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.

A NPK factorial experiment was conducted during two successive cropping seasons to study direct and residual effects of various treatments on the flower initiation and yield of soybeans. Plants were slower to reach the maximum flowering stage in the year of fertilizer application than in the following year. During the first year potassium in association with phosphorus delayed the flower forming process, whereas potassium alone hastened flowering in the second year unless associated with a high dosage of nitrogen. All the treatments gave far greater yields in the first season, suggesting that fertilizers should be applied during every cropping season. Nitrogen and phosphorus at 20 pounds of N2 and P2O5, per acre gave the biggest yields, but potassium failed to show any response. The residual responses to potassium and phosphorus during the second year were significant but not to nitrogen.

Phosphorus (P) is a limiting resource for agricultural production in the tropics. Urochloa spp. is commonly used as a cover crop and has mechanisms to mobilize partially the nonavailable P forms from the soil. The use of Urochloa intercropped with Arabica coffee (Coffea arabica L.) is increasing in Brazil, but P cycling has been overlooked in this system. Here, we proposed two experiments to test the hypothesis that Urochloa decumbens could mobilize and absorb P from deep soil layers and increase overall P cycling of the intercrop system. We measured U. decumbens root and shoot dry mass (SDM), root morphology and activity, nutrient uptake, soil nutrient availability, and soil P fractionation in both experiments. To better understand P cycling by Urochloa alone, in the first experiment, U. decumbens was cultivated in rhizotrons where adequate P was supplied in distinct soil layers – 0.0 to 0.3 m, 0.3 to 0.8 m, 0.8 to 1.3 m, and 1.3 to 2 m. Root dry mass (RDM) and morphology were not affected by P availability. Moreover, total biomass production (root plus shoot) and P uptake were higher when P was available in the superficial top soil layer compared to P availability in more than one layer or only in the bottom layer. Nevertheless, U. decumbens was able to reach and acquire P from depth. Correlation analysis showed that P cycling was strongly dependent on SDM, labile, and moderately labile fractions of soil P and was not significantly correlated with RDM. The second experiment aimed at verifying P uptake and mobilization from different soil depths in field conditions. P was supplied in different depths of the soil profile – 0.3 m, 0.6 m, and 0.9 m – in the field with preestablished U. decumbens intercropped with Arabica coffee plants. Shoot P content was higher at the first sample date when P was supplied at 0.3 m, compared to 0.6 m, 0.9 m, and control with no P. Soil P fractionation showed that there was no P mobilization of less labile forms by U. decumbens during the evaluated time. Our results showed that P fertilization in the top layer rather than suppling P trough the soil profile can maximize U. decumbens growth. Also, Urochloa P accumulation was enough to support coffee demand even in high yields and can be an alternative to increase P use efficiency in coffee production systems, being an effective recycler of P.

Certain statistical techniques, useful in collecting and interpreting ordinal data, are described and their applicability in plant breeding explained. It is suggested that these statistical techniques may be particularly valuable to plant breeders in determining taste Preferences. A series of experiments are described, investigating the taste Preferences of the Itero of Uganda, who show a strong preference for a mixture of cassava, sorghum and Eleusine millet for food. They do not apparently prefer white sorghum grains for food, nor coloured grains for beer, although such Preferences have been recorded elsewhere. They dislike maize and Pennisetum millet. It is suggested that an experimental approach to quality in the breeding of tropical food crops is both desirable and possible, using rank correlation techniques.

Confidence limits of expected twenty-day rainfall have been computed for two widely separated maize-producing regions in Kenya. The 35-km. square survey areas were quite different topographically, and limits were derived for seven rainfall sites in each. Ratios of these limits to the corresponding long-term mean precipitations were evaluated for each site for each twenty-day period during the appropriate maize-growing seasons. For a particular period and confidence level, these ratios were almost constant for either group of seven sites. The variability computed for a single, well-chosen site is therefore representative of quite a large neighbourhood. Expected rainfall totals were also derived for a ‘fictitious’ site, simulating the average precipitation over the whole of the flatter of the two areas. The resulting limits were less extreme than those of any individual site, indicating that areal rainfall, as used in hydrology, is less variable than the agriculturally-important point rainfall.

Legumes are essential to meet nutrition need of growing population in Afghanistan but have low productivity under the farmer practices. With an aim to introduce improved varieties of chickpea (Cicer arietinum) and mung bean (Vigna radiata) along with associated cultivation practices, a number of on-farm demonstration trials were conducted in eight districts covering three provinces to assess their performance in comparison with local practices. The data or information generation from on-farm trials is routine but remains unutilized under the commonly used analysis based on frequentist approach. This study makes use of such prior information to widen the statistical inference framework using a Bayesian approach (BA) for analysing any future on-farm trials. The statistical analysis evaluated the mean performance of the improved and local production packages and risks associated with them to meet a given target. Evaluated at the two districts during 2012, the improved variety of chickpea (Madad) yielded higher than the farmer variety (2.25–2.40 vs. 1.93–1.94 Mg/ha), while that of mung bean (Mash 2008) yielded higher than the farmer variety (1.22–1.24 vs. 0.93–0.94 Mg/ha), both with high probability. The stochastic dominance analysis showed that the recommended package with improved variety Madad has 95% probability of achieving a target of 2 Mg/ha while such a target for local practice was around its one-third when cultivated in Baghlan-e-sannati district. Crossover in the risk curves helped to identify and quantify the region specific risk to meet a given target. BA is then recommended in the analysis of on-farm trials data.

Effects are reported of some factors which may influence emergence and establishment of pigeon pea (Cajanus cajan (L.) Millsp.), including seeding depth, seed dressing, seed grading, seeding rate, variety and temperature. The effect of seeding rate was dependent on mean germination percentage in the field, but circumstantial observations on other factors of possible consequence in determining plant stand are also discussed.

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.