Yield Andquality Research Articles

CORN ROOT AREA MYСOCENOSIS UNDER THE INFLUENSE OF CHAETOMIUM GLOBOSUM AS DESTRUCTOR OF STRAW

Quantitative and qualitative composition offungi in the rhizosphere soil of corn wasstudied. It was shown that introduction of strawinto the soil resulted in an increase the numberof representatives of Fusarium Link and Bipolaris Shoemaker genus, which often includephytopathogenic and phytotoxic fungi, whichcan affect plants, reducing crop yield andquality. It has been established that applicationof Chaetomium globosum 377 fungus as destructor of wheat straw leads to the decrease inrhizosphere of corn plants the number ofrepresentatives of these genus and an increasein Trichoderma Pers ex Fr. Thus application ofC. globosum 377 as destructor of plant residuesupports to increase the antagonistic potentialof corn rhizosphere soil and protect plants frompathogens.

Effects of Seasonal Deficit Irrigation, Potassium Fertilization and Bunch Thinning on Growth, Yield and Quality of Flame Seedless Grapes

Impacts of deficit irrigation levels, potassium fertilization, and bunch thinning on grapevine vegetative growth, yieldand quality of Flame Seedless table grapes were investigated during 2012 and 2013 seasons. Vines were subjected toseasonal irrigation treatments from bud swell to dormancy including: Standard irrigation (100 % of cropevapotranspiration [ETc]), moderate deficit (80 % of ETc), and sever deficit (60 % of ETc). Effects of two levels ofpotassium fertilization (0 and 0.58 kg as K2O per vine per season) and bunch thinning (40 and 30 bunch per vine) werealso investigated. Results showed that vine petiole potassium concentration was significantly dependent upon appliedirrigation level and was highest in standard irrigated potassium fertilized vines. Shoot length, leaf area and pruning weightresponded negatively to irrigation deficit, while bunch thinning increased leaf area in both seasons and pruning weight inthe second season with no effect on shoot length, whereas potassium had no effects on vegetative growth. Vine yield,bunch weight and berry diameter increased significantly with increasing irrigation level and with potassium fertilization.Bunch thinning significantly decreased yield in first season only while increased bunch weight and berry diameter. Cropload (yield/pruning) significantly increased by potassium and decreased by thinning with no effect for irrigation. Wateruse efficiency (yield/irrigation) significantly increased by increasing irrigation level and by potassium fertilization whiledecreased in first season by thinning. Increasing deficit irrigation level resulted in increased berry juice total soluble solids(TSS) and declined titratable acidity (TA), decreased berry firmness, increased skin anthocyanin and total phenolics, andreduced skin color characteristics values of lightness (L*), chroma(C*) and hue angle(h°). Bunch thinning increased berryTSS in first season, did not affect TA and fruit firmness, and increased berry skin anthocyanin and total phenolics, whiledecreased skin L* in the first season, C* and h°. Potassium fertilization increased berry TSS, TA, anthocyanin, totalphenolics, did not affect firmness with no consistent effect on skin color characteristics.

EFFECT OF TRANS PLANTING DATE AND CULTIVAR ON GROWTH, YIELD AND QUALITY OF BROCCOLI

This investigation was conducted at the experimental station of theFaculty of Agriculture, Cairo University, Giza, during the two successivewinter seasons of 2013/2014 and 2014/2015 to study the effect of threeplanting dates, three F1 cultivars and their interactions on growth, yield andquality of broccoli plants. The planting dates were as follows, 1st September,1st October and 1st November with three F1 cultivars, viz. Marathon,Heraklion and Centauro, respectively. Results showed that plant growth,yield and quality of heads were greatly affected by the three cultivars inplanting dates. In this respect, second planting date 1st October gave thehighest values of most vegetative growth traits expressed as number ofleaves, leaf area and total fresh weight plant. As well as the highest values ofmain head and total heads yield/plot and /fed. Plants gave the highest valuesof most of vegetative growth characteristics, yield and quality of broccolifollowed by Marathon plus 1st November planting date recorded the lowestvalues of growth, yield and its components. With respect to the interaction,Centauro plus 1st October planting date was superior in total head yield andphysical characteristics of heads expressed as average head length, diameterand weight. Therefore, it could be recommended for to obtain the highestvalues of head yield and quality of broccoli we are advised to plant Centauroand Marathon, respectively in planting date 1st October.

