Use of high soil solution electrical conductivity to improve the quality of fresh market tomatoes from coastal New South Wales

1989 ◽  
Vol 29 (6) ◽  
pp. 893 ◽  
Author(s):  
PS Cornish ◽  
VQ Nguyen

High electrical conductivity (EC) in the soil solution or hydroponic medium is thought to increase the concentration of total soluble solids (TSS) and thereby improve the flavour of tomato fruit. We used trickle irrigation in 2 field experiments (1988, 1989) to apply KC1 at rates up to 4.4 t/ha to tomatoes to raise soil solution EC and examine the effects on TSS and other components of fruit quality, as well as yield. The KCl was subject to leaching in both years and EC varied widely despite regular additions of KCl. Where a high EC was achieved in 1988 (3.9 mS/cm) there was no effect on fruit firmness or TSS, but titratable acids (TA) increased from 7.25 to 8.0 m.e./100 mL. In 1989, high EC (>7mS/cm) resulted in a small increase in TSS (0.3%) in 1 of 6 harvests but significant (P<0.05) increases in TA in 4 harvests. Yield was unaffected (P>0.05). We conclude that irrigation with salinised water is unlikely to be an effective means of raising the TSS of tomatoes grown on freely draining soils in the high rainfall environment of coastal New South Wales.

1988 ◽  
Vol 28 (1) ◽  
pp. 127 ◽  
Author(s):  
VQ Nguyen ◽  
R Hermus ◽  
WB McGlasson ◽  
SK Meldrum ◽  
ME Trethowan

The aim of the experiments described in this paper was to identify determinate cultivars suited to production of fresh market tomatoes on raised beds in the inland irrigation areas of the south-west area of New South Wales from January to April. Cultivars that produce high yields of first-grade medium to large fruit, and are smooth, nearly round, firm and an even bright red when ripe are required. The plants should have good leaf coverage to prevent sunburn, and jointless pedicels to facilitate harvesting. The period of maturation of the fruit should be short to permit recovery of the crop with a maximum of 3 harvests. Ten lines including Sunny, a .reference cultivar with jointed pedicels, were evaluated at Richmond in the Sydney Greater Metropolitan Area and at Leeton in the Murrumbidgee Irrigation Area, 1984-86. The lines were trickle-irrigated and mulched with black polyethylene film except at Leeton in 1985-86 when a trickle-irrigated, no mulch treatment and a furrow-irrigated treatment were included. The experiments showed that it is possible to produce yields of 50-100 t ha-1 of first-grade fruit with trickle irrigation. No significant advantage was obtained at Leeton in 1985-86 by using polyethylene mulch; however, the mulch largely eliminated the need for hand-chipping of weeds from among the plants. The visual quality of fruit grown at Leeton was excellent but total soluble solids levels were low, ripe fruit were unexpectedly soft, and sensory scores for flavour and general acceptability were only satisfactory. Overall, 2 cultivars that have jointless pedicels, Red Chief and Delta Contender, showed promise. A jointless hybrid line, HARU 83-148, which was bred at Richmond, warrants further evaluation. Some signs of incipient field chilling of fruit were observed at Leeton in fruit harvested after the first week in April.


2011 ◽  
Vol 62 (12) ◽  
pp. 1067 ◽  
Author(s):  
L. G. Gaynor ◽  
R. J. Lawn ◽  
A. T. James

The response of irrigated soybean to sowing date and to plant population was evaluated in field experiments over three years at Leeton, in the Murrumbidgee Irrigation Area (MIA) in southern New South Wales. The aim was to explore the options for later sowings to improve the flexibility for growing soybean in double-cropping rotations with a winter cereal. The experiments were grown on 1.83-m-wide raised soil beds, with 2, 4, or 6 rows per bed (years 1 and 2) or 2 rows per bed only (year 3). Plant population, which was manipulated by changing either the number of rows per bed (years 1 and 2) or the within-row plant spacing (year 3), ranged from 15 to 60 plants/m2 depending on the experiment. Two sowings dates, late November and late December, were compared in years 1 and 3, while in year 2, sowings in early and late January were also included. Three genotypes (early, medium, and late maturity) were grown in years 1 and 2, and four medium-maturing genotypes were grown in year 3. In general, machine-harvested seed yields were highest in the November sowings, and declined as sowing was delayed. Physiological analyses suggested two underlying causes for the yield decline as sowing date was delayed. First and most importantly, the later sown crops flowered sooner after sowing, shortening crop duration and reducing total dry matter (TDM) production. Second, in the late January sowings of the medium- and late-maturing genotypes, harvest index (HI) declined as maturity was pushed later into autumn, exposing the crops to cooler temperatures during pod filling. Attempts to offset the decline in TDM production as sowing was delayed by using higher plant populations were unsuccessful, in part because HI decreased, apparently due to greater severity of lodging. The studies indicated that, in the near term, the yield potential of current indeterminate cultivars at the late December sowing date is adequate, given appropriate management, for commercially viable double-cropping of soybean in the MIA. In the longer term, it is suggested that development of earlier maturing, lodging-resistant genotypes that retain high HI at high sowing density may allow sowing to be delayed to early January.


