Sowing date of spinach hybrids

Размещено на http://www.allbest.ru/

Uman National University of Horticulture

SOWING DATE OF SPINACH HYBRIDS

Shevchuk K. - Doctoral student at the

Department of Vegetable Growing

Annotation

The study was conducted in 2019-2021, in the conditions of the Southern Steppe of Ukraine. The results on the influence of sowing date on the plans productivity of spinach are presented. For our research were used field, statistical, calculation-analytical and laboratory methods. Hybrides Boa F1 and Odysseus F1 were studied. We studied the behavior of plants after six sowing dates. The conveyor growing of spinach should ensure an uninterrupted supply of fresh green products during the spring-summer-autumn period. First sowing was conducted at first decade of April. Second sowing was conducted at third decade of April. Four next sowing were done at second decade of May, at second decade of June, and first decade of August and the last one at third decade of August. Control variant was Boa F1 hybrid after sowing date at first decade of April. We found that plants of both spinach hybrids had a larger more leaves and leaf surface during the early sowing dates. At the phase of beginning of rosette growth it was 114.2-127.7 cm²/plant. At the same time plants which were sown in August had a smaller more leaves and leaf surface - 86.0-106.2 cm²/plant. The highest yield of marketable green mass was obtained for sowing in the III decade of April and the II decade of May depending on the hybrid. So, the Boa F1 hybrid provided 22.9-23.0 t/ha, and the Odysseus F1 hybrid provided 23.3-23.9 t/ha. Such yield was higher than the control variant by 3.2-4.2 t/ha. It was found that there is a strong positive correlation between plant weight and the number of leaves (r = 0.98), the yield of spinach and the plant weight (r = 0.91). Such practice of conveyer sowing of spinach can be recommended to farmers and private farms who grow vegetables for to extend the terms of receipt offresh greens from early spring to autumn from - the third decade of April to the end of September, and in some years even until mid-October.

Key words: spinach, hybrid, sowing date, growth, leaves number, leaves surface, yield.

Анотація

Шевчук K.M. Строки сівби гібридів шпинату

Дослідження проводили у 2019-2021 рр. в умовах Південного Степу України. Наведено результати щодо впливу строків сівби на планову продуктивність шпинату. Для дослідження були використані польові, статистичні, розрахунково-аналітичні та лабораторні методи. Досліджено строк сівби гібридів Боа F1 та Одіссей F1. Вивчали поведінку рослин після сівби у шість строків. Конвеєрне вирощування шпинату городнього має забезпечувати безперебійне постачання свіжої зелені упродовж весняно-літньо-осіннього періоду. Перший посів проводили в першій декаді квітня. Другий посів проводили в третій декаді квітня. Чотири наступні посіви проводили у другій декаді травня, у другій декаді червня та першій декаді серпня і останній у третій декаді серпня. Контрольним варіантом був гібрид Боа F1 за строком сівби 1 декада квітня. Встановлено, що рослини обох гібридів шпинату мали більшу кількість листків і листкову поверхню за ранніх строків сівби. У фазі початку росту розетки листкова поверхня становила 114,2-127,7 см2/рослину. Водночас рослини, які висівали в серпні, мали меншу кількість листків і площу листкової поверхні - 86,0-106,2 см2/рослину. Найбільший урожай товарної зеленої маси отримано за сівби в ІІІ декаді квітня та у ІІ декаді травня залежно від гібриду. Так, гібрид Боа F1 забезпечив 22,9-23,0 т/га, а гібрид Одіссей F1 - 23,3-23,9 т/га. Така врожайність була вищою за контрольний варіант на 3,2-4,2 т/га. Встановлено, що існує сильний позитивний кореляційний зв'язок між масою рослини та кількістю листків (r = 0,98), урожайністю шпинату та масою рослини (r = 0,91). Таку практику сівби шпинату городнього за різних строків можна рекомендувати фермерам та особистим селянським господарствам, які вирощують овочі, щоб продовжити терміни отримання свіжої зелені від ранньої весни до осені - з третьої декади квітня до кінця вересня, а в окремі роки навіть до середини жовтня.

Ключові слова: шпинат, гібрид, строк сівби, ріст, кількість листків, поверхня листків, урожайність.

Formulation of the problem

Most green plants that are used fresh have a fairly short shelf life. If the optimal conditions of transportation, storage, and sale of the green mass of such plants are observed, the storage period is 5-20 days. Therefore, only conveyor belt cultivation of garden spinach makes it possible to provide the consumer with fresh green vegetable products for a long period of time. Thus, in Ukraine, only 4% of the annual amount of vegetables is produced in March-April, 10% in May-June, 58% in July-September, 25% in October-November, and about 3% in December-February.