Effect of potassium and sulphur on nutrient uptake, yieldand quality of Pigeon Pea (Cajanus cajan)

A study was conducted with graded levels of potassium and sulphur on pigeon pea to assess the nutrient uptake, yield and quality at Agronomy Farm, College of Agriculture, Nagpur (M.S.) The data revealed that application of K and S levels significantly influenced the uptake of major and micronutrient in pigeon pea. High N and P uptake was observed due to application of 30 kg potassium and 20 kg sulphur per hectare. Potassium uptake was increased significantly with increasing the levels of K. The highest K uptake was noticed in 45 kg K and 20 kg S per hectare combination. The recovery of NPK was higher in 30 kg potassium per hectare. Due to increased level of potassium and sulpur there was no adverse effect on calcium assimilation and highest uptake of calcium was observed in the application 30 kg K and 20 kg S per hectare. The optimum supply of K and S improves the uptake of micronutrients. Significantly high grain yield and protein yield was observed due to application 30 kg K and 20 kg S per hectare. Therefore balanced fertilization of NPKS nutrients is required in pigeon pea.

Efficacy of dormex (hydrogen cyanamide) on germination, growth, yield andquality of sugarcane

Sugarcane is propagated by vegetative means using cane pieces containing one, two or more buds. After planting the crop begins with the germination of buds which is a complex phenomenon and differs from other seed plants. Under north Indian conditions, the germination of buds varies from 20–45%. In order to determine the effect of Dormex, a product having hormone like properties, an experiment was conducted at research farm of UP Council of sugarcane Research Institute Shahjahanpur (U.P.) during the spring season of planting 2012–13 using variety CoS 96268. Sugarcane setts were treated for fifteen minutes with different concentrations (i.e, 1.0%, 1.5%, 2.0%) of Dormex before planting to explore its efficacy on bud germination. The results indicated that sugarcane planting with setts treated with Dormex increased the germination significantly at 60 days after planting (DAP). The germination at 30 and 45 DAP was also higher than untreated control. The shoot population was also increased with the application of Dormex at a significant level at 30 days intervals. Increase in number of millable canes and cane height also followed the similar trend upto maturity. The cane yield increased in plots treated with Dormex than untreated control. Quality of cane was not affected significantly due to the application of Domex.

Exploratory study on internal recycling of crude glycerol for biodiesel production: Catalyst replacement

The present study evaluated the recycling of crude glycerol as source of catalyst for biodiesel production. For that purpose, two sets of experiments were conducted. In the first set (A), biodiesel was synthesized by conventional methanolysis of sunflower oil using NaOH as catalyst at 65?C during 1 h and varying catalyst concentration (0.4 - 1.2 wt.%) or methanol to oil molar ratio (6:1-12:1). The second set (B) was performed by replicating the conditions of set A and considering the use of crude glycerol as source of catalyst. The evaluation of excess methanol and catalyst distribution in the crude products was performed. For both sets of experiments, product yield and quality (viscosity and purity) were determined. Methanol was predominantly in the glycerol phase (54 - 68%), with negligible effect of variation in catalyst concentration and higher percentages found when higher methanol to oil molar ratios were used, due to a higher polarity of this phase. In most cases, catalyst was predominantly in the crude glycerol (53 wt.% in average) and no clear relation was found between catalyst distribution and the different reaction conditions studied. The results from set A showed a clear influence of catalyst concentration in biodiesel conversion and a minor effect of methanol to oil molar ratio. The best conditions were 6:1 methanol to oil molar ratio and 0.6 wt.% of catalyst leading to a product yield of 95.1 wt.%, a purity of 99.3% and a viscosity of 4.59 mm2s-1. The second set of experiments showed different trends and variability compared to the first one and the results indicated that catalyst might be altered during glycerol storage. It was found an effect of methanol to oil molar ratio in reaction conversion with the highest purity (96.9 wt.%) being obtained when the highest molar ratio was used (12:1) possibly due to the reduced mass transfer limitations. Overall, the results clearly show the potential of using crude glycerol as source of catalyst, avoiding the use of new catalyst and allowing a more sustainable biodiesel production.

