High temperature negatively affects cotton production worldwide. In Pakistan, cotton crop faces high temperature at peak flowering during June–July, which is a major reason for yield losses. The present study was conducted to find some agro-physiological markers for high-temperature tolerance. Fifty cotton genotypes were raised under normal sown (high-temperature stress) and late sown (optimum temperature) conditions for 2 years. Data were recorded for relative cell injury percentage (RCI), chlorophyll content (CC), canopy temperature (CT), boll retention percentage (BR), bolls per plant (BP), boll weight (BW), hundred seed weight (HSW), sympodial branches per plant (SBP), plant height (PH) and seed cotton yield (SCY). A large amount of variability was found among cotton genotypes as proved by descriptive statistics. Stable genotypes were selected based on higher SCY and yield components (BP, BW, HSW, SBP, PH and SCY) performance along with less RCI%, high CC and low CT. The results of heatmap analysis showed that the six cotton genotypes viz., FH-Noor, FH-Lalazar, FH-458, FH-466, NIAB-545 and NIAB-878 performed better under high-temperature stress. These selected genotypes can be a source for breeding high-temperature tolerance. Furthermore, the results from correlation analysis confirmed that the traits such as RCI%, CC and CT can be considered as early selection criteria due to their positive association with SCY. Whilst some other parameters such as BP, BW, BR, SBP and PH might be used as direct selection indices for SCY under high-temperature stress.

The high activity of rumen urease is a major limiting factor in the usefulness of urea as a protein replacement supplement in ruminant diets (Bloomfield, Garner & Muhrer, 1960). The efficiency of urea utilization can be increased by decreasing the activity of rumen urease or by modification of urea in the products which are slow ammoniareleasing (Helmer & Bartley, 1971). An arbitrary formaldehyde treatment of urea was observed to lower the hydrolysis in the intact rumen (Pal & Negi, 1977). In a systematic study carried out in our laboratory a series of urea formaldehyde complexes (UFC) was prepared and their in vitro hydrolysis studied (Lall et al.1980; Makkar et al. 1981). Phosphoric acid is known to catalyse the reaction between aldehyde and urea. In the present study the complexes of urea and formaldehyde (UFC) and urea, formaldehyde and molasses (UFMC) in the presence of a catalyst (phosphoric acid) were prepared and their in vitro ammonia production is presented.

A method for determining the total exchangeable bases of carbonate soils is described. The carbonate in a known weight of soil is decomposed by acetic acid and the carbon dioxide evolved is estimated. By further extraction with acetic acid a solution is obtained which contains not only the bases originally in combination with the carbon dioxide but also the exchangeable bases. The amount of the latter is found by difference.

The control effect of Cucurbita ficifolia (pumpkin) leaf acetone extract on caterpillars of the small cabbage butterfly Pieris rapae Linnaeus (Lepidoptera: Pieridae) was observed in laboratory and field experiments from 1 March 2006 to 30 May 2007. The mechanism of the action by which pumpkin leaf extract (PLE) controls small cabbage caterpillars was examined for feeding restraint, and the values for 0·50 feeding restraint concentration (FC50) and 0·95 feeding restraint concentration (FC95) after 12 and 24 h were estimated. The results showed that the absolute anti-feeding activity for fourth instar caterpillars after 12 h was 0·65 and after 24 h was 0·56, while relative anti-feeding activity was 0·57 after 12 h and 0·59 after 24 h. Field experimental results indicated that the leaf protection effects increased up to day 7, while the feeding control effects remained constant. Comparison of the profits from pest management using indigenous pesticides, biological pesticides and chemical pesticides and without pest management suggested that there are currently economic benefits associated with the use of indigenous pesticides, such as PLE.

The body composition of 18 each of Mashona, Afrikaner and Hereford heifers was measured at the beginning and after 16 and 32 weeks of the experiment. The heifers not slaughtered at the beginning of the experiment were fed a complete diet containing 132 g crude protein and 12·0 MJ metabolizable energy/kg dry matter. Before slaughter, the animals were deprived of food and water for 24 h. Each animal was infused with 1 mCi of tritiated water (TOH) in order to measure total body water (TBW) and to estimate body fat.

The growth rate of the three breeds of heifers was similar despite differences in age and initial live weight. Both TBW and fat proportions, however, differed significantly (P < 0·01) between slaughter stages for each breed and between breeds at each slaughter stage. At the first, second and final slaughter stages the proportions of TBW were: 68·0, 59·4 and 54·5% for Mashona; 70·;5, 64·3 and 58·3% for Afrikaner and 65·3, 57·6 and 46·2% for Hereford heifers respectively. The corresponding proportions of body fat were: 10·2, 18·4 and 24·2% for Mashona; 6·6, 12·0 and 20·0% for Afrikaner and 13·7, 20·8 and 25·8% for Hereford heifers respectively.

