Effect of vermicompost and nitroxin on vegetative and reproductive characteristics of blackberry

Blackberry is a plant of the genus Rubus and family Rosaceae, which due to its nutritional properties has role in human health. One way to increase nutritional properties is to use bio-organic fertilizers such as vermicompost and nitroxin. These fertilizers not only reduce the negative effects of chemical fertilizers, but also improve the growth and reproductive characteristics of blackberries.

To investigate the effect of nitroxin and vermicompost on the vegetative and reproductive characteristics of blackberry, a factorial study was performed in a completely randomized design at 5 levels of vermicompost (0, 10, 20, 30 and 40) and two levels of inoculation and non-inoculation of nitroxin in pots in Noor city. For this experiment, culture media were prepared by mixing different levels of vermicompost with the base soil in the pot. Then, the rooted and uniform seedlings were prepared and selected for use in the experiment and the roots of the plants were placed in nitroxin solution (ratio of 1 to 10 with water) for 10 minutes and then planted in pots.

The results showed that the highest number of buds (42.5 per plant), the number of clusters (5.5 per plant), fruit weight (3.37 grams per plant) and the shortest ripening period were produced in 20% volume of vermicompost. The highest weight of drupelets (0.10 grams) was obtained in 30% volume of vermicompost. In addition, the largest flower diameter (3.77 cm) was seen in nitroxin treatment with 30% vermicompost by volume. The highest internode length (5.65 cm), branch length (2.55 m) produced in nitroxin treatment alone. The highest internode length (5.65 cm), branch length (2.55 m) produced in nitroxin treatment alone. The largest number of nodes (67 per plant) belonged to nitroxin in combination with 20% vermicompost by volume treatment and the largest vegetative branch diameter (2.8 cm) and leaf surface (25.83 cm2) was obtained in vermicompost treatments of 20% and 10% by volume, respectively. The use of vermicompost at the level of 20 to 30 percent by volume can show the greatest effect on fruiting branches, while nitroxin alone or in combination with vermicompost had a greater effect on vegetative branches. Vermicompost improves the growing medium conditions by stimulating beneficial soil microorganisms and the stable supply of mineral elements, especially nitrogen and phosphorus. The physical and chemical properties of humic acid in vermicompost increase plant nitrogen accumulation by increasing nutrient storage capacity and growth regulatory hormones, and plant growth factors such as height, number of nodes, internode distance and leaf area will increase with increasing nitrogen. However, increasing the level of vermicompost increases the concentration of soluble salt, toxicity due to increasing the concentration of heavy elements and the presence of toxic compounds in the plant, which leads to reduced growth and yield. Under these conditions, the use of nitroxin modulates or neutralizes the harmful effects of abiotic stresses. Bio fertilizers that contain growth-promoting bacteria, in addition to providing part of the nutrients and their balanced absorption, increase the nutritional value of the fruit by preventing the imbalance between the plant's internal components.

The use of vermicompost at the level of 20 to 30 percent by volume can show the effect on fruiting branches, while nitroxin alone and together with vermicompost has a greater effect on vegetative branches.