Due to the fact that the conveyor cultivation of garden spinach is closely related to the biology of the plant and climatic conditions, it is possible to provide the consumer with a sufficient amount of fresh green products for a long period.

The analysis of literary sources does not shed light on the solution to the issue of conveyor belt cultivation of garden spinach. Taking into account the above, in our research it was planned to study the morphobiological features of the plant, soil and climatic conditions, in order to develop a scheme for conveyor cultivation of the green mass of garden spinach for the uninterrupted supply of green products to processing points and the population from April to September.

Analysis of recent research and publications

Numerous studies have established that the sowing date effects on the stability, overall survival, water consumption and productivity of plants. It is known that from early to late sowing the accumulation of dry matters consistently decreases. The intensity of the processes of plant and stem death during the spring-summer vegetation period decreases. At the optimal sowing date plants are programmed for high yield, but their productivity decreases both at early and at late sowing date. In the first case, the plant forms a larger vegetative mass and, because of overgrowth, intensively uses reserve substances and becomes less resistant to adverse conditions. In addition, the plant of the early sowing is more damaged by pests, diseases, and is often weedier. Because weeds, by their biological characteristics, are more competitive with plants, they outgrow and shade them, take more nutrients and moisture. All this leads to slowdown in the growth of cultivated plants, thinning of crops and a decrease in yield [1, с. 112-116; 2, с. 39-44; 7, с. 320].

Plants of the late sowing grow and develop more slowly, do not have time to form a full-fledged rosette and sufficient above-ground mass and secondary root system [3, с. 147-151; 8, с. 981-990].

The study of the dependence of the sowing date on soil fertility showed that it is necessary to sow earlier on poor soils, and later on fertile ones, so that the plants do not overgrow. The optimal sowing date on fertilized fields is shifted 10-15 days later, compared to sowing on a less fertilized field [4, с. 225-227; 9, с. 42-43].

The sowing date varies depending on the biological characteristics of the variety, and for classic varieties, the interval of the optimal sowing period is longer. The calendar dates for sowing are 6-12 days later, compared to previously grown varieties, which is due to the biological features of the modern variety. And this is a shortened epicotyl, faster passage of the interphase period, more intense formation of plastic substances and formation of above-ground mass [5, с. 109-113; 10, с. 619-627].

The results of observations of the growth and development of plants in the autumn period showed that the degree of plant development, especially the accumulation of dry matter, is not directly related to the level of adaptive characteristics. They are formed higher during optimal and late sowing [6, с. 10-13; 12, с. 118-124; 13, с. 388-393].

Plants of different ages do not equally consume water from the soil. Crops of early sowing, as they are more physiologically old, use less water than plants of optimal and late sowing [7, с. 321-323; 14, с. 118].

For vegetables, in particular of spinach, the sowing date is important, because the optimal sowing date will help to increase the yield due to the full growth and development of the plant. Therefore, in order to obtain a high yield of green mass several times during the growing season in the Southern Steppe of Ukraine, research was conducted to study the effectiveness of the sowing date for growing spinach.

sowing spinach soil garden

Setting objectives

The purpose of the work is to determine the influence of the sowing period on the yield and quality of garden spinach grown in the conditions of the Southern Steppe of Ukraine. Research on determining the optimal sowing date in the conditions of the Southern Steppe of Ukraine was conducted in 2019-2021 under conditions of drip irrigation. It was determined the influence of the sowing date on the growth, development and yield of the green mass of spinach. The hybrids Boa F1 and Odysseus F1 were used in accordance with methodology of Bondarenko & Yakovenko (2001) [11, С. 119-133].

The control was sown in I decade of April. In order to create a conveyor for the constant supply of fresh product during the spring-summer-autumn period were studied next sowing dates: I and III decades of April, II decade of May, II decade of June, I and III decades of August.

Presentation of the main research material. The sowing of the spinach at different dates shows a positive effect on the results of farming and allowed to obtain reliable data on the plasticity of the crop in terms of growing conditions. The assessment of the influence of the date of the seeds sowing on the growth and development of the spinach under the conditions of growing in open field was conducted based on the fixation of the duration of the phenological phases of plant growth, their development and other indicators. The analysis of the data obtained as a result of research on the growth of the spinach plants and their development in the Southern Steppe of Ukraine showed that the duration of the periods from the germination to the onset of the main phenological phases was the shortest for sowing seeds in the I and II decades of August, regardless of the studied hybrid. The mass germination appeared on the 8th day in the control variety and on the 7th day in the hybrid Odysseus F1 due to sowing seeds in the I decade of April. The mass germination of both researched varieties was noted for 6 days due to sowing seeds in the III decade of April and II decade of May as well as in the hybrid Odysseus F1 due to sowing in the II decade of June. During the August sowing dates, mass germination was recorded at 5th day, regardless of the studied hybrid, which can be associated with the influence of high environmental temperatures.