There was a close relation between empty body weight and live weight at slaughter which was not influenced by breed. Both TBW and fat were estimated more accurately when TOH space and live weight were used jointly. However, the slopes of the prediction equations for each breed were significantly different (P < 0·05) in the case of both total body water and fat. It was necessary to use separate equations for each breed in order to predict either body water or fat. The significance of these findings for the estimation of body fat in live cattle is discussed.

Data collected over a period of 11 years at the Ebini Livestock Station in the intermediate savannahs of Guyana were analysed to determine the effect of breed or cross, sire, sex, year and season of birth of calf, and age and length of calving interval of the dam on weights at birth and at 4, 8 and 12 months of age, in Santa Gertrudis, Sahiwal and Brahman cattle. The heritability of body weights at the different ages was estimated.

1. Extremity skin temperature changes in British and Zebu cross cattle examined in moderate thermal environments followed a thermoregulatory pattern similar to that describedby Whittow (1962). At low environmental temperatures, ear and lower leg skin temperatures were usually only slightly above air temperature. At a variable time after air temperatures began to rise or the animals were fed, extremity skin temperatures increased suddenly to near trunk skin temperature.

2. In eight of the ten pairs of animals studied in rising ambient temperatures and during feeding after fasting for 36–72 hr, increases in ear temperature were measured in the British animal before similar changes occurred in its Zebu counterpart. Changes in lower leg skin temperature followed a similar pattern.

Trunk skin temperatures and respiratory frequencies were significant higher in British cross animals than in Zebu cross animals of similar thermal history. The mean rectal temperature of both British and Zebu cattle was 38·5 °C.

Four of five ‘hairy’ Wiltshire lambs had fibre type arrays (as defined by Dry, 1965) of Plateau (P0 and P1) type, whereas in five ‘woolly’ lambs there was only one Plateau (P3) array, the arrays of the remaining lambs being Ravine or Saddle. In terms of Dry's theory that the severity of pre-natal check determines persistence of wool growth in adults, it appears that the amount of checking in these Saddle and Ravine arrays was insufficient to prevent the casting of the adult coat.

Mulching polybag oil-palm seedlings with bunch refuse, shredded polythene, sawdust, grass, wood shavings and kernel shells ‘all-year’ or throughout the nursery period (May–May), in the ‘wet-season only’ (May-November), and in the ‘dry-season only’ (November–May) resulted in soil temperature differences which did not exceed 1 °C at 5 cm polybag depth. This was attributed to the high rainfall which reduced considerably the soil temperature differences between mulched and unmulched soil in the wet season and to the enhanced leaf canopy in ‘all-year’ and ‘wet season only’ mulchings which shaded soil in polybags in the dry season.

The mulch materials and times of their application significantly influenced growth variables like number of leaves, plant height and stem girth, and number of blast-affected seedlings at 6 months after sowing (wet season). By 12 months after sowing, all growth characters measured were similar in the various treatments, indicating compensatory growth at the latter half of the growing period (dry season).

N, P, K, Mg and Ca contents of seedlings were not significantly affected by either mulch materials or times of their application. The results emphasize that mulching for at least 6 months during the early or late nursery period and the use of various mulches may be beneficial to oil-palm seedling growth.

Experiments were carried out in 1992 with ten male calves, 4 weeks old initially, on a milk diet. Five calves received 80 mg/head virginiamycin (a feed antibiotic) daily for about 14 weeks. Virginiamycin significantly (P < 0·05) increased weight gains (122±2 kg ν. 114±2 kg), digestibility of ash, serum iron and haemoglobin. The feed intake per 1 kg of gain was non-significantly lowered in the virginiamycin group. The phagocytic activity of granulocytes in blood samples of treated calves was slightly increased with a concomitant decrease in the concentration of immunoglobulins. Meat of virginiamycin-fed calves tended to be somewhat darker, to contain more K, Na and Fe and to have a higher pH 24 h post mortem. There were no major differences in other qualitative characteristics of meat between the groups.

In breeding programmes, the genetic selection process is based on the prediction of animal breeding values, and its results may vary according to the employed selection method. The current study developed an economic selection index for animals of the Angus breed; performed cluster analyses using the breeding values in order to evaluate the genetic profile of the animals candidates to selection, and compared the obtained results between the economic selection index and the cluster analyses. The evaluated traits included weaning weight, 18-month weight, scrotal circumference, fat thickness and ribeye area. Economic values were obtained using bioeconomic modelling, simulating a complete cycle production system of beef cattle breeds in Brazil, and the selection objective were the weaning rate and slaughter weight. The chosen selection index was composed of all of the traits used as selection criteria for the simulated production system. During the cluster analyses, the population was divided into two to four groups, in which the groupings containing potential animals were assessed. The animals of the grouping which was used for comparison with the selection index were identified, and most of the bulls that were included in the index were among the best in the analysed group. These results suggest that the cluster analyses can be used as a tool for the selection of animals to be used as parents for future generations.

