Postharvest decay of potato tubers in moist chamber and in two types of soil.
Lozoya-Saldana, H. and Hernandez-Vilchis, A.
Revista Mexicana de Fitopatologia. Volume 19, Number 2, 2001. Pages 140-146.
2001
บทคัดย่อ
Washed and unwashed, as well as Phytophthora infestans inoculated uninoculated potato tubers from eleven recently harvested genotypes were incubated in: (a) the dark, at 100% RH in plastic bags (moist chambers), (b) in naturally infested soil, or (c) in a sterile soil mix. The temperature regime was 4 to 27 deg C day/night 24 h cycle. After four weeks in the plastic bags, tubers from foliage-resistant cultivars Nortena, Michoacan and Montsama exhibited more than 30% decay, while those from Alpha, Atlantic (both foliage-susceptible), Torridon, and clone 53-87 (foliage-resistant) were affected by less than 10%. Inoculated, unwashed potatoes exhibited least decay on the average (11%) and the opposite was true for the uninoculated but washed potatoes (21%). When incubated in infested soil or in sterile mix, susceptible cultivars Alpha and Atlantic, and resistant clones Cruza, 53-87, and 53-101 exhibited least decay on the average among all treatments and genotypes. Foliage resistant cultivars Norten a, Rosita, Michoacan, Montsama, Torridon, and Monserrat were more susceptible to tuber rot when not inoculated compared with those infected with P. infestans, and no direct relationship between foliage and tuber resistance was found among genotypes. Sterile mix resulted in a better substrate for tissue deterioration than natural soil; washed tubers were more susceptible to decay than unwashed ones; and the moist chamber favoured rotting compared with the other two environments (soil and mix). Also, there was significant tissue decomposition in the absence of the oomycete, and whenever natural soil was present, acting as substrate. In the surface of unwashed tubers, general infections were suppressed, as an indication of the presence of antagonistic factors.