Academic literature on the topic 'Seed potatoes – Yields – Western Australia'

Field experiments were conducted over 3 years at 21 sites of varying phosphorus (P) fertiliser histories (Colwell P range: 9–170 g/g) in the Manjimup–Pemberton region of Western Australia to examine the effects of freshly applied (current) and previously applied (residual or soil test ) P on the yield of potatoes (Solanum tuberosum L. cv. Delaware). Phosphorus was placed (banded) at planting, 5 cm either side of and below seed planted at 20 cm depth, at levels up to 800 kg P/ha. Exponential [y = a – b exp (–cx)] regressions were fitted to the relationship between tuber yield and level of applied P at all sites. Weighted (according to the variance) exponential regressions were fitted to the relationship between yield responsiveness (b/a, from the yield versus level of applied P relationship) and Colwell P, and two P sorption indices—phosphate adsorption (P-adsorb) and a modified phosphate retention index (PRI(100)). A weighted exponential regression was also fitted to the relationship between the level of applied P required for 95% of maximum yield (Popt; also from yield versus level of applied P) and P-adsorb and PRI(100). A weighted linear regression best described the relationship between Popt and Colwell P. Phosphorus application significantly (P<0.10; from the regression analysis) increased total tuber yield at all but 4 sites. Marketable tuber yield response paralleled total tuber yield response at all sites and averaged 85% of total yields (range 63–94%). Colwell P gave a good prediction of the likely yield response of potatoes across all sites. For example, the yield responsiveness (b/a) of potatoes in relation to Colwell P decreased exponentially from 1.07 at 0 g/g to 0, or no yield response, at 157 g/g Colwell P (R2 = 0.96) i.e. the critical Colwell P for 95% of maximum yield of potatoes on soils in the Manjimup–Pemberton region. Similarly, no yield response (b/a = 0) would be expected at a P-adsorb of 180 g/g (R2 = 0.69) or a PRI(100) of 46 (R2 = 0.61). The level of applied P required for 95% of maximum yield (Popt) decreased linearly from 124 kg/ha on infertile sites (<5 g/g Colwell P) to 0 kg P/ha at 160 g/g Colwell P (R2 = 0.66). However, a more accurate prediction of Popt was possible using either P-adsorb or PRI(100). For example, Popt increased exponentially from 0 kg/ha at <181 g/g P-adsorb (high P soils) to 153 kg/ha at a P-adsorb of 950 g/g (low P soils) (R2 = 0.75) and exponentially from 0 kg/ha at a PRI(100) of <48 (high P soils) to 147 kg/ha at a PRI(100) of 750 (low P soils) (R2 = 0.80). PRI(100) is preferred as a soil test to predict Popt for potatoes in the Manjimup–Pemberton region because of its superior accuracy to the Colwell test. It is also preferred to P-adsorb because of both superior accuracy and lower cost as it is a simpler and less time consuming procedure — features which are important for adoption by commercial soil testing services. A multiple regression including Colwell P, P-adsorb and PRI(100) only improved the prediction of Popt slightly (R2 = 0.89) over PRI(100) alone. When tubers were 10 mm long, the total P in petioles of youngest fully expanded leaves which corresponded with 95% of maximum yield was 0.41% (dry weight basis). These results show that, while the Colwell soil P test is a useful predictor of the responsiveness of potato yield to applied P across a range of soils in the Manjimup–Pemberton region, consideration of both the soil test P value and the P sorption capacity of the soil, as determined here by PRI(100), is required for accurate predictions of the level of P fertiliser required to achieve maximum yields on individual sites.

