Use of flower and seed colour genetic markers showed that in plots, each 4·5 m × 4·5 m in size, the genetic contamination decreased from 16·96% at 0·9 m to 1·25% at 92 m, and 0·59% at 184 m distance. Maximum contamination from other Viciafaba outside the experimental field and at least 1·1 km away was 0·44%. Implications for the multiplication of stocks in breeding programmes are discussed.

Fourteen rice accessions resistant to bacterial leaf blight (BB), caused by Xanthomonas oryzae pv. oryza (Xoo) and belonging to nine wild Oryza species representing three genomic groups: AA (O. nivara, O. barthii, O. longistaminata, O. rufipogon and O. meridionalis), BBCC (O. punctata, O. malampuzhaensis and O. minuta) and CCDD (O. latifolia) were used to produce hybrids with two O. sativa (2n=24, AA) cultivars PR 106 and Pusa Basmati 1 (PB 1). The seed set in similar genome crosses ranged between 1·4 and 79% depending upon the rice cultivar used. In general, PR 106 showed better crossability with the wild species. Hybrids were obtained from intergenomic crosses with O. malampuzhaensis, O. latifolia and O. punctata, using embryo rescue. Morphologically, the hybrids were more vigorous than their parents and tended to resemble their male parent. Intragenomic hybrids showed little fertility (0·24–8·04%), while the intergenomic hybrids were completely sterile. Meiotic studies revealed irregularities in cell division, with a high frequency of univalents (12·17–18·75), fewer bivalents (2·43–5·80) and occasional multivalents, in intragenomic hybrids. The intergenomic hybrids were characterized by a very high frequency of univalents (34·98–35·35). The reaction of the hybrids to BB revealed the presence of both dominant and recessive genes in the wild gene pool. The hybrids with O. longistaminata, O. punctata, O. latifolia and O. malampuzhaensis showed resistance in the F1 generation, and hence they were likely to carry dominant genes for resistance, while the hybrids with O. barthii, O. nivara, O. meridionalis and O. rufipogon were susceptible and hence carried recessive genes for resistance.

Sheep weighing 27 kg live weight were fed ad libitum three pelleted diets containing alkali-treated ground rice hulls (0, 5 and 15 g NaOH/100 g rice hull dry matter) in a 1:1 ratio with ground non-alkali-treated lucerne and were fed a fourth diet comprising the above control pellet fed ad libitum with a wheat grain supplement to determine the effects of alkali treatment and of energy supplementation on the digestion of cell walls and to assess the dynamics of flow of digesta through the gastrointestinal tract.

Flows of organic matter (OM) and nitrogen (N) to the duodenum were not different for the four diets, but daily whole digesta flow past the duodenum was greater (P < 0·01) for the two alkali-treated diets. Alkali treatment of rice hulls increased the percentage of total digestion of OM that occurred in the foregut (68%) compared with non-alkali-treated diets (52%), did not increase total volatile fatty acid concentration in rumen liquor, or adversely increase rumen pH. The capability of rumen microbiota to synthesize ammo acids was not adversely affected by alkali treatment. The percentage unit digestibility of cell wall constituent OM in the whole tract was increased approximately 1·6-fold by alkali treatment. Grain supplementation increased diet digestibility.

Scanning electron microscope studies revealed confirmatory visual evidence of enhanced degradation of alkali-treated rice hulls in the tract. It is clear from these studies that alkali treatment has caused sheets of silicified cuticle on the outside of rice hulls to dissolve and to lift away from the underlying lignocellulosic (palisade) matrix. It is also clear that this matrix material is itself heavily mineralized. Disappearance of silica across the gut wall was greatest for animals fed alkali-treated diets. No clinical signs of urolithiasis were seen. Sheep readily coped with the sodium intake (33 g/day) associated with alkali-treated diets, partially by an increased water consumption and a greater ruminal and intestinal absorption of this electrolyte.

It is calculated that the OM intakes recorded and nutrients released from alkalitreated rice hull diets provided between 500 and 600 kcal net energy/day.

1. The relationship between the level of feeding herringmeal and its effect on growth rate, feed efficiency and bacon quality has been examined in nine experiments, each consisting of three groups of seven (in one series six pigs). All experiments concerned herringmeal with about 7% petrol ether extracted fat, fed in combination with ground cereal grains and concentrates (Table 2).

2. Seven levels of feeding were tried. In the live weight period 20–30 kg they amounted to 3, 4, 5, 6, 8, 10 and 12%, herringmeal respectively. Later the percentages were successively reduced as follows: in the period 30–50 kg live weight 3/4, in the period 50–65 kg 1/2 and in the period 65–80 1/4 of the original amounts. No herringmeal was fed from 80 to 90 kg when the pigs were slaughtered (Table 1).