Effects of crossing of domestic breed with beef breeds on the quality of meat in PR China and Republic of Serbia

This paper presents the results of crossing Domestic Spotted breed with beef cattle breeds in the People's Republic of China and the Republic of Serbia. China is a big country of beef production and consumption. In 2012, beef production in China was 5,540,000 tons, which accounted for 9.7% of the global beef production, ranking the third in the world. The main sources of China?s beef are from crossbreeding cattle (native breed crossbred with foreign beef cattle). Simmental cattle are the most-widely used beef cattle in China?s improved beef cattle. China has cultivated its own Simmental after over 40 years? crossbreeding and improvement. China?s consumers mainly have three demands for beef quality as follows: expensive beef produced from Wagyu crossbreed with better marbling; lean beef from Simmental, Charolais and Limousin crossbreeds, top parts supplied to hotels while common parts to supermarkets; veal from cow calves. Chinese researchers are carrying out researches which are centered on marbling beef, lean beef and veal on complete techniques of good breed, feeding management, slaughter and cutting and carcass classification. At present, researchers have lively interest in functional genomics of meat quality traits of cattle, they expect to use these methods to study meat quality traits and then improve the meat quality. Improved cattle breeds universally utilized in China are mainly Simmental followed by Charolais, Limousin, Wagyu and Angus. Other three cattle breeds including Belgian blue cattle, Piedmontese and Gelbvien have ever been applied, however, rarely used in present beef cattle production. Republic of Serbia has in the future to quickly and efficiently provide adequate quantities of top quality meat. One of the ways to increase the yield and quality of the meat is crossing of Domestic spotted cattle of lower production traits with French beef cattle breeds. Beef production in the EU is adapted to the consumer taste. Meat must have a light red colour, equally suffused with fat and with pronounced sensory characteristics such as tenderness, juiciness, flavour and aroma. The results on the quality of meat of F1 generation crosses (Domestic Spotted breed with French beef cattle breeds Charolais and Limousine) indicate that by industrial crossing beef, meat-packing and organoleptic characteristics of meat can be improved.

Correlation between protein to fat ratio of milk and chemical parameters and the yield of semi-hard cheese

In order to obtain good cheese quality, the milk has to possess good physical-chemical properties and should originate from healthy cows. Since milk fat and milk protein are the main constituents of cheese, their proportion in milk is of particular importance for the product yield and quality. This paper describes studies on the protein to fat ratio of milk and the consequent influence on the chemical composition and yield of semi-hard cheese, commercially called "Montenegrin naturally dried cheese". The tests were conducted on six bulk milk samples and six cheese samples. The milk parameters were analysed by the Milkoscan 400 unit whereas chemical analysis of cheese and whey were carried out with the Milkoscan FT 120 device. The average composition of the cheeses was: 29.27% fat, 21.90% protein, 55.27% total dry matter and 0.78% sodium chloride. The mean value for the content of dry matter without fat was 26%, whereas the fat content of the cheese dry matter was 53.18%, the moisture content in cheese 44.73% and moisture content in fat-free matter 63.24%. There was a medium positive correlation between the ratio of fat to protein in milk and fat content in cheese (r = 0.60309), the ratio of fat to protein in milk and dry matter of cheese (r = 0.57103), weak positive correlation between the ratio of fat to protein in milk and cheese protein (r = 0.48067) and medium negative correlation between the ratio of fat to protein in milk and moisture content in cheese (r = -0.57103). Medium negative correlation was found between the ratio of protein to fat in milk and content of cheese fat (r = -0.56416), the ratio of protein to fat in milk and cheese protein content (r = -0.51899), the ratio of protein to fat in milk and dry matter of cheese (r = -0.53118) and medium positive correlation between the ratio of protein to fat in milk and moisture content in cheese (r = -0.53118). Ratio fat to protein in milk and the actual yield of cheese was determined as medium positive (r = 0.66459) and the ratio protein to fat in milk and the actual yield of cheese as medium negative correlation (r = -0.67807). The protein to fat ratio in milk influences the decline of fat, protein, dry matter and yield of cheese and increase moisture content in cheese.