The relative effectiveness of broadcasting compared with band-placement of phosphorus (P) fertilisers (0–480 kg P/ha) was compared using potatoes grown on P-deficient sandy soils over 2 seasons in Western Australia (Karrakatta sand in 1993, experiment 1; and Spearwood sand in 1996, experiment 2). The maximum yield of potatoes when P fertiliser was broadcast and incorporated to 20–25 cm before planting (broadcast) was 17 t/ha higher than when P was placed in 2 bands 5 cm to the side of and below seed piece level (banded) in experiment 1, and 13 t/ha higher in experiment 2. However, higher rates of applied P were required to reach 99% of maximum yield on the broadcast compared with the banded plots in both years (i.e. 174 v. 134 kg/ha in experiment 1, and 279 v. 125 kg/ha in experiment 2). Despite the lower levels of applied P required to achieve maximum yield in the banding treatment, banding P fertiliser for potatoes grown on Karrakatta and Spearwood sands would result in significant economic loss. The higher yield in the broadcast treatment corresponded with significantly (P<0.001) higher P concentrations (about 2-fold) in petioles of youngest fully expanded leaves from 56 to 131 days after sowing. When tubers were 10 mm long, the petiole P concentrations corresponding with 95 and 99% of maximum yield were 1.13 and 1.28%, respectively, for the broadcast P treatments in experiment 1, and 0.95 and 1.11% in experiment 2. The reduced yield in the banded treatments was assumed to be due to P fertiliser toxicity in the soil and not P toxicity in the plant tissue. Phosphorus uptake by tubers was significantly (P<0.001) higher (about 2-fold) when P was broadcast rather than banded, especially at high levels of applied P. Phosphorus recovery efficiency by tubers (P uptake by tubers/P applied, both in kg/ha) was higher when P was broadcast rather than banded, particularly at high levels of applied P (e.g. at 480 kg applied P/ha, recovery efficiency was 0.07 in the broadcast treatment compared with 0.03 in the banded treatment). These results show that, for growers to avoid significant economic loss, broadcast applications of P fertilisers should continue to be recommended for potatoes grown on the low P-fixing, sandy soils of the Swan Coastal Plain.

Field trials were conducted in 2 seasons at 13 sites on neutral to alkaline soils in Western Australia, to compare the growth and seed yield of 6 winter grain legume species: field pea (Pisum sativum L.), chickpea (Cicer arietinum L.), faba bean (Vicia faba L.), lentil (Lens culinaris Medik), narrow leaf lupin (Lupinus angustifolius L.), albus lupin (L. albus). In a dry year (1991), overall site mean seed yield was highest for field pea (1.35 t/ha), then faba bean (1.22 t/ha) and narrow leaf lupin (0.85 t/ha). Chickpea, lentil line ILL5728, and albus lupin produced an average seed yield of 0.64 t/ha. Rainfall in 1992 was above average and seed yields of all species except field pea were higher than in 1991. Heavy rainfall in winter and spring caused transient waterlogging at several sites, affecting growth and seed yield of most species. Faba bean responded positively to the increase in rainfall and produced exceptional seed yields of >4 t/ha at 3 sites. Mean seed yield was highest for faba bean, at 2.87 t/ha, then narrow leaf lupin (1.19 t/ha), chickpea (1.1 t/ha), and field pea (1.0 t/ha). Field pea performed poorly at several sites due to its susceptibility to transient waterlogging and black spot disease (caused by Mycosphaerella pinoides). Albus lupin and lentil line ILL5728 produced similar seed yields (0.78 t/ha). Lentil cvv. Laird (1991) and Kye (1992) had low seed yields due to poor adaptation. Seed yield differences between species at various locations were not simply related to any soil chemical parameters or to depth to clay. On a calcareous soil of pH(CaC12) 8 at Dongara, the growth of narrow leaf lupin was severely affected and the crop failed. Days to flowering varied between species; faba bean was earliest to flower (76 days), then field pea. Faba bean and field pea (particularly in 1991) generally produced the most dry matter, both early and at final harvest. The relationship between seed yield and rainfall was complicated by transient waterlogging and fungal disease (e.g. black spot in field pea) at many sites. Seed yield was significantly positively related to final dry matter production but not to harvest index.

Average commercial wheat yields in the southern, high rainfall area of Western Australia have seldom exceeded 1.5 t/ha and wheat is not widely grown. However, the average annual rainfall and length of growing season (>400 mm and >6 months) are conducive to much larger yields. Thirteen factorial experiments with mid and long season cultivars (Aroona and Osprey), 2 levels of applied nitrogen (N) (40 and 80 kg N/ha), 2 seed rates (50 and 100 kg/ha) and with or without fungicide were conducted at 8 sites over 2 seasons. The experiment was done to investigate combinations of cultivar and agronomic practices suitable for increased wheat production in long season environments in Western Australia. Largest grain yields (>4 t/ha) were obtained where wheat followed a grass-free break crop, and the mid season cultivar was used with 80 kg N/ha and 100 kg/ha of seed. Increases due to cultivar and seed rate were more consistent than those due to N, and increases from application of fungicide were less consistent. It is suggested that the optimal wheat production 'package' will include sowing in May in rotation with a grass-free break crop, seed rate of about 100 kg/ha and, when all other factors are optimal, N rates of over 40 kg/ha. The greatest yield increases were associated with the sites where wheat followed a grass-free crop. Increases due to other factors were relatively smaller. Hectolitre weight and percentage of small grain (<2 mm) often reached levels that would have entailed downgrading in commercial deliveries. However, in the most productive crops where root and leaf diseases were minimal, these quality parameters were seldom deficient and grain protein contents exceeded 10% at yields of up to 4 t/ha.