The phase of the appearance of the first true leaf in spinach was recorded after 10-17 days, depending on the variant of the experiment, and it was noted after 12-17 days for the hybrid Boa F1, and 10-15 days for the hybrid Odysseus F1.

The plants reached the technical phase of maturity on the 40th day after the appearance of germination in both studied hybrids due to sowing seeds in the III decade of April and on the 41^st day due to sowing seeds in the II decade of May. The summer sowing date showed that the onset of the technical maturity phase did not depend on the hybrids and occurred on the 37th and 38 th day.

The study of the effect of the hybrid and date of sowing seeds on the duration of the growth phases proves that for all sowing dates the advantage is observed in plants of the hybrid Odysseus F1 the phase of technical maturity came 1-4 days earlier than in the hybrids Boa F1. In its turn, studies have shown that the difference in the speed of passage of phenological phases by spinach plants is more pronounced depending on the date of sowing than on the hybrids.

The influence of the sowing date of spinach and the hybrids is characterized by differences in biometric indicators. The evaluation of the plants of the hybrids Boa F1 and Odysseus F1 in the phase of the beginning of rosette growth shows that plants had height of 6.3-7.3 cm due to the sowing in the III decade of April and in the II decade of May and were taller compared to the plants of later sowing. This fact can be explained by the fact that at lower temperatures the growing season is longer.

An exception to this pattern can be considered the sowing period in the I decades of April, when at the beginning of the growing season, low temperatures, on the contrary, slowed down the growth and development of spinach plants.

It was noted that the height of spinach plants depended to a considerable extent on the sowing date and not on the hybrid. On average, over the years of research, the height of city spinach plants in the phase of green technical maturity, was 24.8-28.2 cm, depending on the hybrid due to sowing in the I decade of April. The research indexes differed and in the hybrid Boa F1 they increased to 26.6-28.9 cm, while in the hybrid Odysseus F1, on the contrary, they decreased to 25.7-26.5 cm due to the sowing of spinach in the III decade of April and in the II decade of May. The indexes of both studied hybrids exceeded the control by 1.8-4.1 cm and 0.9-1.7 cm, respectively.

It has been established that in spinach the number of leaves per plant determines the potential value of the yield, therefore, in the conducted observations, we attached great importance to this index.

In the phase of the beginning of plant rosette growth the number of leaves was, depending on the investigated hybrid, from 5.0 to 6.0 pcs/plant. Observations of 2019-2021 showed us that early sowing dates, especially the III decade of April, the II decade of May and the II decade of June, were more conducive for the hybrid Boa F1, as one plant formed a larger number of leaves from 5.7 to 6.0 pcs/plant. At the time when a significantly lower number of leaves from 5.0 to 5.2 pcs/plant was observed due to late sowing and sowing in the I decade of April. In its turn, in the hybrid Odysseus F1, the number of leaves varied slightly regardless of different sowing dates and ranged from 5.0 to 5.4 leaves per plant.

It was noted that the studied hybrids had different numbers of leaves at the phase of the beginning of the rosette growth. High variability of the index was noted in the Boa F1 hybrid with the highest index due to the sowing in the II decade of May.

During the studies of the influence of the hybrids and sowing date on the number of leaves and their growth throughout the growing season, it should be noted that at the harvesting date the number of leaves increased by 2.5-3.5 times, from 5.0-6.0 to 14-21 pcs/plant.

One of the important indexes of spinach plant growth, which determines their value as a green plant, is the leaf surface and the total leaves surface. The determination of these indexes depending on the date of sowing was conducted at the beginning of the rosette growth and in the phase of technical maturity of the greenery before the bolting (Table 1).

It was established that plants of the Boa F1 hybrid had a larger leaf surface due to sowing in the I decade of April - 22.0 cm²/plant. The smallest leaf surface in the hybrid Boa F1 was found due to sowing seeds in the I decade of August - 17.1 cm²/plant. At the same time, in the hybrid Odysseus F1, the smallest leaf surface was observed due to sowing in the last term - 18.5 cm²/plant, and the largest due to the III decade of April - 23.6 cm²/plant.

The study of the influence of sowing dates on the leaf surface index proves that it is larger at the beginning of growth due to sowing in the III decade of April and the II decade of May, regardless of the hybrid.

Table 1

The spinach leaf surface in different mode of growth and development depending on the hybrid and sowing date, cm²/plant