1992 ◽  
Vol 32 (4) ◽  
pp. 447 ◽  
Author(s):  
G Sweeney ◽  
RS Jessop ◽  
H Harris

The yields and yield structure of cultivars of triticales and bread wheats (with a range of phasic development patterns in both species) were compared in 2 field experiments at Narrabri in northern New South Wales. The experiments were performed on a grey cracking clay soil with irrigation to prevent severe moisture stress. Triticales, both early and midseason types, appeared to have reached yield parity with well-adapted wheat varieties. Meaned over the 2 experiments and all sowings, the triticales yields were 19% greater than the bread wheats. Triticales were generally superior to wheat in all components of yield of the spike (1000-grain weight, grain number/spikelet and spikelet number/spike), whilst the wheats produced more spikes per unit area. The triticales also had higher harvest indices than the wheats. The results are discussed in relation to the overall adaptability of triticale for Australian conditions.


1974 ◽  
Vol 14 (71) ◽  
pp. 790 ◽  
Author(s):  
JV Lovett ◽  
EM Matheson

In field experiments conducted over three years at Armidale, New South Wales, the total winter forage production by barley, oats, wheat and rye was similar. However, barley and rye tended to outyield wheat and oats at early harvests, the reverse applying at late harvests. It is suggested that these characteristics of the cereals could be exploited to meet specific seasonal requirements for dry matter production more effectively than is possible with a single species. Response to high seeding rates in forage production was similar in all cereals and was confined to a late sowing. Significant differences in in vitro digestibility over the winter period were recorded and differences were also apparent in subsequent grain yield.


1963 ◽  
Vol 3 (9) ◽  
pp. 114 ◽  
Author(s):  
JD Colwell

The effects of the different sowing rates of 20, 40, and 60 lb of seed an acre on the yield, bushel weight, composition, and response to fertilizers, of wheat grown on soils of high fertility has been studied in seven field experiments in the wheat-belt of southern New South Wales. Seasonal conditions ranged from drought to lush growing conditions and in addition one experiment was irrigated to reduce the effects of moisture stress on plant growth. Yields ranged from 10 to 70 bushels of wheat an acre and fertilizer treatments gave both positive and negative effects. For the wide range of growth conditions, variation in seeding rate had only small and non-significant effects on grain yields, with the exception of the irrigated experiment where a consistent trend indicated the need for higher seeding rates for maximum yield. Effects of the seeding rates on grain size and composition and fertilizer response, were negligible. Losses in potential grain yield, caused by the exhaustion of soil moisture reserves by excessive vegetative growth of high fertility soils before grain development has been completed, does not seem to be reduced appreciably by the use of low seeding rates.


1992 ◽  
Vol 32 (4) ◽  
pp. 465 ◽  
Author(s):  
AD Doyle ◽  
RW Kingston

The effect of sowing rate (10-110 kg/ha) on the grain yield of barley (Hordeum vulgare L.) was determined from a total of 20 field experiments conducted in northern New South Wales from 1983 to 1986. Effects of sowing rate on kernel weight and grain protein percentage were also determined from 12 experiments conducted in 1985 and 1986. Two barley varieties were tested each year. In all years fallow plus winter rainfall was equal to or greater than average. Grain yield increased with higher sowing rates in most experiments, with the response curve reaching a plateau above 60-70 kg/ha. For 13 of the 40 variety x year combinations, grain yield fell at the highest sowing rates. Only in an experiment where lodging increased substantially with higher sowing rates was there a reduction in yield at a sowing rate of 60 kg/ha. The average sowing rate for which 5 kg grain was produced per kg of seed sown was 63 kg/ha. Grain protein percentage usually fell, and kernel weight invariably fell, with increasing sowing rate. Increasing sowing rates from the normal commercial rate of 35 kg/ha to a rate of 60 kg/ha typically increased grain yields by 100-400 kg/ha, decreased kernel weight by 0.4-2.0 mg, and decreased grain protein by up to 0.5 percentage points. In no case was the grain weight reduced to below malting specifications. It was concluded that sowing rates for barley in northern New South Wales should be increased to about 60 kg/ha.


