A trial was carried out at Pantnagar in India during 1984–85 and 1985–86 to study the productivity of Egyptian clover and oats under intercropping. Cross sowing of both the crops either at full or half seed rates and line sowing of oats in broadcast Egyptian clover was better than other intercropping systems or sole cropping in respect of herbage production, digestible dry matter yield and land equivalent ratio but crude protein yield from the mixed crops was similar to that from sole cropped Egyptian clover.

Four forage bassicas, kale, rape, turnips and swede, and fodder beet were evaluated for adaptation to tropical highland conditions using small-plot experiments and field observations. In a short cropping season turnips were best adapted with a mean yield of 22 t ha−1. The crop was quick to establish and gave good ground cover. Kale and swedes were better adapted to a long season and yielded more than perennial forage grasses or maize. Yield was related to the length of growing season, exceeding 100 t ha−1 by about 250 days. Kale and swedes established poorly on soils high in aluminium. Direct sunlight appeared to damage swede roots, causing secondary soft rots. Rape showed no advantage over kale. Fodder beet failed to establish satisfactorily in any of the experiments.

The effects of spacing and lopping on a mesquite (Prosopis juliflora) and Karnal grass (Leptochloa fusca) agroforestry system on an alkaline soil at Karnal in India was examined over a three year period from planting. There were no significant differences in the height and diameter of the mesquite or in the number of branches at different spacings, but growth was significantly improved by lopping. The oven dried biomass obtained from lopped branches over a 40 month period was greatest at a 2 × 2 m spacing. The green forage yield of Karnal grass was greatest under mesquite spaced 4 × 4 m apart and was markedly improved under lopped mesquite. The inorganic composition of the Karnal grass, including trace elements, made it a valuable fodder in an area with an adverse alkaline soil environment. The calcium and potassium content of the grass increased and the sodium content decreased in successive cuttings. Mesquite and Karnal grass grown together reduced soil pH and EC and improved the organic carbon and available nitrogen content of the soil.

Root growth of two drought tolerant and two drought sensitive bean (Phaseolus vulgaris L.) lines was compared at two locations in Colombia differing primarily in soil conditions. At Palmira, roots of drought tolerant lines reached a depth of 1.3 m, while drought sensitive lines only reached 0.8 m. These differences were associated with differences in seed yield, crop growth, canopy temperature and soil moisture extraction. Under acid soil conditions at Quili-chao, seed yields of supposedly drought tolerant genotypes were similar to those of the drought sensitive lines, and root growth of all four lines was restricted to less than 0.8 m. Drought avoidance through greater root growth and extraction of soil moisture appears to be an important drought tolerance mechanism in common beans, but its usefulness is limited where soil conditions restrict root growth.

In many experiments which compare a large number of different treatments or varieties, it is necessary to decide which sub-sets of treatments or varieties do not differ significantly from each other. Multiple comparison procedures provide a commonly used, but much criticized, way of tackling this problem. As an alternative, techniques known collectively as cluster analysis can be used. An advantage of using certain types of cluster analysis is that their results can be displayed as a dendrogram or tree diagram which gives a very useful picture of the overall relationship between treatments or varieties. These procedures can also be extended readily to multivariate observations from each plot.

A simple Stress Time Index (STI) for predicting yield loss in the tea crop due to drought is proposed, based on the daily summation of the difference between the potential soil water deficit and a specified limiting value. Validation of the technique with results from a line-source irrigation experiment with a single clone in the Southern Highlands of Tanzania suggests that there is a linear relationship between STI and relative yield loss during the warm dry season. As a result of changes in the composition of the shoot population at each harvest the apparent critical deficit at which shoot growth is restricted increases from below 20 to 300 mm as the dry season progresses. The rate of yield loss with increasing STI also varies through the dry season for the same reason.

Three species of lupin, three vetches and a soyabean were evaluated as green manures under tropical highland conditions. With moderate soil fertility and 150 days of rain, all lupin types and a locally obtained vetch gave yields of about 80 t ha−1 fresh material. Under less favourable conditions, low soil pH and high aluminium saturation, only Lupinus luteus achieved these yields. During the short season, with about 60 days of rain, the yield of L. luteus was reduced to 30 t ha−1 and establishment of the vetches was slow and they yielded poorly. Growth of soyabean was poor under cool conditions. Under fertile conditions, lupin grain yields of up to 5.2 t ha−1 were obtained in the long season but in the short season, yields were less than 1 t ha−1. Rhizoctonia solani was the major disease encountered.

The effects of planting potato tubers on four different sides of two ridge orientations was investigated. Soil temperature was coolest on the northern side, followed by the western, eastern and southern sides. Fifty percent emergence took place in 24, 42 and 49 days for tubers planted on the northern, western and eastern sides, respectively. Only 22% of tubers planted on the southern side emerged. The best yield and quality was obtained by planting on the northern side, followed successively by the eastern, western and southern sides of the ridge.

The climates to which lentil (Lens culinaris) crops are exposed can vary appreciably depending on location and date of sowing. The effects on growth, development and seed yield when three USA cultivars experienced relatively warmer or cooler day/night temperatures during the vegetative period were investigated in growth cabinets. Plants were nodulated and supplied with either 20 or 80 ppm inorganic N; they differed appreciably in morphology and vegetative vigour, and so in their potential for subsequent pod production, depending on pre-flowering temperature and on nitrogen nutrition. Variations in seed yield were largely a consequence of treatment and cultivar effects on pod number per plant, and a pre-flowering temperature regime of 21°/7°C (mean 14.9°C) was supra-optimal. The pre-flowering environment clearly affects potential pod production and has persistent effects on the capability of plants to fill the pods produced.