Growing tomatoes on your site, you always want to get a high yield of high quality fruits. In practice, it does not always work out as we would like, especially for inexperienced gardeners. It seems that the care for all tomatoes is the same, but the plants behave differently. And having "tormented" one or two seasons, we complain that we did not guess right with the varieties again. Often the reason for failures is precisely the fact that all varieties and hybrids are "combed" in agricultural technology and forming one size fits all.
Any variety or hybrid initially has a tendency to one or another type of development, therefore, it is necessary to correct the development of plants in time, starting from the stage of growing seedlings. Tomatoes, according to the type of growth and development, can be divided into two groups - with a vegetative and generative type of development. This division is rather conditional than unambiguous, since the type of plant development can be controlled and, if necessary, shifted in one direction or another.
When growing several varieties and hybrids at the same time, it is necessary to find an "approach" to each individually. And maintain this "optimal balance" throughout the season. This is the only way to get high yields of good quality fruits and realize all the best that is inherent in a given variety or hybrid. This can be done in various ways, depending on the specific situation.
Tomatoes with overly vegetative development. In appearance, such a plant can be called "fattening". It has a powerful, thick stem with long, dark green leaves. The crown often has curled leaves that do not straighten with age. Such plants are ahead of others in growth. The stepsons are highly developed. The inflorescence is longer than usual, often ends with a leaf or shoot at the end, it may even be branched, with a large number of flowers. But on one inflorescence, 1-2 flowers bloom at the same time, the set fruits are slowly poured, they have an unequal size and there are many underdeveloped fruits, especially at the ends of the brushes. The flowers are light yellow in color, several brushes can bloom at the same time. The tissues of the stems are "not ripe", tender, and such plants are often affected by diseases and pests. The upper inflorescence is located far from the crown, more than 15 cm. The inflorescences depart from the shoot at an acute angle. In such plants, "all forces" are thrown into the development of roots and green mass, so the yield is extremely low.
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Tomatoes with overly generative development. Such plants, on the contrary, can be relatively tall, but with a compact leaf apparatus. In the future, with an increasing fruit load, the plant greatly slows down or stops vegetative development altogether. The leaves are short, dark green, the top of the plant is thin (thinner than 1 cm in indeterminate tomatoes), the raceme is simple, short, with several bright yellow flowers blooming at the same time. Fruits in a cluster are the same size and set well. The upper raceme is located almost at the very top of the plant, less than 15 cm from it. Inflorescences depart from the shoot not at an acute angle, strongly bent downward. The flowers in the inflorescence are smaller than usual, although the clusters continue to bloom and set fruit. One inflorescence blooms on the plant at the same time. The stepchildren are weak or stop developing altogether. In such plants, "all forces" are thrown into the development of fruits, but to the detriment of the development of the leaf apparatus and the root system, which will also affect the overall yield.
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Both of these extremes are a guarantee of a low yield, so one or another type of plant development should not be allowed to prevail. More precisely, it is important to be able to correctly correct agricultural techniques and promptly redirect the development of the plant in one direction or another.
Initially, it is important to take into account the characteristics of the variety or hybrid itself.Leading seed manufacturing companies always indicate on the packaging briefly the main characteristics or any individual characteristics of a given variety or hybrid. But this is only preliminary, the so-called "starting" information.
In practice, it is necessary to take into account the peculiarities of a particular area, with its weather conditions. And this is not easy, because every year the weather is not the same and the same variety (hybrid) can behave differently. For example, in cool, rainy summers, determinate tomatoes can behave like semi-determinate ones.
In summer cottages, greenhouses, as a rule, are not heated and are not equipped with additional equipment that would allow maintaining optimal conditions for plants. Therefore, in order not to be left without a crop, it is advisable to grow several varieties and hybrids with different characteristics at the same time. For an early harvest, varieties (hybrids) are important that can set fruit well in unstable May weather. In the midst of the summer season, varieties (hybrids) that tolerate heat well will help out.
At the beginning of the growing season (seedling stage), it is important to get the plants by the time of planting in a permanent place with a well-developed leaf apparatus and root system.
