Vegetative multiplication of potato is used routinely to produce disease-free seed tubers and to multiply new potato varieties for trials. The conventional methods of vegetative propagation using virus-tested stem cuttings allow production of 800–900 plants from a single plant in 3 years (Hussey & Stacey, 1981). Use of in vitro propagation allows much more rapid rates of multiplication of new varieties of potatoes (Wooster, 1984). Axillary buds taken from a few tubers can be multiplied to 500 plants within 4 months by repeated subculturing of nodal cuttings on artificial media in sterile conditions.

Thirty-two milk-fed Murrah buffalo calves of 3 weeks of age were randomly allotted to four dietary groups: milk, concentrate-berseem hay in the ratios 1:1 and 1:3, or berseem hay alone. Milk intake was gradually reduced and completely stopped after the sixth week of age in the groups given dry feeds. Two calves from each group were slaughtered at 6, 9, 12 and 15 weeks of age. In addition, four buffalo calves were slaughtered at 21 days of age for comparison.

Observations on ruminal tissue weight, content weight and the ruminal capacity indicate that the ruminant stomach of buffalo calves weaned on dry food after the sixth week of age becomes structurally developed by 9 weeks of age, whereas the rumen remains underdeveloped in calves fed milk to 15 weeks of age.

Sheep are commonly used to graze dairy pastures in the late autumn and early winter, to make use of grass that cows have rejected and to utilize any late growth with a minimum of poaching damage. From late December onwards sheep are less welcome to farmers because of the possible harmful effect on the regrowth of grass in the spring. But if the alternative to grazing from January to March is to bring the sheep indoors and feed them hay or silage, then this cost may be greater than that of the grass lost in the spring. Wilman & Griffiths (1978) concluded that the reduction of yield in spring was directly related to date of last grazing but emphasized that they had made no measurement of herbage remaining at this time. Furthermore, their measurements of subsequent yield were in dry matter to a cutting height of 4 cm with no estimate of the amount of ash or green and dead material.

A relationship between grass N yield and total N supply was derived using data from experiments on grass-white clover swards. This relationship was very similar to that found previously using a larger pool of data from clover-free grass swards. The quantity of N released underground by the clover was estimated to be around 50% of the annual N yield in clover herbage. This is a much lower estimate than that reported by earlier workers.

Data of 2780 Markhoz kids originated from 1216 dams and 211 sires during 1993–2016 in Markhoz Goat Breeding Station, located in Sanandaj, Iran, were used. Traits investigated were body weights at birth, weaning, six-month age [six months weight (6MW)], nine-month age and yearling age [yearling weight (YW)]. Two considered multivariate models including standard multivariate model (SMM) and fully recursive multivariate model (FRM) were compared using deviance information criterion (DIC) and predictive ability measures including mean square of error (MSE) and Pearson's correlation coefficient between the observed and predicted values $(r(y,\hat{y}))$ of records. Spearman's rank correlation coefficients between posterior means of direct genetic effects of the studied traits of kids under SMM and FRM were also calculated across all, 50, 10 and 1% top-ranked animals. In general, FRM performed better than SMM in terms of lower DIC and MSE and also higher $r\lpar y\comma \;\hat{y}\rpar$. For all traits, the lowest MSE and the highest $r\lpar y\comma \;\hat{y}\rpar$ were obtained under FRM. All structural coefficients estimated under FRM were statistically significant except for that of 6MW on YW. Comparisons of Spearman's rank correlations between posterior means of direct genetic effects of kids for growth traits under SMM and FRM revealed that taking the causal relationships among the studied growth traits of Markhoz goat into account may cause considerable re-ranking for the animals in terms of estimated breeding values, especially for the top-ranked animals. It may be concluded that FRM had more plausibility over SMM for genetic evaluation of the studied growth traits in Markhoz goat.

Two field experiments examined the nutritional responses of the white lupin (Lupinus albus L.) agronomic cultivar Lucyanne to lime-amended soil. In the first, plots and boundaries of a pre-existing lime-rate experiment were sampled in 1993. The maximum shoot dry matter production occurred between soil pH 4·9 and 7·2. Whole-shoot Al concentrations increased below soil pH 4·9, and plants died at pH 4·4. Although dry matter production declined in soil above pH 7·2, no chlorosis or plant death was seen. Only the whole-shoot soluble Ca concentration changed from neutral to alkaline pH soil: it was greatest when grown in the alkaline-pH soil. In the second experiment, plants were grown in neutral pH or limed soil in 2000. Shoots were divided into specific tissue types and analysed for Fe III and Fe II, as well as soluble and insoluble Ca fractions. When sampled in April after over-wintering, the higher Ca concentration in the limed compared with neutral-pH soil-grown plants was due mainly to insoluble Ca. No plants were chlorotic and no differences between the treatments in the concentrations of either form of Fe were found. In June no plants were chlorotic, however the concentrations of both total and soluble Ca fractions were greater in the limed than the neutral-pH soil-grown plants, and there was more stem Fe III and less leaf Fe II in these plants. The present study shows that the cultivar Lucyanne is not a reliable crop plant above pH 7·2, and the loss of shoot dry matter can be attributed to nutritional responses at a sub-chlorotic level of stress.

The paper investigates the effect of controlled seasonal breeding on milk production in a herd of Small East African (SEA) goats. Polynomial growth curve models were fitted to both daily and cumulative milk yield data obtained from an experiment conducted over a period of 4 years (1984–88) under simulated pastoral herd management in Isiolo District, northern Kenya. The experimental treatment consisted of six different mating seasons per year, which were replicated three times over the course of the experiment.

