APPLICATION OF THE DRIP IRRIGATION SYSTEM FOR CULTIVATION OF POTATOES IN THE MOSCOW REGION

The article analyzes the indicators of the gross harvest of potatoes in the Moscow region in recent years. It has been proven that an increase in acreage does not always lead to an increase in gross harvest. It is equally important to provide comfortable conditions for the growth and development of plants. Precipitation in the Moscow region in the spring and summer period falls extremely unevenly: days with heavy rains forming a layer of precipitation of tens of millimeters alternate with non-precipitating days and weeks. The necessity of additional irrigation to create an optimal water – air balance for the development of plants is substantiated and the advantages of using drip irrigation for these purpose which allows the delivery of irrigation water directly to the root zone of the plant are estimated. It is recommended to combine operations on the formation of potato ridges with the laying of a drip tape since in the initial period of development the plant has enough moisture reserves of the mother tuber and additional watering is not required. The design of the drip tape stacker based on the Grimme GF-75/4 ridge former has been developed to increase the degree of mechanization when laying the drip tape. At a working speed of 3.2…5.5 km/h the productivity of the machine was 0.51…0.97 ha/h. In the course of further research the irrigation rate was calculated taking into account the elliptical shape of the humidification contour which made it possible to exclude excessive watering. After the installation of the drip irrigation system, irrigation was carried out at a constant rate when the moisture capacity reached 70% of the uultimate field moisture capacity with the adjustment of the time between irrigations. The use of the drip irrigation system made it possible to increase the yield of potatoes of the varieties Red Scarlett and Zhukovsky Early by 26.5% … 28%, respectively.

Perbanyakan Gembili (Dioscorea esculenta) dan Ubi Kelapa (Dioscorea alata) Menggunakan Bibit Set Mini

Ubi kelapa and Gembili are potential sources of fungsional food, because of their high nutrition content. But their production and utilization in Indonesia remains lack behind, due to their low economic value, requiring long cultivation period and high number of tuber-seeds. Experiment was conducted to identify an efficient seed propagation method using miniset cutting. The experiment was carried out at Cikeumeuh ExperimentalStation, Bogor from December 2011 to January 2013. Tuber-seeds of ubi kelapa was divided into miniset cutting of two, six and eight cuttings. For gembili, tubers were cut into two, three and four miniset cuttings. The whole tuber was served as control. Cutting were germinated in polybag, after 30 days the plants were transferred to the field. Each treatment was replicated six times, with one mother tuber as an experimental unit. Plant derived from tuber without cutting produced 463 grams of ubi kelapa seed, while tuber cut into 8 miniset cutting produced 2,986 grams, where the number of tuber seeds were 3 times more than that without cutting. Gembili cut into 4 miniset cutting produced 315 grams of tuber seed with the number of tuber seed 6 times more than that without cutting. Using the miniset cutting could speed up the rate of propagation of both gembili and ubi kelapa seeds.

INFLUENCE OF SITE OF PRODUCTION ON LEVELS OF TUBERIZING STIMULUS IN SEED POTATOES

Single nodal cuttings were used to study the degree of tuberizing stimulus found in Norland and Russet Burbank seed tubers produced at latitudes ranging from 40 to 52°N. Seed tubers were planted in the greenhouse under an inductive 8 h or a non-inductive 18 h photoperiod. Single leaf cuttings taken at several intervals after planting were grown under a 12 h photoperiod and the tuberization characteristics of the cuttings were rated 21 days later. Cuttings derived from seed grown at low latitudes produced more tubers under both photoperiods than cuttings from northern seed. The tuberizing stimulus increased with age of the cutting and/or association with the mother tuber. It appears that previously observed differences in yield potential of seed tubers from varying latitudes may be related to differences in an endogenous tuberizing stimulus derived from the mother tuber.

Phytotoxicity and Translocation of Glyphosate in the Potato (Solanum tuberosum) Prior to Tuber Initiation

Field and greenhouse experiments were conducted to observe and measure the phytotoxicity of glyphosate [N-(phosphonomethyl)glycine] to potatoes (Solanum tuberosumL. ‘Russet Burbank’) applied at different stages of growth and to determine if glyphosate was translocated into the original mother tuber (seed piece) prior to initiation of daughter tubers. Glyphosate injury symptoms appeared 1 day after treatment and at least 50% of the foliage was necrotic within 7 days. Significant decreases in plant height, shoot and root dry matter content, and daughter tuber production were recorded at the 0.28- and 0.56-kg/ha rates. Higher rates of 1.12 and 2.24 kg/ha did not give further significant reductions. Maximum levels of14C activity accumulated in all plant parts 4 days after application of the14C-glyphosate. The14C-glyphosate accumulated primarily in the apical meristem and roots. Extremely low levels of14C activity were detected in the mother tuber regardless of plant age when treated. Phytotoxic effects on the eyes of the mother tuber increased in severity with increasing rates of glyphosate as evidenced by abnormal sprouting.