A study was made of the effect of micronutrients such as boron, copper, zinc, manganese and iron, applied as foliar spray or directly to peat soil, on growth and yields of pepper under greenhouse and field conditions. Combinations of micronutrients were applied in two forms, as salts or as chelates. Results showed positive effects on yield and quality of red pepper, and soil chemical tests substantiated the results.

N, P and K fertilizers improved mulberry leaf, stem and fruit yields on peat, the optimum rates being 100 kg/ha/yr N, 25 kg P and 62·5 kg K, with further leaf responses to N and K if applied together in the ratio of 3:2. Harvesting every 2 months at 60 cm height gave better yearly leaf yields than cuttings 3–12 months apart, but annual stem yields were not affected by harvesting frequency and fruit yields were optimum when plants were cut at intervals of 5–6 months. Harvesting quarterly at 60 cm produced better leaf and stem yields than cutting lower (15 and 30 cm) or higher (100 and 180 cm). Two Thai cvs (Noi I and Mii) were female-sterile but the Local Malaysian produced fruits.

The information collected from an experiment on tea, in which two plucking intervals and three plucking standards were imposed, allowed analysis of the effects on the total value of output (Cloughley et al., 1983; Cloughley, 1983). The analysis can be extended and its practical relevance improved by incorporating harvesting and manufacturing costs. Using information collected in another experiment and readily available economic information the effects of incorporating these costs are presented. A method of simultaneously determining optimal plucking interval and standard is described.

The development of high-yielding, short-duration super-rice hybrids is important for ensuring food security in China where multiple cropping is widely practiced and large-scale farming has gradually emerged. In this study, field experiments were conducted over 3 years to identify the yield formation characteristics in the shorter-duration (∼120 days) super-rice hybrid ‘Guiliangyou 2’ (G2) by comparing it with the longer-duration (∼130 days) super-rice hybrid ‘Y-liangyou 1’ (Y1). The results showed that G2 had a shorter pre-heading growth duration and consequently a shorter total growth duration compared to Y1. Compared to Y1, G2 had lower total biomass production that resulted from lower daily solar radiation, apparent radiation use efficiency (RUE), crop growth rate (CGR), and biomass production during the pre-heading period, but the grain yield was not significantly lower than that of Y1 because it was compensated for by the higher harvest index that resulted from slower leaf senescence (i.e., slower decline in leaf area index during the post-heading period) and higher RUE, CGR, and biomass production during the post-heading period. Our findings suggest that it is feasible to reduce the dependence of yield formation on growth duration to a certain extent in rice by increasing the use efficiency of solar radiation through crop improvement and also highlight the need for a greater fundamental understanding of the physiological processes involved in the higher use efficiency of solar radiation in super-rice hybrids.

Extracted leaf protein is now used regularly as human food in several places. For preliminary, or domestic, trials the equipment used is inconveniently large. A miniature extraction unit, which does not depend on electricity, is described.

Studies were carried out at Kalyani during 1982–83 and 1983–84 to evolve a multiple cropping system with cotton as the main crop. Cotton was intercropped with paddy, greengram, blackgram, peanut and soyabean in the rainy season, and these were also grown as solccrops followed by crops of peanut, lentil, chickpea, wheat and mustard, respectively, in the winter season. All plots were subsequently cropped with sesame in the summer season. There was an increase in total grain yield, land equivalent ratio (LER), area time equivalent ratio (ATER) and relative net return (RNR) values when legumes and cereals were intercropped with cotton. The yield of the winter crops grown with the help of residual soil moisture was in the order: chickpea > mustard > lentil > wheat > peanut. Sesame yielded best after the chickpea and blackgram sequence and yielded almost as well after the lentil and greengram. The greatest net return was obtained from the cotton and paddy (1:1) intercrop followed by sesame.

Shoot and root growth and soil water depletion were studied in mungbean and soyabean grown at three plant populations after non-flooded rice (Oryza sativa) during the post-monsoon dry season in the Philippines. The site had a shallow fluctuating water table (1-2 m) but rooting depth was restricted to 0.8 m by a volcanic tuff layer. Soyabean had a longer duration (89 days) than mungbean (68 days) and intercepted more solar radiation, but from 61 days after sowing was severely stressed and accumulated little dry matter. Mungbean avoided severe water stress due to its short duration. Despite this stress, grain yield (1.0 t ha-1) was similar for the two species and soyabean yielded more grain nitrogen but less straw nitrogen than mungbean. Higher plant population achieved by narrower row spacing increased cumulative light interception and both grain and forage yields in both crops.

K. D. Shepherd, P. J. Gregory, T. Woodhead, R. K. Pandey y E. C Magbujos: Crecimiento de la soja (Glycine max) y del frijol mungo ("Vigna radiata) en la estacidn post-monz6n despuis del arroz de secano.

Observations on the relative degree of root nodulation were made for three successive years on tall and short cultivars of Pisum sativum and Phaseolus vulgaris sown at dates appropriate to each cultivar and grown under conditions of ordinary horticultural practice. In P. sativum, it was found that the shorter the cultivar, the greater were the number and weight of nodules per plant and the weight of nodules as a percentage of plant weight; dwarf cultivars also produced a greater weight of nodules per square metre of ground occupied and per square metre per day of crop growth. In Ph. vulgaris, differences in number and weight of nodules per plant between dwarf and climbing cultivars were not consistent between years. In a single comparison between Ph. uulgaris and Ph. multiflorus (scarlet runner beans), numbers and weights of nodules per plant were almost identical. Some agronomic implications of these findings are discussed.