The relationships among three methods for evaluating texture (sloughing during cooking, hardness of cooked potato dice and shear press value of French fries) and some chemical constituents (Ca, Mg, K, free pectin, phytin and citrate) were investigated, using the main specific gravity classes of seven Dutch potato varieties. The interplay of these constitutents (except K) in the softening of the texture during cooking was expressed as follows: Open image in new window

In Osterreich kommt dem Kartoffelbau in den einzelnen Bundeslandern verschiedene Bedeutung zu. Fur die einzelnen Bundeslander werden Anbauflache und mittlere Hektarertrage angegeben und die Anbauverhaltnisse in Tirol speziell besprochen. Die Tal- und Terrassenlagen Tirols sind in Hohen von 500–900 m fur den Kartoffelbau sehr gut geeignet, da sich Lufttemperaturen und Niederschlage meist im optimalen Bereich befinden (Tabelle 3). Die Ertrage und Klimadaten werden genannt (Tabelle 4–6). Die Ertragsunterschiede sind in Osterreich und Tirol beachtlich und konnen uber die Vegetationszeit integrierend durch Vergleich der mittleren Temperatursummen und Niederschlagssummen vom Mai bis September annahernd erklart werden. Die okologischen Voraussetzungen fur optimale Stoffproduktion von Kartoffelpflanzen sind bei Beleuchtungsstarken von 30.000–50.000 Lux Monatsmittel der Blattemperatur von 17 bis 19 C, mittlere Maxima von 20 bis 23 C und monatlich 80–120 mm Niederschlag.

In a field experiment, F1 progenies betweenAndigenas partially adapted to long days and aTuberosum variety outyielded F1 progenies betweenTuberosum varieties by, on average, 13%. ATuberosum progeny which involved the Continental parentAckersegen outyielded others involving only British parents.Andigena Tuberosum progenies outyielded the BritishTuberosum progenies on average by 19%, the best hybrid progeny being 49% superior to them. Tuber sizes and earliness of maturity were, on average, closely similar inAndigena Tuberosum andTuberosum Tuberosum progenies, though the range of progeny-means was greater inAndigena Tuberosum. Lower-yieldingAndigena Tuberosum progenies were early-maturing, though not all early-maturing progenies were low yielding. Blight resistance was detected in fourAndigena Tuberosum progenies. It is concluded that pre-selection amongAndigenas for desirable characters may enable high-yielding commercially-acceptable varieties to be obtained from the F1 generation ofAndigena Tuberosum hybrids.

Fourteen potato cultivars were grown on sandy land in Norfolk infested withTrichodorus pachydermas carrying tobacco rattle virus (TRV). Four out of five old cultivars showed few or no symptoms of spraing, whereas six out of nine modern cultivars were moderately or severely affected. In cultivars that showed severe spraing, TRV rarely passed from affected tubers to progeny plants and tubers, but did so more often in cultivars that showed slight spraing. Haulm symptoms in progeny plants consisted of stem-mottle, sometimes including figure aucuba. Some of the tubers produced by plants with stem-mottle showed internal markings whose severity was related to that of the primary spraing in that cultivar.Arran Pilot showed neither spraing nor stem-mottle; its roots resisted infection by vector-borne TRV, but its leaves were infected by manual inoculation with infective sap. TRV was transmitted by inoculation of sap to indicator plants from more than 90% of freshly dug tubers showing spraing, and of shoots showing stem-mottle.

The influence of four nitrogen and four potassium levels on sloughing, mealiness, softness, colour and discoloration of cooked potatoes was investigated with the varietiesAristo, Irene, Libertas andIJsselster, grown on twelve trial fields on sandy soils.

Vierjahrige Eignungsprufungen fur die maschinelle Ernte ergaben eine sehr deutliche Differenzierung der Sorten und Stamme in bezug auf Beschadigungswiderstandsfahigkeits. Mit einem von Gall und Lamprecht entwickelten Ruckschlagpendel wurde im Winter 1965/1966 die Elastizitat der Knollen gemessen. Bei den mittelfruhen bis spaten Sorten sind zwischen Beschadigungsempfindlichkeit und geringer Elastizitat enge statistische Beziehungen gefunden worden. In beiden Merkmalen gute Genotypen sind:We, Dl, We, Cl, Lu, Cl, Bintje, Aquila, Li, El undOra. In beiden Merkmalen gute schlecht sind:Kastor, Li. C4, Schwalbe, Ka, Dl, Ka. D2, Li. D2, Pollux, Ka. El undMa. El. Mit dem Auffinden des Selektionsmerkmals “Elastizitat der Knollen” und der Entwicklung des Serienprufgerates ist der Weg fur eine systematische Zuchtung auf Beschadigungswiderstandsfahigkeit geebnet.