1995 ◽  
Vol 2 (4) ◽  
pp. 398 ◽  
Author(s):  
J. C. Noble ◽  
D. J. Tongway ◽  
M. M. Roper ◽  
W. G. Whitford

The effects of prescribed fires on nutrient pools, soil micro-organisms, and vegetation patch dynamics were studied in three semi-arid mallee shrublands in western New South Wales. Repeated sampling of surface soil strata (0–2 and 2–4 cm) was undertaken at strategic times (immediately before and after the fire, after opening autumn rain, mid-season in the winter, and at the end of the spring) in five microsites (inner, middle and outer mallee litter zones, bare soil, and Triodia hummock). These samples were later analysed for pH, electrical conductivity, organic carbon and available nitrogen. The effect of fire on soil micro-organisms in these microsites was also examined by measuring nitrogenase activity and enumerating soil Acari. Carbon and nitrogen levels were consistently higher in the inner mallee microsites whereas bare soil sites provided the lowest values. Significant microsite x soil depth interactions were recorded in two shrubland sites while highly significant (P < 0.001) depth x sampling time interactions were recorded in three sites. The most sensitive soil parameter with respect to microsite was electrical conductivity, particularly in the surface 0–2 cm stratum. Highest values were again recorded from the inner mallee microsites and the lowest from bare soil sites. Nitrogenase activity was highest in soil samples associated with mallee litter and, where litter was removed by fire, activity decreased markedly except in the bare soil samples where activity was higher in the burnt samples. Soil microarthropod populations also declined notably following fire. Mites from the Prostigmata greatly outnumbered those from other suborders, a total of 12 families (15 genera) being enumerated in control sites compared with three families (three genera) only of Cryptostigmata. Nonetheless the most abundant mites were cryptostigmatids (Aphelacarus spp.) found in unburnt hummocks beneath Triodia plants. The ecological and management implications of these spatial and temporal fluxes in soil chemistry and soil biology are discussed in relation to their effects on landscape processes, particularly water and nutrient redistribution.


1992 ◽  
Vol 43 (1) ◽  
pp. 105 ◽  
Author(s):  
DF Herridge ◽  
JF Holland

The effects of tillage practice and double cropping on growth, yield and N economies of summer crops were examined in field experiments near Tamworth, northern New South Wales. Sorghum, sunflower, soybean, mungbean, cowpea and pigeon pea were sown into alkaline, black earth soils which contained either high (Site A, sown January 1983), moderate (Site B, sown December 1983), or low concentrations of nitrate (Site C, sown December 1984). During the previous winters, the land had been sown to wheat (double crop) or fallowed using cultivation or no-tillage practices. At Sites A and B, dry matter yields, averaged over all crops, were increased by 34 and 14% under no-tillage. Average increases in grain yields at the two sites were 22 and 11%. At Site C, tillage practice did not affect yields. Soybean showed the greatest responses to no-tillage. Increases in grain yields were 46, 15 and 18% for Sites A, B and C respectively. The least responsive legume was mungbean. Yields of sorghum were increased by 41% at Site A; responses at Sites B and C ranged between a 9% decrease and a 7% increase. With double cropping, grain yields were, on average, 18 (Site A), 81 (Site B) and 72% (Site C) of the yields in the cultivated (fallow) plots. However, when comparisons were made for the 12 month periods, i.e. wheat and summer crops v. fallow and summer crops, production was more than doubled at Site B and tripled at Site C, compared with the cultivated fallow. Significant in the responses to double cropping were the 192 (Site B) and 230 mm rainfalls (Site C) during November and December that replenished the soil profile with water to a depth of >0.75 m. Assessments of soybean N2 fixation using the ureide method indicated large effects of site and season on the proportion of plant N derived from N2 fixation (range, 0-0.83), on the amount of N2 fixed (range, 0-233 kg N ha-1) and on the N balance as a result of the cropping (range, -69 to +45 kg N ha-1).


Soil Research ◽  
1978 ◽  
Vol 16 (3) ◽  
pp. 355
Author(s):  
GD Batten

Twenty soils from southern New South Wales were analysed for acid extractable phosphate in 1971, and again in 1977 when it was found that an increase had occurred. These same samples were also analysed using reciprocating shakers with different distances of travel. More phosphate was extracted when a shaker with a greater distance of travel was used and when more soil, but at the same soil : solution ratio, was placed in a large vessel. It is suggested that such variations in technique contribute to inter-laboratory error in soil tests for phosphate.


1963 ◽  
Vol 3 (10) ◽  
pp. 190 ◽  
Author(s):  
JD Colwell

The usefulness of five contrasting methods of soil analysis for estimating the phosphorus fertilizer requirements of wheat in southern New South Wales has been investigated, using yield data provided by 27 field experiments. Because the level of yield of wheat is strongly affected by seasonal environmental conditions poor correlations are obtained between soil analysis and absolute or relative yield of wheat, Much better and often significant correlations are obtained between soil analysis and the absolute increase in yield from fertilizer application. The best correlations were obtained with an 0.5M NaHCO3 extraction of soil phosphorus. A regression response surface calculated from these relationships provides a method for making direct estimates of fertilizer requirements for maximum economic return to farmers under average climatic conditions. The precision of these estimates is limited more by the flatness of the response surface and uncontrolled variation in the field data, than by inadequacies in the representation of available phosphorus by the NaHCO3 analysis.


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