3. Increased levels of herringmeal produced increased growth rate and also brought about an increased feed efficiency. Most of the response was obtained with moderate levels, i.e. additions starting with 6–8%. Higher levels exerted more total effect, but these further accelerations progressively lessened. For initial additions of 6% herringmeal the growth rate improved on an average estimated at 8% and the feed efficiency by 5% compared with the performances of the pigs on an all-vegetable control diet, whereas corresponding figures for initial additions of 12% were about 13 and 7, respectively. Lower levels proved of little benefit (Tables 3 and 4 and Figs. 1 and 2). Growth-promoting effect of levels of 6% or more proved significant.

Changes in distribution of amino acid nitrogen of chopped wheat plants ensiled at shooting and flowering when wilted, and at the milk and dough stages as fresh material, were determined as affected by addition of 0·8% propionic acid (PrA) or 2·2% urea phosphate-calcium propionate (UP-CaPr). Analyses were carried out after an ensiling period of 90 days and after a further aerobic exposure period (AE) of 7 days.

Total amino acid (TAA) contents in the dry matter (D.M.) during the fermentation period and in the AE were stable in untreated material (UM) and treated material. Concentration of essential amino acids decreased during fermentation, this decrease being higher in the UM. The free amino acids were low in the fresh material (18·6% of TAA) but increased in the ensiled material to ca. 71 % of the TAA in the silage. In the AE this level was 63% in UM and 69% in treated material. The ammonia-N contents increased during fermentation in UM and especially in the UP-CaPr treatments, while the opposite occurred in the PrA treatments.

The concentrations of and changes in 21 amino acids (AAs) are given. The highest AA concentrations recorded in the fresh material were those of arginine, lysine, glutamic acid, alanine, leucine, proline and glycine. The most marked increments in AAs as a result of fermentation were those of ornithine, γ-amino butyric acid, threonine and methionine. Marked decreases were observed in glutamine, arginine and glutamic acid. PrA increased mainly arginine, asparagine and glutamine, whereas γ-amino butyric acid decreased; UP-CaPr increased arginine, asparagine, lysine and glutamic acid (in silage only) and reduced γ-amino butyric acid and glutamine (in AE only).

During 1962-65 investigation was carried out at Cambridge on the effect of irrigation combined with cutting treatments on vegetative growth, inflorescence formation and yield of seed of S184 white clover sown on gravelly loam of poor waterholding capacity.

Under the conditions described, irrigation was beneficial for seed production when it was applied between the period of shutting-up and the start of clover flowering. An excess of water either from natural precipitation or irrigation during the flowering period had, however, a harmful effect on seed production.

Apart from the first year, the effect of differential cuttings up to the early bud stage was insignificant on the seed yield. The interaction cutting x irrigation was not significant.

The author is grateful to Mr F. R. Home, Director of the National Institute of Agricultural Botany, for opportunities and facilities provided for this experiment.

1. Sodium and potassium balances and the growth rate of steers have been recorded for animalsreceiving a protein supplement on a high and low salt regime.

2. Zebu steers receiving less than an average of 0-2 g. sodium per day were able to grow at 82 % of the rate of Zebu steers receiving salt supplement. Shorthorn steers under the same conditions grew at 72 % of the rate of Shorthorns receiving the supplement.

In a glasshouse experiment, sulphur was applied to 22 soils as 35S-labelled gypsum. Estimates of available sulphur using different extractants were correlated with yield responses and sulphur uptakes by oats. The largest correlation coefficients were obtained with ‘A’ values and sulphur soluble in 0·5 M-NaHC03, 1% NaCl after heating and ammonium acetate–acetic acid. Critical levels of available sulphur obtained by relating these four methods to yield responses were 24·0, 22·0, 11·0 and 10·5 mgS/kg soil respectively.

Mass selection (MS) and bulk selection of a single character (CS) were used for the improvement of a base population, Bl, which was composed of Tai Gu male-sterile progenies of ten high protein content and four high yielding parental lines of wheat (Triticum aestivum L.), transferred by 6–10 backcrossing generations, with equal numbers of plants from each line. Backcross mass selection (BS) was used for the improvement of a second base population, B2, which was formed by Tai Gu malesterile plants of four high yielding parental lines, again with equal numbers of plants from each line. Three cycles of selection were conducted for both population Bl and B2. Direct genetic advances of sterile plants for six traits were studied. The results indicated that use of the Tai Gu male-sterile single dominant gene is effective for recurrent selection of wheat. For improvement of a single character, CS was the most effective method, of which the selective effect in the first cycle (Cl) was greater than in the second (C2) and the third cycle (C3), although multivariate analysis snowed that the CS method was not conducive to the maintenance of variation in a population. The greatest response to selection was found in C2 with the MS method. Multivariate analysis also indicated that both the MS and BS methods increased the variation in the population, but MS was found to be the best selective method as judged by the mean response over three cycles of selection.