SUMMARYNine experiments are reported in which effects of site of seed production on dormancy, sprout and field growth of progeny tubers were recorded. The experiments used early varieties, Home Guard (four experiments), Red Craigs Royal (three experiments) and Arran Comet (two experiments) and in each, seed crops were grown with similar husbandry at sites differing in altitude and location in western England and Wales. There was no consistent effect of site of seed production on the timing of the end of dormancy, and the maximum effect in any year was 11 ± 1·2 (S.E.) days. The small effects of site on dormancy influenced initial sprout lengths, and this effect usually persisted up to planting in Home Guard and Red Craigs Royal, although the effects were small in magnitude. There was no effect of site of seed production on sprout lengths at planting or on field growth and yields in Arran Comet. In the other two varieties there was no effect of site of seed production on yield at early harvests, but at later harvests seed from cooler upland sites sometimes significantly outyielded lowland seed. There was, therefore, no evidence to support the view that locally produced seed was advantageous for early potato production. The results, together with those of the concurrent series with maincrop varieties reported by Wurr (1979), show that on half the occasions on which yields were measured covering the whole of the harvesting period, site of seed production had no effect on yields. In these experiments with early varieties effects of site occurred only at harvests later than the commercial harvesting of such old seed. It is therefore suggested that site of seed production is a much less important determinant of tuber yield than hitherto suggested, and of little practical significance.

Chickpea has become an important grain legume crop in Australia over the last decade. New varieties with improved seed yield and quality are being developed in Australia with varied phenological and agronomic traits. This study examined the optimum time of sowing of several desi chickpea varieties (Dooen, T1587, Sona and Tyson) varying in phenology over a range of dryland Mediterranean-type environments in south-western Australia. Chickpea showed good adaptation, particularly in the northern grain belt of Western Australia where growing conditions are warmer than southern areas. Seed yields varied widely depending on the time of sowing, location and seasonal conditions. Mean seed yields greater than 1000 kg/ha and up to 2000 kg/ha were achieved, but in some cases seed yields were less than 800 kg/ha. In the northern region, seed yield was almost doubled by sowing in early-May (1625 kg/ha) compared with late-June (754 kg/ha). In contrast to this, seed yields were generally lower in the southern regions and greater from late-June sowings (865 kg/ha) compared to earlier mid-May sowings (610 kg/ha). Seed yields were not clearly increased by altering sowing time to match the phenology of the variety to the growing season rainfall and temperatures, except at the early sowing times (April and early-May) where Tyson out-yielded all other varieties. This is most likely due to the lack of photoperiod-responsive, long-duration varieties to match early sowing and low temperatures limiting vegetative and reproductive growth in all varieties, especially in southern areas. However, it is likely that early flowering varieties will show greater adaptation and yield performance in short growing seasons, while later flowering varieties will be better suited to longer growing seasons. The study found that there were significant differences in the optimum sowing time between northern, central and southern sites, based on differences in mean daily temperatures and length of the growing season. Generally, the greatest seed yields were produced by sowing between mid to late June at southern sites, and early May at central and northern sites.

A range of cool season grain legume species have shown considerable potential for soils unsuitable for the production of narrow-leafed lupin (Lupinus angustifolius L.) at limited sites in the Mediterranean-type environments of south-western Australia. In this study the adaptation of these grain legume species was compared by measuring crop phenology, growth, and yield in field experiments at a total of 36 sites over 3 seasons, with the aim of identifying species with suitable adaptation and seed yield for specific environments. The grain legumes examined appeared to fall into 3 categories: (i) field pea (Pisum sativum L.), faba bean (Vicia faba L.), common vetch (Vicia sativa L.), and narbon bean (Vicia narbonensis L.) clearly had superior seed yield to the other species over a wide number of sites and years across south-western Australia (mean 1.0–2.3 t/ha); (ii) albus lupin (Lupinus albus L.), desi chickpea (Cicer arietinum L.), and Lathyrus cicera, L. sativus, and L. ochrus produced seed yields of 1–1.3 t/ha; and (iii) red lentil (Lens culinaris L.), bitter vetch (Vicia ervilia), and kabuli chickpea (Cicer arietinum L.) generally produced the lowest yields (0.6–1.0 t/ha). There were clear species × environment interactions. At low-yielding sites (<1.4 t/ha), field pea was the highest yielding species, while faba bean often produced the highest seed yields under more favourable conditions at high yielding sites. Lentil, bitter vetch, Lathyrus spp., and desi chickpea showed average response to increasing mean site yield. Soil pH and clay content and rainfall were the environmental factors identified as the most important in determining seed yields. Soil pH and clay content appeared to be especially important in the adaptation of lentil, narbon bean, bitter vetch, and kabuli chickpea, with these species performing best in soils with pH >6.0 and clay contents >15%. Seed yields were positively correlated with dry matter production at maturity across a number of sites (r2 = 0.40, P < 0.01). Future improvements in seed yield of these species are likely to come from management practices that increase dry matter production such as increased plant density and early sowing, and through the development of genotypes with greater tolerance to low winter temperatures, and more rapid phenology, canopy development, and dry matter production than existing commercial cultivars.

