Postharvest application of growth regulators on Dioscorea alata (L.) and Dioscorea rotundata (Poir.)

Yam is a tuber that sees high demand and consumption in Colombia, whose post-harvest quality losses during storage have been a challenge for farmers. At the Universidad de Cordoba-Colombia, Agronomy Engineering program, between March and August of 2019, a trial was established to estimate the effect of two growth regulators on the variables: tuber weight loss (TWL), tuber sprouting (TS), starch on a dry basis (SD), and reducing sugars (RS) during storage for 120 days, with evaluations every 30 days. A completely randomized design with a 4×2 factorial arrangement plus two additional treatments with three replications was used. Four concentrations of abscisic acid (ABA) were tested: 0, 10, 15, and 20 mg L-1 in the species D. alata and D. rotundata, plus paclobutrazol (PBZ): 15 mL kg-1, for a total of 10 treatments. Each experiment unit consisted of 12 tubers that were preserved in darkness at 23°C and 53% relative humidity on average. ABA and PBZ exerted effective control over the sprouting and weight loss of the tubers during the first 90 days of storage in both species, which averaged 24.4%, i.e. approximately 488 g, favoring high starch contents, and did not influence the reducing sugar content.

PEMBERIAN PUPUK KASCING DAN POC NASA PADA PERTUMBUHAN DAN PRODUKSI BAWANG MERAH (Allium ascalonicum L.)

ABSTRACT The purpose of this study was to determine the effect of applying vermicompost fertilizer and POC Nasa on the growth and production of shallots (Allium ascalonicum L.). This research has been carried out in the Experimental Garden of the Faculty of Agriculture, Riau Islamic University for 4 months, starting from July to October 2018. The design used in this study was a factorial Completely Randomized Design consisting of 2 factors. The first factor is vermicompost fertilizer (K) which consists of 4 levels namely 0, 200, 400, 600 g / plot and the second factor is POC Nasa (P) consisting of 4 levels namely 0, 2, 4, 6 cc / l water. The parameters observed in this study were plant height, harvest age, number of tubers per clump, wet tuber weight per sample, dry tuber weight per sample, tuber weight loss. The last observation data were statistically analyzed and continued with a BNJ follow-up test at the 5% level. The results showed that the application of vermicompost fertilizer and poc nasa interaction significantly affected the parameters of plant height, age of harvest, the number of tubers per clump, dry tuber weight per sample, shrinkage of tuber weight, and the application of vermicompost fertilizer and poc nasa interactively had no significant effect on wet tuber weight parameters per sample with the best treatment is a concentration of 600 g / plot (K3) and 6 cc / water (P3) is a dose of 44.80 grams/plot. Keywords: POC, Kascing, Shallot

PENGARUH KEPEKATAN NUTRISI DAN BERBAGAI MEDIA TANAM PADA PERTUMBUHAN SERTA PRODUKSI BAWANG MERAH (Allium ascalonicum L) DENGAN HIDROPONIK NFT

ABSTRACT The purpose of this study was to investigate the interaction of the application of AB Mix nutrition and growing media on the growth and production of Shallots (Allium ascalonicum L.) on NFT hydroponics. This study uses a ]Compound Plot Design in the form of a Completely Randomized Design consisting of the main plot, namely the nutrient concentration of AB Mix (N) and subplots of planting media (M). Nutrition AB Mix consists of 4 treatment levels, 600, 1200, 1800, 2400 ppm / l water and various planting media treatments consisting of 3 levels, namely husk, cocopeat, and sawdust charcoal media. Each experimental unit consisted of 4 plants and 2 plants used as samples. The parameters observed were as follows: plant height, harvest age, number of tubers, wet tuber weight, dry tuber weight, tuber weight per tuber, tuber weight loss. The observations of each treatment were statistically analyzed and continued with further tests of Honest Significant Difference at the 5% level. The interaction of the application of AB Mix nutrition and planting media had a real effect on all parameters, with the best AB Mix 1800 ppm and cocopeat growing media. The effect of AB Mix main plot has significantly affected all parameters observed with the best treatment of AB Mix 1800 ppm nutrition. The effect of subplot planting media significantly affected all parameters of observation with the best treatment of cocopeat growing media Keywords: AB Mix, Shallots, NFT hydroponics

Effect of gibberellic acid-3 and 6-benzylaminopurine on dormancy and sprouting of potato (Solanum tuberosum L.) tubers cv. Diacol Capiro

The duration of the dormancy period in tubers is a determining factor in the planning of potato planting and production. The effect of two plant growth regulators on the dormancy period and sprouting of cv. Diacol Capiro tubers was evaluated in this study. The experiment was carried out under storage conditions (15°C and 75% RH) using a completely randomized block design with 3×3×3 factorial arrangement. The factors were: gibberellic acid-3 (GA3) and 6-benzylaminopurine (6BAP) (0, 25, and 50 mg L-1) and the immersion time (iT) (10, 60, and 120 min). The application of GA3 and iT had an effect on dormancy breakage; the treatments with 25 mg L-1 GA3 and 60 min of immersion were enough to reduce dormancy by 18 d (35%) compared to untreated tubers. The factor GA3 increased tuber weight loss (10.2%), generated sprouts with higher weight (25.6-28.4%), higher length growth rate (42.3%), and lower dry matter content (21.8-28.4%), and it increased secondary sprouting (36.2-57.9%) in comparison with untreated tubers. This way, despite the treatments with 25 mg L-1 GA3 reduced the dormancy period, this dose generated sprouts more susceptible to mechanical damage. The treatments with 6BAP did not significantly affect the evaluated variables.

EFFECTS OF MEFLUIDIDE ON PERIDERM DEVELOPMENT AND STORAGE OF RUSSET BURBANK AND NORCHIP POTATOES

The effects of preharvest, foliar applications of mefluidide (N-(2,4-dimethyl-5-(((trifluoromethyl)sulfonyl)amino)phenyl)-acetamide) to potato (Solanum tuberosum L.) plants on subsequent periderm development and on storage quality of Russet Burbank and Norchip tubers were investigated. Mefluidide application caused adnormal periderm development in tubers of both cultivars and resulted in increased tuber weight loss during storage due to enhanced water loss rather than to elevated respiration. Treatment with mefluidide 5 wk before harvest resulted in greater tuber weight loss in storage than treatment 7 wk before harvest. After ca. 26 wk storage, sucrose content generally increased in tubers from treated Russet Burbank plants but not in corresponding Norchip tubers. Despite a perceived periderm enhancement, the abnormal periderm development which increased water loss in stored tubers would suggest that mefluidide has little potential as a preharvest treatment to reduce tuber damage and improve storage of Russet Burbank and Norchip potatoes.Key words: Potato, mefluidide, storage, Russet Burbank, Norchip, periderm