Spain is a country where climatic conditions vary greatly. This has favored the diversity of indigenous crops. Some tomato cultivars have adapted well to regions with an arid climate or salty soils and/or waters. Several experiments have been carried out in field conditions and with different levels of salinity, and has been found intraspecific variability which could be taken advantage of directly from the agronomical usefulness point of view (Astafeva, 1979; Ponomareva and Kubuzenko, 1984; Sinel'nikova et al., 1985; Lapushner et al., 1986; Costa et al., 1986; Martinez et al., 1987; Anastasio et al., 1987).
After these results we have decided to carry out a more precise experiment with autochthonous cultivars collected from areas with drought and/or salinity problems. The principle objective has been to compare their productive potential with respect to other referenced commercial cultivars, in traditional open air cultivation but in soils with an EC level superior to that considered limiting in normal tomato cultivation. The trial was carried out in Alhama Murcia, and 136 cultivars were used: 13 with small fruits ("cherry" type), 92 with middle-sized fruits ("canary" types and others), 16 with large-sized fruits and 15 the "Marmande" type fruits. The experimental design was in blocks at random with 3 repetitions and 5 plants per plot.
The level of EC\e\ in the soil was measured (Abrisqueta et al., 1962) on 5 dates corresponding to the most significant vegetative stages. The average values of EC\e\ were: 36.99 (before transplanting, 33.39, 39.64, 18.98 and 26.99 dS/m; the last measurement was taken in each one of the surviving plants. The maximum oscillation, considering all measurements, was within the limits 15.97 and 59.92 dS/m; we are dealing with very high levels of salinity, now that in general the maximum salinity values of soils dedicated tomato cultivation in our country do not exceed an EC\e\=12 dS/m. The drop in levels of EC\e\ is attributed to utilization of fresh irrigation water and also heavy rains in July and August.
The following characteristics were considered: survival at 2 weeks after transplanting, vegetative development, early and total yield, number of fruit and average weight of fruit per plant. Table 1 indicates the cultivars of greatest interest in relation to their productive characteristics (on average in the 3 repetitions); values are given on percentage with regard to the best cultivar (Hib-84097). Cultivars Hib-84097 and Dario have shown a behavior in agreement with our expectancy, in the same manner as the most sensible to salinity. Other autochthonous cultivars which had never been tried (22-L-30, 22-L-18, 22-L-16 and MUCH-12) have revealed an interesting behavior in this experiment.
We are going to evaluate again those ones which have been tested in this experiment to the maximum salinity; the new levels of salinity will be lower. Those cultivars have been: 7-L-95, 5-L-32, 24-L-4, 67-L-33, MUCH-8, 68-L-14, 68-L-35 and 68-L-39. In the next year we will carry out statistical trials under real cultivation conditions. The behavior of this selected cultivars will be studied with respect to the most important ones grown in saline areas.
Table 1. EC\e\ values at the end of the productive period and index of total yield (I\y\) and average weight of fruit (I\w\).
_____________________________________________________________ Cultivar Type EC\e\ (dS/m) I\y\ (%) I\w\ (%) _____________________________________________________________ 22-L-18 Small 16.9 49 41 22-L-27 Small 16.9 36 22 22-L-30 Middle 13.0 94 103 Hib-84097 Middle 18.3 100 100 Dario Middle 13.5 69 150 22-L-16 Middle 16.5 66 137 24-L-4 Middle 25.7 52 141 68-L-31 Middle 31.3 46 172 MUCH-9 Marmande 12.1 60 266 MUCH-10 Marmande 18.0 53 366 MUCH-11 Marmande 12.6 54 291 MUCH-12 Marmande 25.5 61 266 _____________________________________________________________Acknowledgement: This work was supported by the research project CA 0917/84 held by the CAICYT. We thank J.A. Martinez (S.E.A. Alhama Murcia) for his collaboration.
Literature cited:
Abrisqueta, C.; M.J. Guillen; F.G. Fernandez; M. Caro. 1962. An.Edaf.Agrob. XXI,545 554.
Anastasio, G.; M.S. Catala; G. Palomers; J. Costa; F. Nuez. 1987. Synopses 10th Meeting Tomato Working Group, Eucarpia. Pp. 57 62.
Astafeva, G.I. 1979. Doklady TSJA 256, 112 116.
Costa, J.; M.J. Diez; F. Nuez; G. Palomeres; J. Cuartero. 1986. Acta Horticulturae 191: 107 112.
Lapushner, D.; R. Frankel; Y. Fuchs. 1986. Acta Horticulturae 190, 247 252.
Martinez, V.; A. Cerda; F.G. Fernandez. 1987. Plant and Soil, 97 (2) 233 241.
Ponomereva, S.A.; S.N. Kubuzenco. 1984. Kartofel'i Ovoshchi n^o^ 10, 24 25.
Sinel'nikova, V.N.; E.Ya. Glushchenko; I.A. Kosareva. 1985. Nautchno teknicheskii Byulleten' n^o^132, 24 27.