1. The mean thyroid weights of ewes grazed on the different pastures (perennial rye-grass (P), perennial rye-grass plus white clover (P + C), short-rotation rye-grass (S), short-rotation rye-grass plus white clover (S + C)) did not differ significantly, but those injected with iodinated poppy-seed oil had lighter (P < 0·01) thyroids than the non-injected ewes grazed on the same pastures.

2. Neither the live weights of the ewes nor their lambing performances were affected significantly by treatment with iodine.

3. Lambs from ewes grazed on pastures containing white clover had thyroid glands significantly heavier than those of ewes grazed on rye-grass pastures. The largest thyroids were from the lambs of ewes not treated with iodine and grazed on S.

4. The iodine contents of the thyroids of the lambs at slaughter, measured as percentage dry weight, did not differ significantly. It seems likely that the differences in thyroid weights were caused by factors operating early in the lives of the lambs.

5. The lambs of ewes injected with iodine grew faster after weaning than those of non-injected ewes on the same pastures. The interpretation that this difference was in fact caused by the iodine treatment of the ewes was not wholly acceptable, because the differences in growth rate were not greatest in those groups of lambs showing greatest differences in thyroid weight.

A variety of chemical reagents and treatment methods have been tested for their potential to enhance the digestibility of crop residues. The most universally used chemicals for animal experimentation in residue treatment are sodium or ammonium hydroxide (Chandra & Jackson, 1970; Koers, Prokop & Klopfenstein, 1972; Klopfenstein, 1978; Arndt & Richardson, 1982). These chemical treatments usually improve digestibility of roughages by solubilizing hemicellulose, and increasing the extent and rate of cellulose and hemicellulose digestion (Klopfenstein, 1978). Delignification is not usually considered to be an important aspect of chemical treatment (Klopfenstein et al. 1972), and increases in digestion are usually attributed primarily to breaking of bonds between lignin and carbohydrates rather than lignin removal. The aromatic nuclei of the lignin molecule are quite susceptible to oxidative attack (Sarkenen & Ludwig, 1971), and crop residues may be significantly delignified by oxidative chemical reagents (Sullivan & Hershberger, 1959; Sherrod et al. 1978; Ben-Ghedalia, Shefet & Miron, 1980). Ozonation is a chemical treatment method which is known to oxidize lignin and disrupt the lignocellulose complex. Several researchers have successfully applied the delignifying capability of ozone to improve the in vitro digestibility of roughages (Weakley & Owens, 1975; Ben-Ghedalia & Miron, 1981; Tock et al. 1982). Very little, however, is known of the actual in vivo feeding value of crop residues treated with ozone. These studies were conducted to determine the effect of ozone treatment on the feeding value of sorghum stover.

The ability of subjectively assessed body condition scores, direct measurements of backfat depth, and an objective body condition index (based on the size/weight relationship), to predict the proportion of chemical fat in the body of the live sheep was investigated in three groups of Merino ewes. All three techniques possessed a similar, and practically acceptable ability to predict the proportion of chemical fat in the fleece-free empty body. However, both live weight and fleece-free empty body weight possessed similar predictive powers, and the method of choice in any particular situation could thus be determined by the availability of weighing facilities and the need for speed, objectivity and for minimizing interference with the experimental animals.

For the production of hybrid and synthetic varieties, high rates of cross-fertilization are needed. Two aspects of cross-fertilization in Vicia faba L. were studied at Wageningen in 1989 and 1990. The occurrence of cross-fertilization between pollen receptor lines in large-scale assays for crossfertilization was determined. Furthermore, the contribution of the genotype of the donor, of the receptor, and of their specific interactions in terms of cross-fertilization rate were studied.

Inter-receptor cross-fertilization may represent from 2 to 70% of the total cross-fertilization. Interreceptor cross-fertilization increases when donors and receptors do not match for flowering height.

The genotype of the receptor appeared to be of importance for the cross-fertilization rate. No differences in cross-fertilization rate due to genetic differences between pollen donors were noticed. Also no significant specific donor x receptor interaction effect on cross-fertilization rate could be observed.