Some aspects of improvement of grassland production for grazing of sheep

Grasslands represent significant natural resource with important role in economy and ecology of every country. Properly cultivated and utilized grasslands provide cheap and high quality food for sheep, which they easily transfer into milk and meat. However, extensive management has caused degradation of pasture areas. Improvement of production of forage plants on pastures is achieved by using melioration measures, primarily fertilization. Fertilization is important also from the aspect of increase of yield and quality of forage plants. The effect of application of fertilizer depends on the present plant species in the mixture. Application of nitrogen mineral fertilizers in mixtures reduces the nitrogen fixating abilities of leguminous species, which leads to the diminishing of their competitive abilities and favouring of the grass component in the mixture. Use of excessive quantities of N fertilizer in plants causes the accumulation of nitrates, as a unfavourable quality parameter in plant tissues, which can have harmful effect on animal health. Therefore, attention should be focused on application of N fertilizers, which should be harmonized with the plant requirements, so that used quantities are not excessive and harmful. Objective of this paper is to point out the significance of fertilization as one of the most important melioration measures.

Effect of crop density on yield and quality of alfalfa forage from combined use (forage-seed)

In Serbia, alfalfa is the most important perennial forage legume that is grown at 180-200 thousand hectares. Except for the classic production of forage, alfalfa is very important for seed production. In our conditions Alfalfa seed are produced from the second cut of alfalfa. Higher seed yields are achieved in larger distances between rows. In this system of production first and third cut are used for fodder. This trial tests three different densities and four varieties in order to determine the impact on yield and quality of forage dry matter. In the year of establishment, cultivars from the treatment A1 achieved higher yields of dry matter for 2.3 t ha-1 in relation to the treatment A2. In the second year, yield was higher by 1.4 t ha-1, and in the third higher for 3.1 t ha-1. Treatment A1 compared to A3 treatment had a higher yield of 3.5 t ha-1 (52%). In the second year treatment A1 achieved higher yields of forage then treatment A3 for 3.8 t ha-1 (44%), and in the third year for 4.6 t ha-1 (56%). Cultivars were also significantly affected the yield of forage dry matter at all densities. Influence of density and variety to the chemical composition of forage and the content of macro elements in the forage had no significant effect.

Grain yield and quality of maize hybrids in different FAO maturity groups

An improvement in the quality of maize grain by increasing the level of components responsible for its biological value is possibleby using genetic means. However, a change in the genotype, together with improving the nutrient properties of the grain, also has someadverse consequences connected with a fall in yield and in resistance to diseases.Field experiments were conducted during three years (2003, 2004and 2005) to evaluate environmental effects on grain yield andquality responses of maize hybrids. Twenty one hybrids of various maturity groups (FAO 150-400) were planted to achieve an optimum(60-70 000 plants per hectare) plant populations and grown under the medium-N (80 kg N ha-1) fertilization. Environmental conditionssignificantly affected maize hybrid responses for grain yield, starch, oil and protein contents, and consequently, starch, oil and proteinyields per hectare. Hybrids of flint type, which have a short vegetation period, had high protein and oil content but the yield averageswere low due to the slower rate of starch incorporation. Hybrids of the dent type have a longer growing season and more intensecarbohydrate accumulation, but low protein and oil contents. In wet years there was a higher rate of starch accumulation, while dryyears are favorable for protein and oil accumulation. Positive correlation existed between starch content and grain yield and 1000-weight as well as between oil content and volumetric weight among tested hybrids. Negatively correlation existed between grain oil andstarch content as well as between oil content and grain yield and 1000-weight. Thus, end-users that require high quality maize may needto provide incentives to growers to off set the negative correlation of grain yield with oil and protein content.

EFFECT OF ORGANIC MANURE AND PLANTING DATES ON FORAGE YIELD AND QUALITY OF ALFALFA (MEDICAGO SATIVA) AT FAYOUM GOVERNORATE

Two field experiments were carried out at the ExperimentalFarm, Faculty of Agriculture Fayoum Univ, during the twosuccessive seasons of 2006 and 2007 to study the effect of organicmanure levels (20, 40 and 60 m3/fed.), and planting dates (April insummer season and November in winter season) on forage yield andquality of alfalfa at Fayoum governorate .The results indicated that :1- Applying organic manure fertilizer at levels 20, 40 and 60 m3/fed,had no significant effect on fresh and dry forage yield (ton /fed)during winter and summer seasons with one exception during the2nd cut in the 2nd season only during summer seasons.2- The protein percentage was significantly responded to organicmanure levels. The maximum values were observed by applying60 m3 / fed.3- Increasing organic manure levels from 20, 40 up to 60 m3/fed,affected significantly on total carbohydrates.

