SUMMARYTwo small-grained cereals, Mulga oats and a triticale line, and two legumes, local vetch and local peas, were grown in pure stands and in mixtures at various cereal: legume seed ratios (20:80, 40:60, 60:40 and 80:20) for three successive cropping years, 1981/82 to 1983/84, at Laxia and Dromolaxia, Cyprus, in each year.The cereal pure stands produced, on average, more dry matter, 8·40 t/ha, and more digestible organic matter, 4·12 t/ha, than the legume pure stands, 3·68 and 2·18 t/ha, respectively. On average, total dry matter production decreased linearly as the seed proportion of the legume component in the mixture increased. The proportion of the legume in the harvested material was much lower than expected from the seed ratios. The highest proportion of legume was seen in the mixtures of peas with triticale and ranged from 8·1 to 35·5% at the various sowing rates. Digestibility and crude protein content were highest in the mixtures of triticale and peas.

The effect of six intervals between harvests and three levels of N application on the proportion and yield of green leaf, dead leaf, 'stem' and inflorescence was studied in four ryegrass (Lolium) varieties during a 30-week period in the first harvest year in a field experiment. In one variety, S.23, the 'stem' was divided into true stem, leaf sheath, unemerged leaf and unemerged inflorescence.

The effects of six intervals between harvests and three levels of N application on the initiation, emergence and longevity of leaves and longevity of tillers of Italian ryegrass and on dimensions and weights of leaves of four ryegrass varieties were studied in the first harvest year in field experiments. Dimensions and weights of leaves and ' stems' of the four varieties were recorded on three dates in the second harvest year.The number of leaf primordia on the shoot apex of young Italian ryegrass tillers was increased by N application and seemed to be increased by increasing the period of uninterrupted growth allowed to the parent tillers. The number of leaves which emerged on marked tillers during a 30-week period was approximately halved by increasing the interval between harvests from 3 to 10 weeks, but was not affected by N application. The number of leaves which died on marked tillers was at least doubled by increasing the interval between harvests from 3 to 5 weeks. The second and third leaves to emerge on a tiller had a longer potential life than the first leaf. Increasing the interval between harvests greatly increased the average age of the green leaves in the canopy at the time of harvest.Length and width, but not thickness, of fully expanded green leaf blades were increased by both N application and increased interval between harvests. The effect of applied N in increasing leaf size appeared to be an important reason for the positive effect of N on yield, particularly with the longer intervals. The effect of N in increasing the number of tillers and leaves was important •with the shorter intervals. Applied N reduced dry weight per unit volume of plant tissue and increased 'stem' length and increased weight and volume of herbage per unit volume of canopy. The area of exposed surface of 'stem' seemed too large to be ignored when considering the photosynthetic capacity of the canopy, particularly with the longer intervals. o n e I t a l i a n a n d t h r e e perennial, by Wilman et al.

The effect of six intervals between harvests and three levels of N application on digestibility, digestible yield and nitrogen content and yield was studied in four ryegrass (Lolium) varieties during a 30-week period in the first harvest year in a field experiment.Digestibility was higher with a 3-week than with a longer interval between harvests. Yield of digestible organic matter was increased by extending the interval from 3 to 6 weeks, but was slightly reduced by extending from 6 to 10 weeks.Increase in the level of applied N increased the degree of curvature downwards in the response to extending the interval in both yield of digestible organic matter and yield of N, supporting the view that N use should be accompanied by shortened intervals between harvests.Digestibility varied by up to 15 units D -value from one time of the year to another with a constant interval between harvests. The highest values were in the spring. Autumn values were low in spite of a relatively high proportion of green leaf.During the period immediately following the main period of stem development, doubling the interval from 4 to 8 or from 5 to 10 weeks reduced digestibility by 10 units and reduced digestible yield by 22%.In the absence of applied N, the N yield of S. 321 was 31 % greater than the average of S. 22, S. 23 and S. 24. However, the apparent recovery of applied N in S. 321 was much lower than in the other varieties.

SummaryThree cutting stages, the boot stage, 50% heading and the milk stage of grain, were imposed on eight barley varieties at four sites, two in each of two successive cropping seasons. Dry-matter and digestible yield increased significantly when harvest was delayed from the boot to the milk stage but crude-protein content and digestibility declined with advanced maturity. A similar pattern of response was obtained in most cases when varieties were examined individually. Variety 628 produced the highest yield, 8·34 t D.M./ha, while the most digestible variety was Athenais with 61·9% digestibility. In low-rainfall regions harvesting at the later stages of maturity is recommended, to take advantage of the higher D.M. yields.