Although sheep combat thermal stress mainly by panting, a sizeable amount (40%) of total evaporative heat loss, is from sources other than panting (Hales & Brown, 1974). The frequency of sporadic discharge of sweat glands increases with increase in ambient temperature and is accompanied by a decline in respiration rate (Bligh, 1961). The wool coat can reduce evaporative cooling but sweating may have cooling value in sheep breeds with open fleeces (Rai, Singh & More, 1978). In sheep, the number and size of the sweat glands (Waites & Voglmayr, 1962) and the quantum of sweat production in a particular time period (Ghoshal et al. 1977) varies in different body regions. In view of the possible significance of surface evaporative cooling, thermal sweating in different body regions of sheep was investigated.

1. Palestine Pan, “Nasas”, is found in the coastal plain among red sandy soils and its presence is shown by one or more impermeable layers in the depth.

2. Red sandy soil in which “Nasas” is present is an unstable soil system which is liable to the process of degradation.

3. Observations made on red sandy soil in relation to relief show the transportation of colloidal clay, A1(OH)3 and Fe(OH)3, along the slope and into the depth.

4. The ratio of A1(OH)3 to Fe(OH)3 shows a relatively large downward transportation of A1(OH)3. This increase of A1(OH)3 in the lower layers of the soil is the chief factor in the formation of the impermeable layers.

This study was carried out to investigate the effect of crossing the subtropical fat-tailed Ossimi (O) sheep with the Hampshire (H) on ewe and lamb performance. Data used involved 457 ewe records of Ossimi, Hampshire and four crosses, and 404 lamb records of Ossimi and five crosses.

Hampshire ewes performed less well than the local Ossimi ewes in various reproduction traits. They weaned 0·26 lamb/ewe run with the rams compared with 0·82 from the local ewes mated to Hampshire rams. The Hampshire ewes seemed to be anoestrous during the first part of the normal breeding season of the local ewes (May–July). Different Hampshire–Ossimi cross-bred groups showed better ewe reproduction performance than the purebred Hampshire ewes, but were inferior to the Ossimi. The first cross ewes were, generally, the best among all the cross-bred ewes and the reproduction performance declined with increasing percentage of Hampshire genes. When the first cross was interbred, ewe performance declined clearly in the F2. All cross-bred groups of ewes gave significantly heavier annual greasy-fleece weight than Ossimi ewes.

The only lamb performance trait that was improved by up-grading the Ossiroi sheep with the Hampshire breed was the first greasy-fleece weight, while lamb survival and weaning weight were clearly decreased with the advance of up-grading.

The recombined cross-bred groups ( and ⅝ Hampshire) proved to be the best cross-bred and showed considerable improvement in lamb performance traits over the local Ossimi sheep, except for lamb survival.

It is concluded that crossing Ossimi sheep with the Hampshire improved only fleece weight but not lamb production.

In an intermediate deepwater situation (15–50 cm) at Cuttack, India, three improved high-yielding rice varieties, Utkalprabha (semi-tall), CR 292–8051 (intermediate tall) and Gayatri (semi-dwarf) were sown on 20 May, 30 May and 10 June in 1988 and 1989 with an application of either 0, 20 or 40 kg N/ha at sowing. Tall varieties performed better than the dwarf type but grain yield decreased with delay in sowing. The early-sown crops (20–30 May) germinated with pre-monsoon rains and were established well before water accumulated in the field from mid-June onwards. The late-sown crops (10 June), despite good initial germination, could not withstand immediate waterlogging. The tall variety, Utkalprabha, elongated faster with rising water level and escaped complete submergence; whereas the semi-dwarf Gayatri failed to withstand such extreme excess water stress. Application of N fertilizer up to 40 kg/ha proved beneficial to the crops sown by the end of May. However, with crops sown on 10 June, the application of N could not compensate for the loss in yield due to an inadequate initial crop stand. Therefore, early sowing of tall varieties by the end of May along with a basal application of N fertilizer is recommended for higher productivity of rice under excess water conditions.

The mechanisms responsible for moving K from soil to root were studied by growing perennial ryegrass in pots containing a flinty silt loam from Rothamsted and a sandy Woburn soil, with and without added K, at 0.75 water-holding capacity. More water was taken up from the Rothamsted soil than from the Woburn soil, and less was taken up when K was added without affecting dry-matter production. After 25, 52, 83, 122, 194 and 276 days, K uptake, water uptake and the K concentration in the soil solution were measured and the mass-flow contributionto K uptake calculated.

