Influence de la durée de prégermination et de l'époque de plantation sur le rendement et la qualité technologique de la pomme de terre. 1. Effets sur le rendement en tubercules et amidon

The Effect of Preceding Crop and Pre‐Sprouting on Crop Growth, N Use and Tuber Yield of Maincrop Potatoes for Processing Under Conditions of N Stress

“…According to the present study, the response of crop development to seed‐tuber preparation by pre‐sprouting is much more substantial. The observed shortening of pre‐emergence development has also been reported by other researchers in the past (Reust et al. 1982, Moll 1985).…”

Effect of Presprouting on Yield of Maincrop Potatoes (Solanum tuberosum L.) in Organic Farming

“…plant, smaller values could be observed with the presprouted potatoes compared with the non-presprouted ones (Fig, 1), Such a reduction in the number of stems per plant and number of tubers per plant is reported from most other investigations of the eflfect of presprouting or the effect of increased physiological age of seed tubers. However, as in the work presented here, a reducing effect was not observed with all cultivars and also varied with the presprouting conditions (Reust and Munster 1974, O'Brien et al, 1983, Moll 1985, Van Loon 1987, Haverkort et al, 1990, Hay and Hampson 1991, Van de Waart 1993, On the other hand, an increase in the number of stems and tubers per plant as a result of presprouting was observed only seldom with individual cultivars (Toosey 1962, Hay andHampson 1991), Reduction in the number of stems caused by presprouting or by advancing physiological age is generally ascribed to the promotion of apical dominance in the seed tubers: Fewer sprouts are formed and the number of tuber bearing stems is reduced correspondingly (Moll 1985, Reust 1990, Hay and Hampson 1991, Schuler and Moll 1994,…”

“…The observed shortening of 8-12 days of the preemergence development caused by presprouting (Table 2) lies in a range that has been found by other authors (Burghausen 1962, Reust et al, 1982, Moll 1985, ***(P^ 0,001), ns = not significant; ^Difference in % (non-presprouted = 100); In 1991 a significant interaction site x presprouting (P ^ 0,05) was ascertained. plant, smaller values could be observed with the presprouted potatoes compared with the non-presprouted ones (Fig, 1), Such a reduction in the number of stems per plant and number of tubers per plant is reported from most other investigations of the eflfect of presprouting or the effect of increased physiological age of seed tubers.…”

“…The results from the study of tuber size distribution can be compared only to a limited extent with those of other authors, since different allocations of classes were used. However, most of the other studies also showed that presprouting or increase in physiological age alter the composition of sizes towards fewer small tubers and more large tubers (Ulrich 1957, Keller and Gutswiller 1959, Reust et al, 1982, Haverkort et al, 1990, Only Toosey (1962) observed in 1 year with severe drought in spring more large tubers with non-presprouted potatoes than with presprouted ones.…”

“…Recent studies carried out with (late) maincrop potatoes under prevailing conditions of conventional potato growing have shown only a few cases of yield effects caused by presprouting or physiologically aged seed tubers. Even reduced yields have been observed with seed tubers of very advanced physiological age (Reust et al, 1982, O'Brien et al, 1983, Moll 1985, Allen and O'Brien 1986, Van Loon 1987Haverkort et al, 1990, Nelson andJenkins 1990),…”