"Keep to six and grow with sufficient space, the best way of growing"
How is the head developing? Just one of the questions asked during a talk about Provine, the tomato variety created by Nunhems, introduced officially last year, which offers an option, in fruit weight, between large and medium sized tomatoes-on-the-vine. In an interactive setting led by a trio of experienced experts, a cultivation plan for the variety was discussed, after which the greenhouse and the crops were viewed via VR (virtual reality)-glasses.
The tour of the greenhouse, via the VR glasses, resulted in a lot of laughs, but was also a great demonstration to display the validity of using them for horticultural purpose.
It is a unique experience wearing the VR glasses, which has previously been described to feel like 'you have downed six stiff drinks', by a grower/test person. Still, there is a high chance this 'drunk experience', which the wearer of the glasses quickly becomes accustomed to, will become a regular function of 'being a grower'. It is a great way to look in the greenhouse, without having a fellow grower or cultivation adviser with you, which is not as common as it was in the past due to an increase in viruses and spread of disease.
What is early sowing?
Fortunately, it is still possible to sit around a table with colleagues to have a great discussion and share tips and advice. Our 3 experts came together led by Jan Hanemaaijer, from BASF Vegetable Seeds, Bart de Bakker, from tomato cultivation company De Bakker Westland, (which this year had gained commercial production experience with the new variety growing in the Netherlands on ten hectare in total), and growth adviser Erik de Winter, from Wingrow. With some stimulating conversation, those present were challenged to share their experience and opinion, and it went really well.
Above: Bart de Bakker, Jan Hanemaaijer and Erik de Winter
It is clear, from testing and recent experience, Provine comes into production early. Does that make the variety only suitable for early sowing and then early planting? The response: "well, what is early sowing? The discussion began. At De Bakker, sowing took place on October 12 and the topped and grafted plants were planted at the end of November. Even before Christmas, on December 20 and 21 already, the first flowers appeared.
Bart "And the first tomatoes were harvested in week 11. Make sure the days are not too long and keep an eye on flowering. Do not control too generatively, because the Provine is quite generative of itself."
AC-foil or not? (Europe Conditions):
The discussion then turned to AC-foil. Yes or no? At De Bakker, the answer is 'no', in the coming year, when planting and sowing will start a bit later. Erik is in favour of using foil in the beginning of the cultivation, even though the low gas prices make extra heating attractive and the investment in foil less attractive.
Erik: "With foil, it is easier to achieve a high day temperature which is beneficial for the flower quality. Without foil, you run the risk that plants are too cold at moments". A member of the audience added that there has to be sufficiently light accompanying the high day temperature.
Check here to see what AC-film/foil looks like. https://royalbrinkman.com/knowledge-center/crop-rotation/pull-in-ac-film
Sixes until far in the fall
But, to return to the statement: sowing later, is that possible?
Erik: "Yes, but my advice is to heat to one degree higher, and pay attention that the plant does not become to vegetative."
The growers wanted to know whether continuing longer is possible in that situation?
Jan: "Yes, it is certainly possible. Everything is about the manner of growing, of controlling, and the variety is not susceptible to Botrytis and has the complete package of available resistances, and is also not susceptible to yellow stems. It is no problem to harvest sixes further on in the season, if you standardly remove a truss at the end of summer to make it to the end of the year in good condition." That is also a tip, also by Bart, because at De Bakker they temporarily harvested at five, to proceed, after half July, harvesting at six until far in the fall.
Not too close, not too open:
Another point for consideration is the stem density. In general the advice in Nunhem's cultivation plan is to steer towards a stem density of maximally 3.6 stems per square meter, and maybe even a bit less, at the end of the cultivation.
Erik: "The crops are not too close to each other, with a heightened chance of cracked stems and somewhat elongated fruits, but also not too open, making the crop too vegetative."
Considering all the points above, and not all points have been discussed (go to the cultivation specialists of BASF Vegetable Seeds), is the Provine an easy to grow variety?
Erik: "Yes, if the growers keep to the usual rules. Do not plant too close, and then harvest kilos from the sixes with a good fruit weight around the 140 gram."
A tray of Provine
140 grams: large or medium?
What if the fruit weight is a bit higher, what does the grower put on the label the (German) retailer demands of him? How does the grower put his product on the market, or, for example in Belgium, with all the segmentation rules, how can he put the product on the market and keep to the rules? "Just look at the price", one of the growers joked. But more seriously, in practice it is large rather than medium."
Large grower, no 'gluttons':
Before the VR glasses with 360 degree video, developed together with Recreate, could be put on, it was time for two more statement. One was about nutrients and irrigation, concluding that the Provine is not really a 'glutton' and that keeping to a low nitrogen schedule is recommended to keep the crop from becoming too vegetative.
Moreover, the plant must not grow too fast, which introduced the last point. Is the variety suited for lower, older greenhouses? [JH2] At De Bakker, 3m 30 is just enough, but 3m 50 wire height is ideal, a grower 'defended the Provine'. So greenhouse builders, pay attention: Provine requires a high greenhouse, because it is a grower, both in centimetres (on average 24 per week), as in hectares.
At least, that is the expectation of BASF Vegetable Seeds for next year. "On top of the current ten hectare in the Netherlands, they will be some addition, while also in France, Scandinavian, Australia, and New Zealand a lot of Provine is being grown", Jan told the audience before a relaxed talk about the presentation and their VR experiences, while enjoying a bit of the Big Green Egg and a beverage at host Tomatoworld.
As of week 1 2020, the 20h lighting test with Provine and Adorion at BASF Vegetable Seeds in 's-Gravensande can be viewed on appointment.
For more information:
BASF Vegetable Seeds
Or Contact your New Zealand Nunhems Seed Representitive: