Less Hand Work In Growing Vegetable Crops

Press, Volume CIX, Issue 32233, 27 February 1970, Page 8

Less Hand Work In Growing Vegetable Crops

The horticulture department at Lincoln College is looking at the growing of tomatoes like a farm crop with all operations being done mechanically. At a field day on the vegetable research area at the college last week, Mr R. A. Crowder, lecturer in vegetable production, said that by planting tomatoes close together uniform ripening of the fruit was induced even in a variety that was not bred for this purpose. This was a result of competition. Where plants of a variety such as Fireball were grown close together and they only produced two fruit trusses these ripened at the same stage, lending themselves to mechanical harvesting. Mr Crowder said that last year sowings had been made from only a few thousand plants to the acre up to 70,000. and the higher density plantings had been so superior that this season they had started at 70,000 to the acre and gone up to about 170,000, but it looked as though they had gone over the limit on this occasion and that about 70,000 plants to the acre was about j the optimum. A variety called Mecham- i cal Harvesting bred by the j University of California for this purpose had the char-1 acteristics of producing all ! its fruit at the same time i and did not have the pro- ' blems that were associated a with Fireball, which had de- | veloped blossom end rot — I this seemed to be associated | with the demands on nu- • trient supplies when plants i were grown so closely to- | gether. This problem looked ; to be associated with lime j and potash. Accordingly ; the next step was to look at fertiliser and moisture needs ' under such a situation. , When it matured Fireball 1 had also suffered from sun '

scald of the fruit, but Mechanical Harvesting stood up to the hot sunny weather very well and had a much better type of fruit. However, if there was heavy rain at the ripening stage it might tend to split A disease problem might be associated with high density plantings and in their experiments they had sprayed twice with metasystox and once with thiram to keep insects off the plants when they emerged. Mr Crowder said that they had just started a trial this season comparing di-rectly-sown asparagus with transplanted asparagus. The aim was to show that where asparagus was direct-drilled at a high density it would produce a much higher yield at an earlier stage. It had been suggested that quality would not be so good and there would be diseases under this system. It would be five or six years before they would know the answer but in the United States they were in their seventh

year of direct-drilled asparagus without any harmful consequences. With onions they were also looking at high-density sowing and had found that where the seed was-pelleted they achieved much more precise sowing with the precision drill. Where, for instance, onions were required to all be of 2jin diameter for an overseas order, it, would be possible to obtain the size required by controlling the spacing. Carrots could also be grown precisely. It was possible to control the plant population to produce a produce of the required size and quality. One of the big problems with wider spacings was weed control and with a double row coulter on the drill it was possible to get two rows close together with room to expand out and yet still with room to get a steerage hoe in. It was also possible to sow three rows per coulter but this would possibly be more useful with carrots than onions.