The influence of THI values at different periods of lactation on milk quality and characteristics of lactation curve

The experiment included 90 cows. Cows were chosen according to the time of calving, so that the first third of lactation occurred during the summer in 30 cows (G1), the second third of lactation occurred during the summer in 30 cows (G2), and in the last 30 cows the last third of lactation was in summer period (G3). The value of THI was between 72 and 82, which indicates the existence of the moderate intensity of heat stress. Heat stress does not damage the milk yield, milk fat and protein percentage on the level of the whole lactation, regardless of the lactation period in which the cows were exposed to stress. There was no correlation between THI and milk yield and quality at the level of the whole lactation. Heat stress did not show a significant effect on the parameters of lactation curve, except the peak of yield, which occurred later in cows exposed to heat stress. Increased value of THI showed nonsignificant effect on yield and quality of milk in the first third of lactation. In the middle and at the end of lactation THI was in a significant negative correlation with the yield and quality of milk. Our study showed a significantly lower heat-induced milk yield, milk fat and protein percent in the middle and at the end of lactation.

Genetic variants of milk proteins and their effects on the yieldand quality of cheese.

Abstract Milk protein genes, which are inherited by simple Mendelian genetics, could be used as marker traits for production and milk compositional traits. Genetic variants of certain milk proteins have been shown to be associated with coagulating properties of milk, cheese yield and cheese composition. In most of the cases, the observed differences in cheesemaking properties between some genetic variants are the result of their associations with the levels of fat and casein in the milk, which significantly influence cheese yield and composition. However, in some instances, differences between genetic variants are the result of the direct effect as a result of substitution of amino acids along the polypeptide chain leading to a change in the conformation and hence altering the physiochemical properties of the protein. Differences in heat stability, protein/protein interactions, and rate of proteolysis of different genetic variants are some examples of the direct effects in some cheese varieties. In bovine species, most studies have demonstrated that the B variant of κ-casein and the B variant of β-lactoglobulin (which are associated with higher levels of fat and casein in the milk) give higher cheese yield and better cheese composition than the A variant of the two proteins. Most research on caprine milk has concentrated on the αas1-casein loci. Variant A, which is associated with higher levels of synthesis of αs1-casein and total casein, is more suitable for cheese production than either variant E or F. In the ovine species, it has been shown that variant D of αs1-casein is not favourable for cheesemaking, while β-lactoglobulin A milk is more suitable than β-lactoglobulin B for the making of cheese.

Adubação verde com leguminosas em videira no submédio São Francisco

Os solos do Vale do Submédio São Francisco são, de modo geral, arenosos, com baixa capacidade de retenção de nutrientes e, por se localizarem numa região semi-árida, são muito pobres em matéria orgânica, conseqüentemente, são deficientes em N, tornando-se limitante para produção agrícola. Dessa forma, o uso de leguminosas como adubo verde pode contornar esse problema, porque adiciona C e N ao solo. O trabalho constituiu-se de dois experimentos de leguminosas consorciadas com a cultura da videira (Vitis vinifera) irrigada, realizados em um Argissolo Amarelo de textura arenosa, em Petrolina (PE), de junho de 1996 a julho de 2002, com o objetivo de avaliar o efeito da adubação verde nas características químicas do solo e na produtividade e qualidade da uva. O primeiro experimento foi realizado até à quarta safra de uva. Os tratamentos foram representados por duas leguminosas: crotalária (Crotalaria juncea) e feijão-de-porco (Canavalia ensiformis), submetidas a dois manejos (subtratamentos): (a) ceifada e deixada na superfície do terreno e (b) ceifada e incorporada ao solo, havendo ainda uma testemunha sem leguminosa. O segundo experimento, que se iniciou com o quinto ciclo de produção de uva, abrangeu três tratamentos: (1) testemunha; (2) crotalária júncea e (3) feijão-de-porco, combinados com dois subtratamentos: (1) 100 % da adubação recomendada pela análise de solo e (2) 50 % dessa adubação. Ao todo, houve onze ciclos de leguminosas e nove safras de uva. A produção de biomassa das leguminosas decresceu ao longo do tempo. A adubação verde proporcionou uma melhoria nas características químicas do solo, aumentando os teores da MO e do Ca trocável e o valor da CTC na camada de 0-10 cm de profundidade. Não houve um efeito consistente da adubação verde na produtividade e qualidade da uva.

