The seed productivity of the tomato variety lehin depending on the sowing scheme and fertilization in the Southern Ukrainian Steppe

Abstract

Topicality. Recently, after a reorganization of many agricultural enterprises vegeculture changed the extensive type of production to the intensive one.  The basis of the intensive production are high-yielding cultivars and hybrids of domestic and foreign breeding, various ways of irrigation, especially drip irrigation of crops, special plants nutrition, and, of course, reliable crops protection against insects, diseases and weeds.

Tomato is one of the most popular vegetable crops, which occupies almost the one-third of gross vegetable yields. Because of nutritive value, high yielding capacity, taste, and universal use tomato is spread in all regions and is cultivated as the field and greenhouse crop.

The most efficient way of intensification of agricultural production is cultivar and seed. Perennial researches show that raise of yields up to 20-30% could be achieved only at the expense of cultivar. This is the fastest lever of influence on the production sustainability and increase of crops yields.

Materials and methods used in the research work. Investigations were carried out on the experimental field of the Laboratory of Vegeculture of the Institute of Irrigated Agriculture NAAS in 2016-2018. We were guided by the common methodological recommendations in carrying out field trials and concomitant researches. The humus content in the arable layer is 2.14%, total Nitrogen content – 2.24%, mobile Phosphorus and exchangeable Potassium – 62 and 323 mg/kg of the absolutely dry soil, respectively. The least field water-holding capacity of the 1 m soil layer is 21.3%, wilting point – 9.5% from the dry soil mass, the bulk density of the soil is 1.41 t/m³. рН of the water extract is 7.2. Groundwater lays at the depth of 18-20 m and does not effect on the water and air regime of the zone of active water exchange. Cultivation technology in the trials was common for the irrigated conditions of the South of Ukraine, excluding the studied elements with accordance to the design of the trials: factor А – scheme of sowing – 50+100 cm, 150 cm; factor В – fertilization – 1) no fertilizers; 2) calculated on the planned yield mineral fertilizers dose (further ‑ mineral fertilizers), 3) mineral fertilizers and foliar fertilization with Plantafol; 4) mineral fertilizers and organic fertilizer Bioproferm; 5) mineral fertilizers, organic fertilizer Bioproferm and Plantafol.

Cultivar Lehin is a middle-early one with a vegetation period from the mass sprouting until the beginning of ripeness is 110 days. The cultivar is included in the State Register of Plants Varieties of Ukraine in 2013. The cultivar of an intensive type, sensitive to the high level of agrotechnology, irrigation. The cultivar is suitable for combined harvesting.

The trials were laid out by using the randomized split-plot design method in four replications with accordance to the methodology of field experiments on the improvement of agrotechnological methods of crops cultivation. We used common scientific (analysis, synthesis, observation, comparison, measurement), special (field, laboratory), mathematical and statistical, calculation and comparison methods.

The results of the investigations determined that tomato yields in 2016 averaged to 30.24-98.09 t/ha, in 2017 – 26.62‑87.43 t/ha, in 2018‑ 41.69‑109.17 t/ha, and in 2016-2018– 32.85‑98.23 t/ha.

The highest yields of tomato fruit were obtained in 2018 and averaged to 42.17‑109.17 t/ha under the scheme of sowing 50+100 cm. In average for three years the indexes of fruit yields under the scheme of sowing 50+100 cm were 77.45 t/ha, and under the scheme of sowing 150 cm they were 4.81 t/ha or 6.2% less.

The highest indexes of fruit and seed yields of tomato were obtained under the complex application of mineral and organic fertilizers Bioproferm accompanied by the foliar fertilization with Plantafol. Fruit yields under the scheme of sowing 50+100 cm averaged to 98.23 t/ha that is by 65.2% more than on the control variant with scheme of sowing of 150 cm – 92.76 t/ha, and 65.6%, respectively. In average for the period of 2016-2018 tomato seed yields on this variant were 159.30 kg/ha.

The seeds obtained in the variants in 2018 had such qualitative indexes:  1000 seeds weight – 2.85‑3.35 g, germination energy – 83‑87%, laboratory germination rate ‑ 97‑99%.

In average for the period of study 1000 seeds weight values were within 3.01‑3.4 g. The germination energy under the sheme of sowing 50+100 cm was 0.6% higher, and aboratory germination rate was 0.8% higher than under the scheme of sowing of 150 cm.

Conclusions and recommendations. The yielding indexes of fruit and seeds of tomato cultivar Lehin depend on the studied factors: scheme of sowing and fertilization. The maximum fruit and seed yield were obtained on the variant with the complex application of mineral fertilizers with organic fertilizer Bioproferm and foliar fertilization with Plantafol and averaged to 95.5 t/ha and 159.3 kg/ha, respectively. On average for three years the highest productivity indexes were obtained under the scheme of sowing 50+100 cm – 74.45 t/ha (fruit) and 144.3 kg/ha (seeds). There was established no significant effect of the studied factors on the qualitative indexes of the tomato seeds.

Key words: tomato, productivity, seeds, fertilizers, sowing scheme, seed quality