The combination of advances in knowledge, technology, changes in consumer preference and low cost of manufacturing is accelerating the next technology revolution in crop, livestock and fish production systems. This will have major implications for how, where and by whom food will be produced in the future. This next technology revolution could benefit the producer through substantial improvements in resource use and profitability, but also the environment through reduced externalities. The consumer will ultimately benefit through more nutritious, safe and affordable food diversity, which in turn will also contribute to the acceleration of the next technology. It will create new opportunities in achieving progress towards many of the Sustainable Development Goals, but it will require early recognition of trends and impact, public research and policy guidance to avoid negative trade-offs. Unfortunately, the quantitative predictability of future impacts will remain low and uncertain, while new chocks with unexpected consequences will continue to interrupt current and future outcomes. However, there is a continuing need for improving the predictability of shocks to future food systems especially for ex-ante assessment for policy and planning.

1. The changes in composition of the clay fraction in different horizons of some typical North Welsh profiles have been studied.

2. The changes in the molecular ratio of silica to sesquioxides (SiO2/Al2O3 + Fe2O3) throughout a soil profile afford an indication of the nature of the eluviation which has affected the mineral portion of the soil.

3. The data for North Welsh soils indicate a general tendency to enrichment of the lower layers in sesquioxides, particularly ferric oxide, at the expense of the surface layers.

4. The silica-sesquioxide ratio of the clay fraction is an important aid to series definition.

5. The soils of North Wales, particularly in the uplands, have probably been subjected to considerable erosion in the past. The profiles are therefore considered to be more or less truncated.

Composting from organic municipal solid waste (MSW), such as a separate waste collection, is a valid tool for eliminating a considerable amount of waste that would otherwise be destined for landfills and incinerators, thus representing an effective complement to traditional forms of recycling. It allows organic substance to be recovered and reintegrated into the soil, thus preventing erosion phenomena, increasing the biological fertility of the soil and contributing significantly to the restoration of impoverished sites. Modern winegrowing must address the issue of vineyard fertility in the sustainability context. The goal of this study was to assess the advantages of distributing a sustainable product to the vineyard that can achieve vine balance (vegetative and productive equilibrium). In a Vitis vinifera L. Sangiovese cv., vineyard, four soil treatments were applied (three compost rates and a control): municipal solid waste compost (40 tons per hectare – MSW40, 15 tons per hectare – MSW15, 2.5 tons per hectare – MSW2.5), and no compost (CTRL). The vine physiology (leaf gas exchange and water potential) and berry compositions (phenolic and technological maturity) were studied during the 2018–2019 growing seasons in the Sieci area, Italy. The results of this experiment provide some general insights showing that MSW compost options can be expected to reduce water stress, balanced vine performance and provide sustainable recirculation of organic matter. MSW compost is a true agronomic and environmental resource.

The nutritive value of diets predominantly of dried cassava (Manihot esculenta Crantz.) tubers supplemented with protein concentrates, and roughage were measured in three experiments using steers.

In Expt 1 the digestibility of diets of dried, chipped cassava tubers and tops (80:20) or rolled sorghum grain and cotton seed hulls (80:20), supplemented with 4 or 8% groundnut meal and urea, was determined. The apparent digestibility coefficients of organic matter (OM) of the cassava diets with 4 or 8 % groundnut meal (0·77 and 0·80, respectively) were significantly (P < 0·01) higher than grain diets with 4 or 8% groundnut meal (both 0·74). The digestibility of starch in the cassava diets was significantly (P < 0·01) higher than in the grain diets (1·00, 0·99, 0·94 and 0·93, respectively). There were no significant differences in the digestibility of the N component (0·62 and 0·61 v. 0·58 and 0·59, respectively). The N retained (g/day) was lower (P > 0·05) with cassava (7·8 and 6·8 v. 11·1 and 10·5, respectively) and was utilized (g/100 g apparently absorbed N) less efficiently (P > 0·05) (18 and IS v.28 and 27, respectively).

The high apparent digestibility of the cassava diet suggests that cassava could replace cereal grain in intensive finishing diets. The N retention data suggest that groundnut meal is no better than urea as a N source.

In Expt 2, 15 steers with a mean initial weight of 173 kg were individually fed pelleted diets of sorghum grain, cassava plus urea or cassava plus meat and bone meal (90 concentrate: 10 roughage). The cattle fed the grain diet ate significantly (P < 0·01) more OM (4·3 v. 3·4 kg/day), grew faster (P < 0·01) (1·21 v. 0·85 kg/day) and slightly more efficiently (P > 0·05) (3·6 v. 3·8 kg/kg) than cattle fed cassava with urea. Cattle fed cassava with meat and bone meal were intermediate between the two treatments for intake and daily gain (3·7 and 1·06 kg/day, respectively) but had the best feed conversion (3·5 kg/kg). The acetic/propionic acid ratio was similar on all three diets (1·2, 1·6 and 1·4:1, respectively), but the ratio of propionic/butyric was significantly (P < 0·01) different (5·8, 2·7 and 2·7:1, respectively).

