Dirk wk24 / 2011

The last few weeks good productions were obtained with fast maturing fruits combined with a relative high fruit weight. Due to this the plant load is over his top. We have to be alert that the crop stays generative enough, because of the high plant load last weeks, the top of the plants are somewhat thin

Working the crop

At some companies they already stopped taking out a leaf at the top at half of May.
Although this sometimes is necessary, for instance because of a high plant load combined with pepino. It is advised to start with this in time again. By experience of previous years we learned that most of the time Dirk has benefit by keep pruning a leaf constantly.

Also the policy concerning pruning the coming period is important at the moment. In general it is advised to keep pruning at 6 until the longest day. Then some trusses can be pruned at 5. From half of July pruning at 6 can be done again. In this way we aim for a maximum use of the strength of Dirk.

Temperatures

At powerful crops it is necessary to head for a generative plant. This can be achieved to set a pre-night during 3 to 4 hours, starting 1 hour after sunset at nice days. At balanced crops this is achieved at sunset. A well set average-24-hour-day-temperature for Dirk is 21 to 21.5 degrees at nice weather conditions and 19.5 degrees at dark weather conditions. All this is depending on the position of the crop; a powerful crop can handle a higher temperature with more difference between day and night temperature. At a powerful crop the temperature always must be 22 degrees ore more for a period during the afternoon.
Try to decrease the average-24-hour-day-temperature at hot summer days. This can be achieved to extend the pre-night. At a pre-night of 15 degrees at 2 a.m. at the latest the temperature is increased in 2 to 2.5 hours to the later part of the night with a temperature of 17.5 to 18 degrees.

Fertilizing/watering

Achieve a drain in time at the morning. After 3 times irrigation it is advised to create the drain, but not later than around 10.00 a.m. The quantity of irrigation after 14.30 p.m. is depending on the light intensity. At the last irrigation (approximately 20.00 p.m.) the drain is just a little. At sunny weather conditions the minimum quantity of water is 3.5 times the light intensity (J), at the top of the light intensity the quantity of water is 4 to 4.5 times the light intensity. Start dripping the EC with 3 to 3.2. At nice weather conditions also the EC can be reduced from to 2.8 to 2.9 during the afternoon.
Try to achieve that the PH at the slab and the drain water is lower than 6. This improves the picking up of Fe and Mn. Take care of sufficient Potassium (K) at the slab; this must be 6-7 millimol/l to maintain a good colouring of the fruits.