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201.
Kennebec seed potatoes were stored in various atmospheres of O2 and CO2 at 32 and 41 F (0 and 5 C). Samples were removed every 6 weeks for measurement of bud and parenchyma tissue respiration, rate of ion loss from tissue sections and reducing sugar content. Potatoes remaining at the end of the storage period were warmed, cut and planted immediately in a randomized complete block design for yield evaluation. Intact tuber respiratory rates were higher at 32 F than 41 F. Increasing CO2 increased respiratory rates and decreasing O2 decreased respiratory rates at both temperatures. Decreasing O2 concentration significantly decreased reducing sugar at both 32 and 41 F. Increasing CO2 significantly increased reducing sugar at 41 F but not at 32 F. Kennebec potatoes did not tolerate added CO2 at 32 F but did survive 4% CO2 at 41 F. Reducing oxygen decreased the tolerance to CO2. The onset of carbon dioxide injury was not clearly evident from changes in bud and parenchyma tissue respiration or in loss of electrolytes from cut tissue sections. However, CO2 accelerated tuber breakdown by unidentifiedFusarium Spp. No significant differences in yield were observed between treatments that survived the storage period. 相似文献
202.
Jaime Barros da Silva Filho Paulo Cezar Rezende Fontes Hermínia Emília Prieto Martinez Jose Soares de Lacerda Paulo Roberto Cecon Milton E. McGiffenJr 《American Journal of Potato Research》2018,95(6):687-695
In hydroponics, nutrient management is the limiting factor to obtaining optimal production, and nitrogen (N) is the key component to consider when optimizing nutrient management in these types of systems. The objective of this study is to evaluate different combinations of N fertilizer concentrations in order to optimize the yield of basic seed potato minitubers in a three-phase hydroponic system. Treatments consisted of five combinations of N concentrations, applied before and after 21 days after plant transplant as follows, respectively: 1) 13 and 13, 2) 13 and 0, 3) 13 and 7.8, 4) 13 and 16, and 5) 13 and 26 mmol L?1. Propagation was performed by transplanting 3–4 cm potato plantlets cv. Agata from sprouts. There were significant effects of N treatments on all measured variables (root, leaf, stem, and plant dry weight and minituber number and weight). To obtain the maximum minituber number yield, 9.51 minitubers/plant, corresponding to 67 minitubers/m2, post 21-day adjusted N concentration was 18.4 mmol/L. Treatment 4 promoted higher basic seed potato minituber yield in a three-phase hydroponic system. 相似文献
203.
Jaime Barros da Silva Filho Paulo Cezar Rezende Fontes Paulo Roberto Cecon Milton E. McGiffenJr 《American Journal of Potato Research》2018,95(5):443-450
We evaluated misting nozzle types and the coating on the bucket’s inner wall on the yield of basic potato seed minitubers. Tubers of potato cv. Agata were sprouted in a non-acclimatized greenhouse from June to September 2013. Six treatments were evaluated, three types of misting nozzle (32 L/h with anti-drip, 32 L/h without anti-drip, and 9 L/h without anti-drip) and two types of bucket inner lining, with and without polyurethane, with four replications. Dry weight of roots, stems and leaves besides minituber number and tuber fresh weight were evaluated. The “UFV Aeroponic System” effectively produces minitubers and should be equipped with a fogger with an outflow of 32 L/h without anti-drip and no inner lining of the bucket for optimal yield. 相似文献
204.
Érica Hasui Vinícius X. Silva Rogério G. T. Cunha Flavio N. Ramos Milton C. Ribeiro Mario Sacramento Marco T. P. Coelho Diego G. S. Pereira Bruno R. Ribeiro 《林业研究》2017,28(5):963-974
Species distribution models are used to aid our understanding of the processes driving the spatial patterns of species’ habitats. This approach has received criticism, however, largely because it neglects landscape metrics. We examined the relative impacts of landscape predictors on the accuracy of habitat models by constructing distribution models at regional scales incorporating environmental variables (climate, topography, vegetation, and soil types) and secondary species occurrence data, and using them to predict the occurrence of 36 species in 15 forest fragments where we conducted rapid surveys. We then selected six landscape predictors at the landscape scale and ran general linear models of species presence/absence with either a single scale predictor (the probabilities of occurrence of the distribution models or landscape variables) or multiple scale predictors (distribution models + one landscape variable). Our results indicated that distribution models alone had poor predictive abilities but were improved when landscape predictors were added; the species responses were not, however, similar to the multiple scale predictors. Our study thus highlights the importance of considering landscape metrics to generate more accurate habitat suitability models. 相似文献