STOR RUND TOMATSORTSFORSØG 212 Dette Demonstrationsprojekt er finansieret af Den Europæiske Landbrugsfond for Udvikling af Landdistrikterne: Europa investerer i landdistrikterne http://europa.eu/legislation_summaries/agriculture/general_framework/l632_en.htm samt Produktionsafgift fonden administreret af GAU (Gartneriet Afsætnings Udvalg) http://produktionsafgiftsfond.dk/ Nick Starkey, Consultant, Grotek Consulting ApS ns@grotek.dk GAU (Gartneribrugets Afsætningsudvalg) og følgende frøfirmaer har finansieret projektet: Rijk Zwaan, Enza Zaden, Monsanto De Ruiter, Syngenta, Gautier og Nunhems. Large 1 gram round tomatoes are now a bulk product, with low price the overriding factor for the supermarkets. Therefore total yield and growing costs tend to be the main factors in determining grower choice. An alternative tactic to achieve higher yields could be to choose a variety with a higher fruit weight and to squeeze the fruit size down to the market requirement using more heads/m 2 In 212 nine large round (13 gram plus) varieties were screened for their suitability for this tactic. The majority of the varieties have been bred as truss tomatoes. The final head density for these larger fruited types was 3,6 heads /m 2. They were evaluated against Arvento as the control (standard) 1 gram variety at a head density of 3,3 /m 2. None of the varieties were truss pruned and all were picked loose: Sort Arvento Endeavour Evolution Kanavaro (E26.3464) RZ 72-495 Merlice (DRW ) V 47 Frøfirma Rijk Zwaan Rijk Zwaan Syngenta Enza Zaden Rijk Zwaan Monsanto De Ruiter Nunhems Nunhems Gautier Monsanto De Ruiter The trial site was Alfred Pedersen & Son A/S, Bellinge in Denmark. All varieties were grafted on Maxifort with single heads. The trial was planted in week 3 on rockwool slabs at 1,65 /m 2. Extra tops were set in under the first truss to give 3,6 heads/m 2 in the large round types and at 3,3 heads/m 2 in Arvento. The crop climate was controlled on the basis of the demands of Arvento. The trial stopped at the end of September. 1. GROWTH
The varieties were measured for truss flowering, flower count per single truss, stem diameter and leaf length. Some of the measurements stopped mid-summer to reduce costs of recording. A Fruit production Fig. 1 illustrates the measured flowering rates until week 33. Klase, blomster nr. 27 25 23 21 19 17 15 13 11 9 7 5 3 1 Fig. 1 Blomstringshastighed 8 12 16 2 25 33 Uge MERLICE DRW Three trusses separated the fastest and slowest varieties. All the larger round types were slower than Arvento, which puts them at a disadvantage. Fig. 2 illustrates the flower count per truss until week 25.
Fig. 2 Blomster pr. klase 1 9 8 7 6 5 4 3 MERLICE DRW 2 1 8 12 16 2 25 Week Flower counts per truss varied considerably between varieties (see fig. 2). As the large round varieties have been bred for truss harvest, some of them require little or no pruning. This can be a disadvantage if they are to be picked loose. Are their sufficient fruits /m 2 over the season? If we combine flowering rate and flowers per truss together, we have an estimate of the total fruit set potential (see table 1). Arvento, with the fastest flowering speed and a high flower count, easily produced the highest potential set/m2. Even allowing for the extra heads, few of the trial varieties came close to Arvento s potential set. Tabel 1 Kalkuleret totalsætning Sort Beregnet frugtsat potential /plant Beregnet frugtsat potential /m 2 Arvento 241 775 Endeavour 216 74 Evolution 181 626 Kanavaro (E26.3464) 162 551 RZ 72-495 194 666 Merlice (DRW ) 24 724 216 733 225 782 V 47 2 71 186 623
B Plant vigour Fig. 3 illustrates the amount of power that the varieties had during the season. Most of the larger round types, even those with a low flower count, proved to be weaker in growth than Arvento. 13 Fig. 3 Stængeltykkelse Stængeltykkelse (mm) 12 11 1 9 8 7 8 12 16 2 25 Uge MERLICE DRW Differences became smaller at the start of maximum fruit load (ca. week 16), see fig. 4. Towards mid- summer, differences became larger again. Klase pr. hovedstængel 9 8 7 6 5 4 3 2 1 Fig. 4 Frugtbelastning: klase pr. hovedstængel 8 12 16 2 25 33 Uge MERLICE DRW Fig. 5 gives an indication of how vegetative the varieties were, using leaf length as the measured parameter. Most of the trial varieties were less vegetative, although the Gautier variety was exceptionally strong and vegetative.