Milk yields in the first 2 weeks of lactation were negatively affected (<400 g/day) when kidding took place between June and September, whereas maximum initial yields of about 450 to 550 g/day were achieved at the onset and during the long rainy season. Multiple peaks in milk yield curves were observed when a rainy season occurred after about the first half of the lactation period. In terms of total amount of milk produced until 28 weeks of lactation, the production system could benefit from the introduction of a restricted breeding management allowing does to be bred in the period from June to November, with total milk yields being estimated at approximately 60 kg of milk. Maximum milk production until weaning can be expected to be achieved by does mated between October and January (between 46 and 48 kg of milk). The present experiment has revealed that mating just prior to or during the long rainy season leads to low milk yields until weaning and significantly increases the incidence of early kid deaths.

It is concluded that evaluating milk production in goat herds exposed to strong seasonal changes in forage supply is perhaps best carried out in terms of cumulative milk yields, instead of average daily yields, which are subject to large fluctuations. Furthermore, under these conditions fitting polynomial growth curves to longitudinal milk yield data using the general linear mixed model appears to be more appropriate than the estimation of non-linear algebraic lactation curves.

This paper presents the results of a study conducted in 2016–2018 in the temperate conditions to evaluate the content and uptake of P, K, Ca and Mg in mixtures of narrowleaf lupin with spring triticale grown for green fodder. Two factors were analysed in the experiment: A – the proportion of components in the mixture: narrowleaf lupine 100%, narrowleaf lupine + spring triticale 75 + 25%, 50 + 50%, 25 + 75%, and spring triticale 100%; B – the harvest stage the flowering stage of narrowleaf lupine, the stage of flat green pod of narrowleaf lupine. Increasing the proportion of spring triticale in the sown mixtures in relation to narrowleaf lupine resulted in a decrease in the content of the analysed macroelements by 8.9%–28.7% on a g/kg DM basis. The greatest uptake on a kg/ha basis of macroelements was found in the mixture with an equal share of both components. Harvesting mixtures at a later stage of development increased the uptake of P, K, Ca and Mg by 98.7%–111.8% because of greater DM yield, but reduced the content of these macroelements by 12.6%–20.8% in the more mature fodder. Mixtures of narrowleaf lupine with spring triticale can provide valuable mineral nutrients for livestock.

Nitrification potential of a tropical vertisol saturated with water was estimated during sequential reduction of nitrate (NO3−), ferric iron (Fe3+), sulphate (SO42−) and carbon dioxide (CO2) in terminal electron-accepting processes (TEAPs). In general, the TEAPs enhanced potential nitrification rate (PNR) of the soil. Nitrification was highest at Fe3+ reduction followed by SO42− reduction, NO3− reduction and lowest in unreduced control soil. Predicted PNR correlated significantly with the observed PNR. Electron donor Fe2+ stimulated PNR, while S2− inhibited it significantly. Terminal-restriction fragment length polymorphism targeting the amoA gene of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) highlighted population dynamics during the sequential reduction of terminal electron acceptors. Only the relative abundance of AOA varied significantly during the course of soil reduction. Relative abundance of AOB correlated with NO3− and Fe2+. Linear regression models predicted PNR from the values of NO3−, Fe2+ and relative abundance of AOA. Principal component analysis of PNR during different reducing conditions explained 72.90% variance by PC1 and 19.52% variance by PC2. Results revealed that AOA might have a significant role in nitrification during reducing conditions in the tropical flooded ecosystem of a vertisol.

The current work was designed to compare 13 agronomic and four physiological traits in mungbean isogenic lines (ILs) with different leaflet sizes and numbers. The IL population was developed from a cross made in 2006 at Kasetsart University, Thailand, between two pure lines (one with five small and the other with seven large leaflets), followed by continuous selfing of the progenies until F6. The resulting four IL families each exhibited seven leaflet types, viz. three normal-sized leaflets per leaf, seven large leaflets, nine large, five small, seven small, nine small or 11 small. A trial was conducted in 2008 to compare the 28 ILs using a randomized complete block design with three replications. The large multiple-leaflet lines gave higher values for seeds/pod, pod size, seed weight, seed yield, leaf area, leaf area index and proportion of light interception, but fewer clusters of pods, branches and pods per plant than the small multiple-leaflet ILs. Seed yield/plant was positively correlated with pods/plant, seeds/pod, mean seed weight, light interception, leaf area and plant height at maturity. Leaflet size showed association with more traits than did leaflet number.

Ticks are considered in Europe to be the most important arthropod group responsible for vector-borne diseases in humans, while in the tropics mosquitoes take over this position with ticks being the second most important. Over the last decade, vector-borne diseases have proliferated within Southern Europe (Blue tongue and West Nile viruses, both mosquito-borne diseases) while human ehrlichiosis (a tick-borne disease) has increased dramatically in Eastern Europe.

The suitability was assessed of various designs for field experiments investigating plant diseases caused by airborne pathogens that can be subject to interplot interference. Use of a model to describe such interference showed that the treatments with the most dissimilar effects on controlling the disease should be allocated to experimental plots furthest apart in each block, in order to minimize the interplot interference within a block. When using large square plots, rectangular blocks were more efficient than square blocks in minimizing treatment-comparison biases due to interference between neighbours. For rectangular blocks with the square plots side by side, less biased treatment comparisons were obtained from designs with complete blocks than from designs with incomplete blocks, especially when larger numbers of treatments were included in the experiment. However, when interplot variance is taken into account, incomplete blocks may give better treatment comparisons. Similarly, unbalanced designs composed only of incomplete blocks that yield less biased treatment comparisons may be better than balanced incomplete block designs when interplot variance is low. For high levels of variation, balanced incomplete block designs may be more appropriate, as increasing the precision of the treatment comparisons becomes more important than reducing the bias.