The time and method of placement, and the distance from the plant at which fertilizers should be placed, was studied on sole-crop cowpeas. The development and yield of both early and late season crops were highest where fertilizers were applied at planting. It is suggested that it might be more advantageous to plough the fertilizers under before planting, so that the nutrients will become available to the seedlings from the time they emerge. Application of fertilizer in two bands gave the highest yields, but was not significantly superior to a less laborious method of application in one band. The distance at which the fertilizer was placed, and treatment interactions, did not show any definite trends.

Four sesame varieties were tested at three plant populations to study varietal and population effects on some attributes of vegetative growth. Significant differences between varieties were detected and planting density was found to modify both areas and dry weights of leaves.

The productivity of climax and serai grassland in South Africa was compared at three stocking rates with steers. On climax grassland, over nine years, gains per head at one steer per morgen (= 2·12 acres = 0·86 hectare) were not significantly greater than at two steers per morgen. Liveweight gains per morgen were 70 per cent higher at the heavier stocking rate and were 162 lb and 273 lb at one and two steers respectively. On serai grassland, over three seasons stocked at two steers and three steers per morgen, the liveweight gains per steer were significantly less at the higher stocking rate but there was no significant difference in the gains per morgen, which were 366 lb and 318 lb at two and three steers respectively. The liveweight gains on the seral grassland were significantly higher than on the climax grassland at the same stocking rate Calculation of the total digestible nutrients (T.D.N.) has shown that with heavier stocking more T.D.N. per morgen may be harvested on both grassland types. However, with heavy grazing the efficiency of conversion of T.D.N. into liveweight was less. The quality of the sward, measured in per cent crude protein, P2O5 and crude fibre was better at the heavier stocking owing to delayed maturity of the grass when it is continually grazed short.

The OxG hybrid bunches contain more parthenocarpic fruits (PF) than normal fruits (NF) and present problems of development and ripening due to either an asynchronous opening of flowers or insufficient pollination. The objective of this study was to compare the effect of α-naphthaleneacetic acid (NAA) and gibberellic acid (GA3) in the induction and development of PF and NF, the fatty acid profile (FAP), and the oil potential in the ‘Coari x La Mé’ oil palm hybrid. NAA and GA3 induced parthenocarpy in the fruits and did not alter the FAP of the mesocarp oil. The commercial dose of pollen (0.9 g talc + 0.1 g pollen) resulted in increased bunch weight (BW) (20.8 kg) and lower percentage of PF in the bunch (65.4%). The most effective hormonal doses to induce the formation of PF in the bunch were NAA 300 and 600 mg L-1. GA3 alone or in mixture with NAA increased the percentage of PF but did not increase the BW, indicating that GA3 had no synergistic effect on BW. The NAA applications represent alternatives to complement assisted pollination of OxG hybrids to increase bunch production and oil yield.

Young tea plants were grown for eight months in large polythene bags of soil, with provision to prevent rain from running into the soil. After a preliminary period of establishment, in which all plants were kept well-watered, four soil moisture regimes were applied ranging from watering twice weekly to withholding irrigation until plants had been subjected to a soil moisture tension of 15 bar, as determined by gypsum resistance units, for a period of one week before rewatering. Plant survival and growth were significantly better under the wettest compared with the driest regime.

N-enriched biochar can increase the accumulation of carbon (C), nitrogen (N), phosphorus (P), and biomass in rice plants. On the other hand, the biomass and C, N, and P contents of plant organs are important indicators to reflect plant C, N, and P storages. We established control, 4 t ha−1, and 8 t ha−1 N-enriched biochar treatment plots in a subtropical paddy field in China to investigate the effect of these treatments on C, N, and P storages, ecological stoichiometry in various rice plant organs, and their relationships with edaphic factors. The application of N-enriched biochar increased the biomass and storages of C, N, and P in rice roots, stems, leaves, and grains, mainly at 4 t ha−1. The application of N-enriched biochar decreased the C/N and C/P ratios of rice organs, but increased their N/P ratio. Changes in C/N were mainly due to the changes in storage, while N/P was positively correlated with N storage of stems, leaves, and grains and negatively correlated with P storage in roots. Pearson’s correlation analysis revealed that pH was negatively correlated, and soil N content was positively correlated with P storage in various organs of rice. In addition, soil P content and chlorophyll were positively correlated with N storage. In conclusion, we found that the application of N-enriched biochar improved plant N and P storage and stoichiometrical relations among rice organs.

In trials over 2 years at five locations in Northern Nigeria single inputs were removed from a package of maize practices. The improved variety was most important and increased the yield of the otherwise complete package by 86%. Early sowing and high plant population were not important in all trials. The high fertilizer treatment (125–50–50 kg NPK/ha) consistently exceeded the half rate, with a mean increase of 31%. It was suggested that, with clean weeding, priority should be given to the improved variety, high fertilizer and early sowing. High populations, involving changes to traditional techniques, may be introduced gradually.

The weights of the branches, stems and roots of two or three year old arabica coffee trees were compared with the diameters of the stumps or stems and with the heights of the trees. No formula could be derived, relating the weight of the plants to one or more non-destructive observations, which was valid for all three treatments to which the trees had been subjected, i.e. stripped of crop when two years old, cropping when two years old, and bearing a crop when three years old. Bearing a crop when two years old resulted in thin, light stems and a poor root system.

An experiment was carried out in the glasshouse to determine the availability of P, and utilization of added phosphate fertilizers from three fertilizer materials, applied by two different methods to sugar cane grown in four diverse soil systems. Phosphorus was applied at the equivalent rate of 175 pounds P (400 pounds P2O5) per acre. A larger response from added P in terms of plant yields was obtained from an aluminous ferruginous latosol and least from dark magnesium clay. Differences in yields of sugar cane were evidently associated with differences in P content in the cane plants and, in certain cases, with a reduction in Al content in plant tops, and the less soluble superphosphate increased yields more than the highly soluble NH4H2PO4. Phosphate fertilizers applied as foliar spray greatly increased the P content in the plants, and plants contained twenty times more P when sprayed with NH4H2PO4 than when the same fertilizer was applied to the soil. However, increased P content in the plants did not necessarily indicate that the P was translocated within the plants or that the added P participated in metabolic processes. The evidence indicated that in soils where the ‘A’ value was high the P status of the sugar cane tops was not correspondingly high.

Heritability of four quantitative characters in two crosses of Brassica campestris L. was found to be high. Dominance was detected only for plant height at heading time in both the crosses, and for sowing-to-heading period in Toria-TP × Toria-7. Transgressive segregation was expected in the segregating progenies for all the characters. Epistasis was complementary in all characters except in plant height at ripening time, where it was of the duplicate type. Additive × dominance type of epistasis was most significant and was present in most of the characters. Genes for most of the characters were linked with a major gene for seed colour (Rr). Yield was genetically correlated with the four quantitative characters studied.

COCA (highland), TZPB (lowland) and COCA x TZPB maize varieties were tested at Bambui Plain (1330 m) and Ekona (550 m). Leaf blight and rust were controlled chemically with Dithane-M45 and Benlate, and their use significantly increased the yields of COCA when grown in lowland environments, where it does not possess resistance to lowland leaf blight (H. maydis) and rust (P. polysora); yields of TZPB were similarly increased in highland areas, where it is susceptible to highland leaf blight (H. turcicum) and rust (P. sorghi). COCA x TZPB was intermediate in resistance to both diseases at the two locations.