Effects of length of sprouting period on growth and yield of contrasting early potato varieties

Abstract

SummaryThree experiments carried out in 3 years (1973–5) which examined the effects of length of sprouting period and temperature of sprouting on growth and yield of three early potato varieties are described. In Home Guard in 1973 at the earliest harvests, tuber yields increased with increase in length and temperature of sprouting period. At later harvests tuber yields decreased with increase in sprouting period especially at the higher temperature (13 rather than 8 °C) and increasing the temperature of sprouting reduced tuber yield. In 1974 length of sprouting period had few effects on yield at any harvest and increasing the temperature increased yields only at the first harvest. In Vanessa cold storage at 3 °C prior to entry to sprouting temperatures induced an earlier onset of sprout growth than continuous exposure to temperatures conducive to sprout growth. Long sprouting periods produced less sprout growth and at the earliest harvest lower tuber yields than all except the shortest period. Judged from the onset of sprout growth increases in length and temperature of sprouting generally increased tuber yields especially at early harvests. In Pentland Javelin sprout growth was very slow and tuber yields at early harvests decreased at both sprouting temperatures if sprouting began after mid-November. At later harvests effects of both factors were small.The implications of differences in the effects of sprouting periods according to variety and, in Home Guard, season, are discussed in relation to the provision of the most desirable sprouting environment and to variety testing. The similarity in the effects of lengthening the sprouting period and of increasing the temperature of sprouting suggest that temperature is the major causal factor in sprout growth and its effect on field growth. Sprouting periods may therefore be measured most accurately by accumulated day degrees > 0 °C and a close relationship between such a scale and tuber yields is demonstrated. The relevance of such scales for advice to growers is discussed.Tuber growth rates for Vanessa and to a lesser extent Home Guard in 1974 were extremely high, in excess of 10 t/ha/week for Vanessa. These high rates were associated with high levels of radiation received by coastal sites in May and June and are discussed in relation to the canopy structure of the varieties.

Nitrogen and potassium uptake by high-yielding potato crops

“…There is, therefore, no evidence that increasing total N accumulation is effective in increasing tuber yields. The high yields in these experiments and others at Trefloyne (Allen, 1977;Allen et al 1979) are associated with but not necessarily the consequence of large N accumulation by the crops. While in some circumstances it may be necessary to use heavy fertilizer applications in order to achieve the highest yields, this is not a generally applicable principle and a more effective discriminant of yield variation must be sought.…”

Effects of shoot tipping on development and yield of the tuber crop Plectranthus edulis

“…Also, changing the weight and pre-treatment of the seed tuber (pieces) are candidates for further investigation, because they are known to affect the number of main stems and/or canopy cover in potato (e.g. Bremner & Taha 1966;Allen et al 1979;Lommen & Struik 1994).…”

An analysis of growth of the potato crop

“…However, there is some circumstantial evidence that observed differences in leaf disposition may be significant. At low leaf area indices varieties such as Vanessa (Allen et al 1979) and Maris Bard (J. N. Bean, personal communication), which have relatively prostrate leaves, grow particularly rapidly (Table 2) ; s is 0-4 (x) and 0-6 (#) using the formula…”