ZONE?SUBSOILING RELATIONSHIPS TO BULK DENSITY AND CONE INDEX ON A FURROW?IRRIGATED SOIL

Zone subsoiling on irrigated land has been successfully used to improve potato (Solanum tuberosum L.) yield andquality. Zone subsoiling under furrow irrigation may disrupt water flow and influence infiltration and soil erosion. Wehypothesized that zone subsoiling, done appropriately, will maintain integrity of irrigation furrows, improve small grain anddry bean (Phaseolus vulgaris L.) growth and yield, and not adversely affect water flow, infiltration, or erosion onfurrowirrigated soils. The experiment was conducted at the USDAARS Northwest Irrigation and Soils Research Laboratoryin Kimberly, Idaho. The soil is a Portneuf silt loam (coarsesilty, mixed, superactive, mesic Durinodic Xeric Haplocalcids).Tillage treatments were disk, disk + paratill, paratill, and notill.There were no differences in water infiltration, runoff, orsoil erosion among treatments. Bulk density differences among treatments were largest at the 0.15 to 0.20m depth, and bulkdensity was about 16% to 18% greater on disk and notill treatments than on paratill treatments. The highest frequency oflow cone index (CI) values belonged to paratill treatments (65% to 80% frequency of CI values less than 2 MPa); the lowestfrequency of low CI values belonged to notill treatment (20% frequency less than 2 MPa). Cone index versus bulk densityrelationships depended on soil water content with a slope of 5.81 (r 2 = 0.70) in the wetter year of 1997, and 2.90 in the drieryear of 1995 (r 2 = 0.60). Subsoiling can be accomplished on furrowirrigated lands with no adverse effects on runoff,infiltration, and erosion, but under our conditions did not improve crop growth and yield.

Processing tomato fruit quality: influence of soil water deficits at flowering and ripening

One way to reduce the production cost of tomato solids is to increase fruit solids at harvest time. In a field trial using 200-L containers the effects of early and late soil water deficits (treatments DE and DL) on fruit yield and quality were tested during either flowering or late fruit growth. The effect of standard irrigation, with water cut off during the 3–5 weeks before harvest (SC), was also compared with full-season irrigation (FS). Manual irrigation of containers twice per week replaced soil water loss, measured by time domain reflectometry. A rain shelter was used as needed. The duration of the DL treatment was 43 days, which was intended to equate to 60–70 days of slower root-zone drying by finer textured field soils. Soil matric potentials were as low as –1500 kPa during both DE and DL. Fruit colour change was accelerated by DL; fruit were 97% red at harvest as against 89–93% for the other 3 regimes. Fruit yields of treatments other than DL were all near 93 t/ha. Yield of DL was reduced 38%, mainly due to 35% smaller fruit. Fruit quality parameters [soluble solids concentration (SSC), total solids, and titratable aciditymp;rsqb; were similar in the 3 higher yielding regimes, but were much greater in the DL treatment. Fruit pH was also more favourable (i.e. lower) in DL. The SSC was 2.8;deg;Brix higher in DL, sufficiently so that soluble solids yield/ha was not significantly lower than other treatments. This occurred without a decrease in juice viscosity or consistency (Bostwick). Simple models were developed for predicting soil water deficit effects on fruit quality. There is clearly an opportunity for irrigation management to improve tomato processing quality and profitability.

Effects of enzyme supplementation on the replacement value of canola meal for soybean meal in broiler diets

A broiler growth study was conducted to investigate the replacement value of canola meal (CM) for soybean meal (SBM) in broiler diets with or without the addition of two commercial enzyme products. A total of 3600 broilers were used in this experiment. Four isoenergetic diets replicated 10 times with 90 birds each were fed ad libitum as starter (Day 0–21) and finisher (Day 21–37) crumbles. All diets included a high proportion of sorghum as the main cereal component, and soybean meal (20% and 24.5%) or canola meal (35% and 28.9%) were included as the sole protein concentrate. At Day 38 selected birds from each dietary treatment were commercially processed and carcass yield and weight of selected meat portions were measured. The inclusion of CM in place of SBM and the addition of enzyme to CM-based diets did not affect feed intake, growth, and feed conversion ratio (FCR). Mortality in birds fed the unsupplemented CM diet was significantly reduced compared with the mortality in birds fed the SBM control diet or the CM diets supplemented with enzymes. Birds fed the unsupplemented CM had significantly (P < 0.05) reduced eviscerated weight, breast meat, and thigh yield and a significantly (P < 0.05) reduced water-holding capacity of muscle tissue compared with the SBM control diet. The addition of Enzyme A to CM-based diets increased breast meat and the addition of Enzyme B significantly (P < 0.05) increased dress yield, breast meat, and Marylands (thigh and drumstick portions). Carcass yield and quality on this diet was comparable to the SBM diet.