For low country greenhouses, with a ridge height of 2.0-2.5 m, it is better for lovers of tall tomatoes to select varieties (hybrids) with shortened internodes and form them into two stems. When the plants reach the trellis wire, there will be an average of 3 brushes on each shoot. Additional shoots should be released during the seedling period under the first brush.
As a rule, tall, large-fruited tomatoes are prone to the manifestation of a vegetative type of growth. It is advisable to plant seedlings of varieties (hybrids) with a vegetative type of growth in a greenhouse with the first and second brushes already blooming. Otherwise, it will be very difficult to exclude fattening of plants.
It is advisable to carry out all agrotechnical measures to regulate the development of plants in one direction or another only when the plants receive a balanced mineral nutrition. It is also worth monitoring the load of plants with fruits and adjusting it in time, relying on the existing weather conditions and the characteristics of the variety or hybrid itself. Limit nitrogen to the moment of fruit formation on the first cluster, especially in varieties (hybrids) with a vegetative type of development. Further, throughout the growing season, apply a sufficient amount of phosphorus-potassium fertilizers. During the period of flowering and fruit setting, the tomato experiences an increased need for phosphorus fertilizers, and during the growth of fruits - for nitrogen and potassium fertilizers.
A week before planting in the ground, it is better to stop feeding the seedlings. After planting in the greenhouse, the first feeding should be carried out in 12-14 days. With an excessively vegetative type of development, you can give foliar top dressing on the leaf with an extract from superphosphate and root top dressing with phosphorus-potassium fertilizers. With an overly generative type of development, it is good to give 1-2 top dressing with a solution of fermented weeds without adding phosphorus-potassium fertilizers. In the case when the plants are loaded with fruits and the weather is cool, this can aggravate the situation, since it will delay the ripening of the fruits.
How to initiate the development of tomatoes towards vegetative or generative types of development
There is a whole set of agrotechnical techniques that allows you to shift the development of plants in one direction or another, depending on the situations that arise. This helps maintain optimal plant development throughout the growing period, as well as high yields and good quality fruit.
Unlike industrial greenhouses, where a certain variety (hybrid) is grown in each section, amateur vegetable growers simultaneously grow several varieties (hybrids), and often several crops in one greenhouse. Therefore, I conditionally divided agricultural techniques into two groups.The first group includes techniques, the use of which has a direct effect on all plants in the greenhouse. The second group includes techniques, the use of which on selected plants does not have a direct effect on the rest of the plants in the greenhouse.
Regulation of the type of development when growing in a greenhouse of one variety (hybrid) or several with the same agricultural technique and behavior
a) Using the air temperature
The slow rise in temperature after sunrise stimulates vegetative development. Therefore, it is very important in warm sunny weather to open the transoms as early as possible in order to smooth out the sharp rise in temperature in the greenhouse as much as possible.
When the weather is cool at night, closing the transoms early will retain the heat accumulated during the day, allowing a smooth transition to night temperatures and supporting vegetative development.
A sharp drop in temperature in the evening leads to increased fruit growth due to the outflow of nutrients from cold leaves into warm fruits. It is advisable to use this technique on tomatoes before the fourth cluster blooms, so that there is no further fruit overload. Since in some hybrids not only the mass of fruits increases, but their ripening period is also delayed.
The optimum night temperature for fruit pouring is + 15- + 16 ° C. Temperature + 17 + 18 ° C stimulates the ripening of fruits on plants.
The crop on the plant will begin to ripen when a certain amount of average daily air temperatures for a given variety (hybrid) is reached during the period from the moment the ovaries form until the fruits are fully formed on the first cluster.
b) Using air humidity
The less moisture the plants evaporate, the better the shoots and leaves grow. But here it must be remembered that low humidity less than 65%, as well as high, negatively affects the quality of pollination of flowers. Humidity above 80% is dangerous for the development of fungal diseases.
c) By changing the concentration of carbon dioxide in the air
Increase CO concentration2 in the air of the greenhouse, it is possible by placing containers with fermenting manure or weeds there. This promotes better fruit setting, an increase in their number in the inflorescences. The average weight of fruits also increases and, accordingly, the fruit load on plants. Increase in CO concentration2 initiates the processes of generative development.
d) By whitening the roof
In hot months, to avoid overheating, you can whitewash the greenhouse roof or pull on protective screens. However, this will result in reduced light and can affect yields and enhance vegetative growth of the plants.