The suitability of chickpea (Cicer arietinum L.) as a winter-sown grain crop was evaluated for the Merredin region (310 mm rainfall) in the south-western Australian cereal belt. Few data on performance of chickpea were available from southern Australia, but similarities of the Merredin climate with that of Aleppo in Syria, where chickpea has been grown for centuries, indicated its potential. The response of a desi-type early line of chickpea was studied in a time of sowing by density trial in 1982 and a time of sowing trial in 1983, by relating seed and biological yield to dry matter accumulation and distribution, phenological and morphological development. Seed yields averaged 1.20 t ha-1 over the two years, and was little affected by time of sowing or density over the normal sowing period, and confirmed early flowering as the basic ideotype for the region. Seed yield correlated poorly with harvest index, but highly with biological yield within, but not between years. Time to flowering was fairly constant, averaging 100 days after 1160�C days, and flowering stopped soon after maximum LAI was reached. Detailed observations in 1983 showed that the efficiency of formation of seed bearing pods from flowers increased from 38% for the earliest planting to 83% in the latest planting. The failure of early sown chickpea to exploit the longer growing season resulted from the high abortion rate of early flowers, probably caused by low spring temperatures. The 35% of pods aborted in late spring, in all sowing dates, indicates that water stress can be expected to limit chickpea yields, as in other cultivated species, in the region. Chickpea demonstrated good yield potential for the drier cereal belt on heavy-textured soils at Merredin, to which medics are adapted. The data indicate scope to increase yields by improving tolerance to cold during early flowering and support the concept of increasing seed yields by restricting the number of branches at higher densities, as found in a previous study.

A field experiment at Medina, Western Australia, was designed to test whether seed produced at different locations and containing different phosphorus (P) concentration in the seed would change the relationship between yield and the level of superphosphate drilled with the seed. To produce the seed for the experiment, subsamples of the same source of seed of yellow serradella (Ornithopus compressus cv. Madeira) were grown at Medina and Esperance, Western Australia. Seed of the same size produced at each location, and containing 3 different P concentrations, was sown in the experiment at Medina. Three levels of superphosphate were drilled with the seed. Yields (of dried herbage and seed) were increased 2- to 4-fold as the amount of P drilled with the seed was increased from 5 to 40 kg P/ha. Although the Medina seed contained >0.40% P and the Esperance seed contained <0.40% P, plants grown from Esperance seed produced larger yields than plants grown from Medina seed for each of the 3 levels of P drilled with the seed; yield difference increased from about 14 to 70% as the level of P drilled with the seed increased from 5 to 40 kg P/ha. Higher P concentration in the sown seed increased herbage and seed yields by 35-70% when 5 kg P/ha superphosphate was drilled with the seed, and by about 616% when 40 kg P/ha was P drilled with the seed. Seed grown at Esperance produced larger yields for each seed P concentration than Medina seed; yield differences were about 30-90%. The P concentration measured in dried herbage and seed depended only on the amount of P drilled with the seed. It was unaffected by the P concentration in the seed sown, and for dried herbage, it was unaffected by where the seed sown was produced. However, for seed production, the relationship between yield and P concentration in the seed differed depending on where the seed was grown.

