News in our vegetable crops

DIn most areas, the surface is dry. We try to take this into account in the settings of the seed drills and the control of irrigation.

Mechanical and thermal weeding is easier to organize than last year. Let us keep in mind that the arrival of the next rain showers will inevitably bring new emergencies of weeds.

We must also monitor the crops planted. Several pests have been established or are about to be, while the excipients are not yet in the expansion phase.

aphids

Aphid colonies must be closely monitored, they are found on lettuce, parsley, carrot crops, among other things. We must work methodically to be able to estimate the population’s development. It is not enough to make a count of a hundred plants of our culture. These observations should be repeated at intervals of 5 or 7 days. It will then be possible to objectify the population’s development under pressure from aid workers in the process of settling. If the aphid population develops moderately upwards or stagnates, it will be better not to use insecticide for the next few days. The continuation of observations at the same pace will make it possible to revise its position if necessary.

The observation is made on a hundred leaves in an area of ​​the plot that will serve as a reference. Aphid colonies are never homogeneous. We can have a strong colony on a plant and its neighbors and an almost absence a few meters away.

In the event that we were to bring an insecticide, we would never reach the entire population present. From the few survivors, new colonies of aphids will very quickly develop again. On the other hand, those aids that are not yet well installed risk having to wait even longer. By leaving a strip untreated, we increase the chances of retaining a few aids in the hope that they will quickly recolonize the entire plot thanks to their mobility.

For aphids, it is not enough to count a hundred plants of our culture.  These observations should be repeated at intervals of 5 or 7 days.
For aphids, it is not enough to count a hundred plants of our culture. These observations should be repeated at intervals of 5 or 7 days.

Alliaceae leafminer

Feed bites were observed frequently in week 17 on chives and onions in the Leuze-en-Hainaut region. These observations draw our attention to the importance of monitoring our crops.

The losses caused by this leaf miner (Phytomyza gymnostoma) can be very significant for any cultivated Alliaceae. Spring attacks concern them all and especially onions and shallots.

Cover crops are an effective method, we had the opportunity to discuss it in the SB of 10 February 2022 and 12 August 2021. Cover should of course be placed before laying, at the latest within a few days after the emergence of feeding bites. These are easy to spot early in the day or in the evening. During the day, strong sunlight may require the use of a shade umbrella.

For bulbs, thermal weeding prevents newly hatched larvae from migrating to the bulb.

Several insecticides have been approved subject to the applicable specifications of the horticultural farm, the time before harvest and respect for buffer zones.

Networks are effective.  Be careful when storing between seasons to spread the cost over several years.
Networks are effective. Be careful when storing between seasons to spread the cost over several years.

larvae on cauliflower

The cauliflower plots under veil are at the beginning of the main formation. But the early weather conditions in April and those announced for the next few days may allow the arrival of butterflies, including diamond moths, gamma moths and even the pierids. Monitoring is necessary to identify possible spawning.

The gamma mill is often first seen on Asteraceae at the beginning of the season: lettuce and wild Asteraceae on the edge of plots.

Birds and small mammals

Several techniques can limit the damage. By alternating and combining them, we improve overall efficiency. Fences and nets against pigeons are expensive and quite effective. The use of scarecrows is conditional on requests for permission from the municipality to avoid hearing damage to residents. Wild animals are thirsty, they are looking for a little freshness, installing water troughs can be part of the solution.

Eating bites from the Alliaceae fly (Phytomyza gymnostoma) were observed frequently in week 17 on chives and onions in the Leuze-en-Hainaut region.
Eating bites from the Alliaceae fly (Phytomyza gymnostoma) were observed frequently in week 17 on chives and onions in the Leuze-en-Hainaut region.

Drought

As in 2018, 2019 and especially 2020 marks a period of water deficit crop management.

The special thing about this start of the season is that we started the year with ground structures that suffered hard last year. A well-loosened soil, however, allows deep root penetration after germination or planting.

Tillage is also a source of surface drying, therefore decompacts without spreading: decompacts and re-establishes the surface.

In our weed control we often have to obsolete seedbeds. The technique itself makes it possible to reduce the use of herbicides. But a false seedbed also means a loss of water during this operation. Between two evils it is necessary to take the least, an invasion of weeds is also accompanied by loss of water for the growth of these, the false seedbed remains an interesting technique.

The soil of the soil provides a very large water saving. The combination with the weed effect also allows for a significant reduction in the need for labor to weed. Mulching the crop with a non-thermal veil is an effective technique. The advantage is to limit the evaporation of water from the soil and the evaporation of the plants to limit the influence of the wind. But there is only a slight temperature rise, which is interesting from mid-spring.

Harvesting remains very useful in water management. By breaking the capillarity, aerating the soil and removing weeds, it is used whenever possible. Technological innovations open up hope thanks to automated piloting in both large and small horticultural areas. The interest is especially marked after a blow of the earth on the surface, as after a storm or too violent sprinkling.

Under our usual conditions, the period between sowing and germination or between planting and restoration needs watering. The contributions are small and frequent as long as the culture is not established and resumed.

When the water deficit is significant, as is the case over long periods, we also plan irrigation during crop growth. The contributions are made on the basis of a calculation that takes into account the nature of the soil and the needs of the crop. As a first approach, we keep inputs of 1 mm (ie 1 liter per m²) per. cm of soil to be irrigated for spraying. For drip irrigation, we multiply this number by 0.5 to 0.9 depending on whether the rows are separated or not.

It requires long experience to be able to do without accurate measurements to control its irrigation. Ideally, we measure the development of moisture in the soil using two tensiometers placed at different depths. The highest is placed so that the sensitive cartridge is 8-10 cm deep when mounting the culture. It will then be lowered 15 or 20 cm deep into the growth regime. The other is placed 15 to 20 cm lower.

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