Nile tilapia (Oreochromis niloticus L.) fry growth and development effected from feeding with Enzimsporin supplement
The present research has shown the growth and development of Nile tilapia (Oreochromis niloticus L.) fry effected from feeding Enzimsporin probiotic supplement. During the observation period, the weight of tilapia fry population has increased from 119.5g to 619g in the control group, from 121g to 684g in the 1st experimental group 1 and from 119g to 790g in the 2nd experimental group. Thus, the average daily weight gain per fish is 0.44g, 0.51g and 0.6g, respectively in 22 days. During the observation period an increase in body weight of one fish averaged 3.29±1.63g in the control group, 3.75±1.32g in the 1st experimental group and 4.47±2.40g in 2nd experimental group. During the research period the fry in the 2nd experimental group has shown the highest increase in ichthyomass at the end of the experiment, 9.26g (p≤0.05), which is 2.8g (69.53%) more than in the control group. In the 1st experimental group, the increase is 3.23 g (p≤0.05), which has exceeded the indicators of the control group by 0.8 g (75.23%). The outline fish indicators correspond to the general statistical values of tilapia fry development in the given age period.
Nile tilapia (Oreochromis niloticus L.) fry growth and development effected from feeding with Enzimsporin supplement
The present research has shown the growth and development of Nile tilapia (Oreochromis niloticus L.) fry effected from feeding Enzimsporin probiotic supplement. During the observation period, the weight of tilapia fry population has increased from 119.5g to 619g in the control group, from 121g to 684g in the 1st experimental group 1 and from 119g to 790g in the 2nd experimental group. Thus, the average daily weight gain per fish is 0.44g, 0.51g and 0.6g, respectively in 22 days. During the observation period an increase in body weight of one fish averaged 3.29±1.63g in the control group, 3.75±1.32g in the 1st experimental group and 4.47±2.40g in 2nd experimental group. During the research period the fry in the 2nd experimental group has shown the highest increase in ichthyomass at the end of the experiment, 9.26g (p≤0.05), which is 2.8g (69.53%) more than in the control group. In the 1st experimental group, the increase is 3.23 g (p≤0.05), which has exceeded the indicators of the control group by 0.8 g (75.23%). The outline fish indicators correspond to the general statistical values of tilapia fry development in the given age period.
The yield of ‘Elizabeth’ potato variety depending on weather conditions and fertilizers
On soddy podzolic medium loamy soil of the Vologda region using
fertilizers in N20P20 dose while planting caused a reliable increase in potato yield of 5.4
t/hectare in comparison with control.The potato yield received when precisely calculated
doses of fertilizers were applied increased by 10.7-15.9 t/hectare (76-114%). Mineral
fertilizer system with the maximum dose of potash fertilizers and organic mineral system
differed insignificantly in their impact on the yield of tubers.Applying fertilizers both in
minimum and precisely calculated doses increased the productivity of by-products by
41-123% in comparison with control. Applying mineral doses of fertilizers reduced the
starch content in comparison with control by 0.1-0.2% in absolute value. Precisely
calculated systems of fertilizers increased the nitrates content in comparison with
applying fertilizers only while planting (N20P20) by 36-51%. The nitrates content in
potato tubers in applying precisely calculated systems of fertilizers was about 70-78% of
maximum allowable concentration. The yield of tubers and vegetable tops substantially
depended on weather and agrotechnical conditions, by 33 and 35% respectively, mostly
on fertilizers - by 60%.
The yield of ‘Elizabeth’ potato variety depending on weather conditions and fertilizers
On soddy podzolic medium loamy soil of the Vologda region using
fertilizers in N20P20 dose while planting caused a reliable increase in potato yield of 5.4
t/hectare in comparison with control.The potato yield received when precisely calculated
doses of fertilizers were applied increased by 10.7-15.9 t/hectare (76-114%). Mineral
fertilizer system with the maximum dose of potash fertilizers and organic mineral system
differed insignificantly in their impact on the yield of tubers.Applying fertilizers both in
minimum and precisely calculated doses increased the productivity of by-products by
41-123% in comparison with control. Applying mineral doses of fertilizers reduced the
starch content in comparison with control by 0.1-0.2% in absolute value. Precisely
calculated systems of fertilizers increased the nitrates content in comparison with
applying fertilizers only while planting (N20P20) by 36-51%. The nitrates content in
potato tubers in applying precisely calculated systems of fertilizers was about 70-78% of
maximum allowable concentration. The yield of tubers and vegetable tops substantially
depended on weather and agrotechnical conditions, by 33 and 35% respectively, mostly
on fertilizers - by 60%.
Productivity of winter rye grain, yield of nutritive elements by the culture when using fertilizers in the Vologda region
The calculated fertilizer systems have significantly increased the yield of the Volkhov winter rye in grain by 52-67% and in straw - by 50-59% on the soddy podzolic medium loamy soil of the Vologda region on average for three years of research. Applying fertilizers at the rate of 1cwt/ ha in physical weight when sowing during two years out of three ones has provided a significant increase in the yield of winter rye grain. When using the calculated doses of fertilizers, phosphorus and potassium yields by a unit of production has been slightly below the planned values. When using the calculated doses of fertilizers, nitrogen and potassium yields have increased by 5-6 kg (20-24%) and 3-7 kg (17-39%) compared to the control, respectively.
Productivity of winter rye grain, yield of nutritive elements by the culture when using fertilizers in the Vologda region
The calculated fertilizer systems have significantly increased the yield of the Volkhov winter rye in grain by 52-67% and in straw - by 50-59% on the soddy podzolic medium loamy soil of the Vologda region on average for three years of research. Applying fertilizers at the rate of 1cwt/ ha in physical weight when sowing during two years out of three ones has provided a significant increase in the yield of winter rye grain. When using the calculated doses of fertilizers, phosphorus and potassium yields by a unit of production has been slightly below the planned values. When using the calculated doses of fertilizers, nitrogen and potassium yields have increased by 5-6 kg (20-24%) and 3-7 kg (17-39%) compared to the control, respectively.
