No abstract

Expired seed has a very low vigour and viability which can inhibit the sprout growth due to difficulty in imbibition. Bean sprout extract contains more auxin, cytokinin and gibberellic acid that are important to increase growth potential of expired seed. Therefore, it is a must to pay attention to the concentration and soaking duration of bean sprout extract when soaking the seeds. The research was conducted in March to April 2020 at Sei Rengas I Subdistrict, Medan Kota, North Sumatera, using randomized complete block design with two treatment factors. The result showed that the concentration of bean sprout extract significantly affected the parameters of the membrane leakage rate which the best treatment is soaking in aquadest. The soaking duration significantly affected the parameters of the membrane leakage rate and growth speed which the best soaking duration is 12 hours. The interaction of two treatments significantly affected the parameters of the membrane leakage rate which the best combination is soaking in aquadest for 12 hours.

The field study was conducted to study the growth and yield of sweet corn with different fertilizer at the experimental farm of the Department ofAgrotechnology, Faculty of Agriculture, Universitas Sumatera Utara, Medan, Indonesia from May to August 2018. The experiment was laid out in a Randomized Complete Block Design (RCBD) with six treatments and three replication. Treatments include: 300 kg NPK/ha; 300 kg NPK/ha + 1.2 ton Rhizoculant/ha; 150 kg NPK/ha + 2.4 ton Rhizoculant/ha; 150 kg NPK/ha + 1.2 ton Rhizoculant/ha; 2.4 ton Rhizoculant/ha; and 1.2 ton Rhizoculant/ha. Results showed that fertilizer application had a significant effect on plant height, silking time, leaf area, and shoot-root ratio. The application of 300 kg NPK/ha + 1.2-ton Rhizoculant/ha produced higher values of growth and yield attributes rather than other treatments. The application of nutrients through Rhizoculant only was the lowest values of growth and yield attributes.

Analysis of the physiological characteristics of several sweet potato genotypes at various watering levels in rainfed paddy field indicated that the adaptability of sweet potato genotypes was resistant to drought stress. This research aims to determine the physiological character and yield quality of several sweet potato genotypes (Beta 1 Variety, Perbaungan Accession, and Cengkeh Turi Accession) at various levels of watering (P1 (1 month watering), P2 (2 months watering), and P3 (4 months watering)) in rainfed paddy fields. The research was carried out in the paddy field of Tandem Hilir I Village Deli Serdang and the analysis was carried out in the Tissue Culture Laboratory of the Faculty of Agriculture, the University of Sumatera Utara from March-July 2019. The results of this research indicated that some sweet potato genotypes had no significant effect on the physiological character but had a significant effect on fresh tuber grading. Cengkeh Turi accessions with orange colour tuber had the highest production in the A-class fresh tuber grading category while the Perbaungan accession with orange colour tuber had the lowest production in C-class fresh tuber grading. The watering levels treatment also did not have a significant effect on the physiological character and tuber yield quality.

Gamma ray irradiation is one of way to improve the plant genetic diversity. Seeds of Anjasmoro variety was treated with 100 Gy, 200 Gy and 300 Gy doses of Gamma-rays. The gene action for the agronomy characters in the mutated segregating generation was found out based on the frequency distribution of characters through measurement of skewness and kurtosis value. The frequency distribution for the agronomy characters viz., time of flowering, plant height, number of primary branches, seeds weight per plant and weight of 100 seeds were obtained. The skewness and kurtosis estimate were calculated to study the gene action. The number of primary branches recorded positive skewness value in all the three irradiated doses. The others characters have positive skewness value but different characters of each irradiated doses. This indicates the presence of complementary epistatic gene action for these traits and if selection will be made intensively in the segregating generations the gain will be faster of each characters in the three irradiated doses..