes» ]