Bladlængde (cm) 54 52 5 48 46 44 42 4 38 36 34 Fig. 5 Bladlængde 8 12 2 2 25 Uge MERLICE DRW 2. YIELDS 4 kg/m 2 separated the varieties to the end of May (see fig. 6). Most of the trial varieties were slightly slower picking (se fig. 8) compared to Arvento. Clearly the higher average fruit weights were not enough to compensate for the lower fruit set counts at the start. Fig. 6 Udbytte til slutning af maj 16, 14, Udbytte (kg/m 2 ) 12, 1, 8, 6, 4, 2,, MERLICE DRW TR26 V 47 11 XM FIR 44 By the end of September many of the varieties had caught, or overtaken Arvento, due to their higher fruit weights. The 2 Nunhems varieties had the lowest yields, because their fruit weights were no higher than Arvento (see fig. 9).
Fig. 7 Totaludbytte til sluning af september Udbytte (kg/m 2 ) 56 54 52 5 48 46 44 42 4 38 36 34 32 3 28 26 24 22 2 18 16 14 12 1 8 6 4 2 MERLICE DRW TR26 V 47 11 XM FIR 44 Fig. 8 Udbytte pr. måned UDBYTTE (kg/m 2 ) 16 14 12 1 8 6 4 2 MERLICE DRW TR26 V 47 MARTS APRIL MAJ JUNI JULI AUG SEP OKT NOV 3. AVERAGE FRUIT WEIGHT The biggest differences in fruit weights were in the early harvests (see fig. 9). Clearly the higher density of 3,6/m 2 was not enough to reduce the fruit size a higher density of say 4 heads/m 2 may be necessary.
grams 25 225 2 175 15 125 1 75 5 Fig. 9 Gennemsnitsfrugtvægt pr. måned MELICE DRW 25 APR MAJ JUN JUL AUG SEP OKT NOV It would be difficult, even at a higher density, to get the fruit weights down in some varieties, especially those with a low fruit count per truss (eg. Evolution, Kanavarro, RZ 72 495 and 11XM FIR 44). 175 Fig. 1 Gennemsnitsfrugtvægt til slutningen af september 15 125 grams 1 75 5 25 MELICE DRW 11 XM FIR 44 4 PICKING RATES
As this segment is a bulk product, growers are looking increasingly at a varieties cost of production. We were able to obtain an impression of relative picking costs at intervals during the season see table 2. There was quite a spread of ease of picking between the varieties, with bla bla Tabel 2 Pluninghastighed Sort Arvento Endeavour Evolution Kanavaro (E26.3464) RZ 72-495 Merlice (DRW ) V 47 Plukningshastighed (1 5); 5 = hurtigste 5 BRIX and FRUIT FORM The varieties were tested five times for brix values (soluble sugar content) see fig. 11. Like normal round tomatoes, the extra large round types do not have high brix values and differences are relatively small. Merlice (DRW ) consistently had the lowest values.
Fig. 11 Brix værdier 6, 5, 4, 3, DRW 2, 1,, 2 25 3 34 38 GNS Week 6. BOTRYTIS, MILDEW and BLOSSOM END ROT The two Gautier varieties were more susceptible to mildew compared to the others. All varieties were quite susceptible to botrytis, but there was a considerable difference between the varieties. Table 3 summarises the botrytis scores at the end of the season. Arvento Variety Endeavour Evolution Kanavaro (E26.3464) RZ 72-495 Merlice (DRW ) V 47 Table 3 Botrytis suseptibility The Nunhems variety was much more sensitive to blossom end rot compared to all others. It would be necessary to have a routine spray programme with calcium chloride to hold this
in check and / or a lower K:Ca ratio in the applied feed. Prunus was clearly the least sensitive to blossom end rot 7. CONCLUSIONS This trial was always viewed as a screening trial to try and find some varieties that could be trialed on a larger scale. With this goal, it can be said that the trial has been a success. Some of the varieties can be ruled out on the basis of too low a fruit weight and or yield (eg., and ). Others can be ruled out by having too few fruits per truss and too high a fruit weight (eg Evolution, Kanavarro, and 11XM FIR 44). This leaves Endeavour and Merlice as potential varieties for further trial. It is intended to conduct a further stage 2 trial in 213 using a higher density of 4 heads/m 2 for these 2 varieties. Other new varieties will also be screened for their potential.