Freeze-induced reduction of broccoli yield and quality

Summary. Sub-zero temperatures can result in freezing injury of broccoli (Brassica oleracea L. var. italica Plenck) plants and thereby reduce head yield and quality. In order to predict effects of frosts, it is desirable to know the stages of development at which broccoli plants are most susceptible to freezing injury. In this study, the effect of a range of sub-zero temperatures for a short period at different stages of crop development were assessed and quantified in terms of mortality, yield and quality of broccoli. Whole plants in pots or in the field were subjected to sub-zero temperature regimes from –1 to –19°C. Extracellular ice formation was achieved by reducing temperatures slowly, at –2°C per hour. The floral initiation stage was most sensitive to freezing injury, as yields (fresh and dry head weights) were significantly reduced at –1 and –3°C, and the shoot apices were killed at –5°C. There was no significant yield reduction when the inflorescence buttoning stage was treated at –1 and –3°C. Although shoot apices survived the –5°C treatment at buttoning, very poor quality heads of uneven bud size were produced as a result of arrested development. The lethal temperature for pot-grown broccoli was between –3 and –5°C, whereas the lethal temperature for field-grown broccoli was between –7 and –9°C. The difference was presumably due to variation in cold acclimation. Freezing injury can reduce broccoli head yield and quality and retard plant growth. With regard to yield and maturity prediction, crop development models based only on simple thermal time without restrictions will not apply if broccoli crops are frost damaged.

Legume and opportunity cropping systems in central Queensland. 2. Effect of legumes on following crops

Poor yields and low grain protein in cereal crops resulting from declining soil fertility, especially nitrogen (N), are major threats to the grains industry in central Queensland. The effect of 4 different pasture-ley legumes [siratro (Macroptilium atropurpureum cv. Siratro), lucerne (Medicago sativa cv. Trifecta), lablab (Lablab purpureus cv. Highworth), and desmanthus (Desmanthus virgatus cv. Marc)] on grain yield and quality of sorghum crops was compared with that of a pulse (mungbean; Vigna radiata cv. Satin) or continuous cropping with grain sorghum (Sorghum bicolor). Legume leys consistently resulted in large increases in grain yield (188–272%), N uptake by sorghum (145–345%), and grain protein (0.21–7.0% increase in grain protein) in sorghum test-crops compared with continuous sorghum crops to which no fertiliser N had been added. The positive effect of legumes persisted up to 3 sorghum test-crops after only 1 year of legumes, although by the third year the effect was comparatively small. Mungbean and lablab generally produced the largest benefit in sorghum test-crops in the first year after legumes, whereas desmanthus and lucerne produced the least benefit. Adding fertiliser N (up to 75 kg N/ha) significantly improved grain yields and N uptake of sorghum test-crops in 3 of 4 years. However, responses to fertilisers were less than those resulting from legumes, which was ascribed to increased availability of legume N to sorghum. Legumes progressively increased soil nitrate in all subsequent sorghum test-crops (compared with continuous sorghum crops), rising from 6.8–18.9 kg NO3-N/ha after 1 year of legumes to 24.2–59.6 kg NO3-N/ha after 3 years of legumes. There was little difference between the legumes in their ability to increase soil nitrate, with the exception of desmanthus, which consistently resulted in the lowest amount of soil nitrate for subsequent test-crops and lowest uptake of N by these crops. Plant-available water content (PAWC) at planting of the sorghum test-crop was only significantly (P<0.05) affected by previous species in 1997, when it was lowest in plots previously sown to siratro and lucerne and highest in sorghum and mungbean plots. In both 1996 and 1997, plots sown to sorghum had significantly higher PAWC at anthesis and grain maturity when previous plots were sorghum rather than legumes.