Without added K, mass-flow accounted for only about one-sixth of the K taken up from the Rothamsted soil and about one-third from the Woburn soil. Except at first, diffusion probably accounted for the remainder of uptake but was the rate-controlling step for uptake from the Woburn soil only. With added K, mass-flow became much more important relative to diffusion in both soils, and transported more than enough K to account for the measured K uptake. Root interception probably did not contribute to K uptake after the early part of the experiment, because the pots used were small.

Between 1972 and 1976 a series of 15 trials was carried out at various climatically favoured sites throughout Scotland to assess the potential of new hybrid maize varieties of European origin under Scottish conditions. No meaningful differences were found between varieties in respect of dry-matter yield or maturity.

Seed rates ranged from 100 to 200 × 103 seeds/ha giving final stands from 40 to 194 × 103 plants/ha. Regression analyses for the variety Dekalb 202 included in 54 treatments indicated that the relationship between plant population density and dry-matter yield was partly linear with an important quadratic function, suggesting an optimum of 179 × 103 (± 80 × 103) plants/ha. Plant population density accounted for 65·9% (P < 0·01) of the variance in dry-matter yield but was not significantly related to dry-matter content.

Climatic variation between years had no overriding influence on growth and development. Dry-matter production for the variety Dekalb 202 sown in mid-May ranged from 2·86 (1972) to 14·54 t/ha (1975) with associated dry-matter contents of 15·1 and 24·1% respectively. In a few instances slightly higher dry-matter contents (maximum 28·6%) from mid-May sowings were associated with lower yields.

Neither date of sowing nor accumulated temperature to harvest measured as Ontario Heat Units was significantly related to yield but date of sowing accounted for 29·5% (P < 0·01) of the variance in dry-matter content. Accumulated Ontario Units at harvest were not significantly related to dry-matter content.

An interesting relationship between dry-matter yield and the date on which the crop had received 1379 Ontario Units was found. This relationship may be useful in selecting sites at which maize may be grown or to predict maximum potential final yield in any given season.

1. The average electrode potentials of laboratory silages of various types have been measured.

2. The electrode potentials of ordinary and molassed silages tended to assume values of the order of –0·05 to –0·10 V. from about the third day; the pH of these silages lay in the range pH 4·0 to 5·5.

3. In a number of instances secondary increases of electrode potential were observed, frequently in association with secondary deterioration.

4. The electrode potential of silage prepared with hydrochloric acid and of pH 3·4 remained steady around +0·18 V.; the potential of silage prepared with formic acid and of pH 3·9 was about + 0·35 V. initially but declined towards + 0·23 V. at 35 days.

5. Curves for the ‘pure’ carotene content of laboratory silages displayed minima during the early stages of fermentation except in the case of formic acid silage.

To clarify the reproduction probability of red clover (Trifolium pratense L.) in meadows for herbage cutting, the demography of this legume was studied in a meadow in the central mountainous district of Japan. The present study shows the demography of deposited red clover seeds in a meadow, where timothy (Phleum pratense L.) predominated and herbage had been harvested for making hay or silage in early June and late August of a year. The densities of deposited seeds, buried seeds and seedlings were monitored to determine their survival. Deposited seeds were collected using seed traps, buried seeds were monitored seasonally by sampling them from topsoil and seedlings were counted in ten permanent 1×1 m quadrats. Many permeable and hard seeds of red clover were deposited on the soil surface of the meadow during the mechanical operation of the second haymaking in mid- to late August. Of the population of deposited permeable seeds, 0·16 germinated and 0·84 were lost in the present autumn. Conversely, of the population of deposited hard seeds, 0·11 germinated in the succeeding spring, 0·83 were lost and 0·06 remained as hard seeds until the succeeding autumn. The deposited permeable and hard seeds could contribute to the persistence of red clover population when their seedlings survived for seed setting in the meadow.

This study was carried out to determine the effects of different irrigation levels and different tillage and sowing methods on the amount of irrigation water, evapotranspiration, water productivity (WP) and yield in the second crop soybean in Çukurova Region, Turkey. Three irrigation levels were applied (I100: completion to the field capacity of the available water of 60 cm soil depth weekly. I70: 70% of the water applied to I100, I50: 50% of the water applied to I100), five tillage and sowing methods were used (T1: traditional soil tillage, T2: reduced soil tillage, T3: reduced soil tillage, T4: ridge tillage, T5: no-tillage). The research was carried out in a randomized block split-plot design with three replications. The result of, the highest yield was obtained in I100xT1 with 4990 kg/ha, while the lowest yield was obtained in I50xT3 with 3150 kg/ha in irrigation x tillage interactions. When the water consumption values of plants were analysed, the highest was obtained with 632 mm I100 and the lowest with 399 mm I50. When WP values were analysed, the highest was obtained with 8.7 in I50 and the lowest in 6.6 and I100. As a result, full irrigation and direct sowing methods (I100T1) are recommended in soybean cultivation considering the highest water-yield relationship in the Mediterranean Region.