III. MATERIAL Y MÉTODOS
4.1. La ceguera como figura simbólico-alegórica de la pérdida de la moral
Jõgeva Plant Breeding Institute, EE 48309, Jõgeva, Estonia, e-mail: [email protected]
Abstract
In 2001 were started organic tomato trials at Jogeva Plant Breeding Institute to find high yield and disease resistant varieties for growing under organic conditions. Data were collected from 2001 to 2004 in an unheated plastic greenhouse. Growth substrate was soil fertilized by with cattle manure. 50 tomato varieties - 42 indeterminate, 2 semi-determinate and 6 determinate were tested during the trial years. The tomato varieties originated from several countries, among them 10 from Estonia, one from Latvia and one from Lithuania. Early yield (till July 31), total yield ripened on plants, yield of fruits damaged by diseases such as grey mould (Botrytis cinerea) and late blight (Phytophthora infestans) were measured. The results showed that the superior tomato varieties were different every year
according to weather conditions. Higher early yield was mainly obtained with Estonian early-ripening varieties. The superior one was determinate ‘Mato’ with the highest early yield (3.8 kg/m-2) in 2002. Variation among tomato varieties in total yield was greater than
that in early yield. In warmer summers some later foreign varieties produced superior yields. The highest total yield gave indeterminate ‘Suso’ F1 (10.5 kg/m-2) in 2002. The most disease
resistant variety was cherry type ‘Garten Freude’.
Key words: tomato, yield, diseases, grey mould, organic cultivation
Introduction
Tomato breeding at Jogeva commenced in 1945. There are 11 Jogeva varieties in cultivation nowadays. During these years there have been studied tomato cultivation problems hand in hand with breeding work. In 2001 there was started an organic tomato trial at Jogeva Plant Breeding Institute to find varieties with high yield and disease resistance for growing under organic conditions.
Material and methods
The data were collected in an unheated plastic greenhouse (9x26 m) from 2001 to 2004. The growth substrate was soil fertilized with cattle manure. Soil layer 10-15 cm deep was removed every autumn before manure spreading in order to decrease occurrence of plant diseases. Subsurface irrigation was used. The surface of the soil was dry throughout the tomato–growing period to minimize diseases. Tomatoes were planted in the middle of May. Plants were grown without any mineral fertilizers and pesticides.
50 tomato varieties - 42 indeterminate, 2 semi-determinate and 6 determinate ones were tested during trial years. Two varieties were cherry type. According to ripening time one half of the varieties were of early ripening and the other late ripening. The origin of all tomato varieties is not clear, but among them there were varieties from the Netherlands, Denmark, Lithuania, Latvia and Estonia. In 2001 there were 28, in 2002 – 30, in 2003 – 28 and in 2004 – 23 varieties used in the trials. Out of them 15 varieties were used in the trial every year. Early yield (till July 31), total yield ripened on plants and yield damaged by diseases (grey mould and late blight) were measured.
Results and discussion
The production and quality of yield were influenced by weather conditions. Growing period of tomato plants can be calculated from the middle of May to the middle of September. The severest diseases infection occurred mainly in August and September. The greatest damage was caused by grey mould. At present completely resistant cultivars are not available (Egashira et al., 2000), but some of them are more tolerant than others. 3-5 varieties having less than 1% of damaged fruits occurred every year. Incidence of late blight was rare.
In the warm year of 2001 the early-ripening Estonian varieties ‘Valve’, ‘Maike’ and ‘Mato’ gave the highest early yield (till 31 July). ‘Valve’ and the Netherlands ‘Resyset’F1 and
Danish ‘Garten Freude’ produced higher total yield than other varieties (Table 1). Three disease resistant varieties were found as early-ripening - cherry tomato type ‘Garten Freude’ and late ripening ‘Gardenes Delight’ and Danish ‘Goldene Gönigin’.
The early–ripening varieties had lower total yield than the late-ripening ones under favourable conditions. Higher early yield was produced by the two early-ripening varieties ‘Mato’ and ‘Maike’ and cherry tomato variety ‘Garten Freude’ in extremely warm and dry growing period of 2002. Late-ripening varieties ‘Suso’ F, the Netherlands ‘Ildiko’ F and
cherry tomato ‘Sun Baby’ produced the highest total yields. There was no disease infection observed in 2002.
In 2003 with warm summer and September the early-ripening Estonian variety ‘Koit’, foreign ‘Idol’ and ‘Mato’ gave higher early yields. Late-ripening ‘Ildiko’ F1, ‘Brooklyn’ F1
and ‘Cronos’ F1 (all from the Netherlands) produced higher total yield. Diseases damaged
few varieties like ‘Garten Freude’, ‘Sun Baby’ and Estonian ‘Vilja’.
The trials at Jõgeva have shown that early-ripening varieties survived better under unfavourable weather conditions and gave even higher total yields than the late-ripening ones. In 2004 with cool and rainy summer only early-ripening varieties gave higher total yields compare to other varieties. ‘Maike’, ‘Malle’ F1 (Estonian) and ‘Mato’ had higher early
yield and ‘Erk’ (Estonian), ‘Malle’ F1 and ‘Mato’ had higher total yields than other varieties.
‘Valve’, ‘Malle’ F1 and ‘Garten Freude’ were less damaged by fruit diseases.
Table 1 Superior tomato varieties used in organic trial in 2001-2004
Conclusions
Early yield Total yield Year
variety kg/m2 variety kg/m2
Most resistant to diseases
Valve 1.9 Valve 9.3 Gardenes Delight
Maike 1.7 Resyset F1 8.0 Garten Freude
2001
Mato 1.4 Garten Freude 7.6 Goldene Gönigin
Mato 3.8 Suso F1 10.5 x
Garten Freude 3.7 Ildiko F1 9.4 x
2002
Maike 3.1 Sun Baby 8.7 x
Koit 2.3 Ildiko F1 7.7 Garten Freude
Idol 2.2 Brooklyn F1 7.6 Sun Baby
2003
Mato 1.9 Cronos F1 7.1 Vilja
Maike 0.4 Erk 6.2 Valve
Malle F1 0.4 Malle F1 5.2 Malle F1
2004
Mato 0.2 Mato 4.7 Garten Freude
The results of 4-year trials showed that the superior tomato varieties yielded differently according to weather conditions.
Higher early yield mainly was obtained with Estonian early-ripening tomato varieties. The superior one was determinate ‘Mato’ providing highest total yield of 3.8 kg/m-2 in 2002.
Variation among tomato varieties in total yield was greater than that in early yield. In warmer summers late-ripening foreign varieties produced higher total yields. The highest total yield was produced by indeterminate ‘Suso’ F1 - 10.5 kg/m-2 in 2002.
The most disease resistant variety was cherry type tomato ‘Garten Freude’.
References
Egashira, H., Kuwashima, A., Ishiguro, H., Fukushima, K., Kaya, T., Imanishi, S. Screening of wild accessions resistant to grey mould (Botrytis cinerea Pers.) in Lycopersicon. Acta Physiologiae Plantarum, 22(3), pp. 324-326.