The objectives and management policy of an experimental farm for studies on the sugar beet crop are described. Farm yields of sugar beet and cereals are discussed in relation to yields in experiments and on a national scale. Some aspects of experimental accuracy and design are considered.

The use in analysis of variance of six different ways of calculating the Land Equivalent Ratio (LER) was assessed. Criteria used are (1) normality of the residuals of LER values after fitting block and treatment effects, (2) precision of comparisons arising from the analysis of variance, and (3) possible bias in the means. These were examined in detail for data from one experiment and consistency of the results was investigated for seven other sets of data. Separate standardization in each block had no advantages over using the same standardization in all blocks. The use of many different divisors can lead to problems in the statistical analysis of LERs.

Barley (Hordeum sativum) and field beans (Vicia faba) were grown in pure stands, alternate-row mixtures and within-row mixtures in two field experiments. In both experiments the Land Equivalent Ratio (LER), based on seed yield, was consistently greater than 1.0 only when the crops were grown in alternate rows. The LER was greatest (1.8) when the mixture included more barley than beans. Reasons for the yield advantage of alternate row planting are discussed. Barley was more competitive than beans in mixtures, but this was not significantly affected by planting pattern.

Experiments in Tanzania have shown that green gram planted one week before bulrush millet produced a complimentary protein energy balance optimal for a cereal–legume diet. Grain yields were increased due to additive intercropping (by 13%) and replacement intercropping (27%). Green gram plants were more competitive than bulrush millet plants at the seedling stage but were overpowered in later growth stages.

The performance of three tropical grasses and three legumes (buffel grass, rhodes grass, green panic, butterfly pea, phillipesara and alfalfa), grown in pure stand and in legume–grass mixtures, was evaluated over two seasons when cut monthly at 0, 7 or 14 cm high. Harvesting at 7 cm favoured total dry matter and crude protein production in all cases, with highest yields from butterfly pea grown alone. Buffel grass was the best dry matter producer among grasses in pure stand, while rhodes grass–butterfly pea mixture was the best legume–grass mixture. Forage of these low-protein tropical grasses could be significantly improved by growing them in mixture with legumes.

The yield potential of a highly productive non-commercial Type IV bean cultivar was determined under optimum field conditions, grown in monoculture at 1 plant/m2 on trellises 3 m high. Canopy growth was analysed by dividing the stand into 25 cm horizontal strata. The main components of yield were number of inflorescences and number of pods per stratum. Daily yield for the growing period was 4.9 g dry weight/m2. Although a high yield per plant was recorded (823 g/plant) drop of young pods and seed abortion were the major factors reducing the potential yield.

The effects of three irrigation intervals (7, 10 and 15 days), four nitrogen levels (0N, 1N, 2N and 3N where 1N = 43.8 kg N/ha), and 0 or 11.9 tons/ha gypsum on leaf N, P and K uptake by forage sorghum grown on a highly saline–sodic clay soil were investigated in two successive seasons. The two seasons' data consistently showed that both leaf-N and leaf-K increased significantly with increasing N-rate and by splitting the same quantity of irrigation water into more frequent irrigations. Gypsum had no consistent effect. The responses of both leaf-N and leaf-K to nitrogen rates were significantly linear and a linear response of dry matter yield to leaf-N was also observed. P uptake was improved by more frequent irrigations in the first cutting of 1978, but was not otherwise affected by treatments.

A continuous non-limiting soil water supply, or a non-limiting supply from 120 to 180 days after planting, significantly increased (P = 0.01) female flower production of banana cv Robusta compared with continuous soil water stress. Relieving stress after 120 days produced a significantly higher (P = 0.05) average number of female flowers per inflorescence than when adequate water was supplied throughout. Female flower production is positively correlated with the average growth rates at floral initiation and early floral differentiation and with the final pseudostem girth.

Diurnal variations in soil temperature were measured under tea plants with different kinds of mulches. During the early years after planting temperatures differed, depending on the type of mulch and its heat absorptivity. Black plastic and stone chippings showed the greatest diurnal variations, but the variations disappeared in all treatments when there was a ≥ 60% canopy. Tea plants themselves modify soil temperatures, which could affect growth and yield in places where soil temperatures are generally lower.

Different subspecies of Arachis hypogaea show variation in their ability to nodulate in the hypocotyl region. Some cultivars belonging to subspecies hypogaea nodulate profusely on the hypocotyl, while those of fastigiata nodulate rarely in this region. The utilization of this character in breeding for increased nitrogen fixation is discussed.

The consumptive use of water by cotton (G. hirsutum L.) variety 149F, sown at three dates, was calculated using Penman Et × crop factor method. The earlier the sowing date the more water evapotranspired, mainly due to differences in the length of the growing season and the amount by which it coincided with the monsoonal depression of potential evapotranspiration. An example is given of calculating the irrigation requirements of a mid-June sown cotton, accounting for average rainfall, showing that the water requirements of cotton during the early stages may be adequately met by the establishment irrigation and rains during July. Examples are cited to show that a charged profile at the beginning of the season may sustain good growth and produce satisfactory yield.