In Expt 3, 15 other steers with mean initial weight of 195 kg were individually fed pelleted cassava diets with 0, 5 or 10% fishmeal (82 cassava: 18 roughage). The intake of OM (4·2, 4·5 and 4·7 kg/day, respectively), daily live-weight gain (0·98, 1·27 and 1·32 kg/day, respectively) and feed conversion (4·3, 3·7 and 3·7 kg/kg, respectively) were all better in cattle fed cassava with fishmeal. The proportions of volatile fatty acids in the rumen fluid were similar to that recorded in cassava fed cattle in the earlier trial.

It is concluded that cattle fed high energy diets based on dried cassava tubers can perform well. Although feed intake and daily gain of cattle fed cassava may be lower than for cattle fed grain diets, the conversion of food to live-weight gain should be similar or better.

Two experiments were carried out in which pigs were grown at controlled high, moderate or low growth rates from 18 kg to slaughter at 57 kg live weight. Linear measurements and density determinations were carried out on the carcasses. In the second experiment the right-hand side of each carcass was divided into four joints and each joint was physically dissected into three components, bone, subcutaneous fat plus skin and ‘lean’ meat. The boneless tissue of each joint was analysed for moisture, ether extractable fat and nitrogen.

It was found that an increase in the rate of live-weight gain tended to improve the efficiency with which feed was converted into live weight.

The percentage of fat in the side was significantly increased by more rapid growth rates.

The conformation of the side was altered by treatment, the proportion by weight of the middle region increased with increasing rate of live-weight gain and was accompanied by corresponding reductions in the proportions of the gammon and shoulder regions. These changes were largely due to an effect on the distribution of fat throughout the side, but there were also minor changes in the distributions of bone and fat-free lean.

The high rate of gain was associated with a greater proportion of belly in the side. This was due to an increase in the proportion of lean meat in this region, presumably a functional effect caused by an increased intestinal volume.

There was no treatment effect on the chemical composition of the fat-free boneless meat which was found to differ significantly between joints.

Saving water in irrigated agriculture is a high priority in areas with scarce water resources and impacted by climate change. This paper presents results of measurements on water productivity (WP) under alternative rice growing practices such as alternating wetting and drying, direct seeded rice, modified systems of rice intensification and conventional paddy rice (NI) in two selected districts (Guntur in Andhra Pradesh and Nalgonda in Telangana, India). Under alternative practices, the yields varied from 5.72 to 6.11 t/ha compared with 4.71 t/ha under paddy rice. The average water application varied from 991 to 1494 mm under alternative practices while average application in conventional paddy rice was 2242 mm. Higher yield and lower water application led to an increase in WP varying from 0.45 to 0.59 kg/m3 under alternative practices compared with 0.22 kg/m3 under conventional paddy rice. The measurements showed that less water can be used to produce more crop under alternative rice growing practices. The results are important for water-scarce areas, providing useful information to policy makers, farmers, agricultural departments and water management boards in devising future climate-smart adaptation and mitigation strategies.

Five selected clones of Lolium perenne were selfed and diallel crossed without reciprocals to produce 15 families. These families were grown in a replicated field trial for 2 years at four rates of applied nitrogen – 0, 225, 450 and 675 kg N/ha – per annum. The data recorded included dry-matter yield, number of fertile and sterile tillers per plant, mean dry weight per fertile and sterile tiller and total dry weights of fertile and sterile tillers. Conventional analyses of variance and diallel analyses were applied to the data as well as path analyses, used to examine the interrelationships between yield and the tiller characters.

The main effect of years was significant only for mean dry weights per tiller and dry-matter yield. Increasing the rate of applied nitrogen increased the number of tillers and yields but decreased mean tiller dry weights. Differences between progenies were due to both general and specific combining ability for most characters. Relatively high narrow-sense heritabilities were obtained for the tiller characters although there were differences between the two years.

The progenies achieved their yield through different combinations of tiller characters, some having large numbers of fertile tillers with medium dry weights and others having numerous sterile tillers with high dry weights. Although there was inconsistency in the interrelationships between characters, number of tillers was always more important in determining yield than mean dry weight per tiller.

The results are discussed in relation to the predictive value of tiller characters on yields and the implications for breeding programmes.