Regulation of the type of development when growing in one greenhouse different crops or several varieties (hybrids) of tomatoes with different agricultural techniques and behavior
a) Using the number of leaves on plants
Removing leaves on plants stimulates the processes of generative development. But here you need to know when to stop and not remove the leaves without great need. If possible, you should not delete the whole sheet, it is enough to delete only a part. For example, when planting tomato seedlings with drooping foliage, the lower leaves that lie on the ground can be pruned with pruning shears to the required amount. This will create less stress on the plant than removing multiple leaves at once.
With the beginning of flowering of the fifth cluster in tall tomatoes, you can begin to remove the lower leaves 1-2 per week. But not above the level of the fruiting lower brush.
With strong vegetative growth, you can remove several lower leaves, 3-5 pieces at once, but these are extreme measures. First of all, it is necessary to remove poorly lit castings that face the inside of the bush or aisle. You can also remove a small leaf from the top of the plant.
In greenhouses with a trellis height of 2.0-2.5 m in hot months on tall tomato plants (when formed in one shoot), the number of leaves should be at least 24-26 pieces.In low greenhouses, after limiting the growth of shoots, indeterminate tomatoes (when formed in 2 stems) should have at least 12-14 leaves on each shoot during fruiting.
In varieties (hybrids) with a generative type of development in the hot months, especially in dry weather, it is not advisable to remove the leaves. On the contrary, it is possible to increase the number of leaves on the plant by leaving an additional shoot (without an inflorescence) with a pinch of 1-2 leaves.
To stimulate the generative type of development in tall tomatoes, you can release an additional shoot (stepson) between 3 and 5 brushes in mid-June, leaving one inflorescence on it and 2-3 leaves after it.
b) By standardizing the number of ovaries on plants
With the generative type of development, it is better to normalize the amount of ovary in the brushes before the flowers bloom, which should be removed. If the plant has weak growth and the inflorescences are also weak, then the weak inflorescence can be removed without waiting for the flowers to bloom. This will improve the growth of leaves and root system and shoots, as well as contribute to the development of stronger inflorescences in the future.
Until the first fruits ripen, the plant experiences a constant increase in load. The beginning of flowering on the shoot of the seventh cluster should coincide with the beginning of fruit ripening.
In general, a tomato plant with medium-weight fruits should contain approximately 28-30 fruits at the same time. Therefore, if ripening is delayed, then it is better to remove several large fruits for ripening and thereby unload the plant.
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With the vegetative type of development, rationing of fruits in the brush is best carried out after the opening of the flowers (or even the formation of small ovaries up to 1 cm in size), intended for removal. To increase the fruit load, you can leave more fruit on the brushes.
c) With the help of a garter of plants and support of pouring brushes
When tying plants and twisting the tops of tomatoes in the greenhouse, it is advisable to wrap the twine around the plant, and not vice versa. During the next turn, the twine should always pass over the next hand, and not under it. A full twine twine should fall at 1.5-2.0 internodes, not more often. You can attach the plants to the twine with special clips. The constant twisting of the tops around the twine in generative tomatoes causes an even greater shift in this direction of development.
In varieties (hybrids) prone to wrinkling the brushes, it is necessary to use brush holders or tie the brushes with twine. In this case, it is impossible to press the brushes to the stem, but to maintain their natural angle of deviation from the stem for growth and development. In brushes with a broken axis, the intake of substances is disturbed, the fruits are worse poured or stop growing altogether.
d) By changing soil moisture
A decrease in the level of moisture in the soil inhibits vegetative development and initiates the growth of the root system. Such an event is best done by experienced vegetable growers. There is a risk that drying will worsen fruit set, since the critical humidity limits are very close. Drying the soil by 8-10% stimulates generative development, and by 15% it already leads to a moisture deficit.
Frequent watering in small doses, on the contrary, allows you to maintain a more stable soil moisture, which stimulates the growth of shoots.
