Potato agronomy in a changing industry

Thirteen experiments conducted near Tenby, Dyfed, between 1973 and 1980, examined the effects of seed-tuber weight and within-row spacing on tuber yields of seven potato varieties grown for early production. These data have been used in an attempt to develop an approach to the determination of optimum tuber planting densities in early crops which will provide agronomists with logically applicable principles. Tuber planting densities, which maximized the net crop return (ware value minus seed cost), were estimated for eight ratios of seed cost to ware value ranging from 0-25 to 80. Optimum tuber planting densities decreased with the use of higher ratios of seed cost: ware value and heavier seed, except for ratios of 0-25 and 0-50 applied to yields of tubers > 25 mm harvested in June. In general, later harvesting together with the use of larger riddle sizes give a lower optimum density with ratios < 20. Optimum densities for Red Craigs Royal, Ulster Sceptre and Vanessa were higher than for the other varieties.The results provide an illustration of how to approach the problem of selecting tuber planting densities in order to maximize net crop returns in early potato varieties.

Section: Optimum Tuber Densitiessupporting

confidence: 91%

An approach to determining optimum tuber planting densities in early potato varieties

Wurr¹,

Fellows²,

Allen

1993

“…The narrowest within-row spacings occurred on wider rows and effects of row width were generally detected earlier than effects of planting density. In 1972 when high numbers of stems were achieved, wider rows reduced the number of stems resulting from high planting densities; this result reflects very intense competition since number of stems per seed tuber is determined early in growth and is usually un- affected by within-row spacing (Scott & Younger, 1972). Effects of planting density were not apparent until early June and effects on plant size and morphology persisted and sometimes increased.…”

Section: Discussionmentioning

confidence: 99%

“…Experiments involving * Present address: National Koot Crop Research marked changes in spatial arrangement have Institute, Irish Potato Research, Vom, Jos, Nigeria. generally indicated that potato crops are remark-0. P. IFENKWE AND E. J. ALLEN ably tolerant of such changes (Scott & Younger, 1972), so there is reasonable expectation that rows wider than 91 cm will not produce large reductions in yield. The ability of potato crops to compensate for wider row spacing is primarily dependent on the production of a complete leaf cover, so that wetter environments in which leaf growth is more extensive are likely to be less sensitive to large changes in row width than drier areas.…”

Section: Introductionmentioning

confidence: 99%

Effects of row width and planting density on growth and yield of two maincrop potato varieties. 1. Plant morphology and dry-matter accumulation

Ifenkwe¹,

Allen²

1978

Data are reported from three experiments from 1972 to 1974 in which the effects of two row widths (66 and 132 cm) and five planting densities on the growth of two maincrop potato varieties (De'sire'e and Maris Piper) were studied. The results were consistent over the 3 years and showed that the effects of widening the row width were to reduce the number of axillary branches and their leaves per plant, in Maris Piper L (leaf area index), and early in the season in both varieties dry weights of leaf, stem and underground parts per plant. Row width had no effect on tuber dry weight for most of the season but at the end of sampling, tuber dry weights were greater from 132 cm than from 66 cm rows. Increasing planting density reduced number of axillary branches and their leaves per plant, dry weight of leaf, stem, underground parts and tubers per plant, but increased stem length and tuber dry weight per unit area.Leaf growth of all treatments was rapid during May and high planting densities reached an L of 3 before the end of this month. L was increased by increased planting density throughout growth, but the lower densities were able to maintain an L of 2-3 for much of the season. The rapid early increase in L was not associated with any premature decline and high rates of tuber dry-matter accumulation were achieved and maintained throughout the season.

“…asserted (e.g. Scott & Younger, 1972) that a long sprouting period is essential for good yields in Almost all the seed used for early potato pro-early potato production but few, convincing data duction in U.K. is sprouted for some time (Potato are available to support the practice. With the Marketing Board, 1968).…”

Section: Introductionmentioning

confidence: 99%

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

Allen¹,

Bean²,

Griffith³

et al. 1979

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.