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The number of weed species occurring in agricultural crops in Poland ranges from 300 to 400, and in potato cultivation this number ranges from 29 to 55 species. Potato is a plant which is heavily grown over with weeds, since it is cultivated in wide row spaces and is characterized by slow initial growth. The aim of the 3-year study was to estimate the effect of cultivation practices such as limited mineral fertilization, the use of farmyard and straw, catch crop cultivation, as well as the use of a soil fertilizer on the occurrence of weeds in a potato plantation. It was shown that the numbers of weeds determined in three growing seasons before row closure stayed at low level (2-9 plants per m2), and before tuber harvest it was only slightly higher. Among dicotyledonous weed species, the most frequently occurred: white goose-foot (Chenopodium album L.), field violet (Viola arvensis Murr.), smallflower galinsoga (Galinsogaparviflora Cav.) and shepherd’s purse (Capsella bursa-pastoris L Med.), and of monocotiledonous – barnyard grass (Echinochloa crus galli L.) and quack grass (Elymusrepens L.). The lowest weed infestation, particularly with dicotyledonous species, was recorded after the application of straw as organic fertilizer. Smallest number of dicotyledonous weeds occurred when the standard rate of mineral fertilizers was reduced by 50%. Whereas the use of the soil fertilizer UGmax caused increase in the numbers of monocotyledonous weeds before potato row closure and of both monocotyledonous and dicotyledonous before tuber harvest. The smallest weed infestation occurred when straw fertilization was used, mineral fertilization was reduced by 50% and the soil fertilizer was not applied.
Zarzecka K., Gugała M., Gąsiorowska B. 2001. Skuteczność chwastobójcza herbicydów i ich mieszanek oraz wpływ na wartość konsumpcyjną bulw ziemniaka. Prog. Plant Protect./Post. Ochr. Roślin 41(2): 931-934. Czynnikiem badawczym doświadczenia (2002-2004) były cztery rodzaje herbicydów: Afalon 50 WP, Azogard 50 WP, Sencor 70 WG+adiuwant Olbras 88 EC, Apyros 75 WG+adiuwant Atpolan 80 EC oraz dwie odmiany ziemniaka Rywal i Saturna. Smakowitość bulw gotowanych poddanych ocenie organoleptycznej po 6 miesiącach przechowywania w temp. +4°C oraz wilg. wzgl. pow. 95% w bardzo niewielkim stopniu uległy pogorszeniu w porównaniu do bulw badanych bezpośrednio po zbiorach. Bulwy obu odmian oceniane po przechowywaniu miały nieznacznie ciemniejszą barwę miąższu, w porównaniu do bulw badanych po zbiorach, szczególnie u odmiany Saturna. Obie odmiany zaliczono do typu B, podobnie jak po zbiorach. Po 6-miesięcznym okresie przechowywania bulwy ugotowane, oceniane zarówno po 10 minutach, jaki i po 24 godzinach miały większą skłonność do ciemnienia miąższu niż bulwy analizowane bezpośrednio po zbiorach. Odmiana Saturna, podobnie jak po zbiorach bardziej ciemniała (średnio o 0,4 stopnia w 9-stopniowej skali) od odmiany Rywal, a zastosowane w czasie wegetacji herbicydy podwyższały tę skłonność od 0,1 do 0,6 stopnia w 9-stopniowej skali.
The present study of three vegetation periods evaluated the enzymatic browning process of two different commodities, carrot roots and apples. The influence of the genetic potential (effect of genus and cultivar), of magnesium fertilization is case of carrot and of storage (in case of carrot 6 months in a traditional natural mound and in case of apple 6 months under ultra low oxygen (ULO) conditions) were investigated. In the case of carrot 5 different cultivars were investigated, middle late 'Berjo', late: 'Flacoro', 'Karotan', 'Koral', 'Perfekcja', and magnesium doses (0, 45, 90 kg∙ha-1 of MgO) by constant fertilization with nitrogen (70 kg∙ha-1), phosphorus (80 kg∙ha-1 of P2O5), and potassium (100 kg∙ha-1 of K2O). In October harvested roots were stored for 6 months in the traditional natural mound. In the case of apple fruits seven different cultivars were used: 'Elstar', 'Gloster', 'Honeygold', 'Idared', 'Jonagored', 'Ligol', and 'Szampion', from the commercial Agricultural and Fruit Farm Klimkiewicz, Wtelno (Kuyavian-Pomeranian Voivodeship) using integrated horticulture production procedures. Apple fruits were stored under ULO conditions for 6 months (>2% O2, <2% CO2, 1.5-2.0°C and 95-96% RH). Susceptibility of commodities was evaluated directly after harvest and after the 6 months of storage using collorimetrically determination method at 475 nm. The evaluation of the enzymatic browning process in carrot roots and apple fruits revealed significant dependency on the used plant material (genus). Carrot roots were generally less susceptible to enzymatic browning compared to the apple fruits. Leaf application of magnesium fertilization, especially at the dose of 90 kg MgO per 1 ha inhibited the browning process. Storage time of 6 months in the mound promoted discoloration of carrot roots and thus negatively influenced their quality. In the case of apple fruits the appropriate choice of cultivar was most important for limiting the enzymatic browning process, which is especially important when selecting raw material for juice production. A low susceptibility to enzymatic browning was found in fruits of cv. 'Elstar', whereas the cv. 'Honeygold' was most susceptible. Changes in the susceptibility to the browning processes of fruit flesh after storage were statistically significant, however quite small in comparison to the values measured directly after harvest.
Three-year-long field and storage experiments were carried out to evaluate changes in concentrations of some organic acids in ‘Rywal’ and ‘Saturna’ potato tubers as affected by herbicides used during the growing period. The tubers were stored for 3 and 6 months at 4℃ and 8℃ at relative humidity of 95%. The weed control method did not change acid concentrations in the tubers. However, significant differences between the cultivars were seen. ‘Saturna’ had a higher content of citric, tartaric and fumaric acids, while that of malic acid was lower than in the ‘Rywal’ cultivar. There was a negative correlation between organic acids under study and malic acid after the harvest. The storage period and a lower storage temperature promoted accumulation of malic acid in both cultivars. A reverse relationship was noted in the case of other acids under study. The highest decrease, up to 70%, was found for fumaric acid assessed after 6 months of storage of the ‘Saturna’ cultivar.
The objective of the investigations was to evaluate changes in concentrations of total protein (nitrogen x 6.25), phosphorus and potassium in tubers of two potato cultivars: Rywal and Saturna, as dependent on the application of herbicides (Afalon 50 WP, Azogard 50 WP, Sencor 70 WG, and Apyros 75 WG), after harvest and after 3 and 6 months of storage. Concentrations of total protein, phosphorus and potassium in potato tubers were strongly conditioned by genetic features of the cultivars. The tubers collected from the objects sprayed with the herbicides over the vegetation period contained by 3.7%, 8.1%, and by 3.5% more protein, phosphorus and potassium, respectively, than those nursed exclusively mechanically. The corresponding values in the latter case reached respectively (means for the objects with the use of herbicides) 24.4 g kg-1, 660.5 mg kg-1 and 5351.3 mg kg-1. After 3 and 6 months of storage at 8°C, the content of nitrogen was significantly lower. Similarly, tubers stored at 4oC contained significantly less nitrogen, but not earlier than after 6 months. In contrast, concentrations of phosphorus and potassium did not change significantly over the storage of tubers in chambers with the lower temperature (4°C).
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