In south-eastern South Australia root-knot nematode (Meloidogyne hapla) caused losses to potato crops in fields that were sown once every 5- 15 years and were used for grazing in the intervening years. Although seed used by some growers was infested with M. hapla, the nematode also survived between potato crops on subterranean clover (Trifolium subterraneum), the dominant pasture species, and capeweed (Cryptostemma calendula). Subterranean clover was the most abundant alternate host. Nematodes invaded clover seedlings that established following rain in April and produced eggs about 12 weeks later. A second generation was produced in late winter and spring, so that a relatively high root-knot nematode population was present when potatoes were planted. The population increased rapidly on potatoes and numbers capable of causing severe root damage were observed 10- 15 weeks after planting. The growing of non-host crops, or the use of herbicides or cultivation to eliminate subterranean clover in the winter prior to the potato crop, should be investigated. In a nematicide trial, ethylene dibromide at 70 and 110 kg/ha increased yields of potato cv. Pontiac by about 90%.

Potato (Solanum tuberosum L.) varieties Atlantic and Granola are widely grown in Indonesia. The optimal method of cultivation in the tropics, due to the susceptibility of cut seed for disease, is by small (20 to 55 g) whole seed potatoes. However, the variety Atlantic produces mostly large tubers, which are not suitable for planting as whole seeds. Although Granola produces a reasonable proportion of small tubers it still produces a few in the larger size grades and there is no fresh market in Western Australia for the larger tubers for this variety. The aim of this study was to develop methods to be used in Western Australia that improve the yield of small seed potatoes for export to Indonesia. The influence of seed-potato storage duration (at 4°C) on subsequent stem growth was assessed after 30 days growth in a glasshouse (22°C/18°C, day⁄night). Seed potato storage for 22-28 (Atlantic) and 24-30 (Granola) weeks resulted in development of higher numbers of stems. A series of field experiment were designed to increase yield of small tubers. Apical sprout removal in Granola, but not Atlantic, increased the number of stems (by 27%), yield of 20-55 g potato (by 32%) and total yield (by 17%). Application of herbicide (paraquat + diquat) at low concentration during early tuber initiation decreased total yield in Atlantic (by 14%) and Granola (by 16%). Treating whole seed potatoes with carvone vapor two weeks before planting had no influence on stem or tuber number in both Atlantic and Granola but in Atlantic only, the total yield was reduced by 12%. Spraying plants with paclobutrazol during early tuber initiation inconsistently influenced tuber number and yield between the two varieties and two experiments. The influence of gibberellic acid (GA3) on stem number, total tuber number, yield of 20-55 g tubers and total yield was investigated by dipping seed pieces in a GA3 solution (20 mg⁄L) two days prior to planting. In Atlantic, GA3 treatment increased stem number (by 147%), total tuber number (by 75%) and yield of 20-55 g tubers (by 330%) without influencing total yield. In Granola, GA3 treatment increased stem number (by 50%), total tuber number (by 15%), yield of 20-55 g tubers (by 21%) and total yield (by 10%) The influence of gibberellic acid application (20 mg⁄L) to seed pieces before planting increased the number of small tubers through increased stem number. The shift toward a greater proportion of small tubers, without reducing total yield, had a greater influence in Atlantic than that in Granola. Treatment of GA3 and paclobutrazol together decreased total yield compared to that of GA3 alone

Poland is situated in the Great European Plain between the Baltic Sea and the Carpathian and Sudety mountains. Its territory includes lowlands (91.3%), highlands (7.7%), and mountains (1%). Most of Poland’s soils are light soils of podsolic origin, which are usually of poor quality. It is for this reason that only 25% of the agricultural land, which accounts for 60% of the total territory and engages about 12% of population, is used for producing wheat, barley, sugar beets, rape seed, and vegetables. Average yields of main crops in Poland are lower than in the majority of West European countries. But the higher harvest areas put Poland sixth in Europe in the production of wheat, second in the production of rye and potatoes, and fourth in the production of sugar beet. The variation in the production of these crops during 1990–2000 is shown in figure 13.1. Private farms cover about 84% of the total agricultural land. About 55% of the farms have an individual area < 2 ha. Liquidation of state farms and substantial reduction in the number of cooperative and collective farms have impacted the size of individual farms and increased their importance in agricultural production and Polish export. Since 1980, the average area of individual farms increased from 6.5 to 7.8 ha. Poland is located in the region where precipitation exceeds transpiration. But since the 1960s, annual rainfall has gradually decreased by about 70 mm (Slota et al., 1992). Due to the shortage of precipitation, high temperature fluctuations in the spring, and cool weather during summertime, yields of the main crops have decreased and drought frequency has increased, particularly during the last decade. Drought usually begins in western Poland, moves through the central part, and eventually reaches eastern side (between 51°N and 54°N), which is highly susceptible to droughts. Regions located above 54°N are in the zone of Baltic Sea climate characterized by higher rainfall (600–700 mm) and hence are less prone to drought than the rest of Poland.